Effects of addition of carbide on sewage degradation

Thesis Abstract

The objective of this research is to investigate the effect of addition of carbide on sewage degradation. To provide answers to the above objective, some laboratory tests were conducted which include Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total coliform, pH and Suspended Solids (SS) tests. Six experimental set ups of 5liters of sewage were constructed in the laboratory under anaerobic condition. Each of the sewage contained 0g (which served as control), 1g, 2g, 5g, 8g and 10g of fresh calcium carbide. Samples were collected twice per week for two months for the laboratory tests. The results from the tests showed that there was a gradual increase in the percentage of COD and BOD efficiency removal as the quantity of carbide added increased with time. Also, the number of positive coliform bacteria decreased as the quantity of carbide added increased with time. There was also a gradual increase in suspended solid as the quantity of carbide added increased. pH value increased as the quantity of carbide added increased with time. This could be due to the assumed calcium hydroxide produced from the reaction of sewage with calcium carbide since calcium hydroxide is a base. Calcium carbide can therefore be used in the reduction of BOD, COD and coliform bacteria in sewage.