The Environmental Impact of Thermal Desorption Unit on the Physicochemical Composition of Leachate: A Case Study of Beneku, Ndokwa East, Delta State, Nigeria
No Thumbnail Available
Date
2022-07
Journal Title
Journal ISSN
Volume Title
Publisher
World Journal of Innovative Research (WJIR)
Abstract
The study is on the environmental impact of thermal desorption unit on the physicochemical composition of leachate in Beneku in Ndokwa East Local Government Area, Delta state. Leachates samples were collected from 6 trenches dug into the dumpsites at 1.5m depth. 2-liter plastic containers were used to collect the leachates. Prior to collection, the containers were rinsed with the samples in order to acclimatize to the sample environment. In order to avoid chemical and biological changes that have the potential to change the natural homogeneity of the samples, the sample for heavy metals analysis were preserved by adding 1ml of conc. HNO3 while 2ml Concentrated H2SO4 was added to samples for COD
analysis. The average pH values of the leachate for the wet season was 7.4, while in the dry season it was 6.0. With the pH values varying from 6 to 7.4,which is within the limit of the FMEnv of 6.0 – 9.0, it is a representative of a growing pH from young to old leachate. The electrical conductivity for both the wet and dry seasons are 6119.14 μs/cm and 6206.49 μs/cm respectively, which far exceeded the FMENV standard of 125.00 μs/cm. The BOD average values for the wet and dry seasons are 7.30 mg/l and 7.50 mg/l respectively while the average values of COD were 13.78 mg/l and 14.22 mg/l respectively for the wet and dry seasons. The mean ratio 7.30/13.78 is 0.53 for the wet season and that for the dry season
which is 7.50/14.22 is also 0.53. This figure (0.53) shows that the organic matter in the leachates is readily biodegradable, and has a high organic strength which can be attributed to fact that the study site is active or open, being fed with waste on a continuous basis, which possibly contains organic matter that undergoes biodegradation continually. From the results of the study, the average values of Iron are 249.54 mg/l and 258.88 for
the wet and dry seasons respectively and are over the FMEnv limit of 0.05 mg/l, Manganese had 2.89 mg/l and 2.66 mg/l for the wet and dry seasons respectively are were also above the FMEnv limit of 0.05 mg/l, Cadmium concentrations in the leachate were 0.57 mg/l and 0.69 mg/l for the wet and dry seasons respectively and they were above the FMEnv limit of 0.01 mg/l, Chromium recorded an average of 4.36 mg/l and 6.95
mg/l for the wet and dry seasons respectively and were above the FMEnv limit of 0.20 mg/l. Nickel had an average values of 0008 mg/l and 0.006 mg/l and are below the FMEnv limit of 0.01 mg/l, Lead recorded an average of 0.33 mg/l and 0.48 mg/l for the wet and dry seasons respectively and are above the FMEnv limit of 0.05 mg/l. The use of thermal desorption unit as treatment method for contaminated solids has proved to be effective as shown in this study as most of the parameters tested in the leachate were well below the Federal Ministry of Environment set limits.
Description
Journal Article