BIOACCUMULATION AND TOXICITY OF PLASTIC ENRICHED COMPOST WASTE ON NITRIFYING BACTERIA

ABSTRACT

The Bioaccumulation and toxicity of plastic enriched compost waste on Nitrifying bacteria, earthworm and Talinum triangulare was investigated. Sample site for this research was the dumpsite located at Oluku, Benin city, while the plastic enrichment was done using polyethylene transparent bags. The methodology involved the analysis of the physicochemical parameters of the soil, composting using polyethylene plastic, isolation and Identification of Nitrobacter using Winogradsky medium ( ), and acute toxicity tests on earthworm and Talinum triangulare. The results obtained showed the presence of cadmium, zinc, copper, lead and chromium in the dumpsite. Also, Nitrobacter count ranged from 1.5*10^2 Cafu/g to 10.0*10^2 Cafu/g. Nitrobacter count on plastic enriched soil varied with contact time and plastic contaminant concentration from 3.84mg/g to 8.21mg/g. None of the earthworms in treatment D survived the experiment while variations in the weight and thus survival rates were observed in treatment A-C. The plants were able to grow on all soil treatments but there was no consistent pattern of growth with respect to plant height and leaf area. Plant height ranged from 13.33 ±0.88 to 15.00±1.53 at the end of the experiment while leaf area ranged from 5.17±0.22 to 9.20 ±0.92. Plastics are contaminants of concern and given their ubiquity, they need to be regarded as a factor of global change.The larger the number of species and ecological functions affected by this contaminant, the more likely it is that toxic effects will occur. Therefore, waste should be properly treated before disposal so as to reduce its potentially toxic effects to all forms of life.