CYTOGENOTOXITY OF ANAEROBIC DIGESTATE USING ALIUM CEPA TEST

ABSTRACT

Currently a solution for energy generation and global warming control is Anaerobic digestion. Production of biogas and utilization of the resulting digestates as potential fertilizers (Biofertilizers) for agricultural land application has become as important as producing the maximum yield of biogas.The application of biogas digestates and its environment and human health impacts are still unexplored.Ecotoxicity analyses of digestates before their exploitation in agriculture can predict environmental impact and the necessity for additional treatments. In this present study Allium cepa was exposed to varying concentration of cattle slurry digestate to determine the cytogenotoxicity and chromosomal aberration of the Allium cepa root tip cells. Results of chemical analyses showed that heavy metal concentrations were above permissible limits set for wastewater by World Health Organization with the exception of Zn and Cu. The alterations observed in root tip cells of Allium cepa exposed to 0% (control), 20%, 40% , 60% and 100% concentration of digestate for 48 hours showed abnormal twisting of the roots, dark spot at the root tips of the onions, retarded growth expecially that of 100% concentration. The result showed that the digestate was very toxic and present extremely high environmental risk. It is therefore recommended that a pre-treatment is needed to reduce its toxicity and environmental impact before deployment to agricultural use.