沸石强化生化装置脱氮功能的效果及机理初探

针对石化工业废水开展沸石强化脱氮处理试验研究,通过比较沸石浓度25 mg/L与空白,以及沸石浓度25 mg/L与50 mg/L 2阶段脱氮效果,探讨了沸石促进脱氮功能的机理.结果表明,曝气池中投加沸石可明显提高氨氮和总氮的去除率,硝化细菌总数和硝化功能也得到增强.与空白对照组相比, 沸石浓度25 mg/L的试验组稳定运行后,氨氮去除率提高约10%～13%,总氮去除率约提高13%,出水中NO^-₃-N含量约提高100%,氨氮与总氮之比下降6%,内源硝化耗氧呼吸速率可提高138%,硝化细菌总数是空白对照组2.2倍.沸石浓度提高到50 mg/L后,试验组的脱氮效果略有增加,但效果不明显.通过对试验结果的关联分析,认为沸石提高系统脱氮能力的原因一方面是因为沸石对NH⁺₄及硝态氮的交换吸附,另一方面NH⁺₄离子富集于沸石表面及内部、沸石颗粒独特的好氧-缺氧微环境,以及沸石离解出CO^2-₃ 或HCO^-₃增加碱度等条件,促进了硝化细菌和反硝化细菌的生长,从而提高了系统脱氮能力.

Experimental Study on the Processes and Mechanism of Enhanced Denitrification by Addition Zeolite in Wastewater Treatment

Aim to control the emission of SO2 during coal combustion, desulfurization characteristic of organic calcium was studied by intelligent sulfur determination analyzer. Sulfur releasing curve changed from two "peak value" to one for addition of organic calcium, with velocity of SO2 release decreasing. Efficiency of sulfur reduction was double when organic calcium was used under 1 000 degrees C compared to limestone, and reduction efficiency of calcium magnesium acetate was 73.84%. Sulfur content, furnace temperature, calcium/sulfur ratio and paticle's diameter were important factors as for desulfurizing rate. Sulfur removal efficiency was improved with coal's sulfur content increasing or particle's diameter decreasing. Decreasing degree of reduction efficiency lowered with sulfur content increasing as temperature improved. Efficiency remained high level as 59.08% by calcium magnesium acetate at 1 200 degrees C. Perfect efficiency could be reached as calcium/sulfur ratio being one and augmentation degree was inapparent with more calcium addition. Therefore organic calciums are excellent absorbent for desulfurization and calcium magnesium acetate has best sulfur removal efficiency.