Study of Chlorination Application in Tapioca Wastewater Cyanide Removal

Abstract

Tapioca wastewater contains a high concentration of organic matter and cyanide. Chlorination has known as one of alternative cyanide removal methods. The fact that must be an attention is carcinogenic compound such as Tri Halo Methane could be produced as byproduct chlorination of organic waste. This research aimed to determinecondition of chlorination application in tapioca wastewater cyanide removal especially calcium hypochlorite dosage and pH thus meeting the criteria of the quality standard of waste and Tri Halo Methane identification. Effluent of chlorination using calcium hypochlorite dosage based on stoichiometry reaction between chlor and cyanide (mole ratio chlor : cyanide = 1:1) which carried out at pH operation 8for 60 minutes has observed for cyanide content and Tri Halo Methane identification. Other variation of calcium hypochlorite dosage applied until meet the standart quality or lower cyanide content of effluent with no Tri Halo Methane detected. pH optimum determined from comparation of quality effluent of chlorination using calcium hypochlorite optimum dosage with variation pH operation 6, 7, 8. The results showed that the optimum condition for chlorination application in tapioca wastewater removal was 5,986 mg/L for calcium hypochlorite dosage (1,75 stoichiometry reaction) and 8 for pH operation. This chlorination condition able to reduce cyanide of 192 mg/L to 0,272 mg/L with no Tri Halo Methane detected in the effluent.

The Influence of Calcium Hypochlorite Dosage Adjustment on Tapioca Wastewater Pre-Chlorination Toward Efficiency of Activated Sludge Treatment

“…This was related to the fact that oxidation is the dominant process in chlorination which occured in rapid reaction (Pickup, 2010). In addition, there is not also a part of the active chlorine taking part in chlorination of tapioca wastewater to create halogenated organic by-products (Mulyani and Prasadja, 2014).…”

“…Greater BOD5/COD ratio value will make wastewater become easier to handle by biological means (Chan, Chong, Chung, & Hassel, 2009). In addition, tapioca wastewater chlorination using calcium hypochlorite dosage until 5,986 mg/L (ratio of Cl 2 :CN -= 1,75 stoichiometry reaction) also has proven result in effluent with no Tri Halo Methane detected (Mulyani and Prasadja, 2014).…”