Journal of Environmental Analytical Chemistry

Investigation into occurrence and Remediation of Polychlorinated biphenyls in soil from Jos, Plateau State Nigeria was carried out. The polychlorinated biphenyls in the soil was extracted with 40ml hexane-acetone mixture (1:1) in ultrasonic bath for 30 minutes and cleaned with column chromatography packed with silica gel. The polychlorinated biphenyls were quantified using Agilent 6975 Gas chromatography Mass Spectrophotometer with the following results: PCB 18 (0.71), PCB 20 (0.37), PCB 28 (0.38), PCB 29 (0.38), PCB 44 (0.42), PCB 52 (0.66), PCB 101 (0.61), PCB 105 (0.17), PCB 137 (0.64), PCB 142 (0.33), PCB 153 (0.42), PCB 170 (0.13) and PCB 180 (0.21) all in mg/kg. Remediation with Moringa seed results in the followings; PCB 20 (0.28), PCB 28 (0.28), PCB 29 (0.28), PCB 52 (0.30), PCB 101 (0.18), PCB 143 (0.91) while the other congeners were completely removed. The Moringa seed powder results completely removed the PCBs sake PCB 44. The effectiveness of the powder as compared with the seed in the removal of the PCBs might be attributed to the increased surface area of the seed powder providing for better interaction with the contaminated soil. Whereas the results from the use of activated carbon only removed PCB 105 completely and reduced the concentrations of other congeners as follows: PCB 18 (0.04), PCB 20 (0.011), PCB 28 (0.019), PCB 29 (0.019), PCB 44 (0.021), PCB 52 (0.33), PCB 101 (0.031), PCB137 (0.032), PCB 142 (0.017), PCB 153 (0.021), PCB 170 (0.007) and PCB 180 (0.011) all in mg/kg. The result suggests that Moringa seed powder could possibly serve as an excellent means of remediation for Polychlorinated biphenyls in contaminated soil.

Proper human health risk assessments are rarely conducted for mining communities, consequently when there is need for remediation to be conducted and compensation to be paid to impacted population they are typically done, assuming equal exposure risks from varying mining activities. This study was conducted to compare the distribution of potentially toxic elements in surfaces soils of gemstone and lead mining towns in Nigeria, and their anticipated exposure risks. To achieve this thirty-two surface soil samples were collected from Eggon, a gemstone mining town in Nasarawa State and Enyigba, a lead mining town in Ebonyi State. The samples were air dried, disaggregated and sieved through a 2000 μm mesh with the <2000 fraction retained for aqua regia digestion. Potentially toxic elements bound in the samples were quantified with Agilent Technologies 4210 (MP-AES). Mineral phases were identified and quantified using using a inXitu’s portable transmission XRD/XRF instrument (Terra) with a miniature X-ray tube and a CCD detector for collection both XRD signatures. The PTEs, As, Cd, Mn, Pb and Zn were higher in surface soils of lead mining town. At the gemstone mining town most the PTEs indicated similar concentrations at both mine site and residential areas, while at the lead mining town of the PTEs indicated higher concentrations at mine sites and mine road. At the lead mining town the estimated daily exposure doses for Pb were above threshold values irrespective of the exposure scenario. Mineralogy data indicated most of the PTEs in mineralized phases.

In this research, polyethene packaged sachet water from various producers, sources and distributors were analyzed for its physicochemical and microbiological characteristics. Samples were collected randomly from six (6) different locations/towns in Sagamu Local Government. The samples were analyzed for its physicochemical and bacteriological parameters. The results of the analyses were compared with the permissible limit set by WHO, EPA, Canada, and NIS. It was found that most of the parameters, turbidity 0.08-0.16 with permissible limits of 0.1-5.0, alkalinity 9-17 mg/l with permissible of 5.00 mg/l, Total hardness 3-6 mg/l with permissible limits of <60-100 mg/l, Phosphate 0.12-0.51 mg/l with permissible limits of <5 mg/l, Iron 0.02-0.21 mg/l with permissible limits of <0.03 mg/l, Calcium 2.10-4.80 mg/l with permissible limits of <75-200 mg/l, Nitrate 0.00-2.50 mg/l with permissible limits of <45-50 mg/l, Chlorine 12.8-28.30 mg/l with permissible limits of <250 mg/l were in the expected range of the permissible limits set by WHO, EPA, Canada, and NIS. However, the pH 4.73-6.10 of the sachet water samples tends to be acidic below the expected range 6.5-10.5. The Total Heterotrophic Bacteria count and Enteric Bacteria count tends to be a little lower below the permissible limits, Total Enteric Bacteria 300-480 CFU/100 ml with permissible limits of <500 CFU/100 ml and Enteric Bacteria 280-380 CFU/100 ml. It was recommended that water producing industries should site their raw water site in a safe location free from contamination, the government should involve the participation of equipped private and government hospitals with good laboratory to monitor and report accordingly the situation of all water packaging industries in their vicinity, the government should also involve the participation of genuine and reputable individuals to produce and provide paid pipe borne waters to people in their community and regulatory bodies such as SON and NAFDAC should take responsibility by continually re-assessing the production and packaging quality of drinking water in every community.