BACTERIOLOGICAL AND PHYSICOCHEMICAL IMPACT ASSESSMENT OF INDUSTRIAL AND DOMESTIC WASTES ON RIVER SOKOTO
Bacteriological analysis of the water samples such as heterotrophic counts, coliform counts, Faecal Coliform/Faecal Streptococci (FC/FS) ratio were carried out following standard procedures. Gram-negative bacteria and Gram-positive Staphylococcal species were identified using ID 32E and Microbact 12S kits respectively. Susceptibility of the isolates to ceftazidime, ceftriaxone, cefuroxime, erythromycin, gentamicin, amoxycillin/clavulinate, cloxacillin, ampicillin, ciprofloxacin, ofloxacin and nitrofurantoin were carried out using the agar diffusion method. Susceptibility of the isolates to Dettol®, Savlon® and Izal®was also determined using agar dilution method. Resistant bacteria were subjected to molecular analysis to further ascertain their status.Physicochemical properties of the river water such as pH, temperature, electrical conductivity, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solids (TS), total suspended solids (TSS), hardness, sulphate, chloride, nitrates and alkalinity were analysed using standard methods. Elemental analyses of water samples and bottom soil sediments were carried out using Atomic Absorption Spectrometer (AAS). Analysis of variance (ANOVA) was carried out on the elemental data to determine the level of impact of the wastes on the river water quality. The study revealed generally high levels of heterotrophic and coliform counts throughout the year with sampling point P1 around farmland having the highest counts and P4 on the stream that carried effluents from Sokoto Cement Factory, having the least. FC/FS ratios were generally very high (above 4.0). Of the 434 bacteria isolated, E. coli among the Enterobacteriaceae was highest (11.98%).Pseudomonas aeruginosa(7.37%) constituted the majority of non-EnterobacteriaceaeGram-negative organisms whileStaphylococcus aureus(6.91%) was the highest among the Gram-positive organisms. The antibiotic susceptibility profiles showed that most of the Enterobacteriaceae isolates (˃60%) were sensitive to ceftazidime, gentamicin, amoxycillin/clavulinate, the quinolones (ofloxacin, cloxacillin, ciprofloxacin) and nitrofurantoin. Among the non-fermenting Gram negative isolates, Elizabethkingia meningoseptica were most susceptible to the various test antibiotics, ranging from 68.5% to 100% except with erythromycin, having 50% efficacy. Staphylococcus cohnii, among the Gram-positive isolates were the most susceptible to the various test antibiotics, ranging from 75% to 100% except with cefuroxime, cloxacillin, ciprofloxacin and ampicillin, having 50% efficacy. Multiple antibiotic resistance was shown by 91.30% of Shigella flexneri, 37.50% of Pseudomonas aeruginosa and 50% of Staphylococcus cohnii. The MIC values of the test disinfectants (Dettol®, Savlon® and Izal®) against the isolates showed that the mean MICs of Dettol® and Savlon® were higher for Enterobacteriaceae compare with other Gram-negative organisms with Enterobacter aerogenes having the highest values of 2.50 and 3.00 respectively. The β-lactam (blaTEM), virulence (spvC) and quinolones (qnrS) resistance genes were detected in Pseudomonas aeruginosa while aminoglycosides and quinolone resistance genes (aacC3 and qnrS) were detected in Klebsiella pneumoneae. Physicochemical parameters show varying with changes in the season. Sampling point P1 had the highest values for DO, BOD, COD, TDS and TSS in the dry and rainy seasons while P4 had the highest electrical conductivity value in the rainy season. Concentration of nitrate, ammonia and chloride in the water samples increased and decreased for sulphate and phosphate in the rainy season.AAS analyses of water and bottom soil sediment samples showed that 18 elements were detected, of which five namely Fe, Ag, Cd, Hg and Pb had concentrations above WHO limits. One way ANOVA test of the elemental concentrations of water samples and bottom soil sediments showed that concentrations of Zn, Ag, Cd, Cr, Mn, Fe, Co and Pb were more in sediment than in water. Generally, water of River Sokoto failed both bacteriological and physicochemical tests and therefore not fit for domestic, industrial and agricultural purposes.
1.1 General Introduction
Of all natural resources available to man and vital to man‘s existence and survival, none is as abundant as water. Contaminated water jeopardizes both the physical and social health of all people. It is an affront to human dignity‖ (WHO, 2002).
Water is vital to the existence of all living organisms, but this valued resource is increasingly being threatened as human populations grow and demand more water of high quality for domestic purposes and economic activities. Globally, the rate of groundwater abstraction is increasing by 1% to 2% per year (WWAP, 2012).Water abstraction for domestic use, agricultural production, mining, industrial production, power generation, and forestry practices can lead to deterioration in water quality and quantity that impact not only the aquatic ecosystem, but also the availability of safe water for human consumption (UNEP, 2006).
In spite of the essential role played by water in supporting human life, it also has great potential for transmitting a wide variety of diseases and illnesses (Hutton, 1983).Indeed, understanding the impacts of contaminants on the environment, including the organisms which live in it, is rather complicated (Iscan, 2004).
The world’s rivers are so badly affected by human activity that the water security of almost 5 billion people and the survival of thousands of aquatic species are reportedly threatened (Vaugham, 2010). Even the world’s great rivers, such as the Yangtze, the Nile and the Ganges, are reportedly suffering serious biodiversity and water security stress (Vaugham, 2010).
It has been suggested that water pollution is the leading cause of deaths and diseases, worldwide (Pink,2006).Disposing of sewage waste is a major problem with billions of people on the planet. According to 2013 figures from the World Health Organization (WHO), some 780 million people (11 percent of the world’s population) have no access to safe drinking water, while 2.5 billion (40 percent of the world’s population) have no proper sanitation (hygienic toilet facilities); although there have been great improvements in securing access to clean water, relatively little progress has been made on improving global sanitation in the last decade. Sewage disposal affects people’s immediate environments and leads to water-related illnesses such as diarrhoea that kills 760,000 children under five each year (WHO, 2013).It has been reported that more than one-third of the global population(some 2.4 billion people) do not use improved sanitation facilities; of these, one billion people still practice open defecation (UNICEF/WHO, 2015).
Rapid increase in industrial development has created more awareness in interrelationship between pollution, environment and public health. Industrial development results in the generation of industrial effluents, and if untreated results in water, sediment and soil pollution. (Fakayode and Onianwa, 2002; Fakayode, 2005). Industrial wastes and emission contain toxic and hazardous substances, most of which are detrimental to human health (Ogunfowokan et al.,2005; Jimena et al.,2008; Rajaram et al.,2008). Heavy metals from industrial processes are of special concern because they pollute water and cause chronic poisoning to aquatic animals (Ellis, 1989).While some heavy metals are purely toxic with no cellular role (Shi et al.,2002),other metals are essential for life at low concentrations but become toxic at high concentrations (Badar et al. 2000).It is recognized that a considerable quantity of industrial, domestic and transportation wastes and by-products end up in waterways. The results had devastating consequences on environmental and biological systems hence it is important to constantly assess the risk factors on the ecosystem (Iscan, 2004).
Sokoto is a cosmopolitan town supposed to have regular potable water supply. Unfortunately, potable water supply is not only irregular but does not reach a large percentage of the populace.
This irregularity in potable water supply must have prompted the populace to seek for alternative sources of drinking water by resorting to well, sachet and even river water in order to meet their domestic water needs.
1.2 Wastewater and water pollution
Industries are the major sources of pollution in all environments. Depending on the type of industry, various levels of pollutants can be discharged into the environment directly or indirectly through public sewer lines. Wastewater from industries includes employees‘ sanitary waste, process wastes from manufacturing, wash waters and relatively uncontaminated water from heating and cooling operations (Glyn and Gary, 1996).
Effluents from waste water treatment plants usually end up in surface water streams. These effluents usually contain small amounts of various contaminants but these harmful components accumulate over time in the river, especially in sediments (Cotmanet al., 2001). High levels of pollutants in river water systems cause increase in biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), toxic metals such as Cd, Cr, Ni and Pb (Fakayode, 2005) and fecal coliform and hence make such water unsuitable for drinking, irrigation and aquatic life.
It is estimated that 5-20% of total water is used by industry (UNESCO, 2009). Industrial wastewaters range from high biochemical oxygen demand (BOD) from biodegradable wastes such as those from human sewage, pulp and paper industries, slaughter houses, tanneries and chemical industry. Others include those from metal coating shops and textiles, which may be toxic and require on-site physiochemical pre-treatment before discharge into municipal sewage system (Phiriet al., 2005; UNESCO, 2009; Walakira and Okot-Okumu, 2011; Hussain and Prasad Rao, 2013).
1.2.1 People and water pollution
Historically, the availability of water has long been an important factor in citing of human settlement and their development into towns and cities and the development of great civilizations. The Egyptians civilization flourished around the river Nile. In Nigeria, cities like Kaduna, Lagos, Makurdi and Aba depend very much on its rivers for various purposes. However, the rush by developing countries to industrialize has resulted in discharge of partially treated or raw wastes into the surrounding bodies of water since the development of treatment facilities cannot keep pace with the rate at which the wastes are generated by industries (Nwachukwuet al., 1989). Industrial discharges, therefore contribute a larger portion of the flow of rivers during dry season, with the result that the water quality of rivers is further deminished.
The bacteria-laden river water in contact with the body during use may cause serious hazards to users due to bacteria contamination. Many bodies of water in Nigeria experience seasonal fluctuations, leading to a higher concentration of pollutants during the dry season when effluents are least diluted (Kanuet al., 2006).
Historically, landfills have been the simplest form of eliminating urban solid wastes with minimum cost. They have been the most usual method for discarding solid wastes. However, landfills are considered authentic biochemical reactors that introduce large amounts of contaminants into the environment in the form of gas and leachates (Nolascoet al., 2008).
Over the years, a considerable population growth has taken place in many African countries leading to large increase in urbanization, industrial and agricultural land use. Large quantity of pollutants of various types were thus discharged into receiving water bodies with resultant adverse effects on fisheries and other aquatic animals (Saadet al., 1984).
1.3 Statement of Research Problem
One of the most critical problems of developing countries is improper management of vast amount of wastes generated by various anthropogenic activities. More challenging is the unsafe disposal of these wastes into the ambient environment. Water bodies especially freshwater reservoirs are the most affected. This has often rendered these natural resources unsuitable for both primary and/or secondary usage (Fakayode, 2005).
Industrial effluent contamination of natural water bodies has emerged as a major challenge in developing and densely populated countries like Nigeria. Estuaries and inland water bodies, which are the major sources of drinking water in Nigeria, are often contaminated by the activities of the adjoining populations and industrial establishments (Sangodoyin, 1995).This is because river waters are the primary means for disposal of waste, especially the effluents, from closely located industries. These effluents pollute the water body by alteration of their physical, chemical and biological properties (Sangodoyin, 1991).
Water bodies are major receptacles of treated, untreated, or partially treated industrial wastes. The resultant effects on public health and the environment are usually great in magnitude (Osibanjoet al., 2011).
Ekhaise and Anyasi (2005) had reported the unacceptable level of contamination of Ikpoba River, Benin city, due to brewery effluent discharge with the attendant hazard to human health. Similarly Ogedengbe and Akinbile (2010) reported the adverse effects ofagro-industrial effluents from the factories in Oluyole Estate on the quality of Ona stream water. The downstream Asa River in Ilorin was polluted and its aquatic biota was bacteriologically contaminated and rendered unsafe for human and animal consumption (Kolawoleet al. 2011). Tytler (2011) also reported that the two drainage streams which passed through locations in which several industries and human habitat are situated had negatively impacted the overall quality of River Kaduna, bacteriologically, physicochemical and elementally. Rajiet al. (2010) earlier reported themicrobial contamination of River Sokoto by pathogenic organisms.
River Sokoto is situated adjacent to the industrial area of the metropolis where industries such as Cement, Aluminium, Fertiliser, Foam and Tanning factories are located. The survey of the study area indicated that these factories discharge their effluents into the environment, which end up flowing into the river. The bank of River Sokoto harbours irrigation plots used for vegetable and other sundries farming within the metropolis. The waters of the river are also commonly used for domestic and recreational purposes. A study of the river water will assist the appraisal and suitability of River Sokoto water for the desired purposes and possibly suggest viable remediation efforts.
1.4 Justification for the Study
River Sokoto is a major source of water for domestic, agricultural and industrial uses in Sokoto metropolis.
It is the source water for the water treatment plant that supplies pipe-borne water to the people in the metropolis.
Residents in the locality use water from the river for domestic purposes.
The river water is also used to irrigate adjoining farmlands where for cultivation of onion, sweet potato, maize, tomatoes and vegetables(some of which are often eaten raw).
The factories in the locality use the river as source water for various purposes(such as washing of equipment and cooling of machinery).
The river is also dredged for sand for the local construction industry.
River Sokoto provides recreational facility (swimming) and fishing takes place throughout the year.
All these could pose serious health and environment hazards to the community if not addressed.The study will benefit residents by creating awareness on the bacteriological, physicochemical and biological elemental qualities of River Sokoto with a view to having good quality water.
1.5 Aim and Objectives of study
This study aims to evaluate the impact of industrial and domestic wastes on the bacteriological and physicochemical quality of River Sokoto with a view to creating awareness on the quality of the river water.
a. Determination of the general bacteriological quality of the river water using standard methods. This included bacterial level and identification of contaminants.
b. Determination of the antimicrobial profile (susceptibility and resistance profiles) of isolated organisms against some antibiotics and disinfectants by the agar diffusion and broth dilution methods.
c. Determination of physicochemical characteristics such as pH, conductivity, total organic matter, BOD, OD, acidity, alkalinity and hardness of water samples from points on the river and its drainage streams during raining and dry seasons of the year using standard methods.
d. Determination of the elemental composition of the water and bottom soil sediments using Atomic Absorption Spectroscopy (AAS).
1.6 Limitations and constraint
This study is limited to assessing the bacteriological and some chemical quality of the section of River Sokoto around Sokoto Cement Factory where there are human settlements and irrigation farming.
Other Limitations include:
Samples collection will be limited to the period from January to December, 2014.
Effluents from the industries and factories not in operation at the time of the study will not be evaluated.
The direct impact of the chemical and bacteriological pollution on the health of people living along the bank of the river will not be assessed.
The influence of some elements, particularly heavy metals on the antimicrobial susceptibility profiles of the bacterial isolates will not form part of this study.
The expected constraint would be the collection of water samples during raining season when the river is full to capacity and this problem will be resolved by employing the services of residents who can paddle canoe.