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BackgroundImproper waste disposal is responsible for the contamination of both surface and ground water resources. Heavy metals leached from improperly disposed solid waste constitute grave environmental and health hazards because of their toxic and persistent nature. There are thousands of open dumps in Nigeria one of which is the Enugu State Waste Management Authority dumpsite.MethodForty sampling nodes were systematically established around the Enugu State waste Management Authority central dumpsite located at Ugwuaji, Enugu State, Nigeria. Ten heavy metals (arsenic, cadmium, cobalt, copper, chromium, iron, lead, manganese, nickel and zinc) were sampled at different depths of each node in both rainy and dry seasons.ResultIron and lead were the predominant metals in the vicinity of the waste dump with average values of 132.10 mg/kg and 117.52 mg/kg respectively. The order of abundance of the ten heavy metals monitored is Pb > Fe > As > Zn > Cu > Co > Ni > Cd > Cr > Mn. Generally, there was significant correlation (0.25 to 0.74) among all the metals except between cobalt and manganese in the rainy season. In the dry season, all the metals were significantly correlated (0.29 to 0.813) except for copper and lead, copper and arsenic, zinc and arsenic, and cobalt and manganese. The concentrations of most of the heavy metals approached a constant level at a depth of 1 m. On the other hand, the concentrations of arsenic, cobalt and iron continued to decrease even at a depth of 2 m. The pollution loading index values for the soil are 1.706 for rainy season and 2.54 for dry season.ConclusionThe high pollution loading index represents a significant level of deterioration. It can be concluded that the dumpsite constitute a serious environmental and health hazard.

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The evaluation of porosity and permeability models correlation on the migration of e.coli transport in deltaic environment has been assessed. This is to validate the model generated from the experimental analysis in the study location, this model are generated through the experimental results from both parameters, the theoretical values from both parameters confirm that the models generated is a bench mark that can be applied as a design criteria in preventing the migration of e.coli to ground water aquifer, it has also confirm that it plays a major role in fast transport of e.coli in deltaic environment, the figures displayed shows the level of deposition of geological formation in the study area, the study has also explain the migration of the microbes influenced by porosity and permeability, the results from the experiment that generated theoretical values for porosity and permeability were evaluated to see their relationship in terms of influence on the behaviour of the microbial transport as a system known as plug flow. the results has been confirm that without any inhibition from any other deposition, e.coli will be in progressive phase condition, therefore it is advise that the models generated from the study area should be applied in design of bore hole in other to prevent the pollution emanating from e.coli in the study area, finally the relationships verified from the study has a fit to the existing geological history of the study area that is predominant of alluvium deposition, this condition ascertain the reality of the experimental results generated from the study area ,it should be applied to avoid water related diseases and the threat of life

/ In the search for a cheaper material to effectively condition sludge, oil-free moringa seed was prepared and tested. A Soxhlet apparatus was used to extract the oil from moringa seed (Moringa oteifera). The oil-free seed (marc) has been found to have higher conditioning potential than the ordinary moringa seed. However, the traditional ferric chloride is still a better sludge conditioner than moringa seed marc. For the digested domestic sludge used, optimum conditioning dosages were found to be 0.6, 0.80, and 1.10% of the total solids for ferric chloride, marc of the moringa seed, and ordinary moringa seed, respectively. Since little or no operational material is lost in the extraction process, the moringa seed marc is a promising conditioner in place of the ordinary seed.

This study modeled the relationship between Sludge Filtration Resistance (SFR) and Capillary Suction Time (CST) using the data generated from different concentrations of CaCl 2 for SFR and CST empirically using the Equation proposed by Christensen et al. (1993). The main purpose of conducting CST and SRF tests at wastewater treatment plants is to save operating costs by evaluating the optimal dose of the sludge conditioner, known as the dose of coagulant that yields the minimal capillary suction time or resistance to filtration. In order to establish a relationship between the SFR with CST, there is a relatively good correlation between CST and SFR. The results showed that the values of CST decreased with increasing CaCl 2 concentration, and a good dewaterability could be obtained at the CaCl 2 dosage of 18 g with the corresponding CST of 5.52 s for 20 mm internal cylinder and 30.84 s for 14.5 mm internal cylinder. The results of SFR tests shown decreased with an increase in CaCl 2 dosage. The optimal CaCl 2 dosage was 18 g and the corresponding SFR was 2.65 × 10 8 N•s/m 5. The results of this study for CST recommend larger diameter cylinder to be used to test heavy sludge because the larger cylinder significantly reduces the variability and the time taken to conduct the CST tests.

The study highlights the laboratory use of the concept of Ive's filterability number, 'F', recently formulated for sand filtration of wastewater. Ive , s Filterability Index Equation was modified and used to investigate the performance of sewage sludge undergoing vacuum filtration process. A simple modified form of Coacklely's laboratory apparatus has been described for the evaluation of 'F'. A sludge filtration experiment according to standard procedure suggested by Coackley was mounted. In calculating sludge filterability number and other parameters of the Ive , s equation, vacuum pressures of 20, 16, 12 and 8cmHg were used with the filter medium area of 23.6cm 2 . Four (4) sludge samples of different concentrations obtained from the University of Nigeria, Nsukka treatment plant were prepared. The data generated were used to calculate filterability number F, filtrate volume, Vo and instantaneous velocity 'Vi', for each filtration cycle. The values of 'F' for conditioned sludges were also evaluated from the data using regression analysis. On verification using the experimental data, the theorectical prediction of the modified equation was found to be in consonance with previous findings of other researchers. The filterability index from the generatd data was found to increase numerically with the applied vacuum pressures. Moreover, on verification with Alluminium Sulpahate (Al3SO4) on the effects of chemical conditioner on sludge filterability, it was observed that Filterability Index 'F decreased with increased chemical dosages with the following results: 0.025g/ml, 0.0188g/ml, 0.0130g/ml of Al3SO4 gave corresponding decrease in values of filterability 'F as 5.764, 5.970 and 6.134 for 0.00259g/Cm 3 sludge sample. Similarly, sludge filterarbility showed an earlier increase with sludge initial solids content and reduced after the solids content was further increased with time, t. Such factors as pressure, initial solid content of sludge and chemical conditioning known to have effects on specific resistance and Sludge Dewaterability Number (SDN) have been found to have corresponding effects on sludge filterability index. These results further enhance the suitability of Ives filterability number concept as a measure of sludge filterability.

An equation for sludge dewatering using FMTL An equation for sludge dewatering using FMTL An equation for sludge dewatering using FMTL An equation for sludge dewatering using FMTL plant made of 12mm plant made of 12mm plant made of 12mm plant made of 12mm thick thick thick thick steel plate was used in designing a drying steel plate was used in designing a drying steel plate was used in designing a drying steel plate was used in designing a drying a total area of 0.90m a total area of 0.90m a total area of 0.90m a total area of 0.90m 2 2 2 2 and was used in dewatering sewage sludge from t and was used in dewatering sewage sludge from t and was used in dewatering sewage sludge from t and was used in dewatering sewage sludge from t water water water water treatment plant. Parameters affecting filtration pr treatment plant. Parameters affecting filtration pr treatment plant. Parameters affecting filtration pr treatment plant. Parameters affecting filtration pr analysis approach. The derived equation based on the concept of specific resistance analysis approach. The derived equation based on the concept of specific resistance analysis approach. The derived equation based on the concept of specific resistance analysis approach. The derived equation based on the concept of specific resistance performance o performance o performance o performance of the sand drying bed as a slud f the sand drying bed as a slud f the sand drying bed as a slud f the sand drying bed as a slud obtained from the sewage plant, the theoretical prediction of the derived equation gave a close relationship to the obtained from the sewage plant, the theoretical prediction of the derived equation gave a close relationship to the obtained from the sewage plant, the theoretical prediction of the derived equation gave a close relationship to the obtained from the sewage plant, the theoretical prediction of the derived equation gave a close relationship to the practical values with a correlation of 0.994 practical values with a correlation of 0.994 practical values with a correlation of 0.994