【作者】 王越；

【导师】 季民；

【作者基本信息】 天津大学 ， 市政工程， 2016， 硕士

【摘要】 许多城市污水处理厂接纳较大比例的工业废水,非正常情况下,工业废水中的高浓度重金属会对生物硝化过程产生抑制作用,造成出水氨氮等浓度超标,给环境带来威胁,同时给企业造成经济损失。因此开发硝化菌受抑制后快速恢复的促进剂显得十分必要。本论文选用工业废水中常见的重金属离子Cu²⁺和Cd²⁺为抑制剂,以微生物必需的生长因子为基础开发了生物促进剂,利用间歇式活性污泥法,平行运行多组SBR反应器,通过监测分析出水NH₄⁺-N、NO₂^--N、NO₃^--N浓度,微生物活性及重金属的分布等,研究了Cu²⁺和Cd²⁺对硝化活性的抑制作用,及生物促进剂对硝化菌受抑制后恢复的促进作用,并优化了生物促进剂的配方、投加剂量及投加方式。研究表明,进水中含Cu²⁺为50.00 mg/L时,在4天内可抑制80.00%的硝化活性。进水中含Cd²⁺为25.00 mg/L时,在3天内可抑制85.00%的硝化活性。通过试验,开发出了以L-天冬氨酸、生物素和细胞分裂素为主要成分的硝化菌生长促进剂。将所开发的生物促进剂投加在受铜及受镉抑制的反应体系中,发现其对硝化作用恢复具有显著的促进作用,氨氮降解率可在8到10天内完全恢复。通过机理分析得出,生物促进剂中的N-H和-COOH对重金属有捕集作用,并可修复Cu造成的细胞质膜的破坏,而生物促进剂的特殊结构可缓解Cd的毒性从而利于硝化菌受Cd²⁺抑制后的快速恢复。生物促进剂的投加剂量越大,越有利于硝化菌受抑制后的活性恢复,在试验范围内,生物促进剂投加量为0.048-0.48μg/gMLSS时,硝化菌受抑制后的恢复最快。每周期均匀投加一定剂量的生物促进剂最有利于硝化菌的活性恢复。试验开发的硝化生物促进剂具有硝化恢复效率高,配方简易,操作便捷,成本低廉的特点,市场应用前景广阔。更多还原

【Abstract】 Many municipal Wastewater Treatment Plants（WWTPs）contain industrial wastewater.High concentrations of heavy metals in industrial wastewater will pose inhibitory effects on biological nitrification process,which results in effluent ammonia concentrations exceeding the set standard.The unreasonable effluent will cause economic losses and bring threat to our environment.Therefore,it is of great urgent to develop and optimize bio-accelerators under inhibited-situations.In this study,Cu²⁺ and Cd²⁺ were chosen as inhibitors,bio-accelerators were developed and dosed in parallel SBRs.The effluent NH₄⁺-N,NO₂^--N,and NO₃^--N concentrations,microbial bioactivity,and distribution of heavy metals were investigated,in order to assess variation of bioactivity during inhibitory and recovery periods.Furthermore,the mixture,dosage,and dosing mode of bio-accelerators were optimized.Results showed that,50.00 mg/L Cu²⁺ could inhibit 80.00% nitrification effiency within 4 days,and 25.00 mg/L Cd²⁺ could inhibit 85.00% nitrification effiency within 3 days.Dosing bio-accelerators in recovery period was better than natural recovery process.Dosing biotin,L-aspartic acid,and cytokinin simultaneously was the optimum mixture.Under 50.00 mg/L Cu²⁺and 25.00 mg/L Cd²⁺ inhibition situations,nitrification could recover completely within 8 days and 10 days respectively with dosing those three substances.Amide（NH）and carboxyl（COOH）groups in bio-accelerators could attract heavy metals,and repair membrane loss caused by Cu.Besides,the unique structure in bio-accelerators could help mediate Cd toxicity.In terms of dosage and dosing mode,more bio-accelerators meant higher nitrification recovery efficiency,and 0.048-0.48 μg/gMLSS exhibited the best recovery efficiency.Dosing bio-accelerators evenly at each cycle was the most effective.High efficiency,simple formula,easy operation,and low cost will make the bio-accelerators promising in practical application.更多还原