Abstract:
This research investigated the possibility of enhancing the color removal efficiency in distillery slop using polyaluminium chloride with burned husk, silica alumina and fly ash as a core coagulant in the coagulation process. The experiment was carried out by using the Jar Test. The samples were mixed by rapid mixing at 100 rpm for 1 minute followed by slow mixing at 20 rpm for 20 minutes. They were then left to sedimentate for 1 hour. There are 2 type of the distillery slop in this research. The first one was distillery slop treated by an oxidation pond at a retention time of 392 days. The characteristics of wastewater which was diluted with water 5 times were as follows: pH, 8.1-8.3; suspended solids, 200-500 mg/l; COD, 4,600-4,900 mg/1; and color intensity, 900-1,000 SU. The other type of distillery slop was not treated by a biological treatment. The characteristics of wastewater which was diluted with water 5 times were as follows: suspended solids, 200-500 mg/1; COD, 4,600-4,900 mg/1; color intensity, 900-1,000 SU, adjusted pH about, 8.1-8.3 by sodium hydroxide. The experimental results of the distillery slop treated by a biological treatment indicated that by using polyaluminium chloride at 8 g/1, the color removal efficiency was at 94.64% with a sedimentation of 85%. and COD removal efficiency of 82.78%. By comparison, using polyaluminium chloride (8 g/l) with fly ash at 30 g/1 (at sieve number 200 mesh) as a core coagulant, the results indicated that the color removal efficiency was at 92.16% with a sedimentation of 44%, COD removal efficiency of 81.35%. The estimated cost was 86.6 bath/m3 of distillery slop. The result of distillery slop which was not treated by a biological treatment indicated that by using polyaluminium chloride at 10 g/1, the color removal efficiency was at 65.89% with a sedimentation of 42% and COD removal efficiency of 29.90%. By comparison, using polyaluminium chloride (10 g/1) with fly ash at 10 g/1 (at sieve number 200 mesh) as a core coagulant, the results indicated that the color removal efficiency was at 60.66% with a sedimentation of 22%, COD removal efficiency of 25.89%. The estimated cost was 165.2 bath/m3 of distillery slop.