Water clarification capabilities of indigenous plants used for water treatment by rural communities in Southeastern Nigeria

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1 Sky Journal of Agricultural Research Vol. 3(11), pp , December, 2014 Available online ISSN Sky Journals Full Length Research Paper Water clarification capabilities of indigenous plants used for water treatment by rural communities in Southeastern Nigeria Okoli C. G. 1 *, Etim N. E. 1, Emerenini C. I. 1, Kubkomawa I. H. 2 and Okoli I. C. 2 1 Department of Environmental Technology, Federal University of Technology Owerri, Imo State, Nigeria. 2 Department of Animal Science and Technology, Federal University of Technology Owerri, Imo State, Nigeria. Accepted 29 November, 2014 In this study, the value of indigenous plant seeds of southeastern Nigeria in the clarification of relatively turbid stream water (Otamiri River) was investigated. Four different plant seeds; Moringa oleifera (moringa), Zea mays (maize), Spheno stenocarpa (African bean) and Tetrapleura tetraptera seeds were crushed and used to treat a turbid water of 58 NUT, using 1 and 2 g of each seed type to treat 10 L of raw water drawn from the same location for one and 24 h. Subsequent physicochemical analysis such as electrical conductivity (EC), colour, turbidity, total dissolved solids (TDS), odour, taste, temperature ph, appearance, nitrate, copper and iron ions were carried out on each treatment bucket after 1 and 24 h of treatment. Suspended materials removal efficiency was found to increase with increasing dosage of the seeds in most cases. Values of TDS and total suspended solid (TSS) were below the WHO standards for both the alum and seed treated water with Zea mays and African bean seed powders recording TDS (36 mg/l each) and TSS (9 and 5 mg/l) each respectively after one hour treatment. Over 24 h treatment, both the TDS and TSS values of M. oleifera treated water decreased further from 52 to 38 mg/l and 19 to 7 mg/l respectively indicating that period of exposure is important in the use of this seed powder for water treatment. The turbidity reduction (43.0%) was achieved with M. oleifera seed powder after 1 g for 24 h, while one gram of Z. mays for one hour reduced turbidity by 81.0%. On the other hand, African bean seed powder on the other hand achieved poor turbidity reductions of 39.0 and 37.9% at 1 g treatment for 1 and 24 h periods, respectively, while T. tetraptera seed powder recorded 56.9 and 62.0% reductions after 1 and 24 h treatments, respectively. It would seem therefore from this study that Z. mays and T. tetraptera seed powders have better water clarification capabilities than the other seeds studied. There is need to evaluate the microbial characteristics of such seed treated water before recommendation for human use. Key words: Water treatment, plant seeds, Moringa, maize, Spheno stenocarpa and Tetrapleura tetraptera. INTRODUCTION Many studies have shown that in developing countries, river water drawn for human consumption and several household uses could be highly turbid particularly in the rainy season (Obiekezie et al., 2005). This pollution has their sources from sewage water of which an estimated 90% of wastewater is discharged directly into the rivers and streams without treatment in developing country (Grinning planet.com, 2005). Pesticides applied to farm fields and homeowner s lawns run off into local streams *Corresponding author. chidibygrace@hotmail.com. and rivers or drain down into groundwater, contaminating the fresh water. Manure and chemical fertilizers containing nutrients such as nitrates and phosphates, also causes nutrient-type water pollution. Similarly, the action of rainwater on piles of mining waste (tailings) and sediment transfer toxicants, solid materials, bacteria and other micro organism to freshwater supplies (Obiekezie et al., 2005; Raphel et al., 2009; Aguoru and Katsa, 2009). Industrial waste is not left out as almost all bodies of water in the world have some level of pollution from chemicals (Nwanyanwu, 2010). Owing to these diverse impurities, which result from the solvent capability of water, water is usually not found in its pure form in nature (Obiekezie et al., 2005). Thus,

2 Okoli et al. 229 river water drawn for human consumption and general household uses could be highly turbid, particularly in the rainy season. During this period, rivers churn materials into suspension and run off from fields and other surfaces carry solid materials, bacteria and other microorganisms into the river (Folkard et al., 1993). It is of paramount importance to remove as much of this suspended matter as possible prior to a disinfection stage and subsequent consumption. In developed countries, water authorities use chemicals such as aluminum sulphate to solidify impure particles, which are then removed at treatment works. Treatment technologies are often costly, involving chemicals that may have detrimental effects to health and environment, or may not be readily available to local communities, especially in developing countries (Boucher, 2006). Scarcity of such chemicals, drawing on scant resources of foreign exchange or governmental bureaucracy in such countries may hinder the adequate supply of these materials forcing the populace to consume the polluted water thereby resulting to out break of water borne diseases. Consequently, there is a need to investigate sustainable alternative technologies, adapted for smallscale water treatment units in developing countries. Development of such readily available alternatives could be based on known traditionally water clarification capabilities of native plants. The seeds of many plants native to the tropical parts of African continent contain essential oils and have other properties that have been exploited and found out to be coagulant aids to clarify water, which exhibit relatively high level of suspended solid, disease causing bacteria and other microorganisms, (Jahn, 1986; Kaser et al., 1990; Sani, 1990). Among these is the ability of certain seed extracts to flocculate particulate in water. In this study, effects of indigenous plant seeds treatment on the physicochemical properties of relatively turbid stream water were investigated. MATERIALS AND METHODS Preparation of seeds Four different plant seeds; Moringa oleifera, Zea mays, Spheno stenocarpa and Tetrapheura tetraptera were collected from different locations at Owerri, Nigeria and used as water clarification materials in this study. In each case, the seedpods were allowed to mature and dry naturally to a brown colour on parent plant. Thereafter, pods were harvested and the seeds shelled. The seed kernels were sun dried for a day or more and crushed using an electric blender and sieved through a 0.8 mm mesh. The prepared seeds were then stored in tightly corked and properly labeled plastic bottles. Water sample collection and preparation Prior to water samples collection at source point, the eighteen buckets used were cleaned using cotton wool soaked in ethanol. Thereafter the buckets were sterilized in an autoclave at a temperature of 12OºC for 30 min. The water samples to be analyzed were sourced from Otamiri River directly from a drinking water collection point during morning hours of about 8.30 am. The collection proper was done by dipping the bucket below the surface and then properly covering the bucket immediately. The buckets were then transported to the laboratory where treatment and analyses were carried out immediately. Research design The experimental design is shown in Table 1. In each treatment case, the finely crushed seed powder was mixed with clean water to form a paste, and was then diluted to the required strength. The solution was then shaken for five minutes in order to release the chemicals in the powder. Insoluble material was filtered out using either a fine mesh screen or muslin cloth into the bucket containing 10 L of water to be treated, and stirred rapidly for two minutes, then slowly for min. The treated water was then left to sit, without being disturbed. After the solid materials had settled to the bottom of the bucket, the clean water was in each case carefully collected for physicochemical analyses in sterile plastic container after one and 24 h intervals of treatment. Physiochemical analysis All reagents used were of analytical grade and standard procedures were followed in the analyses (APHA- AWWA-WPCF, 1981). Physiological parameters determined were electrical conductivity, colour, turbidity, total dissolved solids (TDS), odour, taste and temperature. Temperature measurement was carried out using a mercury-in-glass thermometer. Lovibond colour disc with permanent colours of range 0-50 Hu was used to determine the colour of the water samples. Electrical conductivity of the samples was measured using conductivity meter. Odour of the samples was observed by half-filling a wide-mouth, glass-stoppered bottle that had been prewashed thoroughly and rinsed properly with acid and distilled water respectively. The half-filled bottle was shaken vigorously for about 5 s. The stopper was removed and the odour was observed immediately with the nostrils placed very close to the mouth of the bottle. Taste of the samples was similarly determined and recorded as objectionable if it has taste, and unobjectionable if it is tasteless. TDS of the samples was

3 230 Sky. J. Agric. Res. Table 1. Experimental design. Treatment A1 A2 B1 B2 B3 B4 C1 C2 C3 C4 D1 D2 D3 D4 E1 E 2 E 3 E 4 Description Raw drinking from Otamiri River (control) Raw drinking from Otamiri River treated with Alum 1 g Moringa oleifera treated (MOT) seed in 10 L of water for 1 h 1 g Zea mays treated (ZMT) seed in 10 L of water for 1 h 1 g African Bean treated (ABT) seed in 10 L of water for 1 h 1 g Tetrapleura tetraptera treated (TTT) seed in 10 L of water for 1 h 2 g Moringa oleifera treated (MOT) seed in 10 L of water for 1 h 2 g Zea mays treated (ZMT) seed in 10 L of water for 1 h 2 g African Bean treated (ABT) seed in 10 L of water for 1 h 2 g Tetrapleura tetraptera treated (TTT) seed in 10 L of water for 1 h 1 g Moringa oleifera treated (MOT) seed in 10 L of water for 24 h 1 g Zea mays treated (ZMT) seed in 10 L of water for 24 h 1 g African Bean treated (ABT) seed in 10 L of water for 24 h 1 g Tetrapleura tetraptera treated (TTT) seed in 10 L of water for 24 h 2 g Moringa oleifera treated (MOT) seed in 10 L of water for 24 h 2 g Zea mays treated (ZMT) seed in 10 L of water for 24 h 2 g African Bean treated (ABT) seed in 10 L of water for 24 h 2 g Tetrapleura tetraptera treated (TTT) seed in 10 L of water for 24 h Table 2. Comparison of the physicochemical characteristics of Otamiri River, treated with alum and 1 g/10 L of some tropical plant seeds for one hour. Parameters WHO Raw sample Alum MOT ZMT ABT 1 TTT STD treated 1 g/1 h 1 g/1 h g/1 h 1 g/1 h Temperature ph TDS (mg/l) TSS (mg/l) Colour (PLCO) Turbidity (NTU) Appearance Clear Clear Clear Slight Clear Clear Clear Clear Odour Odourless Odourless Odourless Odourless Odourless Odourless Odourless Nitrate (mg/l) Iron (mg/l) Copper (mg/l) Conductivity Moringa oleifera treated water (MOT), Zea mays treated water (ZMT), African Bean treated water (ABT), Tetrapleura tetraptera treated water (TTT). determined using TDS meter. Chemical parameters determined were ph, appearance, nitrate, copper and iron ions were determined using atomic absorption spectrophotometer (AAS, Buck Scientific 200A). Data analyses Data generated were organized in tables and compared with standard values recommended by WHO (1995). Thereafter, percentage reduction of turbidity over time in the treated water using the different seed treatments was calculated. RESULTS AND DISCUSSION The results of water treatments using the M. oleifera, Z. mays, African bean seed and T. tetraptera seeds at different concentrations and duration of treatment are presented in Tables 1 to 5. The source water exhibited turbidity level of 58 NUT, which was greater than the WHO standard of 50 NUT. However treatment with 1 g of the various seeds over a period of 1 h (Table 2) showed that ph remained within the range of 5.03 in African Bean treated water to 5.12 in T. tetraptera treated water, indicating slight acidity. These were different from the more acidic water (ph 3.66) produced from alum treatment and similar to the raw water sample. Values for TDS and total suspended solid (TSS) were below the WHO standards for both the raw, alum and seed treated water. Specifically, raw water and alum treated water values were 61 mg/l for TDS and 32 and 16 for both TDS and TSS respectively during the 1 h treatment period (Table 2). These values were

4 Okoli et al. 231 Table 3. Comparison of the physicochemical characteristics of Otamiri River, treated with alum and 1 g/10 L of some tropical plant seeds for 24 h. Parameters WHO Raw Alum MOT ZMT ABT TTT STD sample treated 1 g/24 h 1 g/24 h 1 g/24 h 1 g/24 h Temperature ph TDS (MG/L) TSS (mg/l) Colour (PLCO) Turbidity (NTU) Appearance Clear Clear Clear Clear Clear Slight clear Slight clear Odour Odourless Odourless Odourless Odourless Odourless Odourless Odourless Nitrate (mg/l) Iron (mg/l) Copper (mg/l) Conductivity Moringa oleifera treated water (MOT), Zea mays treated water (ZMT), African Bean treated water (ABT), Tetrapleura tetraptera treated water (TTT). Table 4. Comparison of the physicochemical characteristics of Otamiri River, treated with alum and 2 g/10 L of some tropical plant seeds for one hour. Parameters WHO STD Raw Sample Alum Treated MOT ABT ZMT TTT Temperature ph TDS (MG/L) TSS (mg/l) Colour (PLCO) Turbidity (NTU) Appearance Clear Clear Clear Milky Slightly Clear Slightly Clear Slightly Clear Odour Odourless Odourless Odourless Odourless Odourless Slight Odour Slight Odour Nitrate (mg/l) Iron (mg/l) Copper (mg/l) Conductivity Moringa oleifera treated water (MOT), Zea mays treated water (ZMT), African Bean treated water (ABT), Tetrapleura tetraptera treated water (TTT). Table 5. Comparison of the physicochemical characteristics of Otamiri River, treated with alum and 2 g/10 L of some tropical plant seeds for 24 h. Parameters WHO STD Raw Sample Alum Treated MOT ZMT ABT TTT Temperature ph TDS (MG/L) TSS (mg/l) Colour (PLCO) Turbidity (NTU) Appearance Clear Clear Clear Clear Slightly Clear Slightly Clear Slightly Clear Odour Odourless Odourless Odourless Odourless Odourless Odourless Odourless Nitrate (mg/l) Iron (mg/l) Copper (mg/l) Conductivity Moringa oleifera treated water (MOT), Zea mays treated water (ZMT), African Bean treated water (ABT), Tetrapleura tetraptera treated water (TTT)

5 232 Sky. J. Agric. Res. Table 6. Percentage reduction in turbidity of water treated with Moringa oleifera seed powder. Plant seeds Moringa oleifera Zea mays African bean Tetrapleura tetraptera Dosage of seed powder (g) Turbidity after 1 h Turbidity after 24 h Reduction after 1 h (%) Reduction after 24 h (%) significantly reduced further by the various seed treatments to ranges of mg/l for TDS, indicating that Z. mays and African Bean seed powders are better TDS (36 mg/l each) and TSS (9 and 5 mg/l, respectively). Colour scores were much higher than the WHO standards especially for the Moringa oleifera seed (MOT) that gave a value of 126 PLCO. Generally treatments with seed, any seed powder led to increase in colour score. Turbidity results followed similar trend indicating that when using low concentrations of treatment seeds for short periods, Z. mays and African Bean seed powders may be preferred as better water clarifiers. Again, treatment with these seed powders significantly reduced the conductivity values when compared with those generated from the other seeds, the raw and alum treated water. Comparison of the physicochemical characteristics of Otamiri River treated with alum and 1 g/10 L of some tropical plant seeds for 24 h were presented in Table 3. It is interesting to note that with increased treatment period, there was observable ph change in the African Bean seed (ABT) and Tetrapleura tetraptera seed (TTT) treated water, which became slightly more acidic (4.95 and 4.88, respectively), for the Zea mays seed (ZMT), the water became more basic. Over 24 h treatment, both the TDS and TSS values of M. oleifera treated water showed some change in values when compare with the values obtained during 1 h treatment (52 to 38 mg/l TDS, and 19 to 7 mg/l TSS), indicating period of treatment is an important factor in the use of this seed powder for water treatment The rate of turbidity reduction was found to be higher at lower dosages and 1 h after treatment process than it was with increased dosages and longer period of treatment (Table 6). However, the reverse was the case with moringa and tetrapleura seed powder that gave reduced turbidity levels with increase in dosage and settling time after treatment. The turbidity reduction (43.0%) was achieved with M. oleifera seed powder after 1 g treatment for 24 h, while one gram treatment with Z. mays for one hour reduced turbidity by 81.0%. African bean seed powder on the other hand achieved poor turbidity reductions of 39.0 and 37.9% at 1 g treatment for 1 and 24 h periods respectively, while T. tetraptera seed powder recorded 56.9 and 62.0% reductions after 1 and 24 h treatments, respectively. Studies by (Okoli et al., 2009) show that the seed kernels contain significant quantities of a low molecularweight, water-soluble proteins which, in solution, carry an overall positive change. The proteins are considered to act similarly to synthetic, positively changed polymer coagulants. When added to raw water the proteins bind to the predominantly negatively charged particles that make raw waters turbid (silt, clay bacteria etc.). Under proper agitation these bound particulates then grow in size to form the flocs, which may be left to settle by gravity or be removed by filtration. There was also an observation of a slight decrease in ph for all treated raw water. For nitrate a fluctuation in measurement was observed though still within WHO recommendation. It was also observed during the study that the insoluble materials from the plant seeds were suspended in the treated water sample and were believed to have escape through the mesh screen into the bucket. These added to the TSS of the sample and therefore settled slowly. In practice, there may therefore be the need for the provision of a filtration system. Finally, the chemical constituent and structure of the plant seeds are not fully elucidated. The interaction of the seeds with chemicals and other substances in raw water also are not fully understood, and the products of interaction are not all known. Further studies would therefore be carried out to provide insight into these which Muyibi et al. (2003) suggests to be caused by the precipitation of insoluble products of the reaction between the experimental plant seeds and the hardness causing ions. Owing to the fact that the appearance of the raw water was clear, it was observed that sample water treated with African bean seed and Z. mays appeared slightly clear, meaning that the colouring matters in the seed has slight

6 Okoli et al. 233 effect on the appearance of raw water. On the other hand M. oleifera and T. teraptera seeds did not affect the appearance of the raw water. The conductivity of the raw water sample was reduce by the seeds to meet up WHO standard except in few cases which further research can explain. It was observed that four plant seeds in question have a possibility of increasing copper content in water, while reducing iron. Conclusion This laboratory investigation have confirmed the seeds, especially Maize and T. teraptera seed to be highly effective in the removal of suspended solids from water containing medium to high initial turbidities. The performance of the seeds is however dependent on the raw water to be treated. Kaser F, Werner C, Nahayo D (1990). Rural water treatment using Moringa oleifera seeds as coagulant. National Resources Development, 33, Muyibi SA, Alfugera AMS (2003). Treatment of surface water with moringa seed extracts and alum. A comparative study using pilot scale water treatment plant. Int. J. Environ. Studies, 60, Nwanyanwu C E (2010). Tolerance of phenol-utilizing bacteria to heavy metals in the Aba River sediments. Int. J. of Nat. and Appl. Sci., 6, Obiekezie SO, Oyeagba RA, Nwaugo VO, Onunkwo A A (2005). Concentrations of Trace metals in water collected from Amicol Lake, Ebonyi State, Nigeria. Int. J. of Nat. and Appl. Sci., 1: Okoli CG, Emerenini CI, Nsikan EE. (2009). Assessment of water treatment capabilities of some Nigerian plants. Int. J. of Agric. and Rural Dev., 11, Raphael P, Tsafe AI, Abdulrahman FW, Itodo AU, Ajagbonna OP, Shabanda IS (2009). Heavy metals concentrations in water bodies around aquamarine and topaz mining sites on Eggon hills, Nasarawa state, Nigeria. Int. J. of Nat. and Appl. Sci., 5, Sani MA (1990). The use of Zogale seeds for water treatment. B. Eng. project report. Bayero University, Kano, Nigeria. WHO (1995). Standards for Drinking water in developing countries. Technical Report , 156p. World Health Organization, Geneva. REFERENCES Aguoru CU, Katsa M M (2009). Quality assessment of drinking water from different sources in Lafia, Nassarawa state, Nigeria. Int. J. of Nat. and Appl. Sci., 5(2): APHA-AWWA-WPCF (1981). Standard methods for the examination of water and wastewater, 7 th edition. American Public Health Association, American Water Work Association and Water Pollution Control Federation, Washington DC. Boucher J (2006). Oleaginous plant seeds and seed by -products for water treatment. These No 3572 (2002) A La Faculte Sciences De Bases Ecole Polytechnique Federale De Lausanne. Folkard GK, Sutherland JP, Grant WP (1993). Natural Coagulants at pilot scale. In J. Pickford, (Ed), Water, environment and management; Proc 18 th WEDC Conference, Kathmandu, Nepal, 30 August - 3 Sept 1992, (pp ) Loughborough University Press, Loughborough. Grinning planet.com (2005). Retrieved from pollution-causes.article.htm Jahn SAA (1986). Proper use of African natural coagulants for rural water supplies. Manual No. 191, Pub: GTZ, Eschbom, Germany.