富硫废水中稳定生物单质硫效果与机制研究

Mechanism and effect insight on stabilizing biological S0 in sulfur-rich wastewater

为提高含硫废水同步脱氮除硫工艺中生物单质硫回收率,开展了富硫废水中稳定生物单质硫效果与机制研究。在富硫废水(S^(2-)质量浓度300 mg/L)和贫硫废水(S^(2-)质量浓度200、100 mg/L)中添加阻断剂硫代硫酸钠进行脱氮除硫实验。结果表明,富硫废水中稳定组(加30 mg/L阻断剂)在60 h时单质硫积累量达到68.79 mg/L,比未稳定组(不添加阻断剂)高25.34 mg/L,单质硫稳定率达58.31%,单质硫回收率为36.84%;而贫硫废水(S^(2-)质量浓度为200、100 mg/L)中单质硫不稳定,单质硫稳定率仅11.2%、14.14%,且回收率低(15.71%、12.39%)。可见,阻断剂在富硫废水中实现了稳定生物单质硫。此外,阻断剂有利于反硝化菌和脱氮硫杆菌增殖积累,富硫废水下高比例的脱氮硫杆菌可促进单质硫稳定。阻断剂抑制了硫代硫酸盐和硫酸盐的生成,使硝酸盐得到更多电子(稳定组比未稳定组多得19.76 mmol/L电子),促进了单质硫的生成,实现了生物单质硫稳定。该技术可为废水中生物单质硫的回收与利用提供理论基础。

To improve the recovery rate of biological elemental sulfur(S0)in the simultaneous denitrification and sul⁃fur removal process in sulfur wastewater,the effect and mechanism of stabilizing biological S0 in sulfur-rich wastewa⁃ter were studied.The experiments were conducted using blockers to stable biological S0 in sulfur-rich wastewater(300 mg/L S^(2-))and sulfur-poor wastewater(200,100 mg/L S^(2-)).It was found that in sulfur-rich wastewater,68.79 mg/L of S0 was accumulated in the stable group(adding 30 mg/L blocker)at 60 h,which was 25.34 mg/L higher than that in the unstable group(adding 0 mg/L blocker),the S0 stability rate reached 58.31%and the S0 recovery rate was 36.84%.However,the S0 in sulfur-poor wastewater(200,100 mg/L S^(2-))was unstable,the S0 stability rate was only 11.2%,14.14%,and the S0 recovery rate was low(15.71%,12.39%).It could be seen that the blockers stabilized the biological S0 in sulfur-rich wastewater.Additionally,the blockers were conducive to the accumulation of denitrifying bacteria and Thiobacillus denitrificans,and the high proportion of Thiobacillus denitrificans was conducive to stable S0 in sulfur-rich wastewater.The blockers inhibited the formation of thiosulfate and sulfate and made nitrate get more electrons(19.76 mmol/L more electrons in stable group than in unstable group),promoting the generation and stabil⁃ity of biological S0.This technology could provide a theoretical basis for the recovery and utilization of biological S0 in wastewater.