ABSTRACT
Management of hospital wastes remains a subject of public health interest due to their
hazardous nature. Most of the hospital wastes are not easily degradable by natural
phenomena of biochemical decomposition. However, they can be attenuated by
adsorption on a suitable medium and recovered or isolated through various treatment
techniques. Commercial adsorbents are expensive and not readily available locally
although activated carbon has been developed from natural materials. The need to
further research on these wastes to convert them into adsorbent in order to reduce waste
and conserve cost is the key to the research work. The present research produced and
used activated carbon from neem (Azadirachta indica) husk and seed cake to treat
hospital wastewater. The wastewater sample used was obtained from the University of
Abuja Teaching Hospital (UATH) wastewater treatment plant after certification and
approval by the Hospital Ethical Committee (HEC). The raw neem husk and seed cake
were carbonized at 400oC and activated with ZnCl2 and H3PO4 at 500oC and 550oC
respectively. The moisture content of the Raw Neem Husk (RNH) and Raw Neem Cake
(RNC) were found to be 4.45% and 8.95% respectively. The microstructural, structural
and thermal properties of the adsorbents were studied using nitrogen gas adsorption
analysis, SEM, FTIR and TGA. The surface areas and pore size of the neem activated
carbons are in this order: NCH (352 m
2
g; 34.26 Å)> NCZ (252.18 m
2
g; 24.16 Å) >
NHZ (238.56 m
2
g; 22.46 Å) >NHH (230.79 m
2
g; 22.22 Å). The FTIR results showed
slight changes in the absorption band of the raw neem material compared to that of the
activated neem carbon. This showed that the activation process was successful. The
TGA results showed that the activated carbon were hydrophobic and thermally stable up
to 450oC. The adsorbent has been found to be effective and efficient in reducing the
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investigated parameters in a multi component system. The adsorbents (Neem Cake
activated with H3PO4 (NCH), Neem Cake activated with ZnCl2 (NCZ), Neem Husk
activated with ZnCl2 (NHZ) and Neem Husk activated with H3PO4 (NHH)) reduced
nitrates and chloride ions by 100%, phosphate ions by 95%, total bacterial load by 99%,
total fungal load by 90%, chromium ion by 82%, lead ion by 70%, nickel ion by 61%,
zinc ion by 59% and cadmium ion by 36%. The kinetic data were fed into the pseudosecond-order rate and the Weber and Morris intraparticle diffusion models. The results
showed that the mechanism of removal of the pollutants was by chemisorption and that
intraparticle diffusion was not the only rate determining step in the process. The
Equilibria results were modelled using the Langmuir and Freundlich isotherm models.
The adsorption pattern fitted into the two models but more favourably described by the
Langmuir isotherm than the Freundlich isotherm, suggesting the adsorption was
predominantly monolayer rather than multilayer. Column studies showed that the
adsorption of nickel ion onto neem husk activated with H3PO4 (NHH) depends on flow
rate, inlet concentration and bed height. This was analyzed using the Admas–Bohart
model. Studies on regeneration and reuse of the adsorbent on the wastewater showed
that the adsorbents can be reused up to the fifth cycle.
TABLE OF CONTENTS
t
DECLARATION…………………………………………………………………………………………………………. ii
CERTIFICATION ……………………………………………………………………………………………………… iii
DEDICATION……………………………………………………………………………………………………………. iv
ACKNOWLEDGEMENT……………………………………………………………………………………………. v
ABSTRACT………………………………………………………………………………………………………………. vii
Table of Content…………………………………………………………………………………………………………. ix
List of Appendices…………………………………………………………………………………………………….. xvi
List of Figures………………………………………………………………………………………………………….. xvii
List of Tables…………………………………………………………………………………………………………… xxiii
List of Abbreviations……………………………………………………………………………………………….. xxiv
CHAPTER ONE………………………………………………………………………………………………………….. 1
1.0 INTRODUCTION………………………………………………………………………………………………… 1
1.1 Origin of Wastewater …………………………………………………………………………………………………… 2
1.1.1 Wastewater constituents…………………………………………………………………………………………..2
1.1.2 Effect of untreated wastewater on the environment……………………………………………………..3
1.1.3. Hospital wastewater ……………………………………………………………………………………………….4
1.2 Statement of the Problem……………………………………………………………………………………………. 6
1.3 Justification……………………………………………………………………………………………………………………. 7
1.4 Aim and Objectives ………………………………………………………………………………………………………. 7
CHAPTER TWO…………………………………………………………………………………………………………. 9
2.0 LITERATURE REVIEW……………………………………………………………………………………….. 9
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2.1 History of Activated Carbon………………………………………………………………………………………… 9
2.2 Structure of Activated carbon……………………………………………………………………………………11
2.3 Sources of Activated Carbon………………………………………………………………………………………13
2.4 Adsorptive Properties of Activated Carbon …………………………………………………………….14
2.5 Preparation of Activated Carbon ………………………………………………………………………………15
2.5.1 Carbonization ……………………………………………………………………………………………………….15
2.5.2 Activation …………………………………………………………………………………………………………….17
2.6 General Uses of Activated Carbon……………………………………………………………………………..20
2.7 Application of Activated Carbon in Environmental Pollution Studies ………………..21
2.7.1 Activated carbon in drinking water treatment……………………………………………………………21
2.7.2 Municipal wastewater treatment ……………………………………………………………………………..22
2.7.3. Industrial wastewater treatment ……………………………………………………………………………..23
2.7.4. Hospital wastewater treatment ……………………………………………………………………………….23
2.8 Activated Carbon Adsorption…………………………………………………………………………………….25
2.9 Theory of adsorption ………………………………………………………………………………………………….25
2.9.1 Types of adsorption……………………………………………………………………………………………….26
2.9.2 Extent of adsorption ………………………………………………………………………………………………27
2.9.3 Adsorption equilibria and the adsorption isotherm…………………………………………………….27
2.9.4 Types of adsorption isotherms ………………………………………………………………………………..27
2.9.5 Langmuir adsorption isotherm: ……………………………………………………………………………….31
2.9.6 Freundlich adsorption isotherm……………………………………………………………………………….31
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2.9.7 Factors affecting adsorption ……………………………………………………………………………………33
2.10 Adsorption Process …………………………………………………………………………………………………..34
2.11 Modeling of Column Study Results: Bohart–Adams Model …………………………………36
2.12 The Pseudo-Second Order Rate Kinetic Model……………………………………………………..37
2.13 The Weber-Morris Intraparticle Diffusion Model………………………………………………..38
CHAPTER THREE …………………………………………………………………………………………………… 39
3.0 MATERIALS AND METHODS………………………………………………………………………….. 39
3.1 Materials……………………………………………………………………………………………………………………….39
3.2 Sample Collection………………………………………………………………………………………………………..39
3.2.1 Neem sample collection …………………………………………………………………………………………39
3.2.2 Wastewater sample collection…………………………………………………………………………………39
3.2.3 Description of wastewater sampling area………………………………………………………………….40
3.3 Neem Sample Preparation …………………………………………………………………………………………42
3.4 Carbonization of Neem samples………………………………………………………………………………..42
3.5 Chemical Activation of the Carbon ……………………………………………………………………………43
3.6 Physico-chemical Characterization of Raw and Modified Neem Samples…………..43
3.6.1 Moisture and dry matter content ……………………………………………………………………………..44
3.6.2 Ash content…………………………………………………………………………………………………………..44
3.6.3 Volatile matter content…………………………………………………………………………………………..45
3.6.4 Fixed carbon content ……………………………………………………………………………………………..45
3.6.5 Density and bulk density ………………………………………………………………………………………..46
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3.7 Structural and Morphological Characterization……………………………………………………..46
3.7.1 Brunauer Emmet Teller (BET) surface area………………………………………………………………47
3.7.2 Fourier Transform Infrared Spectroscopy (FTIR) analysis………………………………………….48
3.7.3 Scanning Electron Microscopy (SEM) analysis…………………………………………………………48
3.7.4 Thermal Gravimetric Analysis (TGA) ……………………………………………………………………..48
3.8 Physico-Chemical Parameters of Wastewater ………………………………………………………..49
3.8.1 pH……………………………………………………………………………………………………………………….49
3.8.2 Turbidity Test……………………………………………………………………………………………………….49
3.8.3 Conductivity…………………………………………………………………………………………………………50
3.8.4 Biological Oxygen Demand (BOD)…………………………………………………………………………50
3.8.5 Chemical Oxygen Demand (COD) ………………………………………………………………………….50
3.8.6 Total Dissolved Solid (TDS)…………………………………………………………………………………..51
3.8.7 Total Solids (TS)…………………………………………………………………………………………………..52
3.8.8 Determination of metal ions……………………………………………………………………………………52
3.8.9 Nitrate, Phosphate and Sulphate………………………………………………………………………………53
3.8.10 Microbial Analysis and Enumeration………………………………………………………………..53
3.9 Column Adsorption Studies ……………………………………………………………………………………….54
3.9.1 Column breakthrough studies………………………………………………………………………………….55
3.9.2 The effect of contact time……………………………………………………………………………………….57
3.9.3 The effect of wastewater volume …………………………………………………………………………….57
3.9.4 Regeneration Studies……………………………………………………………………………………………..57
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CHAPTER FOUR……………………………………………………………………………………………………… 58
4.0 RESULTS……………………………………………………………………………………………………………. 58
4.1 Physicochemical Properties of Raw Neem and the Prepared Activated
Carbons ……………………………………………………………………………………………………………………………….58
4.2 The BET Surface Area and Pore Characterization of the prepared
Activated Carbon………………………………………………………………………………………………………………..58
4.3 Fourier Transform Infrared (FTIR) Analysis…………………………………………………………..67
4.4 Scanning Electron Microscope (SEM) ……………………………………………………………………….67
4.5 Thermal-Analytical Studies ……………………………………………………………………………………….79
4.6 Physicochemical Characteristics of the Hospital Wastewater Before and
After Treatment …………………………………………………………………………………………………………………79
4.7 Kinetic Studies……………………………………………………………………………………………………………..91
4.8 Pseudo-Second-Order Rate Models……………………………………………………………………….. 110
4.9 Weber and Morris Intraparticle Diffusion Models ……………………………………………… 110
4.10 Effect of initial wastewater volume on physicochemical parameters of
the wastewater ……………………………………………………………………………………………………………….. 129
4.11 Langmuir Adsorption Isotherm…………………………………………………………………………… 129
4.12 Freundlich Adsorption Isotherm…………………………………………………………………………. 158
4.13: Regeneration and Reuse Studies………………………………………………………………………… 158
4.14 Bohart Adams Adsorption Model………………………………………………………………………… 169
CHAPTER FIVE……………………………………………………………………………………………………… 174
5.0 DISCUSSION …………………………………………………………………………………………………….. 174
xiv
5.1 Physicochemical properties of raw neem and the prepared activated
carbons…………………………………………………………………………………………………………………………….. 174
5.2 Carbonization of Neem Husk and Cake…………………………………………………………………. 175
5.3 Activation of Neem Husk and Cake………………………………………………………………………… 176
5.4 BET Surface Area and Pore Characterization of the Prepared Activated
Carbon ……………………………………………………………………………………………………………………………… 176
5.5 Fourier Transform Infrared (FTIR) Analysis……………………………………………………….. 177
5.6 Scanning Electron Microscope (SEM) ……………………………………………………………………. 179
5.7 Thermoanalytical Studies……………………………………………………………………………………….. 180
5.8 Physicochemical Characteristics of the Hospital Wastewater Before
Treatment………………………………………………………………………………………………………………………… 181
5.9 Physicochemical parameters of the treated Water…………………………………………….. 182
5.9.1 pH……………………………………………………………………………………………………………………..183
5.9.3 Turbidity…………………………………………………………………………………………………………….184
5.9.4 Total Hardness (TH)…………………………………………………………………………………………….184
5.9.5 Chemical Oxygen Demand (COD) ………………………………………………………………………..185
5.9.6 Biochemical Oxygen Demand (BOD) ……………………………………………………………………185
5.9.7 Dissolved Oxygen (DO)……………………………………………………………………………………….186
5.9.8 Nitrate………………………………………………………………………………………………………………..186
5.9.9 Phosphates………………………………………………………………………………………………………….187
5.9.10 Chloride……………………………………………………………………………………………………………187
5.9.11 Heavy metals…………………………………………………………………………………………………….188
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5.10 Microbial load reduction activities of Neem Activated Carbon………………………. 189
5.11 The Pseudo-Second-Order Rate Kinetic Model…………………………………………………. 190
5.12 The Weber-Morris Intraparticle Diffusion Model…………………………………………….. 191
5.13 Equilibrium Adsorption Studies………………………………………………………………………….. 192
5.13.1 Effect of initial wastewater volume on physicochemical parameters of the
wastewater………………………………………………………………………………………………………………….192
5.14 The Langmuir Sorption Isotherm………………………………………………………………………… 194
5.15 Freundlich Adsorption Isotherm…………………………………………………………………………. 195
5.16 Regeneration and Reuse Studies…………………………………………………………………………. 195
5.17 Bohart Adams Model …………………………………………………………………………………………….. 196
CHAPTER SIX………………………………………………………………………………………………………… 197
6.0 SUMMARY, CONCLUSION AND RECOMMENDATION ………………………………… 197
6.1 Summary……………………………………………………………………………………………………………………. 197
6.2 Conclusion…………………………………………………………………………………………………………………. 198
6.3 Recommendation …………………………………………………………………………………………………….. 200
REFERENCES………………………………………………………………………………………………………… 201
APPENDICES …………………………………………………………………………………………………………. 212
CHAPTER ONE
1.0 INTRODUCTION
The world economy is focusing on better waste management policies so as to reduce wastes and to protect the environment (Tchnohanoglous et al., 1979). The present generation has an obligation to leave the next generation a more habitable environment than a surrounding littered with pollutants. This is in recognition that the world is finite and the continued pollution of the environment will, if not controlled, be difficult to rectify in the future. In Nigeria, it has been reported that poor management of waste cost the Nation roughly US$5 billion annually (Christen, 1996). Much of the damage results from oil exploration and oil spills in the Niger Delta region, poor agricultural practices, grazing, hospital waste and habitat destruction (Christen, 1996). Indiscriminate waste disposal remains a contentious issue with no end in sight. Refuse is thrown onto roadways, spread on pedestrian walkways or even dumped into gutters. The problem becomes compounded during the rainy season; water, no longer flowing freely along the gutters, remains stagnant, creating the conducive conditions for mosquitoes and vector borne diseases like malaria (Coker, 2009).
Wastewater is any water that has been adversely affected in quality by anthropogenic influence (Akter et al., 1999). Municipal wastewater is usually conveyed in a combined sewer or sanitary sewer, and treated at a wastewater treatment plant. The treated wastewater is then discharged into receiving water via an effluent sewer. Wastewaters generated in areas without access to centralized sewer systems rely on on-site wastewater systems. These typically comprise a septic tank, drain field, and optionally an on-site treatment unit (USEPA, 2008).
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1.1 Origin of Wastewater
Some of the origins of wastewater or sewage include: human waste ( used toilet paper or wipes, urine, or other bodily fluids), also known as blackwater, usually from lavatories; Cesspit leakage; Septic tank discharge; Sewage treatment plant discharge; washing water (personal, clothes, floors and dishes), also known as greywater or sullage; rainfall collected on roofs, yards, hard-standings (generally clean with traces of oils and fuel); Groundwater infiltrated into sewage; Surplus manufactured liquids from domestic sources (drinks, cooking oil, pesticides, lubricating oil, paint and cleaning liquids); Urban rainfall runoff from roads, carparks, roofs, sidewalks/pavements (contains oils, animal faeces, litter, gasoline/petrol, diesel or rubber residues, soapscum, metals from vehicle exhausts); hospital waste; Industrial waste; Industrial site drainage which include; silt, sand, alkali, oil, chemical residues (USEPA, 2008).
1.1.1 Wastewater constituents
The composition of wastewater varies widely; a partial list of these constituents are: (i) Water (more than 95 percent), which is often added during flushing to carry waste down a drain; (ii) Pathogens such as bacteria, viruses, prions and parasitic worms; (iii) Non-pathogenic bacteria; Organic particles such as faeces, hairs, food, vomit, paper fibres, plant material and humus; (iv) Soluble organic material such as urea, fruit sugars, soluble proteins, drugs, pharmaceuticals; (v) Inorganic particles such as sand, grit, metal particles, ceramics; (vi) Soluble inorganic material such as ammonia, road-salt, sea-salt, chloride, cyanide, hydrogen sulfide, nitrite, thiocyanates, thiosulfates, phosphate; (vii) Animals such as protozoa, insects, arthropods, small fish; (viii) Macro-solids such as sanitary napkins, nappies/diapers, condoms, needles, children’s toys, dead animals or plants; (ix) Gases such as hydrogen sulfide, carbon dioxide, methane; (x) Emulsions
3
such as paints, adhesives, mayonnaise, hair colorants, emulsified oils; (xi) Toxins such as pesticides, poisons, herbicides; Pharmaceuticals and hormones (USEPA, 2008).
1.1.2 Effect of untreated wastewater on the environment Management of healthcare wastes (HCW) should be considered as an integral part of hospital hygiene and infection control (David et al., 2012). The HCW generated within a healthcare facility should always follow an appropriate and well define treatment process starting from their point of generation until their final disposal (David et al., 2012). The poor segregation, handling and disposal practices of many hospitals, clinics and health centres are likely representatives of practices throughout Nigeria and pose serious health hazards to people living in the vicinity of healthcare institutions (Ferreira and Veiga, 2003; Da Silver et al., 2005; Tudor et al., 2005; Ndidi et al., 2009).
Untreated wastewater may drain directly into major watersheds, this can have serious impacts on the quality of an environment and on the health of people. Pathogens contained in such water can cause a variety of illnesses. Some chemicals pose risks even at very low concentrations and can remain a threat for long periods of time because of bioaccumulation in animal or human tissue and a significant portion of the waste management is non-degradable (Clescerl et al., 2010). It was reported that some health care institutions dispose of all wastes to municipal dumpsites without pre-treatment, leading to an unhealthy and hazardous environment around the health institutions, affecting patients, staff and the community Stephen and Elija (2011). Same findings have been reported by Al-Khatib et al. (2009) in Palestine, Akinwale et al. (2010) in Nigeria and Mesfin et al. (2011) in Ethopia. Studies have shown that infectious stools or bodily fluids that are not treated before being disposed can create and even extend epidemics (Rhodes et al., 2000). Mumtaz and Mirza (2014) reported that the absence of
4
proper sterilization procedures is believed to have increased the severity and size of cholera epidemics in Africa during the last decade.
1.1.3. Hospital wastewater
Hospital waste in simple term is any waste generated during the diagnosis, treatment, or immunization of human beings or animals or in research activities in these fields (Ogunlowo et. al., 1991). It may include items like disposables, anatomical waste, cultures, discarded medicines, chemicals, disposable syringes, swabs, bandages, body fluids, human and excreta. This waste are highly infectious and can be a serious threat to human health if not managed in a scientific and discriminate manner. It had been roughly estimated that of the 4 kg of waste generated in a hospital at least 1kg would be infectious (Ogunlowo et al., 1991).
Hospital waste can be classified into infectious and non-infectious wastes (Patil and Shekdar, 2001). Infectious wastes contain pathogens in quantities sufficient to transmit infectious diseases on exposure to them. Health care waste is also categorized as non hazardous (non risky) and hazardous (risky) wastes (Pruss et al., 1999). A hazardous waste may be toxic, genotoxic, corrosive, shock sensitive, flammable, reactive, explosive, radioactive, containing infectious agents and/or sharps (Pruss et al., 1999). In 1999, WHO classified healthcare waste into two broad categories, the first is the communal waste which comprises of all solid waste not including infectious, chemical, or radioactive waste. This waste stream can include items such as packaging materials and office supplies. Generally, this stream can be disposed of in a communal land fill or other such arrangement. Segregation of materials which are able to be reused or recycled will greatly reduce the impact burden of this waste stream. The second category is called the special waste which consists of several different subcategories:
5
Infectious: Discarded materials from health-care activities on humans or animals which have the potential of transmitting infectious agents to humans. These include discarded materials or equipment from the diagnosis, treatment and prevention of disease, assessment of health status or identification purposes, that have been in contact with blood and its derivatives, tissues, tissue fluids or excreta, or wastes from infection isolation wards. Such wastes shall include, but are not limited to, cultures and stocks; tissues; dressings, swabs or other items soaked with blood; syringe needles; scalpels; diapers; blood bags. Incontinence material from nursing homes, home treatment or from specialized health-care establishments which do not routinely treat infectious diseases (e.g. psychiatric clinics) is an exception to this definition and are not considered as infectious health-care waste. Sharps, whether contaminated or not, should be considered as a subgroup of infectious health-care waste includes: Syringe needles, scalpels, infusion sets, knives, blades, broken glass.
Anatomic: consists of recognizable body parts.
Pharmaceutical: Consisting of/or containing pharmaceuticals, including: expired, no longer needed; containers and/or packaging, items contaminated by or containing pharmaceuticals (bottles, boxes).
Genotoxic: Consisting of, or containing substances with genotoxic properties, including cytotoxic and antineoplasic drugs; genotoxic chemicals.
Chemical: Consisting of, or containing chemical substances, including: laboratory chemicals; film developer; disinfectants expired or no longer needed; solvents, cleaning agents and others.
Heavy Metals: Consisting of both materials and equipment with heavy metals and derivatives, including: batteries, thermometers, manometers.
6
Pressurized containers: Consisting of full or empty containers with pressurized liquids, gas, or powdered materials, including gas containers and aerosol cans.
Radioactive materials: Includes: unused liquids from radiotherapy or laboratory research; contaminated glassware, packages or absorbent paper; urine and excreta from patients treated or tested with unsealed radionuclides; sealed sources (WHO, 1999).
1.2 Statement of the Problem It has been reported that several hundreds of tonnes of HCWs are deposited in open dumpsites untreated alongside non-hazardous solid wastes (Alagoz and Kocasay, 2007), Abah and Ohimain, 2010) which pose health risks to health workers, cleaning staff, patients, visitors, waste collectors, disposal site staff, waste pickers, drug addicts and those who knowingly or unknowingly use “recycled” contaminated syringes and needles. A study conducted by Wyasu and Okereke (2011) established that hospital wastewater from Ahmadu Bello University Teaching Hospital contained significant amount of the following parameters; micro organisms, nitrate, sulphate and phosphate, heavy metals and organic contaminants which can cause serious health hazard to humans, aquatic biota, euthrophication of the water bodies, depreciation of land values, and other environmental challenges if left untreated or improper treatment. This is contrary to the international policy on waste management which states that the generator of waste is responsible for the proper management, treatment and disposal of waste (Ngwuluka et al., 2009). The World Health Organization estimates that each year there are about 8 to 16 million new cases of Hepatitis B virus (HBV), 2.3 to 4.7 million cases of Hepatitis C virus (HCV) and 80,000 to 160,000 cases of human immune deficiency virus (HIV) due to unsafe injections and mostly due to very poor waste management systems (WHO, 1999; Townend and Cheeseman, 2005). Recent studies in Nigeria have estimated waste generation of between 0.562 to 0.670 kg/bed/day (Longe
7
and Williams, 2006). Most of this hospital wastes are difficult to be degraded by natural phenomena of biochemical decomposition and the processes are expensive.
1.3 Justification In a largely agrarian country such as Nigeria, there are so many agricultural by-products lying waste, littering and polluting the environment. The National Research Institute for Chemical Technology (NARICT) Bassawa, Zaria conducted series of researches on the neem tree (Azadirachta indica) and produced biodiesel and organic fertilizers from the neem kernel. Neem husk and seed cake are waste from the process. Several conventional techniques have been employed to treat wastewater in the past but all of these methods suffer from one or more limitations (efficiency, cost-effectiveness and availability) except adsorption Hajira and Muhammed (2008). It is known that the commercially made adsorbents are expensive. To this effect, within the last decade, several methods were developed to modify natural local materials and convert them to adsorbent to treat and adsorb waste and pollutants from effluents. The need to further research on these wastes to convert them into agents of environmental control in order to reduce waste and conserve cost is the key to the present research work.
1.4 Aim and Objectives The aim of this research is to activate neem (Azadirachta indica) husk and seed cake with H3PO4 and ZnCl2 and apply the prepared adsorbents for treatment of wastewater from hospital in a multi-component system. This aim was achieved through the following objectives;
i. to carry out physicochemical and structural characterization on the raw and modified neem (Azadirachta indica) husks and cakes using standard analytical techniques;
8
ii. to prepare activated carbon (AC) from neem (Azadirachta indica) husks and cakes by carbonization and impregnation methods using ZnCl2 and H3PO4 as activating agents;
iii. to determine the structural and morphological characteristics of the raw and modified neem carbon by gravimetric, thermal and spectrometric methods;
iv. to determine the optimum carbonization and activation temperatures;
v. to study the effect of contact time and initial volume of the adsorbents and the adsorbates;
vi. to characterize the wastewater obtained from the hospital by determining the level of selected heavy metal ions ( chromium, cadmium, nickel, lead and zinc), anions, DO, COD, BOD and other physicochemical parameters before and after treatment;
vii. to evaluate the efficiency of the activated carbon in a multi-component system;
viii. to investigate the adsorptive capacity of the adsorbent on microbial parameters ( bacterial and fungal load); and
ix. to investigate the regeneration and reuse of the adsorbent on waste water.
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