Modeling and Optimization of Electrocoagulation Voltage and Water Immersion Time on Heavy Metal Reduction in Fish

Abstract

Fish that are in polluted waters can contain heavy metals reaching 0.62 mg/kg. While the maximum limit of heavy metals in fish is only up to 0.3 mg/kg. Consumption of fish containing high heavy metals can cause poisoning to death. This study aimed to model and optimize electrocoagulation stress and distilled water immersion time on heavy metals content by using response surface methodology (RSM). Several studies have proven the effectiveness of the electrocoagulation process and the process of distilled water immersion to reduce levels of heavy metals in fish. If the two methods are combined, it might increase the effectiveness of reducing heavy metals. This study used two treatment factors, i.e., the distilled water immersion time factor of 30-90 minutes and the electrocoagulation voltage factor of 6-18 volts. From the results of the RSM, the best model to reduce the heavy metals content was a quadratic model. From the control point of heavy metals contamination in tilapia fish of 14.73 ppm, it was found that the highest heavy metals reduction was at the treatment of 35.51 minutes immersion time and 6.24 volts of electrocoagulation voltage. The maximum result of heavy metals reduction in tilapia fish based on predictions was 86.319%. In comparison, the validation test in the actual experiment was 90.21%, so the optimization results can be said to be valid because of the error value (4.5%) was less than 5%.