1.1 BACKGROUND OF THE STUDY
Water is a vital resource, but presents a worrisome depletion in recent time. Adequate water supply for human consumption is a concern since most of this resource is found in oceans where the high salt contents makes it unsuitable for drinking. Factors such as growing populations increase economic activities and industrialization home resulted in high demand for drinking water and the subsequent misuse of these natural resources, which is severe. This hinders the treatability process and increases water treatment costs. For these reasons, coagulation-flocculation procedures associated with other process of great importance in order to separate contaminating components and achieving high degree of drinking water quality.
Aluminum Sulphate (alum) has been the chemical coagulant used for drinking water treatment to low cost, attainability and comfortable handling, however continuous use of alum has caused several problems affecting human health. Studies have shown that aluminum is one of the causes of Alzheimer’s syndrome (Rondeau D. Commenges).
In addition, Aluminum Sulphate generates inconveniences because of the large amount of sediments, which may be regarded as highly hazardous waste (D.B George S. Hall and H. Hall).
Another adverse characteristic of aluminum sulphate is the permanence in the drinking water life – cycle that is present in natural water resources, animals, people and plant (J.D Birchall, C. Exley). Owing to the various problem generated by the use of alum, new alternatives for drinking water treatment should be studied (S. Syafalni).
Nigeria hold diverse natural resources, which are able to offer various alternative methods to treat water. This study aims to promote the use of natural substances in drinking water treatments through easy applicable method suitable for a small population that requires them. According to G. Folkard and J. Sutherland, in the Pasto two decades, an innovative drinking water treatment strategy using natural coagulants has shown high reliability for coagulation flocculation techniques achieving high efficiency in turbidity remove and colour while providing additional advantage such as low cost and manageability, e.g. Okra gum, Moringaceae – Moringa Oleifera and Moringa stenopetela have been used to clarify turbid water.
Pollution of water bodies is a major health issues in many fast growing cities where population growth far exceeds the rate of development of wastewater collection and treatment infrastructure (Meybeck, 1989). Estimates show that more than 90% of wastewater in developing countries undergoes no treatment (Homsi, 2000). Nigeria has few small capacity wastewater treatment facilities, most of these are in poor operating conditions, leaving large volume of untreated wastewater flowing through urban streams and drains. This has adversely affected the quality of surface water bodies in an around the main cities.
In Nigeria, most wastewater is generated mainly from domestic sources, as Nigeria’s Industrial development is concentrated along the coastal time where waste water is disposed off into the ocean. However, in some inland cities like Kaduna, there are some limited industrial activities such as food processing (breweries, soft drink bottling factories) and light vehicle industries, waste water generated is disposed off into urban drains and gutters, which eventually ends up in urban streams. Some activities like farming, fishing, and domestic water use which rely on these sources of water have badly been affected.
1.2 STATEMENT OF PROBLEM
Contamination of drinking water supplies form industrial waste is as a result of various types of industrial process and disposal practices. Industries that use large amounts of water for processing have the potential to pollute waterways through the discharge of their water into streams and rivers, or by run-off and seepage of stored wastes into nearby water sources. Other disposal practices which causes water contamination include deep well injection and improper disposal of waste in surface impoundments. Industrial water consists of both organic and inorganic substances. Organic wastes include pesticides residues, solvents and cleaning fluids, dissolved residue from fruits and vegetables, and lignin from pulp and paper. This impacts high organic pollutants on receiving waters consequently creating high competition for oxygen within the ecosystem. (Osibanjo and Adie, 2007). Effluents can also contain inorganic wastes such as brine salts and metals.
A number of toxic substances human being encounter regularly may pose serious health risks. Pesticide residues on vegetable crops, mercury in fish and many industrially produced chemicals may cause cancer, birth defects, genetic mutations or death. Discharge of metals and some non metals into water bodies have serious environmental effects.
Lead a prime environmental pollutant, is a multiorgan poison which in addition well known toxic effects depresses immune status (Anetor and Adedeji, 1998). Causes damage to the central nervous system, kidney and reproductive system. (Ademoroti, 1998). Ingestion leads to a disease known as plumbism. It is also known to produce developmental neurotoxicity in particular infants and children are differentially sensitive to environmental lead exposure (Johnson, 1997). Lead is toxic to plants although a few are tolerant. In non-ferrous metal industries that produce batteries, pigments, stabilizers and plastics. The primary heavy metals discharged are lead, zinc, and calcium, also cement manufacturer results in high emission of mercury as well as these heavy metals except zinc. Arsenic and Zinc gain access to the water environment through mining operations. Nickel and cobalt are used in the electroplating industry. Effluents contain these heavy metal which are harmful to human health either through direct ingestion or from fish and other animals or plants. Heavy metals particularly arsenic, Mercury and lead are environmental pollutants threatening the health of human population and natural ecosystem (Mercier et al, 1998)
1.3 SIGNIFICANCE OF THE STUDY
The supply of freshwater is limited and threatened by indiscriminate discharge of untreated wastewater effluents. In developed countries, municipal wastewater systems are well organized and cover most part of the regions but this is not the case in developing countries like Nigeria. Water is a scarce commodity and there is the need to protect the available water resources from discharges of untreated waste water. Various forms of waters treatment exist in Nigeria; however, this study provides valuable information on the use of Watermelon seed as a means of ensuring a cost effective treatment system that meets standard requirements before discharge into surface water.
Furthermore, the study is planned to generate information that could be used by wastewater treatment plant managers and the Environmental protection Agency of Nigeria in order to develop or review an effective policy for wastewater treatment plants in meeting standard requirements for discharge of effluents into water sources.
1.4 AIM AND OBJECTIVES
The aim of this research work is to investigate the use of watermelon (Citrillus Lanatus) seed as a coagulant in the treatment of industrial wastewater.
1. Obtain the watermelon seed and waste water sample.
2. Treatment of the waste water sample with the watermelon as coagulant
3. Analysis and presentation of results.
1.5 SCOPE AND LIMITATION
This research work shall solely focus on the treatment of brewery effluent. Hence, wastewater samples shall be collected and their properties will be investigated before further works will be carried out. Investigation into the treatment of domestic wastewater is outside the scope of this work.
In this study, we will examine the purifying capacities of watermelon seed treatments applied to industrial wastewater generated by the breweries.
1.6 MATERIALS AND METHODOLOGY
Material to be used in this work includes watermelon seed cake (coagulant), N – hexane, Brewery effluent from Nigeria Breweries Kaduna-Nigeria, Distilled water, sox wet extractor, Digital PH meter, Electronic weighing balance, turbid meter, conductivity meter, and stop watch (timer). All reagent to be used are analytical grade.
i. Water melon seed (coagulant) Preparation
Fresh seed of water melon (citrillus Lanatus) of the Cucurbitaceous family will be obtain from the local market (station) in Kaduna, Kaduna state, Nigeria. This fruits will be slice open suing clean stainless steel laboratory knife. The seed will be washed severally with water, sum-dried for a week. Sort to remove bad ones, shelled and grind with a high speed laboratory electric blender, packed in an air tight container. 1509g of the crush seed will then be packed in a thimble and place in a sox helt extraction apparatus. 500ml of the n-Hexane will be use to extract oil from the crush seed in the coloumn. The apparatus will be left running for about 6hours and stop when the extraction is complete the cake will be wash with distilled water to remove residual n-Hexane, dry in an oven till constant weight and then sieve. The timer particles will then be use as the coagulant.
ii. Sample water collection
The raw water sample will be collected from Nigeria Brewer located in Kaduna state, North West of Nigeria. The water will be collected by immersing a plastic container until it is full. The cap will be inserted while it is still underway. The water will then be treated using the prepare coagulant.
iii. Jar Test Operations: A conventional jar test apparatus will use for this experiment to coagulate water samples collect from the source, series of experiment for determining turbidity removal by water Melkon seed cake, and final PH will be conducted and repeat three times to confirm the obtain results.
All test will be carried out with 1h sample in I.S.L breakers. These beakers will be fill with 100ml of water with identical rabidity level, and placed on each slot in a jar tester. Water melon seed cake which will be prepare will be added into beakers in sole use for testing turbidity. The water sample will be mix homogenously before the operation. All beakers will agitate at 15rpm for 1mm, and the mixing speed will be reduce to 40rpm for 7.5 by adding 0.1 Hcl or 0.1 M NaoH in all coagulant tests. After sedimentation for 30min, a sample of the treated water from the mid depth of the beaker will be sued for the analysis.
iv. Analytical Methods: Turbidity Measurement: turbidity measurement will be conducted using a turbidity meter instrument. After the sedimentation phase, sample of turbidity measurement will collected from the upper depth of the water samples. Sample vial wash with distilled water and then with treated water before recording the turbidity. In order to eliminate any differences in turbidity due to different sedimentation times, two sample will be taken according to the following order: 1-2-3-4-5-6-6-5-4-3-2-1, and average value will be recorded.
v. Total Solid: Sample of the raw water shall be taken in 100ml beaker. A clean and dry crucible shall be weighed employ and the sample will be pour into it and reweighed. The respective weights will be recorded and the crucible together with the sample water will then be placed on a hot plate at 1040C to evaporate the water. When all the water evaporates, the crucible will be allow to cool down and reweigh together with the residue. The total solid present will calculated using the equation.
TS = 100 (A – B)/ 200ml. where
A = weight of (crucible + water) – weight of emply crucible
B = weight of (crucible + residue)
vi. Total Suspended Solid (TSS): Sample of the raw water 100ml in a sample bottle. The weight of a dry filter paper will be taking empty and the sample was will be filtered and the residue to dries at about 35 – 400C in an oven. The new weight of filter paper plus residue will be taken. The difference in the weight of the filter paper empty and -with residue after drying will be calculated and divided by total volume of sample.
vii. Total Dissolved Solid (TDS) This will be obtained by taken the difference between TSS and TS or two – thirds of the conductivity using the conductivity meter
viii. PH Measurement: the PH of water will be measured by using a PH meter.
ix. Biological Oxygen Demand (BOD): Biological Oxygen Demand (BOD) is expressed as weight of oxygen consumed per unit volume of water during a destined period of time at a defined temperature ws calculated following procedure of Hammer (1986). For this, the sample of waste water will be incubated for 5days at 200C in the dark. The reduction in dissolved oxygen concentration during the incubation period yields a measure of the biochemical oxygen demand.
x. Chemical oxygen Demand: The COD is determine by titration with ( 0.25m) ferrous suphate using 1:10 phenonthroline6 (United Kingdom, Department of environmental, 1974).