Penurunan Kadar Krom (Cr) dalam Limbah Cair Industri Penyamakan Kulit dengan Metode Elektrokoagulasi secara Batch

Abstract

Some industries produce wastewatercontaining heavy metals, such as chromium, that can pollutethe environment and is harmful to the living things. An alternativewayto treat such wasteis electro-coagulationwhichis an integration of both electrochemical andcoagulation processes by passing a direct electrical current. This research was aimed to treat wastewater containing chromium from a leather tanning industry by applying electro-coagulation process and to obtain the optimum voltage and time, as well. This laboratory work was carried outon the wastewaterfromPTAdiSatriaAbadiBantul withhigh content ofchromium(about761.504ppm). It was conducted in a batch mode by processing 7.5liters of waste in a glass tuband by using an electrode of aluminum (Al) plate (20cmx30cmx0.12cm). The electrical voltagewas variedat 2,4, 6, and 8volts,while thetime of electro-coagulation was variedfor 1, 2, 3, 4, and5hours. Content of chromium in the wastewater was therefore analyzed byAAS(atomic adsorptionspectroscopy) method. This study concluded that theelectro-coagulationprocess was effectively able to reduce the contentof chromiumin the wastewater. In addition, the variations ofvoltage and processing time significantly influenced on the decreasing of content ofchromium. The optimum voltageandtimeofelectro-coagulationwas obtained at 6volts and 8 volts for 3hours and 2 hours, respectively. The best result of electro-coagulation process of the wastewater performed on the voltage of 8 volts for 5 hours yielded the chromium content of 1.76 ppm. Such condition has promisingly reduced the content of chromium until 99.77% ofthe initial waste.