DECLARATION AND APPROVAL OF SUPERVISOR

I have prepared this report with inputs from my supervisor. I have taken care of

the formatting as per the guidelines circulated. I have not copied any section from any

other report, website or article.

SIGNATURE OF STUDENT

Report entitled “Extraction of Zirconium from Acidic Raffinate Stream using Tri-n-butyl Phosphate” is approved

SIGNATURE OF SUPERVISOR

iii

ABSTRACT

This work deals in wastewater treatment for phenol removal using electrocoagulation

technique. Various parameters affecting the phenol removal efficiency have been

discussed here like pH, Conductivity of the solution, electrolysis time, current density,

initial phenol concentration, geometry of electrode and residence time. Each parameter

was optimized using experimental method treating 400ml of synthetic solution in each

run. With concentration of samples as 1mg/l, 10mg/l & 40mg/l of phenol, increasing the

electrolysis time from 30 minutes to 120 minutes showed increase in phenol removal

efficiency of the electrocoagulation technique. Conductivity of the solution was adjusted

using NaCl concentration, here it was kept at 2 g/l. Current supply was changed from 0.5,

1 and 3 A and voltage supply as 5 V and 9V for the experiments conducted. Phenol

concentration in treated water is detected by reacting 4AAP with phenol in the presence

of Potassium Ferrycyanide which gives reddish brown colour which can be detected

through spectrophotometric method. The pre evaluated calibration curve of absorbance

v/s phenol concentration helps in detecting the concentration of the treated sample.

Maximum efficiency of 86% phenol removal was achieved with 10mg/l phenol

concentration, Electrolysis time of 60 min, Punched electrode with 4 holes of 2mm dia,

Current Input of 3A, Voltage supply of 9V and Nacl concentration of 2 g/l. The

efficiency of electrocoagulation technique depends upon various parameters and this

technique is easy to simulate at lab scale so that it can be implemented at industrial scale

with good accuracy and applicability.

.

iv

ACKNOWLEDGMENTS

First and foremost, I would like to express my heartfelt gratitude to My Supervisor Prof.

Ashok N Bhaskarwar, Department of chemical Engineering, Indian Institute of

Technology, Delhi. Who provided me the opportunity to work in a wonderful research

environment and constant guidance in every aspect of this project work. His crucial

remarks, positive attitude and support made my M.Tech thesis project a joyous and a

good learning experience. It was an honor to have a chance of working under his

supervision and have been part of the pollution control lab, Chemical Engineering

Department, Indian Institute of Technology, Delhi.

I would like to acknowledge the Department of Chemical Engineering, Indian Institute

of Technology, Delhi for giving me the chance to undertake this study. Also many thanks

to the Head of Chemical Engineering Department Prof. S. Basu for providing me all the

necessary laboratory facilities during my research.

I would also like to express my gratitude to my project assessment panel members, Prof.

S. Basu, Prof. A. K. Gupta, Dr. A. Shukla and Dr. Anil Verma for their constructive

suggestions and helpful discussions.

I would like to thank all the faculty members, laboratory and office staff of the Chemical

Engineering Department. I am grateful that I had Ms. Pramila, Ms. Manjari and Ms.

Shushma as my senior and labmates who always contributed in making the lab

environment healthy and positive.

v

TABLE OF CONTENTS

TITLE PAGE

ABSTRACT iii

ACKNOWLEDGMENTS iv

TABLE OF CONTENTS v

LIST OF TABLES vii

LIST OF FIGURES viii

1 INTRODUCTION 1

1.1 Wastewater Treatment and Techniques 1

1.2 Phenol 1

1.3 Scope and objective of the study 2

1.4 Organisation of the Report 3

2 REVIEW OF LITERATURE 4

2.1 Phenol 4

2.1.1

Chemical and Physical properties of Phenol 4

2.1.2

Phenol as a hazard and its acceptable limits 4

2.2 Electrocoagulation theory 5

2.3 Factors affecting Phenol Removal efficiency 6

2.4 Phenol determination methods 11

3 EXPERIMETAL METHODS/MODELLING

3.1 Materials and Methodology 12

3.2 Experimental Part 12

3.2.1

Chemicals and analyticals 12

3.2.2

Electrolysis cell setup 13

3.3 Cost analysis 14

4 RESULTS AND DISCUSSION 15

4.1 Effect of pH 15

vi

4.2 Effect of NaCl concentration 16

4.3 Effect of agitation speed 18

4.4 Effect of changing initial Phenol concentration 19

4.5 Effect of changing electrode material and electrolysis time 20

4.6 Effect of changing current density 21

4.7 Effect of temperature variation 22

4.8 Effect of geometry of electrode over phenol removal efficiency 23

4.9 Phenol removal efficiency variation is case of smooth and rough 23

electrodes.

4.10 Cost analysis 24

5.1 CONCLUSIONS 26

5.2 Scope for future work 26

REFERENCES 28

APPENDIX-A1: SYMBOLS 31

vii

LIST OF TABLES

TABLE NO TITLE PAGE

2.1 Results of pollutant removal using 8electrocoagulation technique

2.2 Comparison of results from Phenol 9

removal using different techniques

4.1 Data of electrode consumption and Cost 24

accrued for treatment using different type

of electrodes.

viii

LIST OF FIGURES

FIGURE NO TITLE PAGE

3.1 Electrolytic cell setup 13

4.1 Different types of Aluminium Hydroxides 14

4.2 % Phenol Removal v/s pH of solution 15

4.3 pH Value vs electrolysis time 16

4.4 % phenol removal vs NaCl concentration 17

4.5 Salvation process of water 17

4.6 % Phenol removal vs agitation speed 19

4.7 % Phenol removal vs Intial phenol concentration. 19

4.8 % Phenol removal vs different electrodes for 60min. 20

4.9 % Phenol removal vs current input 21

4.10 % Phenol armoal vs temperature 22

4.11 % Phenol removal with no. of hole in electrode 23

4.12 %Phenol removal for smooth and rough surface 24

electrode

4.13 Electrode consumption with electrode type 25

4.14 Cost accruedvs electrode type 25

1

CHAPTER 1

INTRODUCTION

1.1 Wastewater treatment and techniques

Chemical industries development is one the major consequence of this industrialization

which incorporates use and discharge of water in huge scale due to various operations

occur in an industry. This pollutes the water bodies by discharging hazardous chemical

into it and puts a burden over them to fulfill the water requirement of the ecosystem.

These chemicals impose adverse effects to the ecosystem hence to sustain in such an

environment there is a shear requirement of efficient techniques to remove those

hazardous chemicals from the generated wastewater.

Various techniques are available to treat the wastewater these are categorized in physical,

chemical, electrolytic treatment etc. One of the most prevalent forms of organic chemical

pollutants in industrial wastewaters is Phenol and phenolic compound. High

concentrations of phenol and phenolic compounds typically are found in aqueous effluents

of oil refineries, petrochemical, ceramic, and steel plants, coal conversion processes,

phenolic resin and pharmaceutical industries. Since phenol and its derivatives are toxic

and harmful to living organisms even at low concentrations, they are known as noxious

pollutants [5]. The most widely used methods for phenol removal from aqueous solutions

are adsorption, chemical oxidation, biological treatment, precipitation, distillation, solvent

extraction, ion exchange, membrane processes, reverse osmosis, and electrochemical

methods(Kulkarni & Kaware, 2013). However, these methods have some disadvantages

such as high cost, low efficiency, and generation of toxic by-products(Gouhua, 2004). On

the other hand, electrochemical methods have little or no harmful effects on the

environment and electrochemical reactions, they are more or less independent of the

conditions of the wastewater(Najel & Abbas, 2013;Saroha & Khandegar, 2013).

1.2 Phenol

An intense research has been going from last two decades on phenolic compounds, this

has resulted in the advent of the better water purification techniques for the preservation of

2

our environment from water pollution. Phenol is the common name of hydroxybenzene,

C6H5OH, an aromatic compound having one hydroxyl group attached to the benzene ring.

It is also known as carbolic acid, phenic acid, phenylic acid, phenyl hydroxide or

oxybenzene. Phenol is produced both naturally and synthetically by chemical processes.

Naturally, phenol has been extracted from coal tar distillation. Synthetically, cumene

oxidation accounts for 95% of phenol production worldwide at a rate of 6.4 million metric

tons produced in 2001 (Jordan et al. 2002). Despite being toxic in nature phenol is used in

various applications, below are some important uses of phenol:

- Bisphenol A which is a resultant product of the condensation reaction of two moles of

phenol and one mole of acetone. It has wide uses in the production of polycarbonates,

ophthalmic lens and automotive components.

- Phenolic resins are products of condensation of phenol and formaldehyde, they have

greater use as adhesives in the plywood industry and as plasticizers. They are also used as

disinfectants and in germicidal paints. Aminophenols are obtained from phenol which are

used in the manufacture of dyes and photographic applications.

- Acetylsalicylic acid, a derivative of phenol, is used in the manufacture of aspirin.

Phenol has been selected as a model compound in this study because it is a common

pollutant found in the effluent of various industrial wastes including petroleum operations,

and phenol like compounds are produced in the degradation pathways of high molecular

weight polycyclic aromatic hydrocarbons (PAHs).

1.3 Scope and objectives of the study

Electrocoagulation is an alternative for the treatment of various kinds of wastewater, by

virtue of various benefits including environmental capability, energy efficiency, selectivity

and cost effectiveness. Electrocoagulation technique has good potential of removing

various impurities/pollutants from wastewater at low power consumption. The main

objective of the present study is to explore the potential of electrocoagulation for treatment

of industrial effluent having Phenol in it. The specific objectives are as follows:

To explore the potential of electrocoagulation for the treatment of industrial effluent.

To study operating parameters such as pH of the solution, current density, agitation

speed, electrolysis time, retention time, initial dye concentration, distance between the

electrodes and electrolyte concentration.

3

1.4 Organization of report:

Chapter-1 introduces the Industrial application of Phenol and its hazardous

effects. How phenol is harmful in water and what are the methods of its treatment. This

part suggests how Electrocoagulation can be an alternative for treatment of wastewater

having phenol in it. Chapter-2 discusses the literature on the theory of

Electrocoagulation its advantages over other conventional methods for treating

wastewater containing various impurities. This part also focuses on the parameters

affecting the removal efficiency of the technique. Chapter-3 tells about the materials and

methodology adopted to pursue this study. It also tells about Making of different

analytical reagents, wastewater treatment procedure using electrocoagulation and phenol

concentration detection method using spectrophotometry. Chapter-4 this part details the

analysis done in this project work and its outcomes. It entails about the relation of phenol

removal efficiency with different parameters and achieved optimized value of each

parameter with the help of graphical representation. In Chapter -5 this is the concluding

part of the thesis where the final outcomes and achievements are highlighted. This part

also suggests some precautions observed during the course of pursuing this study. In

Chapter-6 Future scope and aspects of Electrocoagulation technique has been discussed.

In this section some of the suggestins are madeso that better study can be conducted in

this field using modern techniques and tools. Last part of this thesis consists the various

journals and literature reviewed and cited to understand this particular field of study.

4

CHAPTER 2

REVIEW OF LITERATURE

Water pollution by industrial effluents of chemical industries is a serious problem

in most countries. Increased industrial activities are contribution to more discharge of

effluent into rivers which is becoming the cause of depletion of clear water reserves.

Exposure to these discharged toxic substances can cause cancer, delayed nervous

damage, malformation in urban children, mutagenic changes, neurological disorders

etc(El-Ashtoukhy et al, 2013; Taghavi & Zazouli, 2012; Girih & Murthy, 2012).

Phenol and phenolic compounds are the major contaminant present in the effluent

discharged from the various chemical industrial processes such as wood preserving, metal

finishing, petroleum refining, leather tanning and finishing, paint and ink formulation,

pulp and paper industry, Textile Industry Pharmaceutical industry and manufacturing of

automobile parts industries (Nakhli et al, 2014; Kulkarni & Kaware 2013; El-Ashtoukhy

et al, 2013; Girish & Murthy, 2012)

2.1 Phenol

2.1.1 Chemical and physical properties of phenol: Phenol is a colorless, hygroscopic

crystalline solid at room temperature. Phenol is a White Crystalline Solid. It contains a

six-membered aromatic ring, bonded directly to a hydroxyl group (OH) having

chemical formula C6H5OH. Phenol is a hygroscopic, slightly acidic by nature. It has a

distinctive odour. Its molecular weight is 94.11, density is 1.072 and the boiling point

is 181.9°C. Its other names are Carbolic acid, Benzenol, PhenylicAcid,

Hydroxybenzene, Phenic acid(Toxicological Review of phenol.EPA.2012;CAS No.

108-95-2.)

2.1.2 Phenol as a hazard and its acceptable limits: Intense exposure to phenol causes

disorders of central nervous system. Hypothermia, myocardial depression, burning

effect on skin, irritation of the eyes, it also causes gastrointestinal

disturbance(Toxicological Review of phenol.EPA.2012;CAS No. 108-95-2.). Central

pollution control board has prescribed a guideline for the minimum permissible level

5

for phenol in environment which is 0.1mg/l [Kumaran and Paruchuri, (1996); Nuhoglu