麦饭石促进异养反硝化去除水中硝酸盐的研究

微生物异养反硝化技术是市政污水处理中广泛应用的技术,但在实际应用中,微生物活性易受冲击负荷、重金属胁迫等环境条件影响,使出水效果不稳定。麦饭石作为一种天然硅酸盐矿物,能有效提高微生物活性及对环境胁迫的抗性,可以将其应用于微生物污染治理领域。通过批实验研究麦饭石的剂量、处理方式对异养反硝化的促进作用并探究麦饭石作用于微生物的机理。结果表明,麦饭石的投加剂量和处理方式均显著影响了微生物对硝酸盐的去除效果。硝酸盐去除率与麦饭石投加量呈正相关,麦饭石投加量为350 g/L时硝酸盐去除率可达96%,未添加麦饭石的空白组硝酸盐去除率仅为25%;处理方式会影响麦饭石对反硝化过程的强化作用,研磨后过200目筛的麦饭石在投加量<150 g/L时具有优势,投加量继续增大后,未经处理的麦饭石表现出更强的反硝化促进作用。进一步采用未经处理的麦饭石、研磨后过200目筛麦饭石及球磨麦饭石浸出液进行反硝化的促进实验及微生物毒性实验探究麦饭石作用于微生物的机理。实验结果表明,麦饭石浸出液能够提高微生物的活性及对环境胁迫的抗性,影响麦饭石生物促进作用的主要因素为其溶出微量元素的成分及浓度。本研究为天然矿物麦饭石应用于微生物污染治理提供理论依据和实际应用价值。

Study on Chinese Maifanite in Promotion of Heterotrophic Denitrification in Water

Microbial heterotrophic denitrification technology is widely used in municipal wastewater treatment. However, in practice, microbial activity is readily affected by environmental conditions (e.g., shock load and heavy metal stress), making the effluent unstable. Chinese maifanite, a natural silicate mineral, can effectively improve microbial activity and is resistate to environmental stress. Therefore, it can be used in microbial pollution control. Through batch experiments, the dosage and the effect of treatment methods of natural silicate mineral (Chinese maifanite) on heterotrophic denitrification were studied, and the mechanism of Chinese maifanite on microorganisms was explored. The results show that the dosage and treatment method would significantly affect the nitrate removal by microorganisms. The nitrate removal rate correlates positively with the Chinese maifanite dosage. When the dosage of Chinese maifanite is 350 g/L, the nitrate removal rate can reach 96%, while that of the control group is only 25%. The treatment method would affect the increasing effect of Chinese maifanite on denitrification. The ground Chinese maifanite has an advantage when the dosage is below 150 g/L. With increasing dosage, the untreated Chinese maifanite facilitates denitrification better. The untreated/ground/ball-milled Chinese maifanite extract was furtherly used in the denitrification promotion and microbial toxicity experiments. The experimental results show that the Chinese maifanite extract can improve the microorganism activity and environmental stress resistance. The main biological promotion factor of Chinese maifanite is the composition and concentration of the dissolved trace elements. Our results provide theoretical basis and practical application value for the microbial treatment stimulated by natural Chinese maifanite.