Optimasi Penggunaan Koagulan Terhadap Rancangan Unit Koagulasi, Flokulasi, dan Sedimentasi pada Pengolahan Air Limbah Laboratorium

Abstract

Laboratories wastewater of Bogor Agricultural University (IPB) Dramaga is one of the parties who contribute environmental pollution. Waste Water Treatment Plant (WWTP) located in front of the Veterinary Medicine Faculty serves to treat wastewater in order that appropiate with the treshold. The systems which is used in WWTP IPB is coagulation, flocculation, sedimentation, filter system (sand filters and carbon filters), and disinfection. The objective of this research is to analyze the characteristics of laboratiories wastewater, optimization of using coagulants, and designing coagulation-flocculation and sedimentation units, along with making the mass balance. This study done in two stages, the first stage was primary and secondary data collecting and the second stage was wastewater characteristics analyzing, doing jar test, and design units. Based on the results, the parameters pH, N-NO2, NH3, H2S has met quality standards but TDS, COD, BOD, oil and grease do not meet the threshold . The final concentration of TDS, COD, BOD, and oil and grease in a row at 11273 mg /L, 3300 mg/L, 442 mg/L, and 181 mg/L. The optimum dose of coagulant that can be used for wastewater treatment lab was 6250 mg/L PAC + 62500 mg/L alum. The mass balance indicates that TSS concentration at efluent already under the threshold that is 93 mg/L, whereas BOD was still above the threshold which was 331.77 mg / L. On coagulation and flocculation unit, stirrer speed does not meet the criteria. On sedimentation unit, BOD can be reduced up to 48 % and TSS reduction can be up to 70 %.