ABR反应器中COD/SO_4^(2-)值和硫酸盐负荷对SO_4^(2-)去除影响

Effects of COD/SO_4^(2-) Ratio and Sulfate Loading Rate on Sulfate Removal in Anaerobic Baffle Reactor

利用厌氧折流板反应器,分别考察了反应器启动,及不同COD/SO42-比值和硫酸盐负荷对模拟废水中SO42-去除的影响。实验在(32±0.1)℃,pH为6.0~6.5的条件下连续运行。结果表明:ABR经过约90 d的启动驯化阶段后,进水硫酸盐及COD浓度分别为1 500 mg/L和3 000 mg/L,水力停留时间为12 h条件下,硫酸盐去除率达到了92%。固定COD/SO42-比值为2.5时,随着进水SO42-浓度的增加(1 500~3 500 mg/L),SO42-去除率逐渐下降,最低为60%,相反SO42-去除速率随着硫酸盐浓度的增加而增加,最大为7.98 kg(/m3.d);维持恒定的硫酸盐浓度(1 500 mg/L),逐渐缩短水力停留时间以提高反应器中硫酸盐负荷,SO42-去除率呈现先上升后下降的复杂变化趋势,当水力停留时间为6 h时,SO42-去除率达到最大;随着COD/SO42-比值的提高,硫酸盐去除能力增强,且反应体系对硫酸盐负荷的耐受能力也逐渐增强。

Start-up period and effects of different COD/SO42-ratios and sulfate loading rates on sulfate removal of simulated wastewater containing high sulfate concentration were assessed at（32±0.1）℃ and pH 6.0~6.5 in a laboratory scale anaerobic baffled reactor（ABR）.Results showed that the final sulfate removal efficiency rose to 92% with influent SO42-1 500 mg/L and COD 3 000 mg/L,HRT 12h,through the procedure of about 90 d stat-up.With fixed COD/SO42-ratio as 2.5,sulfate removal efficiencies all above 60% reduced with an increase in the influent sulfate concentration ranging from 1 500 mg/L to 3 500 mg/L,yet removal rate of sulfate increased to the maximum 7.98 kg（/ m3.d）.With fixed influent sulfate concentration 1 500 mg/L,hydraulic retention time（HRT） had a complex effect on sulfate removal,and sulfate removal efficiencies peaked when HRT was 6h,regardless of COD/SO42-ratios.With an up-regulation of COD/SO42-ratio ranging from 2 to 5,removal efficiencies of sulfate ascended and the system presented stronger tolerance to the sulfate loading rate.