EFEK LOGAM Cr (VI) TERHADAP STABILITAS UNIT PROSES AEROB IPAL LABORATORIUM JTK UGM

• Main Authors: , SATYA DARMAYANI, , Dr. Ir. Sarto., M.Sc.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2013
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/126059/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=66249
• Institution: Universitas Gadjah Mada

Chemical Engineering Department, Gadjah Mada University, has a wastewater treatment plant (WWTP) to process wastewater produced by its laboratories. The WWTP consists of equalization, anaerobic, aerobic and phytoremediation ponds. WWTP operates with the adding of starch as substrate and NPK as nutrient. However this WWTP could not treat wastewater which contained a variety of chemical compounds, so that it did not operate properly. Therefore WWTP revitalization should be done in order to make it operate optimally. The purposes of the research are to determine the effect of Cr(VI) on the WWTP stability conditions, and the performance of aerobic activated sludge. The experiment was done by controlling substrates flow as much as 3 liters per day to the aerobic pond in a laboratory scale pond made from plastic with the capacity of 10 liters. The pond was run continuosly, the samples of wastewater was taken to measure its BOD,COD,MLSS and MLVSS along with the waste feeding. Microorganisms in the aeration basin were grown for ± 20 days. The operating conditions that must be considered are the degree of acidity (pH) 6.5 to 8.5, and temperature (25oC). After adaptation phase had been completed that was characterized by constantly COD value, Cr(VI) metal, in K2Cr2O7 form, was added into aeration basin periodically until the value of BOD, COD and Cr (VI) content were constantly obtained. The results showed that the higher Cr (VI) concentration the longer time required by aerobic bacteria to degrade it into Cr(III). Aerobic bacteria are able to reduce the BOD - COD of waste-water that contains Cr (VI) up to 50% on various concentrations. The addition of 0.05 gram Cr (VI) can inhibit the growth of microorganisms indicatd from MLSS and MLVSS analysis results which showed that the number of microorganisms was reduced by 35%. The adding of K2Cr2O7 as 0.025 g has less inhibition effect due to bacterial performace compare to K2Cr2O7 as 0.05 g. The time required to obtain a new condition with the addition of Cr (VI) 0.05 g of Cr (VI) and 0.025 g were 14 days and 12 days to reach a constant point.