Comparison of Standard Operating Procedure DOC Biodegradation Materials Die-Away with Closed Bottle Methods

Abstract

Tests for biodegradation of chemicals by the Organization for Economic Cooperation and Development (OECD) are divided into two types, which are ready and inherent biodegradations. Dissolved organic carbon (DOC) die-away and the closed bottle are the method in ready biodegradation test. Results from material decomposition by microorganisms in waters can be seen in the concentration of dissolved organic carbon (DOC method of die-away) and dissolved oxygen consumption (closed bottle method) by microorganisms. Analysis on number of colony is performed to determine the existence of microorganisme. In this research, microorganisms analysis was conducted by cup count method. Number of colonies grown on the agar media counted with naked eye and the result was 2.13 × 104 colonies/mL for DOC mud and 2.3 × 106 colonies/mL for the covered bottle mud. Degradation percentage of DOC die-away methods which measures the ratio between DOC concentrations at the appointed time with the initial concentration of DOC obtained better results than the closed bottle method is the ratio between BOD value divided by ThOD (theoretical oxygen demand) or COD. Sodium benzoate as a control showeed ThOD about 1.66 mg O2/mg materials meanwhile the test materials had COD value of 1.83 mg O2/mg materials.