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UREMED

PROLOGUEThe harmful effects of exposure to radon, a radioactive gas often found in uranium mines, are well-known.Those people living closer to waste site were more likely to have hypertension, auto-immune disease, while people who had history of exposure during active mining had an additional likelihood of kidney disease.

Cleanup of Abandoned Uranium mines involves Comprehensive Environmental Response, Compensation, and Liability. Such cleanup is required to clean soil, water, and Air from radioactivity.

These abandoned mines may possess unstable geological structures, oxygen-deficient atmospheres, and the presence of mine gases such as radon.

Reclamation program should include1. Eliminating physical safety hazards that have resulted from previous mining

activities2. Re-contouring these abandoned areas to grow as much vegetation as possible;3. Treating stored water, storm water form mining areas away to eliminate the

possibility of water flow and leaching4. Decreasing the potential for the general inhabitant's exposure to radiological

materials.

RISKS INVOLVED DEPENDS ON:The extent to which the abandoned uranium mines

pose a significant radiation health hazard to the health and safety of the inhabitation nearby

pose some other significant threat to health and safety of the inhabitation nearby Have caused, or may cause, significant degradation of sored or storm water or leachate

quality

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Have caused, or may cause, environmental pollution

Thus reclamation of such abandoned uranium mines can be taken up by experienced and skilled team by employing the following procedures

1. Soil amendments2. Treating the water3. Allow more flora and fauna to grow, preferably which can tolerate/ hyper-accumulate

radioactive materials

Soil Amendments:1. Burying highly radioactive ores after cursory radiological scans of the mine site to

identify those areas containing bulk, residual radioactive materials.2. Top soiling deep mined soils after treating the bottom soil with UREMEDIATE as

given at the bottom of this article.3. For topping up a blend of the following may be used.

Commercial peat (Peat), local lake sediment, Lignite, Potassium Humate, Coir pith, Psyllium husk, soil free from radioactive materials and heavy metals, Animal Dung, beneficial soil microflora, micronutrients, Agri-residues, Press Mud Cake, Palm oil Empty fruit bunch, Oxygen Liberating Compounds etc.

4. After allowing for one season suitable vegetation may be grown.

Treating the Water:1. Treating with UREMEDIATE as given at the bottom of this article

2. This water after treatment can be used for irrigating the vegetation that is planned for growing.

INTRODUCTION

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Mill tailings typical characteristicsGrain size 0.040–0.074 mmpH 4.42–6.10SiO2 70.65–74.89 %Fe 1.80–2.10 %Al 2.85–3.25 %Ca 3.35–3.56 %Mg 0.14–0.17 %P 0.0012–0.093 %K 0.0027–0.0052 %B 0.0008–0.0012 %Mo 0.0063–0.0071 %Cl- 0.024–0.031 %SO4 0.026–0.035 %NO3 0.28–0.32 %Total C 2.86–4.52 %CEC 8.65–9.87 cmol kg-1U 6.03–46.5 lg g-1Th 4.75–19.8 lg g-1226Ra 7.32–29.52 Bq g-1

The characteristics of radioactive waste are important factors to be considered in selecting the natural plant species for phytoremediation, since they will impact the growth of the candidate for phytoremediation of the radioactive waste. Based on the characteristics of radioactive waste, preliminary treatments, such as adjusting pH value for plant growth, supplying fertilizer to improve the physicochemical properties of radionuclides, and adding the chelating agent to increase the bioavailability of radionuclides in the radioactive waste, could be conducted.

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Scenario of UKRAINE

• A group of independent environmentalists has uncovered a zone in Ukraine'sDnipropetrovsk region where the radiation level is higher than that in Chernobyl, the Ukrainian paper Segodnya said on Friday (Dec. 3).

• Cleanup of Dniprodzerzhynsk uranium mill tailings stuck by insufficient allocation of funds

• Dniprodzerzhynsk uranium mill tailings threaten residents• The tailings of Dniprodzerzhynsk mine cover an area of 600 hectares. • Every Dniprodzerzhynsk resident receives a dose of 5.6 Millisieverts a year, this is

some 460 per cent in excess of normal level. • It would take millions of dollars to remove the waste to a safe and properly

equipped depository, but local authorities do not have such a sum. (Novyy Kanal television, Kiev / BBC Monitoring Service - United Kingdom; Mar 21, 2002)

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TECHNOLOGY OF PHYTO REMEDIATION

AND MICROBIAL REMEDIATION

MECHANISM OF BIOACCUMULATION Since the plants or microbes do not need U and Th neither for their metabolism, nor for their structure, it follows that the assimilation of these elements is being done through passive processes. The passive absorption implies the diffusion of uranyl ions and organically bound Th4+ from the soils in the endodermis of the roots, or in the cell walls due to their imperfect selectivity and increased of permeability of cell membranes.(Lucian PETRESCUa & E. BILALb; NATURAL ACTINIDES STUDIES IN CONIFERS GROWN ON URANIUM MINING DUMPS (THE EAST CARPATHIANS, ROMANIA); CARPTH. J. OF EARTH AND ENVIRONMENTAL SCIENCES, 2006 VOL. 1, NO. 1, P. 63 – 80)

I. MICROBIAL REMEDIATIONUse of the potential of bacteria in treating heavy metals and radionuclides in the hazardous uranium waste piles.

Contamination of soils, water, and sediments by radionuclides and toxic metals from uranium mill tailings, nuclear fuel manufacturing and nuclear weapons production is a major concern. Studies of the mechanisms of biotransformation of uranium and toxic metals under various microbial process conditions has resulted in the development of two treatment processes:

(i) stabilization of uranium and toxic metals with reduction in waste volume and

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(ii) removal and recovery of uranium and toxic metals from wastes and contaminated soils.

Stabilization of uranium and toxic metals in wastes is accomplished by exploiting the unique metabolic capabilities of the anaerobic bacterium, Clostridium sp. The radionuclides and toxic metals are solubilized by the bacteria directly by enzymatic reductive dissolution, or indirectly due to the production of organic acid metabolites. The radionuclides and toxic metals released into solution are immobilized by enzymatic reductive precipitation, biosorption and redistribution with stable mineral phases in the waste. Non-hazardous bulk components of the waste such as Ca, Fe, K, Mg and Na released into solution are removed, thus reducing the waste volume. In the second process uranium and toxic metals are removed from wastes or contaminated soils by extracting with the complexing agent citric acid. The citric-acid extract is subjected to biodegradation to recover the toxic metals, followed by photochemical degradation of the uranium citrate complex which is recalcitrant to biodegradation. The toxic metals and uranium are recovered in separate fractions for recycling or for disposal. The use of combined chemical and microbiological treatment process is more efficient than present methods and should result in considerable savings in clean-up and disposal costs.(https://www.bnl.gov/isd/documents/18332.pdf)

Migration of radionuclides from the radioactive waste repository sites, as well as from uranium mill tailings and mining piles, is of serious environmental concern. About 231000 tons of uranium were produced in Eastern Germany from 1946 to 1990 (Meinrath et al., 2003). More than 5 x 108 tons of radioactive wastes, a total of 3000 piles and about 20 tailings had to be remediated or decontaminated (Beleites, 1992). The fate and the transport of uranium are governed by the contrasting chemistry of U(IV) and U(VI). U(VI) generally forms soluble, and thus mobile, complexes with carbonate and hydroxide, while U(IV) precipitates as the highly insoluble mineral uraninite (Nyman et al., 2006). Abiotic factors such as ions and minerals strongly influence the migration process of uranium (Barnett et al., 2000; Arnold et al., 2001; Duff et al., 2002; Baik et al., 2004). In addition, microbial processes can influence the mobility of heavy metals and radionuclides and, thereby, their migration behaviour (Francis, 1998; Lloyd & Lovley, 2001; Merroun & Selenska-Pobell, 2001; Lloyd & Macaskie, 2002; Selenska-Pobell, 2002; Merroun et al., 2003, 2005, 2006; Suzuki et al., 2003, 2005; Kalinowski et al., 2004; Lloyd & Renshaw, 2005; Lloyd et al., 2005; Pedersen, 2005). These processes can act metal immobilising or mobilising and involve biotransformations as oxidation (DiSpirito & Tuovinen, 1982; Beller, 2005) and reduction (Lovley et al., 1991, 1993a; Lloyd, 2003; Khijniak et al., 2005; Wu et al., 2006), biosorption by cell surface polymers (Selenska-Pobell et al., 1999; Raff et al., 2003; Beveridge, 2005; Merroun et al., 2005), uptake of metals inside the cells (McLean & Beveridge, 2001; Merroun et al., 2003; Francis et al., 2004; Suzuki & Banfield, 2004), metal precipitation and generation of minerals (Macaskie et al., 2000; Merroun et al., 2006; Nedelkova et al., 2006) and chelation by siderophores and other microbial compounds (Kalinowski et al., 2004; Pedersen, 2005)

For developing cost-effective in situ bioremediation technologies, the microbial reduction of U(VI) has been intensively studied (Lovley et al., 1991, 1993a, 1993b).

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Chemolithoautrophic bacteria, such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, as well as heterotrophic bacteria such as Desulfovibrio spp., Pseudomonas spp. as well as strains related to Agrobacterium, Rhizobium and Sphingomonas were isolated from different uranium mining waste piles (Merroun & Selenska-Pobell, 2001; Selenska-Pobell et al., 2002; Selenska-Pobell, 2002; Merroun et al., 2003).

Most part of the bacteria present in uranium mining wastes belong to not yet cultured species due to the limited knowledge about their nutrient and other life necessities (Selenska-Pobell, 2002; Fields et al., 2005).

A mobilisation of uranium was observed by Sulfolobus metallicus Kra 23 (Huber & Stetter, 1991) and by Metallosphaera sedula TH2 from an ore mixture (Huber et al., 1989). It was demonstrated that cell suspensions of the hyperthermophilic crenarchaeon Pyrobaculum islandicum can reduce U(VI), Tc(VII), Cr(VI), Co(III), Mn(IV) and Au(III) with hydrogen as an electron donor at ca. 100 °C (Kashefi & Lovley, 2000, Kashefi et al., 2001). It was also observed that the euryarchaeon Halobacterium halobium accumulates uranium extracellularly as dense deposits (Francis et al., 2004).

Schematic of Microbial Uranium Reduction(http://web.stanford.edu/group/evpilot/uranium.htm)

Different studies were performed by addition of nutrients to uranium contaminated groundwaters and soils to increase the number and activity of indigenous microorganisms prospective for bioremediation (Holmes et al., 2002; Anderson et al., 2003; Nevin et al., 2003; Suzuki et al., 2003; North et al., 2004; Brodie et al., 2006; Nyman et al., 2006). Changes in the microbial community were observed when U(VI) reduction was stimulated by addition of acetate in sediments from three different uranium-contaminated sites in the floodplain of the San Juan River in Shiprock, New Mexico, USA.

In the present study, EXAFS analysis indicated that U(VI) is mainly coordinated in the Arthrobacter accumulates by organic phosphate groups in a monodentate binding mode. A survey of structural parameters of the uranium complexes formed by different bacterial cells and their components at pH 4.5 found in the literature demonstrated that this radionuclide is coordinated differently to microbial cells: i) by organic phosphate groups as for instance by cells of A. ferrooxidans (Merroun et al., 2003b); ii) by carboxylic and phosphate groups of the cells and S-layer sheets of Bacillus sphaericus JG-A12, a bacterium isolated from the same uranium mining waste pile (Merroun et al., 2005), and iii) by inorganic phosphate groups forming a m-autunite-like phases by the cells of Microbacterium oxydans S15-M2 and Sphingomonas sp. S15-1 isolated from the S15 deep-well monitoring site near the Siberian radioactive subsurface depository Tomsk-7, Russia (Merroun et al., 2006; Nedelkova et al.,

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2006). Interestingly, in the case of the Sphingomonas sp. S15-1 cells, electron-dense intracellular granules and uranium-bearing precipitates at the cell membrane were localised by TEM. It was suggested that intracellular granules correspond to the cell polyphosphate bodies (Merroun et al., 2006). An intracellular accumulation of uranium closely associated with polyphosphate granules was also suggested for a high G+C Gram-positive isolate, closely related to Arthrobacter ilicis, by using TEM and EDX (Suzuki & Banfield, 2004)(d-nb.info/988321181/34)

Members of the family Geobacteracea are known for their ability to reduce Fe(III) and U(VI) (Lovley et al., 1991, 1993) in presence of electron donors such as lactate and acetate

Due to their capability to tolerate radioactivity (Chicote et al., 2005), to bioaccumulate uranium (Selenska-Pobell et al., 1999; Merroun et al., 2003a,b, 2005; Francis et al., 2004; Suzuki & Banfield, 2004; Ohnuki et al., 2005), and to biotransform it (DiSpirito & Tuovinen, 1982; Lovley et al., 1991) bacteria are considered at present, along with minerals, as one of the most important factors influencing the transport of uranium in contaminated environments. Moreover, it was demonstrated that bacteria can be used for bioremediation of uranium-contaminated sites by in situ biostimulation (Holmes et al., 2002; Anderson et al., 2003; Nevin et al., 2003; Suzuki et al., 2003, 2005; Istok et al., 2004; North et al., 2004) or for construction of biologically coated ceramic filters for cleaning of waters polluted with uranium (Raff et al., 2003).

Ohnuki et al. (2005) demonstrated that at acidic conditions, corresponding to those of the depleted uranium mining waste piles, U(VI) was preferentially bound by the cells of B. subtilis and not by kaolinite particles.

To monitor the long-term stability of bioreduced U(IV), flow through column incubations for more than 500 days, using soil from another area of the uranium contaminated FRC at Oak Ridge, Tennessee were performed by adding Na-lactate (Wan et al., 2005; Brodie et al., 2006). In this case, U(VI) reduction and immobilisation was successful within the first 100 days, followed by reoxidation and remobilisation of U(IV) under continuous reducing conditions (Wan et al., 2005).

By using Mössbauer spectroscopy it was revealed that the amount of Fe(II) increased in the samples treated with uranyl nitrate for 4 and for 14 weeks under anaerobic conditions, which indicated the reduction of Fe(III). Reduction of Fe(III) to Fe(II) was observed associated with the reduction of U(VI) after biostimulation with acetate (Anderson et al., 2003) and by the incubation of uranium contaminated sediments under anaerobic conditions (Suzuki et al., 2005). The reduction of Fe(III) can occur abiotically with hydrogen sulphide or U(IV) as the reductant (Luther et al., 2001; Senko et al., 2005a) or biologically by Fe(III)-reducing bacteria.

The strain Bacillus sphaericus JG-A12 was used for construction of biological ceramics (biocers) via sol-gel immobilisation of its vegetative cells, spores or surface layer sheets. These biocers demonstrated high binding capacity of uranium and copper from contaminated waters (Raff et al., 2003).

More interesting, the only uranium resistant group found in the sub-sample treated with uranyl nitrate under anaerobic conditions was represented by the sequence JG35+U4-KF23

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(Table S2.3). This sequence was almost identical to the sequence JG35+U1-AG27 and also to JG35-K4-AG9. The closest match of cultured organisms to these groups was Janthinobacterium agaricidamnosum SAFR-022.(d-nb.info/988321181/34)

Applying several modern molecular biological approaches, such as Ribosomal Intergenic Spacer Amplification (RISA) and 16S ribosomal DNA (rDNA) Amplification, Pulsed-field Gel Electrophoresis (PFGE), Random Amplified Polymorphic DNA (RAPD), Repetive Primer Amplified Polymorphic DNA (rep-APD), as well as Time-resolved Laser Fluorescence Spectroscopy (TRLFS), we have found in several uranium wastes in Saxony - the "Haberland Halde" near Johanngeorgenstadt, and the mill tailings near Steinsee Deponie 1, Gitersee/Coschüth and Schlema/Alberoda; extremely high bacterial diversity occurs in the samples investigated. In particular, the presence of several dominant 16S rDNA groups related to the genera Thiobacillus, Bacillus, Desulfovibrio and Pseudomonas was demonstrated.

Thiobacillus ferrooxidansOne of these 16S rDNA groups was affiliated to the species Thiobacillus ferrooxidans. The strains of this species are chemolithoautotrophic, they can oxidise U4+ and Fe2+ as well as also many different metal sulphides from the natural minerals. The latter is known as bioleaching or solubilization of metals. These bacteria can also accumulate uranium in acidic liquors (pH 1,5). Interestingly, we have found three different 16S rDNA types corresponding to the species T. ferrooxidans. These types possess slightly different 16S rDNA patterns. Strains of T. ferrooxidans possessing two of the mentioned three 16S rDNA types were recovered from two soil samples polluted in different extend with heavy metals. The two groups of isolates have different genomic organization than the known reference strains.

In addition, the members of the group recovered from the more polluted sample are tolerant to higher concentrations of uranyl ions which are lethal for the isolates of the second group. The expression of at least three genes of the U-tolerant strains is influenced by the presence of uranyl ions in the nutrient medium. The capability of the U-mine isolates to interact with U(VI) was studied, and it was found that they accumulate

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significantly higher amounts of U(VI) in comparison to several reference T. ferrooxidans strains recovered from other environments. Using time-resolved laser fluorescence spectroscopy it was shown that the complexes build by one of the U-waste isolates with U(VI) are much stronger than those build by the reference strains.

Time-resolved laser fluorescence spectroscopy of Uranium onto T. ferrooxidansThis is the first demonstration of microdiversity in closely related natural isolates of T. ferrooxidans. We suggest that the microdiversity observed reflects the genetic adaptation of the strains studied to the different heavy metal concentrations in their natural environments.

BacillusThe second uranium waste bacterial group belongs to the genus Bacillus. We have classified three of the Bacillus waste isolates, as B. cereus, B. megaterium and B. sphaericus, and we have demonstrated that they are able to selectively accumulate different heavy metals from drain waters of the "Haberland Halde".

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Selective bioaccumulation of heavy metals in groundwaterWe have found that the Bacillus strains are binding significantly higher amounts of uranium at pH 4.8 in comparison to the above mentioned T. ferrooxidans strains. However, the complexes built between the Bacillus isolates and uranium are much weaker than those built by the T. ferrooxidans strains. The latter was confirmed using TRLFS as well.

S-LayerOne of the uranium waste isolates, JG-A12, possesses a novel kind of S-Layer protein.

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TEM micrograph of negatively stained S-Layer from the Bacillus sphaericus isolate JG A-12, recovered from a uranium mining waste pile.

S-Layers are porous crystalline protein membranes 5-15 nm thick, which completely cover the cell surface and can provide microorganisms with a selective advantage by functioning as protective coats, molecular sieves, molecule and ion traps, etc. They possess a great potential for biotechnology, medicine and nanotechnology.

DesulfovibrioThe third group of uranium waste isolates belongs to the genus Desulfovibrio. These sulphate-reducing bacteria are able also to reduce U(VI) to U(IV). Up to date we have analysed two uranium waste Desulfovibrio isolates which were recovered in Umweltforschungszentrum Leipzig. These isolates are closely related to the species Desulfovibrio vulgaris subspecies (oxamicus).

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Dendrogram of the phylogenetical relationships of Desulfovibrio strainsIn addition their genomic organization differs significantly from those of the type strain of this species. In addition, the analysis of the kinetic of the uranium reduction by one of the Desulfovibrio isolates has shown that the waste isolate is able to reduce significantly faster larger amounts of U(VI) than the reference Desulfovibrio strain. In contrast to the reference strain, the waste isolate reduced uranium independently on the pH range of the medium. To our knowledge, no other bacterium of the genus Desulfovibrio is able to reduce and precipitate U(VI) from solutions so rapidly and effectively as this isolate.

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The natural uranium waste bacterial isolates analysed in our laboratory might be of great importance for the development of bioremediation procedures for the environments polluted with uranium and other heavy metals, because they are well adapted to their extremely complex geological, chemical and biological conditions.(Pedersen et al., 1996; Crozier et al., 1999; Selenska-Pobell et al., 2001; Selenska-Pobell, 2002; Selenska-Pobell et al., 2002; Suzuki et al., 2003, 2005; Fredrickson et al., 2004; Satchanska et al., 2004; Fields et al., 2005; Radeva & Selenska-Pobell, 2005; Satchanska & Selenska-Pobell, 2005).

The following mechanisms of direct bacteria-uranium interactions are described: i) oxidation of U(IV) to U(VI) resulting in solubilisation (DiSpirito & Tuovinen, 1982; Beller, 2005); ii) reduction of U(VI) to insoluble U(IV) (Lovley et al., 1991, 1993; Lovley & Phillips, 1992; Francis et al., 1994; Tebo & Obraztzova, 1998; Lloyd, 2003; Khijniak et al., 2005; Wu et al., 2006); iii) bioaccumulation, which includes processes of biosorption by cell surface polymers (Friis & Myers-Keith, 1986; Selenska-Pobell et al., 1999; Fowle et al., 2000; Francis et al., 2004; Raff et al., 2004; Tsuruta, 2004; Merroun et al., 2005) and/or uptake inside the cells (Marqués et al., 1991; Merroun et al., 2002; Francis et al., 2004; Suzuki & Banfield, 2004). The U(VI) accumulated both on the bacterial surfaces or inside the cells as well as biologically reduced U(IV) precipitates can initiate biomineralisation processes, which result in immobilisation of additional amounts of uranium (Francis, 1998). On the other hand, transport and release of the bioaccumulated uranium by the migrating parts of the bacterial populations are also possible by decomposition processes after their dead (Francis, 1998).

MODE OF ACTIONThe following mechanisms of direct bacteria-uranium interactions are described:

i) oxidation of U(IV) to U(VI) resulting in solubilisation (DiSpirito & Tuovinen, 1982; Beller, 2005);

ii) reduction of U(VI) to insoluble U(IV) (Lovley et al., 1991, 1993; Lovley & Phillips, 1992; Francis et al., 1994; Tebo & Obraztzova, 1998; Lloyd, 2003; Khijniak et al., 2005; Wu et al., 2006);

iii) bioaccumulation, which includes processes of biosorption by cell surface polymers (Friis & Myers-Keith, 1986; Selenska-Pobell et al., 1999; Fowle et al., 2000; Francis et al., 2004; Raff et al., 2004; Tsuruta, 2004; Merroun et al., 2005) and/or uptake inside the cells (Marqués et al., 1991; Merroun et al., 2002; Francis et al., 2004; Suzuki & Banfield, 2004).

The U(VI) accumulated both on the bacterial surfaces or inside the cells as well as biologically reduced U(IV) precipitates can initiate biomineralisation processes, which result in immobilisation of additional amounts of uranium (Francis, 1998). On the other hand, transport and release of the bioaccumulated uranium by the migrating parts of the bacterial populations are also possible by decomposition processes after their dead (Francis, 1998).

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CONTENTS OF UREMED_ MICROBIAL MICROBIAL REMEDIATION:

1. Bacillus megaterium2. Bacillus novalis3. Bacillus sphaericus 4. Calcium lactate5. Cellulomonas gelida6. Citrobacter sp. 7. Desulfovibrio desulfuricans8. Extract of Pterocarpus santalinus9. Kaolin10. Oxyrich11. Pseudomonas fluorescens 12. Sodium acetate13. Sodium Nitrate14. Streptomyces longwoodensis15. Thiobacillus denitrificans16. Thiobacillus ferrooxidans

OPTIMUM CONDITIONS:Temperature: 32 Deg CpH: 4-5Retention Time: 350-500 Days.Frequency of Treatment: once in 21 daysDose rate: 300 g per Ton Biomass

FOR BETTER RESULTS:PROVIDE 10% ETHANOL @ 2 L/ Ton biomass 2 days before using UREMED

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II. PHTO REMEDIATIONCITATIONS:Phytoremediation is based on the capability of plants to remove hazardous contaminants present in the environment. This study aimed to demonstrate some factors controlling the phytoremediation efficiency of live floating plant, water hyacinth (Eichhornia crassipes), towards the effluents contaminated with 137Cs and/or 60Co. Cesium has unknown vital biological role for plant while cobalt is one of the essential trace elements required for plant. The main idea of this work i.e. using undesirable species, water hyacinth, in purification of radiocontaminated aqueous solutions has been receiving much attention. The controlling factors such as radioactivity concentration, pH values, the amount of biomass and the light were studied. The uptake rate of radiocesium from the simulated waste solution is inversely proportional to the initial activity content and directly proportional to the increase in mass of plant and sunlight exposure. A spiked solution of pH ≈ 4.9 was found to be the suitable medium for the treatment process. The uptake efficiency of 137Cs present with 60Co in mixed solution was higher than if it was present separately. On the contrary, uptake of 60Co is affected negatively by the presence of 137Cs in their mixed solution. Sunlight is the most required factor for the plant vitality and radiation resistance. The results of the present study indicated that water hyacinth may be a potential candidate plant of high concentration ratios (CR) for phytoremediation of radionuclides such as 137Cs and 60Co.(http://www.sciencedirect.com/science/article/pii/S002954931100896X)

Today, many researchers, institutes, and companies are funding scientific efforts to test different plants' effectiveness at removing a wide range of contaminants. Raskin favors Brassica juncea and Brassica carinata, two members of the mustard family, for phytoremediation. In laboratory tests with metals loaded onto artificial soil (a mix of sand and vermiculite), these plants appeared to be the best at removing large quantities of chromium, lead, copper, and nickel. Several members of this family are edible and yield additional products such as birdseed, mustard oil, and erucic acid, which is used in margarine and cooking oil. Researchers at the DuPont Company have found that corn, Zea mays, can take up incredibly high levels of lead. Z. mays, a monocot in the Poaceae or grass family, is the most important cultivated cereal next to wheat and rice, yielding such products as corn meal, corn flour, cornflakes, cooking oil, beer, and animal feed. Phytokinetics, a company in Logan, Utah, is testing plants for their ability to remove organic contaminants such as gasoline from soil and water. Applied Natural Sciences in Hamilton, Ohio, is taking a slightly different route by using trees to clean up deeper soils, a process they call "treemediation." University researchers from the UK reported in the May 1999 issue of Nature Biotechnology that transgenic tobacco plants can play a role in cleaning up explosives.

Helianthella sp.

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In February 1996, Phytotech, Inc., a Princeton, NJ-based company, reported that it had developed transgenic strains of sunflowers, Helianthus sp., that could remove as much as 95% of toxic contaminants in as little as 24 hours. Subsequently, Helianthus was planted on a styrofoam raft at one end of a contaminated pond near Chernobyl, and in twelve days the cesium concentrations within its roots were reportedly 8,000 times that of the water, while the strontium concentrations were 2,000 times that of the water. Helianthus is in the composite, or Asteraceae, family and has edible seeds. It also produces an oil that is used for cooking, in margarine, and as a paint additive. H. tuberosus was used by Native Americans as a carbohydrate source for diabetics.

Cannabis sativa.

In 1998, Phytotech, along with Consolidated Growers and Processors (CGP) and the Ukraine's Institute of Bast Crops, planted industrial hemp, Cannabis sp., for the purpose of removing contaminants near the Chernobyl site. Cannabis is in the Cannabidaceae family and is valuable for its fiber, which is used in ropes and other products. This industrial variety of hemp, incidentally, has

Fruit of Brassicaceae. Zea mays.

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only trace amounts of THC, the chemical that produces the "high" in a plant of the same genus commonly known as marijuana.

Overall, phytoremediation has great potential for cleaning up toxic metals, pesticides, solvents, gasoline, and explosives. The U.S. Environmental Protection Agency (EPA) estimates that more than 30,000 sites in the United States alone require hazardous waste treatment. Restoring these areas and their soil, as well as disposing of the wastes, are costly projects, but the costs are expected to be reduced drastically if plants provide the phytoremediation results everyone is hoping for. Meanwhile, of the original four reactors at Chernobyl, Reactors 1 and 3 are still operating today, providing 6,000 jobs and about 6% of the Ukraine's electricity. Reactor 2 was closed after a fire in 1991; the construction of Reactors 5 and 6 came to a grinding halt after the explosion.

References, Websites, and Further Reading "Sunflowers Bloom in Tests to Remove Radioactive Metals from Soil and Water," Wall Street Journal, 29 February 1996. International Atomic Energy Association Environmental Protection Agency research and scientists page From Plants Sites & Parks magazine, May/June 1996: Attacking the Root of the Problem. Central Oregon Green Pages: Hemp "Eats" Chernobyl Waste Stern, Introductory Plant Biology, 8th Edition

Nearly six months after the devastating tsunami hit Japan, communities are turning to mother nature to help restore theirs homes and hopes. Millions of sunflowers have been planted in radioactive areas to soak up toxins from the ground and brighten the hillside of Fukashima.The nuclear fallout from the tsunami forced nearly 80,000 people to evacuate their homes, not knowing if or when they may return. The 30 miles surrounding the Fukushima Daiichi nuclear plant has been left contaminated and relatively barren. Even more disturbing, reports of radioactive rice, beef, vegetables, milk, seafood, and even tea have been found more than 60 miles away from the site, outside the mandatory evacuation zone.

Koyu Abe, chief monk at the Buddhist Joenji temple has been distributing sunflowers and their seeds to be planted all over Fukushima. The plants are known to soak up toxins from the soil, and patches of sunflowers are now growing between buildings, in backyards, alongside the nuclear plant, and anywhere else they will possibly fit. At least 8 million sunflowers and 200,000 other plants have been distributed by the Joenji Buddhist temple. “We plant sunflowers, field mustard, amaranthus and cockscomb, which are all believed to absorb radiation,” Abe says.(http://inhabitat.com/thousands-of-sunflowers-soak-up-nuclear-radiation-in-fukushima/)

Vetiver grass (Vetiveria zizanoides) L. Nash plantlets when tested for their potential to remove (90)Sr and (137)Cs (5 x 10(3) k Bq l(-1)) from solutions spiked with individual radionuclide showed that 94% of (90)Sr and 61% of (137)Cs could be removed from solutions after 168 h. When both (90)Sr and (137)Cs were supplemented together to the solution, 91% of (90)Sr and 59% of (137)Cs were removed at the end of 168 h. In case of (137)Cs, accumulation occurred more in roots than shoots, while (90)Sr accumulated more in shoots than roots. When experiments were performed to study the effect of analogous elements, K(+) ions reduced the uptake of (137)Cs, while (90)Sr accumulation was found to decrease in the presence of Ca(2+) ions. Plants of V. zizanoides could also effectively remove radioactive elements from low-level nuclear waste and the level of radioactivity was reduced below detection limit at the end of 15 days of exposure. The results of the present study indicate that V. zizanoides may be a potential candidate plant for phytoremediation of (90)Sr and (137)Cs.(http://www.ncbi.nlm.nih.gov/pubmed/17257679)

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Is using phytoremediation a practical way for individuals to clean up their property?Phytoremediation could be used to clean up individual, privately owned property that has been exposed to radiation providing that the problems associated with disposal of materials could be minimized, overcome or resolved. For the home owner trying to clean soil or water that has only modest levels of radiation some of the following plants may be beneficial; sunflowers, barley, alfalfa, fennel, sugar beets, spinach, lettuce and mustard. The plants that are harvested should not be consumed nor should they be composted back into the garden because radiation is concentrated as it progresses from soil or water into the food chain. Furthermore, the area being treated for radiation should be isolated from foraging animals such as deer.(http://www.naturalnews.com/032747_phytoremediation_radiation.html#ixzz3rSmhem5K)

The Poaceae and Asteraceae were the dominant families colonizing the impoundment and had 16 and 13 species, respectively, the Rosaceae and Cyperaceae had 5 species each, and the rest had less than 3 species. There were also some trees, including Broussonetia papyrifera, Paulownia fortunei, Cinnamomum camphora, Salix matsudana, Rhus chinensis, and Melia azedarach. Based on the life-form, most of the species were shallow-rooted, drought-tolerant plants and belonged to common native plants.

Probable candidates Kyllinga brevifolia, Phragmites australis, Imperata cylindrica, Setaria viridis, Pteris multifida, Pteris cretica L. var. nervosa, and Pteridium aquilinum, Oxalis corymbosa, Avena fatua, Paspalum scrobiculatum, Eleusine indica, Miscanthus floxidulus, Polypogon fugax, Erigeron annuus, Erigeron canadensis, Solanum nigrum, Trema dielsian, R. chinensis, and Dryopteris scottii, Persicaria hydropiper, P. fortunei, C. camphora, Cyperus difformis,Rubus alceaefolius, Digitaria sanguinalis, Herba taraxaci, S. matsudana, Amaranthusspinosus, Plantago asiatica, Plantago major, Boehmeria nivea, Pterocarpus santalinus and Medicago sativa

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Plant community composition on the sampling sites at uranium mill tailingsimpoundment in South China (Hu et al. 2014)Family Species Abundancea

S1 S2 S3 S4 S5 S6 S7 S8 S9Moraceae Morus alba 0 0 1 2 1 0 0 3 0Broussonetia papyrifera 0 0 3 5 2 2 0 4 4Humulus scandens 0 1 0 4 0 0 0 3 3Polygonaceae Polygonum posumbu 0 0 2 1 2 1 0 0 2P. lapathifolium 0 1 1 2 0 2 0 2 2P. hydropiper 0 0 1 0 2 0 0 0 1Scrophu lariaceae Paulownia fortunei 0 0 1 0 0 0 0 1 2Lauraceae Cinnamomum camphora 0 0 0 1 0 0 0 1 2Oxalidaceae Oxalis violacea 1 0 0 1 1 2 1 0 0O. corymbosa 1 1 3 4 2 3 0 4 3Verbenaceae Vitex negundo 0 0 0 4 1 1 0 2 3Clerodendrum cyrtophyllum 0 0 3 2 4 3 0 3 3Cyperaceae Kyllinga brevifolia 1 1 2 4 1 1 1 2 3Juncellus serotinus 1 0 2 3 1 1 0 2 2Cyperus iria 0 0 2 3 2 0 1 3 4C. difformis 0 0 0 1 0 0 1 2 0Cyperus rotundus 0 1 3 4 2 2 0 3 4Rosaceae Duchesnea indica 0 1 0 1 2 1 0 1 0Rosa laevigata 0 0 0 2 0 1 1 0 1Rubus corchorifolius 0 0 1 0 2 0 2 1 0R. alceaefolius 0 0 0 1 0 1 0 0 1R. hanceanus 0 1 1 3 3 4 1 2 4Phytolaccaceae Phytolacca acinosa 0 0 2 0 2 2 0 5 5Portulacaceae Portulaca oleracea 0 0 2 1 2 1 0 0 2Poaceae Avena fatua 1 1 2 4 0 2 1 4 4Alopecurus aequalis 0 1 0 0 0 1 0 3 4Digitaria sanguinalis 0 0 0 0 1 0 0 3 2Phragmites australis 3 4 1 2 3 2 4 2 2Paspalum scrobiculatum 2 2 1 2 2 2 1 3 0P. distichum 0 2 1 0 2 1 0 2 3Potamogeton pectinatus 0 0 2 1 2 1 0 1 1Poa pratensis 0 0 2 1 2 1 0 3 4Rhizoma imperatae 0 0 1 2 0 0 0 1 2Imperata cylindrica 2 4 1 2 2 2 4 2 3Eragrostis pilosa 0 1 3 2 2 3 0 2 3Eleusine indica 1 0 2 1 3 1 2 3 3Miscanthus floxidulus 2 1 3 3 5 5 1 3 0Phleum alpinum 0 1 1 2 2 2 0 2 2Polypogon fugax 1 0 3 2 1 1 1 2 3Setaria viridis 2 4 2 2 2 1 4 3 2

Asteraceae Artemisia lavandulaefolia 1 0 1 3 2 1 0 1 1

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Artemisia capillaris 1 0 2 3 1 3 1 3 4Bidens pilosa 0 0 0 1 2 0 0 3 3Erigeron annuus 1 1 2 4 2 3 0 2 2E. canadensis 1 0 2 1 2 3 1 3 2E. sonchifolia 1 0 0 4 1 1 0 1 1Herba taraxaci 0 0 0 1 0 1 0 0 1H. gnaphaii 0 0 3 1 4 1 0 2 2Ixeris chinensis 0 0 2 0 3 2 3 2 3Senecio scandens 0 0 1 2 3 2 0 0 2Gynura crepidioides 0 0 2 0 0 1 0 1 1Youngia japonica 0 0 1 2 2 0 0 0 1Xanthium sibiricum 0 0 1 3 1 0 0 2 2Solanaceae Solanum nigrum 0 2 3 1 3 2 1 3 3S. lyratum 0 0 2 2 0 0 0 1 1Ulmaceae Trema dielsian 1 0 2 3 2 3 2 3 3Ulmus parvifolia 0 0 2 1 1 0 0 1 2Hamamelidaceae Loropetalum chinense 0 0 1 4 1 1 0 4 5Liliaceae Smilax china 0 0 1 1 0 0 0 1 1Salicaceae Salix matsudana 0 0 0 0 0 0 0 1 1Oleaceae Ligustrum quihoui 0 0 0 1 0 1 0 1 1Amaranthaceae Amaranthus spinosus 0 0 0 1 0 0 0 2 1Alternanthera philoxeroides 0 0 0 2 1 1 0 1 1Euphorbiaceae Ricinus communis 0 0 1 1 2 2 0 3 4Mallotus apelta 1 3 0 2 3 3 1 2 0Anacardiaceae Rhus chinensis 2 1 0 1 1 2 3 2 2Zingiberaceae Alpinia japonica 0 0 2 0 1 1 0 0 1Plantaginaceae Plantago asiatica 0 0 1 0 1 0 0 0 1P. major 0 0 0 1 0 1 0 1 0Pteridaceae Pteris multifida 3 2 3 4 2 2 3 4 3P. nervosa 3 3 4 2 2 4 2 4 4Malvaceae Hibiscus syriacus 0 0 0 2 2 1 0 1 3Aquifoliaceae Ilex cornuta 0 0 3 3 4 3 0 4 3Pteridiaceae Pteridium aquilinum 3 4 5 5 4 3 2 4 3Meliaceae Melia azedarach 0 0 1 2 1 0 0 2 3Papaveraceae Macleaya cordata 0 1 3 4 3 3 2 3 5Urticaceae Boehmeria nivea 0 0 0 2 0 1 0 0 3Legum inosae Medicago sativa 0 0 0 0 0 1 0 0 2Lespedeza cuneata 0 0 1 1 1 0 0 0 1Dryopteridaceae Dryopteris scottii 1 1 3 0 2 3 3 2 1Note a Abundance is classified as five grades: 0 means absent; 1 means very rare; 2 means rare; 3 means occasional; 4 means frequent; and 5 means abundant

In recent years, phytoremediation studies concerning the treatment of radionuclide-contaminated soils have been carried out using different plant species under various conditions, and the improvement of the uptake by adding fertilizers, organic acids, or chelating agents (Khatir Sam 1995; Papastefanou 1996; Huang et al. 1998; Carini 1999; Madruga et al. 2001; Blanco Rodríguez et al. 2002; Shahandeh and Hossner 2002;

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Dushenkov 2003; Karunakara et al. 2003; Shinonaga et al. 2005; Soudek et al. 2007a, b, 2010, 2011; Pulhani et al. 2005; Chen et al. 2005; AbdEl-Sabour 2007; Thiry and Van 2008; Vera et al. 2008, 2009; Cukrov et al. 2009; Blanco Rodríguez et al. 2010; Dragovic´ et al.2010; Srivastava et al. 2010; Cˇ erne et al. 2011; Li et al. 2011; Hu et al. 2014).

Based on this approach, C. iria and J. serotinus satisfied the criteria for a hyperaccumulator for U. P. multifida, P. aquilinum, and D. scottii satisfied the criteria for ahyperaccumulator for 226Ra.

Concentrations of U and Th in the plant and tailings samples collected from the uraniummill tailings impoundment in South China (DW lg g-1) (Li et al. 2011)Site Family Species Plant part U Th

Plant Tailings Plant Tailings1 Gramineae Paspalum paspaloides Shoot 8.32 26.7 1.21 4.75

Root 1.98 0.782 Gramineae Miscanthus floridulus Leaf 0.96 23.3 0.19 8.84

Stalk 0.64 0.56Root 1.26 1.20

Verbenaceae Vitex negundo var .cannabifolia

Leaf 1.53 0.62Stalk 0.61 0.16

3 Gramineae Paspalum orbiculare Shoot 6.99 39.6 2.32 19.8Root 1.38 0.23

Phytolaccaceae Phytolacca acinosa Seed 3.55 0.55Stalk 1.40 0.09

Compositae Artemisia capillaris Shoot 0.94 0.294 Euphorbiaceae Euphorbia hirta Shoot 1.70 21.8 0.26 10.4

Root 4.98 0.755 Moraceae Broussonetia papyrifera Leaf 1.54 29.9 0.41 17.8

Stalk 0.78 0.096 Gramineae Phragmites australis Seed 1.56 46.5 0.42 10.9

Leaf 0.36 0.06Stalk 20.6 2.52Root 8.87 1.54

Cynodon dactylon Shoot 1.54 0.257 Cyperaceae Kyllinga brevifolia Seed 1.09 8.93 0.31 16.6

Leaf 4.03 2.41Root 7.73 0.53

8 Cyperaceae Cyperus iria Shoot 36.4 6.03 2.54 19.2Root 2.43 1.54

9 Cyperaceae Juncellus serotinus Shoot 16.9 42.1 2.21 8.71Root 20.8 3.66

10 Dicksoniaceae Cibotium barometz Shoot 5.15 17.3 0.33 18.8Root 21.3 1.77

11 Vitaceae Parthenocissus quinquefolia Leaf 1.58 26.9 0.04 19.5Stalk 0.22 0.57

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Average biomass (g) and the removal capability for U and Th (lg plant-1) of the plantscollected from the uranium mill tailings impoundment in South China (Li et al. 2011)Species Plant part Biomassing Removal capability (lg plant-1)

U ThPaspalum paspaloides Shoot 1.90 ± 0.15 16.6 ± 1.37 2.61 ± 0.23

Root 0.40 ± 0.06Miscanthus floridulus Leaf 53.50 ± 6.25 102 ± 15.9 56.3 ± 10.2

Stalk 49.80 ± 8.24Root 15.20 ± 3.63

Vitex negundo var. cannabifolia Leaf 16.20 ± 1.32 38.0 ± 4.25 13.5 ± 1.40Stalk 21.60 ± 3.65

Paspalum orbiculare Shoot 2.40 ± 0.56 17.6 ± 3.96 5.71 ± 1.31Root 0.60 ± 0.03

Phytolacca acinosa Seed 2.70 ± 0.03 43.6 ± 3.16 3.68 ± 0.21Stalk 24.30 ± 2.18

Artemisia capillaris Shoot 17.80 ± 1.95 16.7 ± 1.83 5.16 ± 0.57Euphorbia hirta Shoot 5.60 ± 0.46 13.5 ± 1.08 2.06 ± 0.16

Root 0.80 ± 0.06Broussonetia papyrifera Leaf 18.80 ± 2.36 51.2 ± 6.45 10.3 ± 1.29

Stalk 28.50 ± 3.61Phragmites australis Seed 1.28 ± 0.05 820 ± 114 103 ± 14.1

Leaf 13.60 ± 1.65Stalk 37.00 ± 5.32Root 5.62 ± 0.36

Cynodon dactylon Shoot 0.68 ± 0.02 1.05 ± 0.03 0.17 ± 0.01Kyllinga brevifolia Seed 0.22 ± 0.01 7.18 ± 0.89 3.32 ± 0.49

Leaf 1.30 ± 0.20Root 0.22 ± 0.01

Cyperus iria Shoot 1.26 ± 0.13 46.2 ± 4.76 3.42 ± 0.35Root 0.14 ± 0.01

Juncellus serotinus Shoot 1.42 ± 0.13 28.8 ± 2.62 3.98 ± 0.36Root 0.23 ± 0.02

Cibotium barometz Shoot 3.64 ± 0.26 37.1 ± 2.62 2.72 ± 0.19Root 0.86 ± 0.06

Parthenocissus quinquefolia Leaf 18.50 ± 2.19 30.5 ± 3.60 3.93 ± 0.45Stalk 5.60 ± 0.64

Transfer factor (TF) and phytoremediation factor (PF) for U and Th of the plants collected from the uranium mill tailings impoundment in South China (Li et al. 2011)

Species TF PFU Th U Th

Paspalum paspaloides 0.27 0.24 0.59 0.48Miscanthus floridulus 0.04 0.05 3.58 4.30Vitex negundo var. cannabifolia 0.04 0.04 1.63 1.53Paspalum orbiculare 0.15 0.10 0.42 0.28Phytolacca acinosa 0.04 0.01 1.10 0.19Artemisia capillaris 0.02 0.01 0.42 0.26Euphorbia hirta 0.10 0.03 0.44 0.14Broussonetia papyrifera 0.04 0.01 1.71 0.58Phragmites australis 0.31 0.16 16.6 8.68

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Cynodon dactylon 0.03 0.02 0.02 0.02Kyllinga brevifolia 0.46 0.11 0.61 0.19Cyperus iria 5.48 0.13 7.61 0.17Juncellus serotinus 0.41 0.28 0.57 0.36Cibotium barometz 0.48 0.03 1.08 0.06Parthenocissus quinquefolia 0.05 0.01 1.13 0.20

(Natural Plant Selection for Radioactive Waste Remediation; Nan Hu, Dexin Ding and Guangyue Li)

Role of mycorrhizal fungi

A study done by Entry et al. (1999) included three grass species: bahia grass (Paspalum notatum), johnson grass (Sorghum halpense), and switchgrass (Panicum virgatum). These three species were selected for this experiment because they produce a high amount of biomass in relatively short periods of time. These grasses were inoculated with two species of arbuscular mycorrhizae: Glomus mosseae and Glomus intraradices. Plants with their fungal associations were grown in the greenhouse for six months and above-ground biomass harvested every two months. At the end of the study, the above-ground portion of the three grasses that had been inoculated with fungi accumulated 41.7% to 71.7% of the total cesium-137 that had been added to the soil while noninoculated plants accumulated 26.3% to 45.5%. The inoculated plants took up 42.0% to 88.7% of the total strontium-90 and the noninoculated plants only took up 23.8% to 52.6%. Plants inoculated with G. mosseae resulted in the highest above ground biomass and percent accumulation of both radionuclides. Overall, the plants in this study accumulated higher amounts of radionuclides than previously published studies. Entry et al. (1999) suggested several reasons for the observed high accumulations, including optimal growing conditions, high root density, low concentrations of K and Ca in the soil, and high amounts of mycorrhizal fungi.(Mycorrhizal Plants for Phytoremediation of Soils Contaminated with Radionuclides Alex Westhoff)

Hyper accumulation of radioactive materials by Pterocarpus santalinus Linn

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It is fast-growing when young, reaching 5 metres (16 ft) tall in three years, even on degraded soils. It is not frost tolerant, being killed by temperatures of −1 °C.

Studies on interaction of gamma radiation have been the subject of interest for the last several decades. Study of gamma-ray interaction has made profound impact in the fields of atomic physics, radiation physics, material science, environmental science, biology, health physics, agricultural, cancer therapy and forensic science etc. The mass attenuation coefficient is a measurement of how strongly a chemical species or substance absorbs or scatters light at a given wavelength, over a unit mass of material. With the development of technology, human health has started to be exposed extra radiation and this can damage human cell (Elias et al, 1986). In order to be protected from radiation three different methods are commonly used. Those are time, distance and the shielding. The latter one is the most important method in which shielding materials become important.

Gamma radiation from radio nuclides, such as K40, Th232 and U238 series and their decay products, represents the main external source of irradiation to the human body (Auwal et al, 2011).

Attenuation coefficient depends on the energy of incident photons and the nature of the absorbing woods.

Mass attenuation coefficient obtained from dividing the linear attenuation coefficient with density. Attenuation coefficient decreases with increasing energy and attenuation coefficient increases with increasing density of the wood.

It can be seen that Pterocarpus santalinus has the lowest half value layer It means that at the same energy of incident radiation, a lesser thickness of Pterocarpus santalinus will be required to attenuation gamma radiation. A lesser thickness of Pterocarpus santalinus will be required to attenuation gamma radiation to half its original intensity, when compared with other woods used in this experiment. The lowest half value layer of wood has the highest attenuation ability, this implies a good absorber of radiation.

A close look of the attenuation coefficient against energy graph in figure-4 revealed that Redsandal (Pterocarpus santalinus) has the highest attenuation ability.

As a result of high attenuation coefficient, Pterocarpus santalinus is considered a very good absorber and a good material for shielding gamma-rays.

Effect of different doses of gamma irradiation on germination and growth parameters of P.santalinus.Means within a column followed by the same letter are not significantly different (P: 0.05). The data shown are means of five replicates ±SD.SL.No Dose Germination% Germination Shoot Root Vigor No.of Dry

Speed length(cm) length(cm) index(V) leaves weight(g)1 Control 23.5±1.5 e 0.605±0.2de 14.75±3.15 a 25.45±9.3ab 784.3±259.1c 7.16±1.47a 0.2±0.12d2 10gy 34.3±2.5 c 0.904±0.011ab 12.57 ±2.27abc 23.14±5.05abc 1073.6±317.5bc 5.96±1.5ab 0.4±0.1ab3 25Gy 36.6±2.08bc 0.95±0.015a 12.09±1.72bc 26.2±5.5ab 1294.5±509.3b 6.92±1.2a 0. 26±0.028 cd4 50Gy 51 ±2.64 a 0.803±0.009abc 12.29±1.7bc 27.4±7.26a 1827.18±820a 7.23±1.165a 0.39±0.13abc5 100Gy 30.6±1.5d 0.876±0.019ab 13.66±2.3ab 25.18±10.14ab 966.9±504.3c 7±2.16a 0.42±0.134 a6 150Gy 30.3±1.5d 0.654±0.01cde 13.88±1.127ab 21.94±6.14abc 890±355.83c 6.4±1.8a 0.329±.0.029bcd7 200Gy 35.3±1.5bc 0.754±0.011bcd 12.88±2.08abc 19.78±6.14bc 1051.0±309bc 7±1.7a 0.3±0.1bcd8 250Gy 29.6±0.015d 0.582±1.2e 11.28±2.05 cd 19.5±6.29bc 901.3±215.7 c 6.3±1.03ab 0.21±0.04 d9 300Gy 38.6±1.5b 0.78±0.023abc 9.827±1.86 d 17.76±4.95c 1037.7±321bc 5.3±1.6b 0.23±0.075d

The descending order of their shielding abilities is as follows: Pterocarpus santalinus, Pterocarpus marsupium, Tectona grandis L, Azadirachta indica L, Eucalyptus Melliodora, Albizia saman, Mangifera indica L and Acacia Nilotica.

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As a result of high attenuation coefficient, Pterocarpus santalinus is considered a very good absorber and a good material for shielding gamma-rays.

Table 3: Experimental Result of Attenuation Coefficient Μ (Cm-1)Scientific Name 0.511MeV 0.662MeV 1.173MeV 1.275MeV 1.332MeVAcacia Nilotica 0.0493 0.0471 0.0422 0.0360 0.0326Mangifera indica L 0.0564 0.0513 0.0455 0.0436 0.0396Albizia saman 0.0661 0.0620 0.0553 0.0485 0.0478Eucalyptus Melliodora 0.0670 0.0625 0.0577 0.0520 0.0496Azadirachta indica L 0.0718 0.0687 0.0661 0.0643 0.0595Tectona grandis L 0.0835 0.0806 0.0721 0.0615 0.0522Pterocarpus marsupium 0.1026 0.0914 0.0675 0.0627 0.0575Pterocarpus santalinus 0.1050 0.0946 0.0922 0.0798 0.0777

Table 4: Experimental Result of Mass Attenuation Coefficient Μ/Ρ (Cm2 /Gm)Scientific Name 0.511MeV 0.662MeV 1.173MeV 1.275MeV 1.332MeVAcacia Nilotica 0.0484 0.0462 0.0415 0.0353 0.0320Mangifera indica L 0.0652 0.0593 0.0526 0.0504 0.0458Albizia saman 0.0556 0.0521 0.0465 0.0408 0.0402Eucalyptus Melliodora 0.0757 0.0706 0.0652 0.0587 0.0561Azadirachta indica L 0.0947 0.0905 0.0871 0.0847 0.0784Tectona grandis L 0.1109 0.1071 0.0958 0.0817 0.0694Pterocarpus marsupium 0.1254 0.1114 0.1124 0.0972 0.0947Pterocarpus santalinus 0.1083 0.0975 0.0696 0.0646 0.0593

Table 5: Result of Calculation of Half Value Layer (HVL) (Cm)Scientific Name 0.511MeV 0.662MeV 1.173MeV 1.275MeV 1.332MeVAcacia Nilotica 14.0567 14.7133 16.4218 19.2500 21.2576Mangifera indica L 12.2872 13.5087 15.2307 15.8944 17.5000Albizia saman 10.4841 11.1774 12.5316 14.2886 14.4979Eucalyptus Melliodora 10.3432 11.088 12.0103 13.3269 13.9717Azadirachta indica L 9.6518 10.0873 10.4841 10.7776 11.6470Tectona grandis L 8.2994 8.5980 9.6116 11.2682 13.2758Pterocarpus marsupium 6.7346 7.5820 10.2666 11.0526 12.0521Pterocarpus santalinus 6.6000 7.3255 7.5162 8.6842 8.9189

In this study attenuation coefficients of gamma rays for wood samples were measured at 0.511MeV to 1.332MeV using a gamma spectrometer NaI(Tl) detector. Attenuation coefficient decreases with increasing energy and attenuation coefficient increases with increasing density of wood. It was observed that in terms of radiation shielding the Pterocarpus santalinus and Acacia Nilotica wood samples were more suitable than other tested wood samples. The study of the shielding characteristics of woods is a necessary research that should continue. It is therefore recommended that more research on shielding ability of material be carried out and using more unexplored tropical woods for radiation shielding applications.

(E. RAJASEKHAR & R. JEEVAN KUMAR, Molecular Biophysical Laboratory, Department of Physics, Sri Krishna Devaraya University, Anantapuram, Andhra Pradesh, India have reported in their article “EXPERIMENTAL INVESTIGATION OF GAMMA RADIATION SHIELDING CHARACTERISTICS OF WOOD “; International Journal of Humanities, Arts, Medicine and Sciences (BEST: IJHAMS) ISSN 2348-0521 Vol. 2, Issue 6, Jun 2014, 21-26)

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(Excerpts from my book “Comprehensive Medicinal Plants Volume 5 pages 276 to 278, published by Studium Press, Houston, TEXAS, 77072; 2011)

MoA

Analytical protocolsfor determining U and Th

from samples ofbio accumulated microbial cell biomass dried /

bio accumulated whole plant dried and pulverized

The lithium metaborate fusion technique for analysis of samples has been adapted for the alpha spectrometric determination of uranium and thorium isotope abundances in hyper accumulated dried microbial bio mass or hyper accumulated dried whole plant biomass. Powdered sample is spiked with a solution of a uranium-thorium isotope tracer, mixed with LiBO2 in a 1:3 ratio and fused at 950°C in a graphite crucible. The mixture is poured into 1 M HNO3 and stirred until dissolved. Uranium and thorium are simultaneously extracted with 10% tributylphosphate (TBP) in amyl acetate using Al(NO3)3 as the salting agent, and then back-extracted into 1 M H2SO4. Uranium is separated from thorium using anion exchange resin and, after further purification, each is plated onto steel discs for alpha counting. Preliminary tests show the TBP extraction step to be almost quantitative for both elements, in spite of the presence of impurities like Silicon and Aluminum. This procedure is much faster than the usual acid digestion technique, and uranium and thorium discs for counting can be prepared in approximately eight hours, starting from sample powder.

Production of thorium chloride reagent, ThCl4(DME)2. Th-ING:Thorium nitrate is reacted with aqueous hydrochloric acid under mild conditions. The 100 C process can be performed using conventional glassware in a traditional laboratory setting without using hazardous chemicals such as chlorine gas or carbon tetrachloride. The reaction produces ThCl4(H2O)4; a novel combination of anhydrous hydrochloric acid and trimethylsilyl chloride then removes the coordinated water molecules, replacing them with dimethoxyethane (DME) to make the new thorium chloride reagent.

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EXTRACTION AND PURIFICATION METHODS CURRENTLY EMPLOYED

1. Amex Process (amine Extraction)2. TBP (Purification of Thorium)3. Dialkylphosphoric Acid Extraction (Dapex) Process for Uranium

WEB REFERENCES:http://www.sciencedirect.com/science/article/pii/S1569486002800377http://www.qucosa.de/recherche/frontdoor/?tx_slubopus4frontend[id]=urn:nbn:de:bsz:105-5486188

REFERENCES:

1. Alexander B, Priest FG (1990) Numerical classification and identification of Bacillus sphaericus including some strains pathogenic for mosquito larvae. Journal of General and Applied Microbiology 136, 367-376.

2. Anderson RT, Vrionis HA, Ortiz-Bernad I, Resch CT, Long PE, Dayvault R, Karp K, Marutzky S, Metzler DR, Peacock A, White DC, Lowe M, Lovley DR (2003) Stimulating the in situ activity of Geobacter species to remove uranium from the groundwater of a uranium-contaminated aquifer. Applied and Environmental Microbiology 69, 5884-5891.

3. Arnold RG, DiChristina TJ, Hoffmann MR (1986) Inhibitor studies of dissimilative Fe(III) reduction by Pseudomonas sp. strain 200 (“Pseudomonas ferrireductans”). Applied and Environmental Microbiology 52, 281-289.

4. Beller HR (2005) Anaerobic, nitrate-dependent oxidation of U(IV) oxide minerals by the chemolithoautotrophic bacterium Thiobacillus denitrificans. Applied and Environmental Microbiology 71, 2170-2174.

5. Chicote E, Garcia AM, Moreno DA, Sarró MI, Lorenzo PI, Montero F (2005) Isolation and identification of bacteria from spent nuclear fuel pools. Journal of Industrial Microbiology and Biotechnology 32, 155-162.

6. DiSpirito AA, Tuovinen OH (1982) Uranous ion oxidation and carbon dioxide fixation by Thiobacillus ferrooxidans. Archives of Microbiology 133, 28-32.

7. Francis AJ (1998) Biotransformation of uranium and other actinides in radioactive wastes. Journal of Alloys and Compounds 271-273, 78-84.

8. Francis AJ, Dodge CJ, Lu F, Halada GP, Clayton CR (1994) XPS and XANES studies of uranium reduction by Clostridium sp. Environmental Science and Technology 28, 636-639.

9. Friis N, Myers-Keith P (1986) Biosorption of uranium and lead by Streptomyces longwoodensis. Biotechnology and Bioengineering 28, 21-28.

10. Hennig C, Panak P, Reich T, Roßberg A, Raff J, Selenska-Pobell S, Matz W, Bucher JJ, Bernhard G, Nitsche H (2001) EXAFS investigation of uranium(VI) complexes formed at Bacillus cereus and Bacillus sphaericus surfaces. Radiochimica Acta 89, 625-631.

11. Heyrman J, Vanparys B, Logan NA, Balcaen A, Rodgríguez-Díaz M, Felske A, De Vos P (2004) Bacillus novalis sp. nov., Bacillus vireti sp. nov., Bacillus soli sp. nov., Bacillus bataviensis sp. nov. and Bacillus drentensis sp. nov., from the Drentse A grasslands. International Journal of Systematic and Evolutionary Microbiology 54, 47-57.

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12. Kalinowski BE, Oskarsson A, Albinsson Y, Arlinger J, Ödegaard-Jensen A, Andlid T, Pedersen K (2004) Microbial leaching of uranium and other trace elements from shale mine tailings at Ranstad. Geoderma 122, 177-194.

13. Khijniak TV, Slobodkin AI, Coker V, Renshaw JC, Livens FR, Bonch-Osmolovskaya EA, Birkeland N-K, Medvedeva-Lyalikova NN, Lloyd JR (2005) Reduction of uranium(VI) phosphate during growth of the thermophilic bacterium Thermoterrabacterium ferrireducens. Applied and Environmental Microbiology 71, 6423-6426.

14. Kotelnikova S, Macario AJL, Pedersen K (1998) Methanobacterium subterraneum sp. nov., a new alkaliphilic, eurythermic and halotolerant methanogen isolated from deep granitic groundwater. International Journal of Systematic Bacteriology 48, 357-367.

15. Lovley DR, Giovannoni SJ, White DC, Champine JE, Phillips EJP, Gorby YA, Goodwin S (1993) Geobacter metallireducens gen. nov. sp. nov., a microorganism capable of coupling the complete oxidation of organic compounds to the reduction of iron and other metals. Archives of Microbiology 159, 336-344.

16. Lovley DR, Phillips EJP (1992) Reduction of uranium by Desulfovibrio desulfuricans. Applied and Environmental Microbiology 58, 850-856.

17. Lovley DR, Widman PK, Woodward JC, Phillips EJP (1993b) Reduction of uranium by cytochrome c3 of Desulfovibrio vulgaris. Applied and Environmental Microbiology 59, 3572-3576.

18. Macaskie LE, Bonthrone KM, Young P, Goddard DT (2000) Enzymically mediated bioprecipitation of uranium by a Citrobacter sp.: a concerted role for exocellular lipo-polysaccharide and associated phosphatase in biomineral formation. Microbiology 146, 1855-1867.

19. Macaskie LE, Empson RM, Cheetham AK, Grey CP, Skarnulis AJ (1992) Uranium bioaccumulation by Citrobacter sp. as a result of enzymically mediated growth of polycrystalline HUO2PO4. Science 257, 782-784.

20. Merroun M, Hennig C, Rossberg A, Geipel G, Reich T, Selenska-Pobell S (2002) Molecular and atomic analysis of uranium complexes formed by three eco-types of Acidithiobacillus ferrooxidans. Biochemical Society Transactions 30, 669-672.

21. Merroun M, Hennig C, Rossberg A, Reich T, Selenska-Pobell S (2003a) Characterization of U(VI)-Acidithiobacillus ferrooxidans complexes using EXAFS, transmission electron microscopy, and energy-dispersive X-ray analysis. Radiochimica Acta 91, 583-591.

22. Merroun M, Selenska-Pobell, S (2001) Interactions of three eco-types of Acidithiobacillus ferrooxidans with U(VI). BioMetals 14, 171-179.

23. Merroun ML, Hennig C, Rossberg A, Reich T, Selenska-Pobell S (2003) Characterization of U(VI)-Acidithiobacillus ferrooxidans complexes using EXAFS, transmission electron microscopy and energy-dispersive X-ray analysis. Radiochimica Acta 91, 583-591.

24. Motamedi M, Pedersen K (1998) Desulfovibrio aespoeensis sp. nov., a mesophilic sulphate-reducing bacterium from deep groundwater at Äspö hard rock laboratory, Sweden. International Journal of Systematic Bacteriology 48, 311-315.

25. Nevin KP, Finneran KT, Lovley DR (2003) Microorganisms associated with uranium bioremediation in a high-salinity subsurface sediment. Applied and Environmental Microbiology 69, 3672-3675.

26. Okazaki M, Sugita T, Shimizu M, Ohode Y, Iwamoto K, DE Vrind-DE Jong EW, DE Vrind JPM, Corstjens PLAM (1997) Partial purification and characterization of manganese-oxidizing factors of Pseudomonas fluorescens GB-1. Applied and Environmental Microbiology 63, 4793-4799.

27. Pollmann K, Raff J, Schnorpfeil M, Radeva G, Selenska-Pobell S (2005) Novel surface layer protein genes in Bacillus sphaericus associated with unusual insertion elements. Microbiology 151, 2961-2973.

28. Sani RK, Peyton BM, Smith WA, Apel WA, Petersen JN (2002) Dissimilatory reduction of Cr(VI), Fe(III), and U(VI) by Cellulomonas isolates. Applied Microbiology and Biotechnology 60, 192-199.

29. Selenska-Pobell S (2002) Diversity and activity of bacteria in uranium waste piles. In Interactions of Microorganisms with Radionuclides (eds Keith-Roach MJ, Livens FR) Elsevier Sciences Ltd, Oxford, UK, pp. 225-254.

30. Selenska-Pobell S, Panak P, Miteva V, Boudakov I, Bernhard G, Nitsche H (1999) Selective accumulation of heavy metals by three indigenous Bacillus strains, B. cereus, B. megaterium and B. sphaericus from drain waters of a uranium waste pile. FEMS Microbiology Ecology 29, 59-67.

31. Suzuki Y, Kelly SD, Kemner KM, Banfield JF (2004) Enzymatic U(VI) reduction by Desulfosporosinus species. Radiochimica Acta 92, 11-16.

[Type here]

32. Vijayaraghavan Gonuguntla; Comprehensive Medicinal Plants Volume 5 pages 276 to 278, published by Studium Press, Houston, TEXAS, 77072; 2011

33. Wu Q, Sanford RA, Löffler FE (2006) Uranium(VI) reduction by Anaeromyxobacter dehalogenans strain 2CP-C. Applied and Environmental Microbiology 72, 3608-3614.

34. D. J. Crouse and K. B. Brown, "Amine Extraction Processes for Uranium Recovery from Sulfate Liquors," ORNL-195 9 (Sept. 30, 1955).

35. C. F. Coleman, K. B. Brown, J. G. Moore, and D. J. Crouse, "Solvent Extraction with Alkyl Amines," Ind. Eng. Chem., 50: 1756 (1958) .

36. J. G. Moore, K. B. Brown, and C. F. Coleman, "Further Studies of Amines as Extractants for Uranium from Acid Sulfate Solutions," ORNL-1922 (June 24, 1955).

37. D. J. Crouse, K. B. Brown, and W. D. Arnold, "Progress Report on Separation and Recovery of Uranium and Thorium from Sulfate Liquors by the Amex Process," ORNL-2173 (Dec. 26, 1956).

38. Ibid., vol. II, BMI-243A (Sept. 15, 1950). 39. M. E. Whatley, M. Smutz, and G. L. Bridger, "Purification of Thorium by Solvent Extraction," ISC-415

(July, 1953). i^mtwuswiifewiinman=•• -55- 40. K. B. Brown, C. F. Coleman, D. J. Crouse, J. 0. Denis, and J. G. Moore, "The Use of Amines as

Extractants for Uranium from Acidic Sulfate Liquors: A Preliminary Report," ORNL-1734 (May 27, 1954).

41. C. A. Blake, D. J. Crouse, C. F. Coleman, K. B. Brown, and A. D. Kelmers, "Progress Report: Further Studies of the Dialkylphosphoric Acid Extraction (Dapex) Process for Uranium," ORNL-2172 (Dec. 18, 1956).