【作者】 刘博；

【导师】 刘正乾； 陆谢娟；

【作者基本信息】 华中科技大学 ， 建筑与土木工程， 2020， 硕士

【摘要】 目前乡镇污水处理常用生物/生态处理工艺,如人工湿地、人工快速渗滤和生态滤床等技术,但是这些工艺普遍存在后端碳源不足问题,影响系统反硝化脱氮效果。本研究在传统生态滤床基础上引入了硫自养反硝化体系,实现硫自养反硝化脱氮,克服传统生态滤床碳源不足问题,提高反硝化效率。本研究通过柱试验对比研究了硫磺/硫铁矿、硫磺/海绵铁、硫磺/硫铁矿/有机碳源和硫磺/海绵铁/有机碳源等不同填料组合条件下的生态滤床的脱氮除磷效果,结果表明硫自养复合生态滤床脱氮效果明显优于普通生态滤床。在总氮（Total Nitrogen）和总磷（Total Phosphorus）平均进水浓度分别为16.93mg/L和1.2mg/L情况下,硫磺/硫铁矿/有机碳源的组合脱氮除磷效果最佳且出水中SO₄^2-含量最低;其中TN去除率为87.52%,TP去除率接近100%,出水中SO₄^2-含量仅为57.3mg/L。通过研究不同曝气量、水力负荷、进水浓度以及间歇曝气对不同填料组合生态滤床脱氮除磷效果的影响,表明曝气量为0.04L/min时,水力负荷为0.6m/d或0.75m/d条件下的生态滤床出水水质均可以的稳定达到《城镇污水厂污染物排放标准》（GB18918-2002）的一级A标准,且水力负荷为0.6m/d效果最佳,硫磺/硫铁矿/有机碳源组合填料生态滤床对氨氮去除率达到99%以上。TN去除率达到91%以上;间歇曝气的最佳曝停比为1:2,脱氮效果略低于连续曝气,出水稳定满足一级A排放标准,间歇曝气的运行方式可以显著降低能耗。通过使用16s r RNA测序技术,检测分析了硫磺/硫铁矿、硫磺/硫铁矿/有机碳源和普通生态滤床三组装置的好氧区与缺氧区的微生物多样性,6个样品的稀释性曲线、Rank-abundance曲线以及Shannon、Ace、Simpson等指数表明各个区域物种的丰富度以及相似性均有所差异。在属级别上,缺氧区添加了硫磺/硫铁矿的装置中硫氧化菌属占有很大的比例,如Tiomonas相对丰度为46.77%、Sulfuriferula相对丰度为10.46%,而添加了硫磺/硫铁矿/有机固态碳源的装置中硫氧化菌占比降低,且存在异养反硝化菌和硫酸盐还原菌（Sulfate Reducing Bacteria）,异养反硝化同时会生成碱度,使硫自养消耗的碱度得到补充,出水p H（6.5）值高于硫磺/硫铁矿组合（6.1）;在挂膜完成后的运行阶段硫磺/硫铁矿/固态碳源组合出水中SO₄^2-浓度仅为57.3mg/L,硫磺/硫铁矿组合出水SO₄^2-浓度为100.5mg/L;说明SRB可以还原SO₄^2-,降低出水中SO₄^2-浓度,结合有机固态碳源的硫自养/异养反硝化可以克服硫自养反硝化出水硫酸根偏高的缺陷。更多还原

【Abstract】 At present,Biological/Ecological treatment processes,such as Artificial wetland,Artificial rapid infiltration and Ecological filter bed,are commonly used in township sewage treatment.However,these processes generally have insufficient carbon source at the back end,which affects the denitrification efficiency of the system.In this study,sulfur autotrophic denitrification system was introduced into the traditional ecological filter bed to achieve more effective denitrification,which can overcome the shortage of carbon source in traditional ecological filter bed,and improve the denitrification efficiency.In this study,Ecological filter beds with different filler combinations,such as sulfur/pyrite,sulfur/sponge iron,sulfur/pyrite/organic carbon source and sulfur/sponge iron/organic carbon source,were conducted to investigate their effect on the removals of nitrogen and phosphorus.The results showed that the nitrogen removal efficiency of the sulfur autotrophic composite ecological filter bed was significantly higher than that of the common ecological filter bed.When the average influent concentrations of total nitrogen and total phosphorus were 16.93mg/L and 1.2mg/L,respectively,the combination of sulfur/pyrite/organic carbon source had the best nitrogen and phosphorus removal efficiency,and the SO₄^2-concentration in the effluent was the lowest.Total Nitrogen（TN）removal rate was 87.52%,Total Phosphorus（TP）removal rate was nearly 100%,and the SO₄^2-concentration in the effluent was only 57.3 mg/L.The effects of operation parameters,concering aeration rate,Hydraulic load,influent concentration and intermittent aeration,on the removal efficiencies of nitrogen and phosphorus were studied using Ecological filter bed with different filler combinations.The results showed that when the aeration rate was 0.04L/min,the effluent quality of Ecological filter bed with Hydraulic load of both 0.6m/d and 0.75m/d can stably meet the class A standard of"Discharge standard for pollutants from Municipal wastewater treatment plant"（GB18918-2002）,and the better treatment efficiency could be achieved with a Hydraulic load of 0.6m/d.The results showed that the removal efficiency of ammonia nitrogen was over 99%in the ecological filter bed with sulfur/pyrite/organic carbon.The TN removal efficiency is more than 91%.The optimal run-stop ratio of intermittent aeration is 1:2,the denitrification effect is slightly lower than that of continuous aeration,while the quality of effluent is still can meet the class A standard of"Discharge standard for pollutants from Municipal wastewater treatment plant"（GB18918-2002）stably.Therefore,the operation mode of intermittent aeration will be a better choice due to the much lower energy consumption.The 16s r RNA sequencing technology was used to detect and analyze the microbial diversity in the aerobic and anoxic areas of three groups of devices:sulfur/pyrite,sulfur/pyrite/organic carbon source,and common ecological filter bed.The results of dilution curve,rank independence curve and Shannon、ACE and Simpson indices of six samples showed that the species richness and similarity in each area were difference.In terms of genus level,sulfur oxidizing bacteria account for a large proportion in the unit with sulfur/pyrite added in the anoxic area,such as the relative abundance of Tiominas was 46.77%and the relative abundance of Sulfuriferula was 10.46%,while sulfur oxidizing bacteria account for a small proportion in the unit with the addition of sulfur/pyrite/organic solid carbon source,and Heterotrophic denitrifying bacteria and Sulfate reducing bacteria（SRB）exist.Heterotrophic denitrification will also generate alkalinity,which will supplement the alkalinity consumed by sulfur autotrophic.In addition,the p H value of effluent（6.5）is higher than that of sulfur/pyrite combination（6.1）,In the operation stage after the completion of biofilm,the concentration of SO₄^2-in the effluent of sulfur/pyrite/solid carbon source is only 57.3mg/l,and that of sulfur/pyrite is 100.5mg/l,which indicates that SRB can reduce SO₄^2-and reduce SO₄^2-concentration in effluent.Sulfur autotrophic/heterotrophic denitrification combined with organic solid carbon source can overcome the defect of high sulfate content in the effluent of sulfur autotrophic denitrification.更多还原