The Effectiveness of Polyaluminium Chloride (PAC) as An Alternative Coagulant to Treat Tannery Waste

Document Type : Original Article

Authors

1 Leather Processing Technology, Polytechnic ATK Yogyakarta, Ministry of Industry of Indonesia Republic

2 Research Center for Environmental and Clean Technology, National Research and Innovation Agency (BRIN)

3 Department of Leather Processing Technology, Polytechnic ATK Yogyakarta

Abstract

Research on the effectiveness of PAC coagulants for processing tannery waste was carried out to determine the optimum pH and determine the % effectiveness of PAC in reducing BOD, COD, chromium, TSS, sulfide, ammonia and pH in leather waste. The test jar method is carried out with a beaker filled with 300 mL of liquid waste each. A series of test jar experiments using a flocculator with pH variations, namely 4, 5, 6, 7, 8, 9 with fast stirring at 100 rpm for 2 minutes, and slow stirring at 25 rpm for 15 minutes. Dose variations were carried out with doses of 25 ppm, 50 ppm, 75 ppm, 100 ppm, 125 ppm. Determination of the optimum pH is done by measuring the final turbidity value. The optimum pH value for processing tannery waste with PAC coagulant is pH 8. The dose of PAC in reducing turbidity was greatest at a dose of 125 ppm. The effectiveness of 125 ppm PAC can reduce BOD 32.44 %, COD 12.23%, chrome 94.86%, TSS 91.62%. PAC coagulant with a dose of 125 ppm in leather processing waste increased the sulfide value from 103 ppm to 134 ppm and ammonia from 72 ppm to 134.11 ppm.

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