ABSTRACT
The assessment of the surface andground water sources within the vicinity of Ahmadu Bello University Teaching Hospital liquid waste treatment plant was conducted. A total of sixty-six (66) water samples were collected from eight sites (S1, S2, S3, S4, U1, U2, U3 and U4) from the study area. These samples were examined for heavy metal contamination using Atomic Absorption Spectrophotometer (AAS), organic contamination using Gas Chromatography Mass Spectrometer (GCMS), bacteriological contamination and some physicochemical parameters. The levels of seven (7)heavy metals (chromium, lead, cadmium, iron, manganese, nickel and cobalt) in the water samples were analysed. Sites S1-S4 had the level of Cr ranging from 0.16-0.58 mg/l,Pb from 1.10-2.60 mg/l, Cd from 0.04-0.10 mg/l, Fe from 4.10-9.70 mg/l,Mn from 0.04-0.64 mg/l, Ni from 0.05-0.63 mg/l,Co from 0.50-0.90 mg/l and sites U1-U4 had the level of Cr ranging from 0.20-0.80 mg/l, Pb from 1.71-3.20 mg/l, Cd from 0.02-0.10 mg/l, Fe from 2.19-11.40 mg/l, Mn from 0.05-0.50 mg/l, Ni from 0.04-0.14 mg/l and Co from 0.22-0.40 mg/l. The levels were found to be above the World Health Organization (WHO) permissible limit for most of the sites. Xylene, ethylbenzene, butylatedhydroxytoluene and toluene were identified in the samples using GCMS. The bacteriological analysis showed that the total coliform count ranged from 2×104 (Cfu/ml) to 31×104 (Cfu/ml) which is an indication of faecal contamination. The dissolved oxygen(1.03-1.50 mg/l) of the samples was lower than the World Health Organization (WHO) standard for aquatic life, indicating poor support for aquatic life. The turbidity (3.1-9.70 NTU) exceeded the permissible levels set by World Health Organization (WHO). All other physicochemical parameters(pH ranged from 6.30 – 7.70, electrical conductivity 43 – 820μS/cm, sulphate 1.20 – 6.90 mg/l, nitrate 3.00 – 18.90 mg/l, phosphate 0.10 – 3.30 mg/l, biochemical oxygen demand 0.13 – 0.80 mg/l, chemical oxygen demand 1.10 – 6.70 mg/l and temperature 24 – 27ºC) were below the WHO permissible limits. This study shows that hospital effluent and other human activities have a negating influence on water quality. Strict compliance to government policies on waste disposal and management is therefore recommended for Ahmadu Bello University Teaching Hospital liquid wastes.
TABLE OF CONTENTS
Title page——————————————————————————————————iii
Declaration—————————————————————————————————-iv
Certification—————————————————————————————————-v
Dedication—————————————————————————————————–vi
Acknowledgement——————————————————————————————-vii
Abstract——————————————————————————————————–iii
Table of Contents———————————————————————————————ix
List of Tables ————————————————————————————————xii
List of Figures———————————————————————————————–xvi
List of Abbreviations————————————————————————————–vii
1.0 INTRODUCTION———————————————————————————-1
1.1 Background of the study————————————————————————- 1
1.2 Justification——————————————————————————————4
1.3 Aim and objectives of study———————————————————————–5
2.0 LITERATURE REVIEW—————————————————————– ——-6
2.1 Water————————————————————————————————- 6
2.2 Water pollution————————————————————————– ——-7
2.2.1 Ground and surface water pollution—————————————————————7
2.3 Hospital waste——————————————————————————- ——12
2.3.1 General waste ——————————————————————————— ——12
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2.3.2 Infectious waste————————————————————————————12
2.3.3 Pathological waste———————————————————————————12
2.3.4 Sharps————————————————————————————————12
2.3.5 Pharmaceutical waste——————————————————————————13
2.3.6 Genotoxic waste————————————————————————————13
2.3.7 Chemical waste————————————————————————————-13
2.3.8 Radioactive waste———————————————————————————-13
2.4 Water quality test———————————————————————————14
2.4.1 Physico-chemical parameters———————————————————————14
2.4.1.1 Nitrate————————————————————————————————14
2.4.1.2 Sulphate———————————————————————————————-15
2.4.1.3 Taste and Odour————————————————————————————15
2.4.1.4 Colour————————————————————————————————16
2.4.1.5 Turbidity———————————————————————————————17
2.4.1.6 Total dissolved solid——————————————————————————17
2.4.1.7 Electrical conductivity—————————————————————————18
2.4.1.8 pH—————————————————————————————————–18
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2.4.1.9 Alkalinity ——————————————————————————————–19
2.4.1.10 Hardness of water———————————————————————————19
2.4.2 Metallic pollutants———————————————————————————-19
2.4.2.1 Cadmium———————————————————————————————20
2.4.2.2 Chromium——————————————————————————————–21
2.4.2.3 Lead—————————————————————————————————21
2.4.2.4 Manganese——————————————————————————————-22
2.4.2.5 Iron—————————————————————————————————-23
2.4.2.6 Nickel————————————————————————————————-24
2.4.2.7 Cobalt————————————————————————————————-24
2.4.3 Organic contaminants——————————————————————————26
2.4.4 Biological contaminants—————————————————————————28
3.0 Materials and methods—————————————————————————30
3.1 Description of studyarea————————————————————————30
3.2 Sample collection———————————————————————————-33
3.2.1 Collection of surface water samples————————————————————–33
3.2.2 Collection of underground water samples——————————————————-33
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3.3 Sample preparation——————————————————————————-34
3.3.1 Wet digestion of samples————————————————————————–34
3.3.2 Preparation of samples for GCMS using solvent extraction———————————-35
3.4 Preparation of standard solutions for AAS————————————————–35
3.5 Microbial Analysis——————————————————————————–37
3.6 Analysis of physico-chemical parameters—————————————————-37
3.6.1 Determination of electrical conductivity——————————————————–38
3.6.2 Determination of nitrate, phosphate and sulphate———————————————-38
3.6.3 Determination of temperature———————————————————————39
3.6.4 Determination of pH——————————————————————————–39
3.6.5 Determination of dissolved oxygen————————————————————–39
3.6.6 Determination of biological oxygen demand—————————————————39
3.6.7 Determination of chemical oxygen demand—————————————————–39
3.7 Statistical analysis———————————————————————————40
4.0 Results———————————————————————————————–42
4.1 Physicochemical parameters——————————————————————–42
4.2 Heavy metal concentration in samples——————————————————–46
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4.3 Organic contaminants in samples————————————————————–55
4.4 Microbial analysis of samples——————————————————————-55
5.0 Discussion——————————————————————————————-70
5.1 Physicochemical parameters of samples——————————————————70
5.2 Heavy metal concentration in samples——————————————————–73
5.3 Organic contaminants in samples————————————————————–75
5.4 Microbial Analysis——————————————————————————–76
6.0 Conclusion and recommendation————————————————————–77
6.1Conclusion——————————————————————————————77
6.2Recommendations———————————————————————————78
REFERENCES————————————————————————————79
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CHAPTER ONE
1.0 INTRODUCTION
1.1 Background of Study
Water is vital to life. Adequate supply of fresh and clean drinking water is a basic need for all human beings on the earth. The main sources of fresh water are ground and surface water. These sources of freshwater resources are threatened by overexploitation, poor management and pollution.
Waste water from hospitals is usually referred to as hospital waste and is defined as a special category of waste which comprise of all waste, biological or non-biological that is discarded from hospital/health care centres and not intended for further use (Oyelekeet al., 2008). Hospital effluents consist of both organic and inorganic substances including pathogenic microorganisms, toxic chemicals, radioactive elements and heavy metals. Their presence in such effluent, especially in high quantity could sometimes pose grave problem for the populace (Omoruyiet al., 2011).The amount of waste water discharged from hospitals varies from hospital to hospital. Tsakonaet al (2006) reported an estimate on per capital production of waste water in hospitals to be 1000litres/person/day.
About 85% of hospital waste is said to be non-hazardous, 10% infective/hazardous and 5% not infective in the United States of America (Oyeleke and Istifanus, 2009). Meanwhile about 15% of hospital waste is regarded infective in most developed countries. In India, it was reported that the value could increase from 15% to 35% depending on the total amount of hospital waste generated. In Pakistan, about 20% of hospital waste could be found potentially infective or hazardous (Agarwal, 1998; Ekhaise and Omavwoya, 2008). Hazardous medical wastes consist primarily of chemicals and discarded cytotoxic drugs which find their way into the environment due to improper
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usage and indiscriminate disposal. Their presence in the environment have been reported to pose serious environmental health risk due to their toxic, genotoxic and/or carcinogenic effects (Akteret al.,1998;Shaner, 1997; Omoruyiet al., 2011) and could have potential negative effects on the biological balance of the natural environment.The direct exposure of workers and members of the public, soil and water bodies to hospital wastewater increases the hazard that it pose to the environment.
The major health risk posed by hospital wastewater to the inhabitants of the terrestrial and aquatic ecosystem includes contamination of surface water and ground water,accumulation of toxic non-biodegradable hospital waste products andaccumulation of heavy metals and unprotected landfills as well as inefficient sorting of waste materials.The toxic substances discharged into water bodies are likely toaccumulatethrough the food chain (Odiete, 1999).
Different countries are however putting down systems for complete management of hospital effluents. All healthcare units in Greece for example are obliged to design and implement a comprehensive management strategy so as to safeguard the public and the environment (Tsakonaet al., 2006). Some countries, especially developing countries are however yet to put down legislature as to reducing the environmental effects of hospital effluents. In Nigeria, many healthcare centres/hospitals lack effluent treatment plants, the untreated waste are either disposed on the ground or discharged into nearby water bodies which may pose serious health problems to host communities (Odiete, 1999; Chukwuraand Okpokwasil,1997). Such hospital waste can have effects even at low concentrations. Aquatic organisms for instance respond negatively to concentrations of formaldehyde which is a frequently found contaminant in hospital effluents (Murphyet al.,1989). It was reported that formaldehyde in the range of 10-100mg/l was toxic to the microorganisms used in wastewater treatment system (Lu and Hegeann, 1998). In
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addition, the presence of organochlorine compounds in high concentrations in hospital effluents has also been reported as toxic to aquatic life (Gartiseret al., 1996).
Fish are often at the top of the aquatic food chain and may concentrate large amount of heavy metals from polluted water that build up by ingestion, ion-exchange of dissolved metals across lipophilic membranes and absorption on tissue and membrane surfaces (Mendilet al., 2005; Agbozuet al., 2007). Some metals areessential to human health. Heavy metalpollution is a serious and widespread environmentalproblem due to thetoxicity of the metals (Kalay and Canli, 2000).
Pollutants are responsible for many illnesses such as cancer, neurological conditions, chronic bronchitis and asthma (Kump, 1996). Pollutants therefore have been classified into two groups; primary pollutants which are those which exert harmful effects in the form in which they enter the environment and secondary pollutants which are synthesized as a result of chemical processes from less harmful precursors in the environment. Most pollutants enter the environment as emissions or discharges (to water bodies) either from discrete point such as factories, hospitals or diffuse sources such as runoff from agricultural lands. The effect of any pollutant discharged into the environment depends on its toxicity, persistence, dispersion properties, chemical reactions including the decomposition of the compound, tendency to be bioaccumulated in food chains and ease of control. Every type ofpollution has a pathway which involves the pollutant, the source, the medium of transport (air, water and land) and the target (ecosystem) (Holdgate, 1979).
1.2 Justification
Effluents discharged from liquid waste treatment plants in hospitals contain both organic and inorganic substances including heavy metals and pathogenic microorganisms.
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Thepresence of these substances in effluents especially in high quantity could pose grave danger to the receiving environment (Omoruyiet al., 2011).
This study was undertaken to ascertain the concentrations of organic pollutants, heavy metals, faecal coliform bacteria and the physicochemical parameters of the surface water sources andground water sources in the vicinity of Ahmadu Bello University Teaching Hospital liquid waste treatment plant. This is being embarked on to investigate the quality of the water bodies in the vicinity of the liquid waste treatment plant so as to establish a correlation between the effluent, human activities and the perceived pollution of the water bodies.
1.3 Aim and Objectives of the Study
The aim of the study is to validate the correlation between poorly treated hospital effluents, human activities and the pollution of surface water and ground water sources around the immediate environment of Ahmadu Bello University Teaching Hospital liquid waste treatment plant.
To achieve this aim, the following objectives have been outlined:
i. To determine some physicochemical parameters which are temperature, conductivity, pH, sulphate, nitrate, phosphate, turbidity, dissolved oxygen (DO), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of the surface and ground water samples collected from the study area;
ii. To identify and determine the amount of heavy metals (Pb, Cd, Fe, Ni, Mn, Co and Cr) present in the surface water andground watersourceswithin the study area and to comparethe levels of the metals with the World Health Organization (WHO) permissible levels;
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iii. To identify organic pollutants (methylene chloride, xylene, butylatedhydoxyltoluene, ethyl benzene,toluene and formaldehyde) present in the surface and ground water sources and
iv. To determine the colony forming unit in the surface water and ground water sources in the study area.
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