Removal of Chromium Industrial Wastewater by Bagasse Resin (การลดปริมาณโลหะหนักในน้ำเสียโรงงานชุบโครเมียมด้วยเรซินชานอ้อย)

Abstract

Effectiveness of using bagasse resin to reduce the amount of chromium contaminated in industrial wastewater at 10.40 mg/ I from chromium coating industries was investigated. A particular objective was 10 optimise the amount of bagasse resin, pH level and treatment time suitable for a chromium removal process. An experiment was divided into 4 steps, bagasse was first chemically treated by mean s of the carboxymethy lation reaction to get a weak acidic cationic bagasse resin. Various amount s of bagasse resin i.e. 5, 6, 7, 8 and 9 g/ I, al pH 9 and treatment time of  12 hours were 1ested to obtain an optimum dose of bagasse resin. By using the optimum dose of bagasse resin, various pH levels i.e. 7, 8, 9 and 10 and various treatment time i .e. 6, 12, 18 and 24 hours were then examined to find the most effective condition for the chromium removal process. Finally, the leachate extraction procedure according to the announcement of the ministry of industry No. 6 (1997) was employed to find the amount of chromium absorbed by bagasse resin after the chromium removal treatment. The results from this study showed that the optimium dose of bagasse resin was 8 g/I at pH 9 and treatment time of 12 hours. The efficiency of chromium removal process at this condition was at 56.95%. It was also found that the level of pH significantly influenced the amount of chromium absorbed by bagasse resin at 95% confidence limit (p < 0.05). The amount of chromium absorbed by bagasse resin, on other hand, was not affected by the treatment time which were longer than 12 hours. The optimium condition for the chromium removal process was at pH 7 and at treatment time of 12 hours which was capable of reducing the amount of chromium in wastewater at the efficiency of 45.71%. By using the optimum condition, the amount of absorbed chromium within the bagasse resin after the treatment was 3.046 mg / I which was more than the maxim um limit of chromium (5.0 mg/I ) allowed by the ministry of industry. As a result, the bagasse resin no can be directly destroyed or land-filled after the chromium removal process any further treatments.