Cleaner Production Options in Pharmaceutical Sector of Pakistan

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CLEANER PRODUCTION OPTIONS INPHARMACEUTICAL SECTOR OF PAKISTAN

R. Mushtaq and Javed A. Chattha*WAPDA GHS Rt. Bank Colony Tarbela Dam Project Tarbela, Pakistan

*Faculty of Mechanical Engineering, GIK Institute of Engineering Sciences and Technology, Topi,

Distt. Swabi, NWFP, Pakistan

The paper presents a comprehensive analysis of environmental issues in thepharmaceutical sector of Pakistan based on the environmental audits. Remedialmeasures have been proposed to mitigate the pollution problems to facilitate cleanproduct ion. Cost estimates have been also provided for some technical equipment tofacilitate Clean Production in the pharmaceutical industries of Pakistan.

INTRODUCTION

Pharmaceutical sector can be classified as one of the most organized sector with respect toits institutional arrangements. About 200, local and multinational industries are operating inthis sector in which the market sales of the leading multinational companies are 50%. Most ofthese industries are located in Sindh and Punjab. Pharmaceutical production processes canbe divided in three stages:

1. Research & development;2. Conversion of organic & natural substances into bulk pharmaceutical substances or

ingredients through fermentation, extraction and/or chemical synthesis; and3. Formulation of the final pharmaceutical product.

In Pakistan, only the formulation of pharmaceutical products is carried out and wide variety ofchemical and pharmaceutical products are produced which includes anesthetics,

disinfectants, water soluble salt, muscle relaxants, anti clotting agents, analgesic, anti-hypertensives, antibiotics, diuretics, anti-infective, anti depressant and vitamins. Theindustries of Pakistan formulate, fill and pack a variety of pharmaceutical products, withdifferent trade names in the form of Tablets, Capsules, syrups, oral powders for suspension,creams, ointments and lotions, injectibles and ampoules.Raw material (including active raw materials) as well as excipients like sugar, lactose etc. areused to manufacture different pharmaceutical products. Besides the major raw materials,solvents such as Methylene Chloride, Di-chloro Ethane, Ethyl Acetate and Methanol aremostly used. Most of the requirements of raw materials are met through import. Mostconsumed utilities in pharmaceutical industry are electricity, water, diesel and natural gas.

Generally water is required in most of the processes. Beside this, it is also consumed ingeneral office use, cleaning, rinsing, washing, showering, etc. Electricity consumptiondepends on the size of the unit and the degree of dependence on electric appliances. Naturalgas and diesel are mostly used as fuel for heating purpose such as for water heatingsystems, incinerators, generators etc. Air-handling units, generators, boilers, water treatmentsystems are some of the commonly used ancillaries in Pharmaceutical sector. PakistanPharmaceutical Manufacturers Association (PPMA) is the apex body for pharmaceuticalsector with 180 members. PPMA also has an ‘Environmental Committee’ to look after thesectoral issues related to environment. Most of the progressive pharmaceutical units havealready under taken number of environmental initiatives; some of these are installation ofincinerator, wastewater treatment plant, shredder, air handling system etc.



THE NEED FOR CLEANER PRODUCTION (CP) The need for cleaner production emerges in pharmaceutical industry due to someenvironmental problems associated with formulation processes. Water pollution is the keyissue pertaining to end-of-pipe (EOP) solution at pharmaceutical industry. Other issues ofconcern are air emissions and solid waste.

Wastewater GenerationIn pharmaceutical industries wastewater is mainly generated through the washing activitiesof the equipment. The main sources of wastewater in any pharmaceutical industry arehighlighted in the following section.

Major Sources of Wastewater Washing activities of process section generate significant quantity of wastewater, high in

BOD, COD, SS and DS.

• Floor washing wastewater contains traces of spilled chemicals.

• Washing of ampoules generates a clean stream of wastewater.

•

Wastewater generated from Laboratory is contaminated with solvents, raw materials,laboratory reagents/chemicals or ingredient of the pharmaceutical products.

• Wastewater generated from water softener is high in TDS and salt content.

• Periodic discharge of boiler blow down, is high in TDS.

• Cooling water system intermittent blow down that is high in TDS, is usually carried outto prevent the scaling and corrosion problem.

• Some of the industries, who do not have a closed steam system in boilers, dischargetheir returned steam (condensate) into drain.

• Other sources of wastewater include the domestic wastewater originating fromwashrooms, showers and cafeteria. The cafeteria wastewater is usually contaminatedwith organic material, detergents and oil & grease.

Unit total wastewater quantities, including the sanitary wastewater originating from office use,floor washings and general cleaning operations, are estimated to be 120-160 liters per Kg ofraw ingredients.

Since a significant part of the wastewater results from periodic discharges from batchprocesses, with varying discharge intervals, the wastewater flow rates would show arelatively higher level of daily and seasonal fluctuations. One of the factors which maycontribute to large temporal variations is processing of raw pharmaceutical ingredients,different types and chemical natures, at different times [1,2].

The above factors make it difficult to establish a well-defined range for quality characteristicsof pharmaceutical wastewater. The characteristics, therefore, given in Table-1 should betaken as indicative only. The main pollutants in effluent are organic chemicals (responsiblefor BOD & COD), Grease & Oil, Sulfate, Ammonia Sulfide, Phenols, TSS, TDS, etc.



Table 1: Wastewater Analysis

Parameters Typical Concentrations* NEQS

pH 6.0-7.5 6-9

BOD5 300-400 80

COD 400-800 150

Total SuspendedSolids (TSS)

200-600 200

Grease & Oil 0-13 10

Sulfide (S) 0-15 1.0

Phenol 0-1.5 0.1

* All values in mg/L except pH Source: PP Pharmaceutical Sector Report 2001

The table reveals that the ranges of BOD and COD are higher than the limits defined byNEQS. While in some industries the concentration of oil & grease, sulphide and TSS are alsoon the higher side. Most of the Pharmaceutical industries treat their process and domesticwastewater in septic tanks. Septic tank is considered to be an appropriate treatment only fordomestic wastewater, as its function is to separate the sludge from the effluent whichundergoes partial treatment under anaerobic condition. The baffles in the septic tankenhance the separation of water from the sludge and the clear water is thus drained. Clearwater is discharged and sludge is cleaned periodically from the tank. Some of the premierindustries are endeavouring to slash the concentration of pollutants in their wastewaterthrough wastewater treatment plant. The treatment system is based on activated sludgesystem. In this treatment system wastewater is treated by micro-organisms (activatedsludge) under aerobic condition. Main components of the system are aeration tank, de-gassifier, settling tank and sludge silo.

Ai r EmissionsBroadly the air emissions can be classified as point and diffused emissions. Point emissionsare mainly from stacks of incinerator, boilers and generators. These emissions mainlycomprise of particulate matter, NOx, SOx, CO and CO2. These emissions are due to fuelcombustion. Measured concentrations of various pollutants in samples drawn from somestacks of standby power generators (diesel) and boilers (fuel gas or furnace oil), ofpharmaceutical industry, reveal the following:

a. Oxides of nitrogen and Sulphur are within NEQS limits, in most of the cases. In somecases they exceed the NEQS values.

b. Carbon monoxide, in most of the cases, exceeds the NEQS values. In some cases, it

is found to be as high as 20 times the NEQS limiting value.c. Relative concentrations of oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2)

and hydrocarbons (HC), in the exhaust, indicate trends of incomplete combustion insome generators and boiler.

Diffused emissions are those which do not come through stacks or any exhaust andgenerally get directly into the occupational atmosphere of the production areas. The majorsources of these emissions are dispersion of particulate matter from processing of powderedand granular materials and VOC emissions from printing operations. Most of the dispensingof ingredients is carried out manually. Therefore fumes dispersion in to working air takesplace, where spot ventilation is inadequate or its operation is ineffective. In a number of

formulation processes, powdered or granular ingredients are fed manually to mixing vessels



and generates significant amount of emission. Milling operation in tablet manufacturing isused as a grinding mill for obtaining uniform particle size. Milling machine is equipped with aspot dust collector. Dust emissions to the working air are excessive where spot ventilation isineffective. Volatile solvents, used in the printing machines, are the major contributors ofVOC in the working air. Most of the pharmaceutical industries have a combination of local orspot and area ventilation systems, in the processing areas. Spot forced ventilation systems

capture emissions at the source, whereas area ventilation of the production areas is carriedout, to continuously replace the working air, with the fresh air. But no data is available on theoccupational air quality of the production areas of the pharmaceutical industries.

Solid WasteMajor sources of process solid waste and waste chemicals in pharmaceutical industry andthe existing common disposal practices are summarized in Table 2.

Table 2: Sources and Existing Disposal Practices of Process Solid Waste & Waste Chemicals

Type, Sources & Processes Existing Disposal Practices

Contaminated Waste

Waste chemicals and solvents • Incinerated Expired or rejected medicines or capsules • Incinerated or burnt in

an open pit

Spillage cleaning materials i.e. sawdust,cotton rags or vacuum cleaner

• Incinerated

• Dumped

Filter & Dust from Bag Filters of airhandling system

• Incinerated

Contaminated Glass wares includingbottles of solvents from laboratorydamaged glass wares of lab, rejected or

damaged ampules rejected or damagedmedicine bottles

• Crushed in shredder

• Sold to contractor

Empty Drums of the raw material • Sold to contractor

• Deformed

Non Consumable WasteNon Contaminated Glass Wares • Crushed and sent to

contractor for reuse

Corrugated cartons, poly bags, damagedrejected labels, fiber drums, aluminumcans, wooden pallets, iron scrap etc.

• Sold forrecycling/reuse

Source: PP Pharmaceutical Sector Report 2001

Some of the progressive units have installed their own in-house incinerators for the disposalof hazardous waste chemicals and contaminated solid waste of pharmaceutical industry. It isa multistage unit comprising primary, secondary and settling chamber, for incineration of alltypes of waste chemicals and contaminated solid waste. Whereas some of the units areusing of-site commercial facilities for incineration of there contaminated waste. Some of thelocal industries are practicing open burning of their contaminated waste. Due to uncontrolledburning, fumes and chemicals of the pharmaceutical chemicals, dispersed in the communityair which can pose very serious health hazards to the people.



Noise PollutionPermissible noise level, as promulgated by NEQS, is 85 dB(A). Noise levels in different unitsshow a significant temporal variation, depending upon the operations being conducted. Majorhigh noise generating equipment are tableting machines (80-84 db), capsule manufacturingmachine (86-89 db), chillers, shredder machine, generator (102-120 db), tablet compression

machine etc. In most cases, the workers generally refrain from using personal protectiongears, even where provided.

CLEANER PRODUCTION (CP) TECHNIQUESPharmaceutical industry in Pakistan can substantially improve its environmental status bytaking some CP measures. Not all measures are necessarily appropriate for all units.Individual units have to select options which are most suitable to their own situations. Therecommendations given below have been developed and worked out on the basis of thepresent state of information. For further development and cost estimation of eachrecommendation, more specific data would be necessary.It is suggested that prior to going for the implementation of wastewater treatment, theindustrial unit should carry out detailed flow monitoring and characterization of thewastewater. Generally BOD-to-COD ratio ranges from 0.4 to 0.75 for pharmaceuticalwastewater, which shows that it is highly biodegradable and would respond effectively to thebiological treatment [3,4]. In some plants sulfides and phenols are present in very highconcentrations in the wastewater. In such cases, wastewater will also require additionaltreatment for their removal. Brief description of the proposed treatment facilities is given inthe following section.

Wastewater Treatment systems for Pharmaceutical Industry Extended Aeration Activated Sludge (EAAS) Process: Extended aeration activated sludge

process is being commonly employed for the treatment of combined wastewater frompharmaceutical industries. The system is contrasted from the conventional activated sludgeprocess, by relatively low food-to-microorganism ratios and longer retention periods. Thesludge production is less as compared to conventional activated sludge process. Thesystem, due to longer hydraulic retention periods, can absorb pollution load fluctuations andis relatively easy to operate and monitor, as compared to the conventional activated sludgeprocess [1,2].Extended aeration activated sludge process in general would comprise the following processfacilities.i. Wastewater Screening and Pumping Stationii. Aeration Tank

iii. Secondary Clarifieriv. Sludge Pumping Stationv. Sludge Drying Beds or Sludge Thickening Tank + Sludge Press Filters.



Removal of SulfidesSulfides change their forms in water medium, with change in its pH value. It is expected thathydrogen sulfide present, in close-to-neutral or slightly acidic pharmaceutical wastewater,would be stripped of and removed consequent to forced aeration of wastewater, in activatedsludge reactor. Stripping of hydrogen sulfide, from wastewater at an instant, would lead toformation of more hydrogen sulfide, to maintain the chemical balance. Extended aeration fora period of 24 hrs would result in a continuous chain reaction of formation and stripping ofhydrogen sulfide. It is envisaged that in extended aeration activated sludge process, requiredremoval of sulfides would also be achieved, and no separate treatment for removal ofsulfides would be required.

Removal of Toxic substancesPharmaceutical wastewater may sometimes, contain substances, which are toxic to themicroorganisms. Presence of such substances may inhibit the microbial growth, required forproper functioning of the activated sludge process. In such cases, toxicity of wastewater canbe controlled by addition of powdered charcoal in the aeration tank. Charcoal exhibitsexcellent potential for absorbing a variety of toxic organic chemicals.

Sludge TreatmentThe excess sludge produced from the aeration tank contains about 1% solids and needs

dewatering before final disposal. The waste sludge can be dewatered and dried on sludgedrying beds or in sludge filter press, a sludge thickener shall also be installed before the filterpress. The sludge incase of pharmaceutical industries should be treated as contaminatedsolid waste and be incinerated. Excess sludge can also be directly incinerated without anydewatering; but this will incur very high operational costs.

Estimated Unit Cost of Treatment SystemUnit capital cost of extended aeration activated sludge treatment system, with provision ofsludge drying beds, including civil, mechanical and electrical works for a pharmaceuticalindustry, is estimated as Rs. 20,000 to 30,000 per Kg/d of BOD load. Due to the fixed costfactors, however the capital cost of the smallest plant would not be less than Rs. 2.00 million.

Unit annual operation and maintenance (O&M) cost (excluding the dried sludge incineration



cost) is estimated as Rs. 10 to 15 per kg of annual BOD load, with a minimum total annualO&M cost of Rs. 250,000.

Activated Carbon Adsorption Treatment for Removal of PhenolsIn some pharmaceutical wastewaters, phenols are found to be present, in concentrations

exceeding the NEQS values and treatment would be required for their removal. Activated

carbon is very effective for removing a number of dissolved organic chemicals, by process ofchemical adsorption. In this system, wastewater is filtered through an activated carbon filter. After a period of use, depending upon the total pollution load of dissolved organiccompounds removed by the filter, the activated carbon media gets exhausted and becomesineffective. The spent media shall then either be replaced with fresh activated carbon oralternatively it can be reused after regeneration. One most commonly used method ofexhausted activated carbon regeneration is its incineration at high temperatures. In order tomaximize the effectiveness of the activated carbon adsorption, it is suggested that, whererequired, this treatment shall be carried out after activated sludge process.

Measures with respect to improvement of air quality The process of controlling the occupational air quality comprises the following sequentialsteps:

• Establishing the occupational air quality criteria for the protection of the health andsafety of the workers.

• Planning, design, installation and operation of a comprehensive system, whichensures maintenance of the occupational air quality, within the desirable limits. Such asystem would comprise the following components:

• Enclosure of the emission sources would minimize the health risks, for workers,particularly those working very close to these machines.

• Local or spot ventilation system shall mainly comprise collection hoods, air

Transmission ducts, exhaust-air blowers and pre-emission air treatment system.• General area or room ventilation system shall be required to continuously replace the

working air and to control the concentrations of toxic vapours and particulates, beinggenerated from non-point sources and those, not captured by the spot ventilationsystem.

• Working air sampling and laboratory testing, to establish occupational airconcentrations for pollutants, should be carried out on continuous basis at a specifiedinterval.

• In the powder filling and granule units the levels of particulate matter (PM10) shouldalso be monitored.

• The exhaust air carrying particulate matter should be treated with fabric bag filters.

Under optimum conditions, a fabric filter can remove 99% of the particles of sizeabove 1 micron. The fabric filters shall be cleaned or replaced at intervals to removethe dust. The exhaust filter and the dust should be treated as contaminated solidwaste. The efficiency of the fabric filters should be monitored and evaluated regularlyon the basis of particulate matter in influent and effluent air streams.

Incineration is at present considered to be a suitable technology for the disposal of wastechemicals and contaminated solid waste but generally the provision of a proper in-houseincineration facility would not be economically feasible for most of the pharmaceutical units;because capital costs of duly equipped incinerators are quite high.



Suggested contaminated waste incinerator, for the pharmaceutical industry, is rotary kilntype, which can simultaneously incinerate solid as well as liquid contaminated wastes. It shallcomprise rotary kiln (primary combustion chamber), an after-burner (secondary combustionchamber), exhaust Air Pollution Control System (APCS) and necessary instrumentation forcontrol of incineration process and air quality sampling and monitoring. The highesttemperatures to be maintained in the kiln and after-burner should be of the order of 850 0C

and 1200 0C, respectively [3,4]. Solid waste shall be fed to the kiln and the liquid wastes tothe after-burner, injected through an atomizer, to convert the liquid into droplets as small asone microgram. The system should be provided with a blower of appropriate size to force airinto it to increase the combustion efficiency and produce turbulence. Both the kiln and after-burner shall have provisions for introducing supplementary fuel.

The function of Air Pollution Control System (APCS) is to cool and clean the emitted gases.The APCS should be capable of bringing the quality of emission gases within the applicableNEQS limits, for the worst type of waste anticipated. other measures with respect to safedisposal of solid waste and waste chemicals have been suggested in the following section

Management of Solid Waste & Waste Chemicals

Segregation of WasteIt is suggested to set up and carry out a solid waste segregation program, which includes:

• Collection and documentation of data on generation rates, collection/handling

practices, storage and disposal activities, for different types of wastes.• Hazardous and non hazardous waste should be stored separately

• All the contaminated solid waste and chemicals should be segregated from otherwastes and stored under controlled conditions

• The storage time of waste should be as low as possible

Disposal of Contaminated Emptied Drums

• The contaminated drums should not be sold to contractor without decontaminatingthem.

• It is advisable to mutilate or crush all the contaminated drums and sold to the market,for recycling.



• Use of a drum-deforming machine, instead of the manual crushing should bepreferable

Prevention of Waste GenerationThis could be achieved by proper training of workers, creating awareness on reduction inwaste generation and setting practicable limits on amount of waste produced.

Disposal of Contaminated Glassware All the contaminated glassware should be shredded, prior to its dispatch to the market forrecycling purposes. This practice is required to prevent a direct reuse of the glassware, byany downstream consumer.

Health & Safety Measures • General measures to ensure Health and safety are as under

• Keep fire sensitive areas to a minimum.

• All insect removers must work properly.

•

No obstruction of the fire exits or fire fighting equipment.• MSDS should be available to everyone who is working with chemicals.

• The washing frequency of uniforms should be increased.

• Accidents should be recorded in a logbook.

• Appropriate measures should be taken to prevent the same accident happeningagain.

• Training of employees to appropriate use of first aid.

• Content of the boxes and expiry date on medicines should be regularly checked.

• It was observed that mostly manual fire extinguishers are available in the warehouse. As many toxic fumes are formed in case of fire, manual extinguishing is dangerouswithout protection.

• Smoke detectors should be installed at all fire sensitive areas.

• Safety exits should open from inside, not be locked with material or equipment andhave proper signs.

CONCLUSIONSThere is a dire need to take immediate measures to eliminate the environmental pollutantsproduced from the pharmaceutical industries of Pakistan. It is hoped that results of this studywill help the pharmaceutical industry to take a leap towards cleaner production.

ACKNOWLEDGEMENTS

Authors acknowledge valuable and kind support of Federation of Pakistan Chambers ofCommerce and Industry (FPCCI) for providing necessary data for this study.

References[1] Report and Brochure “Environ. Tech. Program for Industry” on pharmaceutical sector

2001[2] Ellenhorn, M. J., Ellenhorns Medical Toxicology (Second Edition), Williams & Wilkins,

Baltimore, 1997.[3] Davis, M. L. & D. A. Cornwell, Introduction to Environmental Engineering (Second

Edition), McGraw -Hill, Inc., New York, 1991[4] LaGrega, M. D., P. L. Buckingham & J. C. Evans, Hazardous Waste Management,

McGraw-Hill, Inc., New York, 1994



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Cleaner Production Options in Pharmaceutical Sector of Pakistan