Abstract:
Treatment of chlorine contaminated wastewater by granular activated carbon-sequencing batch reactor(GAC - SBR) system was carried out in this study. The experiments were conducted by using synthetic wastewater contained BOD as the concentration of 2,000 mg/l. The experiments were devided into 3 parts as determinations of cool storage plant wastewater properties, adsorption capacity of activated carbon and efficiency of GAC - SBR system at various conditions of hydraulic retention time (HRT) as 1, 2, 3, 5 and 10 days. For the determination of efficiency of GAC - SBR system, the synthetic wastewater contained chlorine at the concentration 0,5, 10 and 20 mg/land the concentration of granular activated carbon(GAC) in the SBR system as 1,000 mdl were used.The results show that the cool storage wastewater contained organic matter (BOD) and clllorine at the concentration of 468-3763 mg/l and 0.2-5 mg/l , respectively. The COD adsorption capacity of GAC in cool storage factory wastewater was 209.12 mg/gGAC .But, The COD adsorption capacity of GAC in synthetic wastewater was quite low. The chlorine adsorption capacity of GAC was depended on the concentration of clllorine in the wastewater. The clllorine adsorption capacity of GAC in synthetic wastewater at chlorineconcentration 50, 100, 150, 200 mg/l were 346.657, 6 19.44, 946.45 and 1 189.87 mg/gGAC, respectively. The results of COD adsorption capacity of GAC in aeration and without aeration condilions slwwcd that tbc COD adsorption eflicicncy uscd acration was 20% llighcr thanwithout aeration. In the GAC - SBR system, the removal efficiency were increased when the hydraulic retention time (HRT) of the system was increased in both non-chlorine and chlorine contan~inated wastewater. However, the efiiciency of the system for the non-chlorinecontained wastewater was higher than in chlorine contained wastewater.At HRT of 10 days, the COD were reduced from 2,000 mg/l to 24.52, 26.80,28.49 and 32.37 mgA or the removal efficiencied were 98.75, 98.66, 98.48 and 98.3 1% when the wastewater contained chlorine atthe concentrations of 0, 5, 10 and 20 mg/l, respectively. At HRT of 5 days, the COD were reduced from 2,000 mg/l to 23.52, 26.04, 28.99 and 36.10 mg/l or the removal efficiencied were 98.81, 98.64, 98.49 and 98.19 % when the wastewater contained chlorine at the concentration of 0,5, 10 and 20 mg/l, respectively. At HRT of 3 days, the COD were reduced from 2,000 mg/l to 27.27,32.54,36.20 and 45.94 mg/l or the removal efficiencied were 98.57, 98.30,98.13 and 97.58 % when the wastewater contained chlorine at the concentration of 0, 5, 10 and 20 mg/l, respectively. AT HRT 2 days, the COD were reduced from 2,000 mg/l to 34.80, 69.62, 81.23 and 163.12 mg/l or the removal efficiencied were 98.26, 96.53, 95.95 and 91.87 % when the wastewater contained chlorine at the concentration of 0, 5, 10 and 20 mdl, respectively. At HRT 1 day, the COD were reduced from 2,000 mg/l to 84.62, 163.24, 266.32 and 1522.62 11lg/1 or the removal efficiencied were 96.08, 92.43, 87.65 and 29.38 % when the wastewater contained chlorine at the concentration of 0, 5, 10 and 20 mdl, respectively. For the chlorine concentration in the effluent, we could not detected the chlorine in the effluent in all case of experiments. In mean that the chlorine could be renloval by above operating condition.