Treatment of waste water from soil washing processes

The levels of the organic and inorganic contaminants in the soils have increased day by day due to industrialization and excessive agricultural usage. The contaminants accumulated in the soil may be transported to long distances by atmospheric movements or groundwater flows and can be accumulated in the plants and lipid fraction of living organisms. Thus, it is necessary to clean such soils by using environmentally friendly chemicals and processes. This thesis examines the electro-oxidation treatment of wastewater, which was formed as a result of washing the soil containing weathered DDT and its metabolites of DDD and DDE with Plant Based Material (PBM). By adding 2,30 grams of PBM to a 4 L beaker, the volume was made up to 4 L with distilled water and mixed at 120 rpm for 1 day. The solution was filtered and stored at +4 oC to use the soil washing and control experiments. The wastewater obtained after washing the DDE contaminated soil with the solution of the PBM was used in the electro-oxidation experiments. DDE and Total organic carbon were measured by Gas Chromotogrphy and TOC analyzer, respectively. The effect of different electrodes and currents on TOC removal efficiency was investigated. The best result was obtained by the Boron doped diamond electrode which was 81,9 % of TOC removal efficiency at 2 amperes of the current for 5 hours. Further research needs to be done on the biological treatment of PBM-containing solutions.