Abstract:
The research aimed to study the efficiency of sequencing batch reactor (SBR) system for treatment of electroplating wastewater containing cyanide compounds (EPWW). The studies concerned on four items. First experiment was concerned on the effect of the glucose on the efficiency of SBR system. The glucose was added into the EPWW to adjust the BOD5 concentration of the wastewater as 100, 200, 267, 400, 600 and 800 mg/l (BOD5 : total nitrogen ratio of the wastewater were 100:40, 100:20, 100:15, 100:10, 100:6.7 and 100:5). Second, the effect of dilution rate of the EPWW (10, 5 and 2.5 times) on the efficiency of SBR was carried out. Third, the effects of glucose addition on the treatment of 10 times diluted EPWW was treated for selection of the suitable BOD5:TN ratio of the wastewater. Fourth, the application of Thai rice noodle (ka-nom-chin) wastewater in EPWW for increasing the efficiency of the SBR system for treatment of EPWW.
The results showed that the addition of glucose into the EPWW could increase the efficiency of SBR system. The SBR system showed the highest COD, BOD5, TKN and cyanide removal efficiencies of 54.0?6.9, 71.0?6.5, 66.2?6.0 and 36.5?6.0 %, respectively were showed when the 400 mg/l of glucose was added into the EPWW (BOD5:TN of 100:10).
The dilution times of EPWW was also effected to the efficiency of the SBR system. The efficiency of the SBR system was increased with the increased of dilution rate of EPWW. The SBR system showed the highest COD, BOD5 ,TKN and cyanide removal efficiencies of 81.0?0.7, 72.0?3.0, 68.2?2.1 and 97.5?0.1 %, respectively when the EPWW was dilution for 10 time and supplemented with 400 mg/l glucose (BOD5 : TN of 100: 10) and HRT of 10 days.
The efficiency of the SBR system with EPWW was also increased with the supplemented of glucose. The experiment was carried out with 10 times dilution EPWW that was added with 400 mg/l glucose (BOD5 : TN of 100 : 10) showed the highest. The COD, BOD5, TKN and cyanide removal efficiencies of the SBR system with 10 times dilution EPWW containing 400 mg/l glucose (BOD5 : TN of 100 : 10) were highest of 80.3?1.0, 75.6?2.7, 45.3?3.0 and 98.4?0.5 % , respectively with HRT of 10 days. And also the effluent quality, it was found that Ammonia-nitrogen of the effluent was decreased while Nitrate-nitrogen and Nitrite-nitrogen was increased.
Effect of Thai rice noodle wastewater on the efficiency of the SBR system with EPWW, the supplemented were carried out on the effect of percentage of Ka-nom-chin factory wastewater adding until BOD5 400 mg/l . The results showed that the SBR gave the highest COD, BOD5, TKN and cyanide removal efficiencies of 78.5?2.2, 84.8?3.0, 49.0?2.1 and 97.7?0.7 %, respectively when the 400 mg/l of Thai rice noodle wastewater (BOD5 : TN of 100 : 10) was adding. And also the effluent quality, it was found that the ammonia-nitrogen of the effluent was decreased while nitrate-nitrogen and nitrite-nitrogen was increased.