【作者】 李巍；

【导师】 赵庆良；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2008， 博士

【摘要】 随着工农业的发展,大量高浓度氨氮和硫酸盐有机污染废水排入自然水体导致全球水污染日益严重,废水除氮和脱硫问题逐渐成为污水处理领域研究的热点。研究出一套高效的生物脱氮除硫技术,改善现有的水环境,具有较高的理论价值和现实意义。本文将好氧硝化/厌氧硫酸盐还原-厌氧脱硫反硝化联合工艺应用于同步生物脱氮除硫:分别启动三种不同形式的反应器并对三个单元的运行影响因素、处理效能及反应机理进行了探讨;采用适合的操作参数优化运行各反应器;将独立稳定运行的三种反应器联合起来协调处理硫酸盐有机废水和氨氮废水,实现了氮、硫和碳的高效去除。以高负荷富集方式成功启动容积为2.26L的好氧硝化反应器,溶解氧为0.7mg/L、pH值为8~9、温度为35oC、进水氨氮不大于600mg/L利于反应器内亚硝化效果的稳定,为了保证整体处理工艺的协调运行,调整并优化好氧硝化反应器,氨氮去除率和亚硝酸盐生成率分别达98.8%和64.2%。用低负荷富集培养的方法成功启动容积为5.01L的厌氧硫酸盐还原生物膜反应器,进水pH值不小于7.5、水力停留时间为6.2~10.2h、进水硫酸盐为1500~1800mg/L、进水有机碳与硫酸盐之比大于0.45利于硫酸盐和有机碳的高效去除及出水高浓度硫化物的保持。优化运行厌氧硫酸盐还原反应器,硫酸盐和有机碳去除率分别达90.6%和87%,硫化物生成率可达91.5%。硫酸盐还原菌与产甲烷菌争夺共同的底物有机碳时,由于硫酸盐还原菌对有机碳有较高亲和力而在竞争中取胜。硫酸盐还原菌降解硫酸盐速率不符合Monod双曲饱和型曲线,而符合Hill变构模型的S型曲线。以低负荷富集培养方式成功启动容积为3.52L的厌氧脱硫反硝化生物膜反应器,进水亚硝酸盐为20~80mgN/L、有机碳小于100mg/L、葡萄糖为碳源、硫化物为200~300mg/L、无机碳为100~150mg/L、水力停留时间为9.5~2.67h利于硫化物向单质硫的转化以及各种污染物质的高效去除。进水中有硫酸盐和氨氮会降低硫化物和硝酸盐的去除率。亚硝酸盐对电子供体的竞争力大于硝酸盐。根据调整后预处理反应器出水中各物质的比例,调整脱硫反硝化反应器的运行,硫化物、有机碳、亚硝酸盐及硝酸盐的去除率分别达到95.9%、81.9%、99.9%和99.9%。在兼养脱硫反硝化反应器中,硫化物和有机碳均以硝酸盐和亚硝酸盐作为电子供体,最终转化为单质硫、二氧化碳和氮气。单质硫转化为硫酸盐的速率低于硫化物转化为单质硫的速率,因此单质硫在反应器内累积。有机碳和硫化物共同将高浓度的亚硝酸盐还原为氮气,降低了硫化物和亚硝酸盐对微生物的抑制,使反应容易进行。反应器底部填料附着微生物量和种类多于顶部,填料外层微生物量和种类多于内层,底部外层丝状菌、球菌和短杆菌为优势菌种,底部内层杆菌为优势菌种,顶部外层以球菌为优势菌种,顶部内层以长杆菌为优势菌种。反应器内不同部位填料上附着大量不同种类的微生物是脱硫反硝化反应器能够处理成分复杂的废水并取得较高污染物去除率的主要原因。将好氧硝化反应器、厌氧硫酸盐还原反应器和厌氧脱硫反硝化反应器按照工艺流程连接,氨氮、硫酸盐及有机碳去除率分别为99.8%、91.5%和97.5%。对进出反应系统的氮、硫和碳元素进行物料平衡计算,检测原因和微生物同化作用造成的氮、硫和碳元素误差分别为3.3%、5.4%和3.8%。更多还原

【Abstract】 With the development of industry and agriculture, a great deal of wastewater containing either ammonium-nitrogen or sulfate and organic carbon has been discharged into nature waterbodies. The water pollution around the world is becoming serious. The removal of ammonium-nitrogen and sulfate has been one of the research hotspots in wastewater treatment. The development of the high-efficiency process for the simultaneous removal of ammonium-nitrogen and sulfate may lead to the amendment of the nature water environment, which has high theoretical value and realistic significance.The aerobic nitrification/anaerobic sulfate reduction-anaerobic desulfurization-denitrification process was introduced to the simultaneous removal of ammonium-nitrogen and sulfate in this research. Three different types of bioreactors were started up separately. Meantime, the impact factors, treatment efficiencies and reaction mechanisms to these three operating phases were discussed. And the operation of each bioreactor was optimized by adopting advantageous impact factors. Three independent bioreactors were finally connected to treat the wastewater containing either ammonium-nitrogen or sulfate and organic carbon, which actrualized the high removal of nitrogenous, sulfurous and carbonous compounds.The aerobic nitrification bioreactor of 2.26L was started up successfully by means of high-load enrichement. The dissolved oxgygen of 0.7mg/L, pH value of 8~9, temperature of 35oC, influent ammonium-nitrogen of no more than 600mg/L were beneficial to the stability of nitrification via nitrite. In order to maintain the harmonious performing of the whole process, the operation parameters were adjusted to optimize the aerobic nitrification bioreactor, while the removal efficiencies of ammonium-nitrogen and the generating efficiency of nitrite reached 98.8% and 64.2%, respectively.The anaerobic sulfate reduction biofilm reactor of 5.01L was started up successfully by means of low-load enrichment. The influent pH value of no less than 7.5, hydraulic retention time of 6.2~10.2h, sulfate of 1500~1800mg/L, mass ratio of influent organic carbon to sulfate of no less than 0.45 were advantageous to the high removals of sulfate and organic carbon with high generation of sulfide. The optimal operation of the anaerobic sulfate reduction biofilm reactor led to the sulfate and organic carbon removal efficiencies of 90.6% and 87% with the sulfide generating efficiency of 91.5%. Sufate Reducing Bacteria won in the competition for organic carbon with Methane Producing Bacteria, as it had higher affinity to organic carbon. The degradation velocity of sulfate by Sufate Reducing Bacteria was inconsistent with Monod hyperbolic saturation curve but consistent with Hill allosteric model of S-curve.The microorganisms for desulfurization-denitrification were successfully enriched in the anaerobic desulfurization-denitrification bioreactor of 3.52L at mixotrophic conditions. The influent nitrite of 20~80mgN/L, organic carbon of no more than 100mg/L, glucose as organic carbon source, sulfide of 200~300mg/L, inorganic carbon of 100~150mg/L and hydraulic retention time of 9.5~2.67h were advantageous to the oxidation of sulfide to element sulfur and high removals of contaminants. The sulfate and ammonium in the influent could decrease the removals of sulfide and nitrate. The competive power of nitrite to electron donors was higher than nitrate. The mixotrophic desulfurization-denitrification bioreactor was adjusted by the proportion of each substrate in the effluents from pretreatment bioreactors. The removal efficiencies of sulfide, organic carbon, nitrite and nitrate could reach 95.9%, 81.9%, 99.9% and 99.9%, respectively.The sulfide and organic carbon could be oxidized respectively to element sulfur and carbon dioxide, when their electrons were transfered to nitrate and nitrite. Meanwhile, the nitrate could be reduced to nitrite and the nitrite could be reduced to nitrogen gas. The rate of element sulfur convertion to sulfate was lower than the rate of sulfide conversion to element sulfur. Therefore, the element sulfur would be accumulated in the bioreactor. The degradation of sulfide and nitrite to element sulfur and nitrogen gas decreased the inhibition on the microorganisms, which made it easy for the microorganisms to carry out the mixotrophic desulfurization-denitrification. The quantities and species of the microorganisms attached on the media at lower layer were more than the upper layer. And the quantities and species of the microorganisms attached on the media at outer layer were more than the inner layer. On the outer layer of the media at the lower layer, the filamentous bacteria, coccus and brevibacterium predominated. On the inner layer of the media at lower layer, the bacillus was the dominant bacteria. The coccus predominated on the outer layer of the media at upper layer, while the the long bacilli was the dominant bacteria on the inner layer of the media at upper layer. The more species and higher quantities of the microorganisms attached on the media were advantageous for the denitrification-desulfurization process to treat wastewater with complicated characteristics and obtain high removals of contaminants.According to the aerobic nitrification/anaerobic sulfate reduction -anaerobic desulfurization-denitrification process, each single bioreactor was connected. The removal efficiencies of ammonium-nitrogen, sulfate and organic carbon were around 99.8%, 91.5% and 97.5%, respectively. The mass balance calculation of nitrogen, sulfur and carbon in the process was carried out. The measurement occation error and microorganisms anabolism led to the nitrogen, sulfur and carbon disappearance of 3.3%, 5.4% and 3.8%, respectively.更多还原