Addition of EM-4 (effective microorganisms-4) to reduce BOD (biologycal oxygen demand) of batik cap waste in Pekalongan City

The Biologycal Oxygen Demand (BOD) level of batik cap liquid waste in Pekalongan City exceeds the quality standard, which is 3549.67.53 mg/l. The purpose of this study was to determine the effect of the addition of EM-4 on the decrease in BOD of batik cap liquid waste. The method used in this research was pretest-postest with control group. The population of this study was a stamped batik making home industry that does not yet have an IPAL. Samples were taken from liquid batik cap waste from the production process. The study used 3 variations of EM-4 doses, namely 0 ml / l, 5 ml / l, 10 ml / l and 15 ml / l with incubation time for 1, 2, 3 days and replication 3 times. From the results of the study obtained a decrease in BOD with the addition of EM-4 (5 ml/l, 10 ml/l, and 15 ml/l) of 61.24%, 90.71% and 92.42%. BOD levels after treatment decreased to quality standards, namely; 300 mg/l. The results of statistical tests using two-way anova show that there is an effect of the addition of EM-4 on the decrease in BOD of stamped batik liquid waste.