Effectiveness of Utilization Kerang Dara Shell’s (Andara Granosa) As A Coagulants in Industrial Waste Water Treatment Processing

Abstract

Andara granosa shell is one of the bivalves that is found in Indonesia. The high level of andara granosa is meat consumption without being followed by right processing of the shells, makes andara granosa shells become a waste that distrupts the environment. Andara granosa is contain a lot of CaCO3 Andara granosa shells contain a lot of CaCO3 which makes it can be used as a coagulant. Shells containing CaCO3 are converted into CaO (Calcite) first by the process of calcination. In this study, calcite was obtained through the process of calcining of andara granosa shells at 800 °C for 4 hours, which was dried and destructed before. The calcite optimization test in andara granosa is done by analyzing the ratio of calcite concentration variation (600 ppm, 700 ppm, 800 ppm, 900 ppm, 1000 ppm) to the decrease in BOD, COD, and TSS values in industrial liquid waste. The test results show the optimal optimal decrease in BOD, COD, and TSS values is at a concentration of 900 ppm with an effectiveness of 80.53%. The relationship between the concentration of coagulant to decrease in BOD value is shown by the equation y = -6.7043x2-50.275x + 599.83 and R2 = 0.9356,% effectiveness of COD 81.16%. The relationship between the concentration of coagulant to decrease in COD value is shown by the equation y = -4.3214x2-130.15 x + 1033.4 and R2 = 0.9492,% effectiveness of TSS 96.10%. The relationship between coagulant concentrations and the decrease in TSS values is shown by the equation y = 32.611x2-304.24x + 697.95 and R2 = 0.9088. Thus calcite with raw material of blood shells can reduce the optimal BOD, COD, and TSS values at a concentration of 900ppm.