无机废水中好氧颗粒污泥脱氮及钇吸附性能研究

以好氧颗粒污泥（AGS）处理无机高氨氮废水脱氮性能及对钇离子（Y（Ⅲ））吸附效果为研究对象，探索了“好氧+缺氧”模式下自养硝化颗粒污泥（ANGS）的脱氮性能及“好氧+缺氧+好氧”模式下AGS的脱氮性能及短期钇离子冲击下系统稳定性，利用热力学、动力学模型等研究了AGS对Y （Ⅲ）的吸附能力和机理。结果表明，“好氧+缺氧”模式导致混合液悬浮物固体浓度（MLSS）及平均粒径持续减小，通过降低进水氮负荷并补充ANGS使氨氮去除率逐渐增大（3.25%～73.51%）；采用“好氧+缺氧+好氧”运行模式并补充AGS后，氨氮去除率超过72.00%(50～72天)，MLSS及平均粒径增大，总无机氮（TIN）含量基本保持不变。72天后投入碳源，氨氮去除率减小至40%以下、TIN去除率增大至30%左右。第78天起Y（Ⅲ）浓度在0.01～0.82 mg/L之间，去除率基本稳定在88%以上；通过改变曝气方式和外投碳源后，AGS内Nitrosomonas丰度明显下降（47.43%～11.08%），而Thauera、 unclassified＿Chitinophagaceae、 unclassified＿Comam...     

SBR中混合接种不同储存方式的好氧颗粒污泥的恢复

考察了混合接种不同储存时间及储存方式的好氧颗粒污泥(AGS)的恢复效果。储存后的AGS表现出不同的形态特征:常温湿式储存两年的AGS形态松散, 出现了明显的解体现象;常温湿式储存一年的AGS未出现明显的解体现象, 但颜色明显变黑;琼脂包埋干式储存五个月的硝化颗粒污泥颜色、形态及沉降性能变化不大。重新曝气后, 污泥的MLSS(4.85~10.51 g/L)与MLVSS/MLSS(0.6~0.75)、EPS(15.05~38.36 mg/g MLSS)、平均粒径(0.61~1.12 mm)及颗粒化率(80.92%~97.60%)迅速增大, COD及氨氮去除率也分别在19天与15天上升至90%以上。恢复过程中, 颗粒污泥经历了先破裂后重新颗粒化的过程。根据恢复过程中颗粒污泥的理化特性可知, 混合污泥在21天内成功实现了稳定性及效果恢复。研究结果表明混合部分储存后的硝化颗粒污泥有效提高了硝化细菌的富集速度, 为应用时AGS中硝化细菌的快速富集提供了一种新思路。      

Carrousel氧化沟同步硝化反硝化的影响因素研究

[目的]为城市污水处理厂的优化脱氮和节能运行提供参考.[方法]采用有效容积为 240 L 的中试 Carrousel 氧化沟处理模拟生活污水,研究溶解氧、进水 COD 负荷和进水氨氮负荷对 Carrousel 氧化沟同步硝化反硝化的影响.(结果]综合氨氮和总氮的去除率,能够满足同步硝化反硝化的最佳溶解氧浓度为 1.0 mg/L,最佳进水 COD 负荷为 0.25 kg COD/(kgMLSS·d).较小的进水氨氮负荷有利于同步硝化反硝化过程的进行.[结论]溶解氧是控制氧化沟内发生同步硝化反硝化过程的最关键的因素.进水 COD 负荷对同步硝化反硝化过程的影响主要是体现在进水 COD 负荷对实现较好硝化效果的限制.     

稀土矿区低碳氨氮废水短程硝化SBR过程研究

采用SBR工艺处理稀土矿区低碳氨氮废水, 对活性污泥进行驯化培养并考察了曝气量、曝气时间及碳氮比对短程硝化系统的影响。试验结果表明:温度为(28±1) ℃、曝气量为65 L/h, pH值为8的条件下, 经过69 d的驯化培养后, 系统对氨氮的去除率达92%, 亚硝态氮积累率稳定在90%以上, 对短程硝化过程启动前后样品进行高通量测序, 结果表明:污泥中微生物种类减少, 多样性降低, 亚硝化单胞菌属成为优势种群, 占比达11.5%。提高曝气量至120 L/h并在此条件下运行7 d后, 亚硝态氮积累率下降至82%;维持C/N在3.5~7.6之间, 系统中NH₄+-N的去除率均能稳定在95%左右, NO₂--N积累率也均可达93%以上;过度曝气会破坏短程硝化系统, 过度曝气至第8天, 亚硝态氮的积累率降至48.89%。      

新型强化内源反硝化MBR工艺处理高氮、磷污水的研究

研究了采用新型强化内源反硝化MBR组合工艺处理高氮、磷污水。结果表明,新型强化内源反硝化MBR组合工艺的最佳运行条件为:试验装置总池容40L,污泥龄(SRT)30d,水力停留时间(HRT)为16h。最佳条件下,污水CODcr、氨氮、总磷的去除率分别为86.88%、99.22%和82.4%,出水水质满足《城镇污水处理厂污染物排放标准》一级A标准。     

常温下猪场厌氧消化液的亚硝化研究

[目的]探求常温下猪场厌氧消化液亚硝化的最优工艺参数.[方法]在常温(15-30℃)条件下,以模拟低C/N、高氨氯的猪场厌氧消化液为进水,通过反应器启动和运行,研究猪场厌氧消化液亚硝化的最优工艺参数及影响因素.[结果]反应器在常温下作全程硝化启动时,氨氮进水浓度为100 mg/L,COD进水浓度为180 mg/L,之后逐渐增加进水浓度以提高容积负荷,经过25 d的培养成功启动.反应器启动后连续运行70 d,在未控制pH条件下,随着硝化反应产酸的积累,氨氮去除率下降至54.86%,NO<,2>-N下降至0.029 mg/L;在调节pH条件下,氨氮浓度平均去除率为93%,NO<,2>-N平均累积率稳定为90%;pH适宜范围在7.0-8.0,FA适宜范围为3.02-12.1mg/L,曝气量为200 mg/L.[结论]该研究为猪场厌氧消化液亚硝化的后续厌氧氨氧化进一步脱氮奠定了基础.     

短程硝化-反硝化中铁炭填料对污水中氮、磷去除的研究

研究了用短程硝化-反硝化系统生物反应器去除废水中的氮、磷。在短程硝化-反硝化系统生物反应器好氧区投加铁炭填料,调节反应器内好氧区的pH(7.8~8.7)和DO(3~5mg/L),可使亚硝酸盐快速累积,其累积率可达45%以上;同时,该系统对NH_4~+-N、COD、TP去除率在稳定工况下分别可达92%、88%、90.5%。     

前置反硝化曝气生物滤池工艺处理生活污水的挂膜启动研究

在曝气生物滤池(BAF)中生物膜是整个处理过程的核心,生物膜的数量和活性的高低对污水的处理效果起着决定性作用,而滤料的挂膜过程是在滤池中形成良好生物膜的前提,也是生物滤池稳定运行的基础。试验对以球形轻质多孔生物陶粒为载体的前置反硝化曝气生物滤池工艺处理生活污水进行挂膜启动,依据硝化菌、反硝化菌及异氧菌的生理特性,采用两阶段式自然挂膜方法。两级曝气生物滤池系统启动历时25 d,曝气生物滤池C/N反应器对COD和NH3-N的去除率分别达到76%和83%,曝气生物滤池DN反应器对TN的去除率约43%,此时,C/N反应器中滤料上附着大量的钟虫、变形虫、轮虫、线虫及线状细菌等,构成种群丰富、结构完整、功能稳定的生态系统,标志挂膜成功。分析讨论表明:载体表面结构、COD/NH3-N、悬浮物、曝气强度、水力停留时间和温度是挂膜过程的主要影响因素。     

高效藻类塘对小城镇养殖废水净化效能的影响

[目的]探索高效藻类螗中藻类、曝气和底泥对小城镇养殖废水净化效能的影响.[方法]设置4个独立人工池塘作对比试验,通过控制试验塘中的藻类浓度、底泥及曝气程度,测定养殖废水中的还原性物质、氮和磷的变化量,进而比较藻类、底泥和曝气对废水净化效能的影响.[结果]高效藻类塘对还原性物质、氟和磷的去除率分别达到88.3%、69.2%和59.7%,而普通塘对其去除率分别仅有48.0%,43.4%和22.8%.藻类对TP的去除影响最为明显,其次是对COD,对TN的影响最弱;曝气对COD代表的还原性物质的去除率影响最大,其次是对TN的降低,对TP的影响最弱;底泥对TP的去除影响极为显著,其次是对TN,而对.COD的降低影响最弱.[结论]高效藻类塘中藻类、曝气和底泥均对养殖废水的净化产生较大影响.     

不同基质对人工湿地脱氮效果和硝化及反硝化细菌分布的影响

对组合基质和煤渣基质潜流式人工湿地的脱氮效果进行了对比研究,结果表明:组合基质人工湿地的脱氮效果较好,氨氮和总氮的平均去除率达到81.9%和75.7%,而煤渣基质人工湿地的去除率相对较低,氨氮和总氮的平均去除率仅为59.6%和51.8%.为进一步探讨2组人工湿地脱氮效果差异显著的原因,研究了不同基质潜流式人工湿地系统内硝化细菌和反硝化细菌的空间分布.实验结果表明:基质类型对人工湿地中硝化细菌和反硝化细菌的数量和空间分布有较大影响;在上层,组合基质人工湿地硝化细菌数是煤渣基质人工湿地的2.8倍,在下层,反硝化细菌数是煤渣基质人工湿地的1.8倍.人工湿地表层溶解氧水平较高,硝化细菌密度大,底层溶解氧水平较低,反硝化细菌密度大,使得湿地中形成上层以硝化菌为主的硝化反应区和下层以反硝化菌为主的反硝化区.     

Influence of COD:N:P Ratio on Nitrogen and Phosphorus Removal in Fixed-Bed Filter

This study examined the effects of COD:N:P ratio on nitrogen and phosphorus removal in a single upflow fixed-bed filter provided with anaerobic, anoxic, and aerobic conditions through effluent and sludge recirculation and diffused air aeration. A high-strength wastewater mainly made of peptone, ammonium chloride, monopotassium phosphate, and sodium bicarbonate with varying COD, N, and P concentrations (COD: 2,500–6,000, N: 25–100, and P: 20–50 mg/L) was used as a substrate feed. Sodium acetate provided about 1,500 mg/L of the wastewater COD while the remainder was provided by glucose and peptone. A series of orthogonal tests using three factors, namely, COD, N, and P concentrations, at three different concentration levels were carried out. The experimental results obtained revealed that phosphorus removal efficiency was affected more by its own concentration than that of COD and N concentrations; while nitrogen removal efficiency was unaffected by different phosphorus concentrations. At a COD:N:P ratio of 300:5:1, both nitrogen and phosphorus were effectively removed using the filter, with removal efficiencies at 87 and 76%, respectively, under volumetric loadings of 0.1?kg?N/m3?d and 0.02?kg?P/m3?d.     

Combined System for Biological Removal of Nitrogen and Carbon from a Fish Cannery Wastewater

A combined system composed of three sequentially arranged reactors, anaerobic-anoxic-aerobic reactors, was used to treat the wastewater generated in the tuna cookers of a fish canning factory. These wastewaters are characterized by high chemical oxygen demand (COD) and nitrogen concentrations. The anaerobic process was performed in an upflow anaerobic sludge blanket reactor operated in two steps. During Step I different influent COD concentrations were applied and organic loading rates (OLRs) up to 4 g COD/(L?d) were achieved. During Step II hydraulic retention time (HRT) was varied from 0.5 to 0.8 days while COD concentration in the influent was constant at 6 g COD/L. The OLRs treated were up to 15 g COD/(L?d). When HRTs longer than 0.8 days were used, COD removal percentages of 60% were obtained and these values decreased to 40% for a HRT of 0.5 days. The denitrification process carried out in an upflow anoxic filter was clearly influenced by the amount of carbon source supplied. When available carbon was present, the necessary COD/N ratio for complete denitrification was around 4 and denitrification percentages of 80% were obtained. The nitrification process was successful and was almost unaffected by the presence of organic carbon (0.2–0.8 g TOC/L), with ammonia removal percentages of 100%. Three recycling ratios (R/F) between the denitrification and nitrification reactors were applied at 1, 2, and 2.5. The overall balance of the combined system indicated that COD and N removal percentages of 90% and up to 60%, respectively, were achieved when the R/F ratio was between 2 and 2.5.     

Operational Optimization and Mass Balances in a Two-Stage MBR Treating High Strength Pet Food Wastewater

A two-stage membrane bioreactor (MBR) system was evaluated for the treatment of high strength pet food wastewater characterized by oil and grease, chemical oxygen demand (COD), biochemical oxygen demand (BOD)5, total suspended solids (TSS), total Kjeldahl nitrogen (TKN), NH4–N, and TP concentrations of 2,800, 25,000, 10,000, 4,500, 1,650, 1,300, and 370?mg/L, respectively, to meet stringent surface discharge criteria of BOD5, TSS, and NH4–N of <10?mg/L, and TP of <1?mg/L. Pretreatment of the dissolved air flotation effluent with FeCl3 at a dose of 3.5?g/L, corresponding to a Fe:P molar ratio of 1.3:1 affected TP, TSS, volatile suspended solids (VSS), COD, BOD5, and TKN reductions of 88, 72, 75, 11, 11, 36, and 17%, respectively. The two-stage MBR operating at a total hydraulic retention time of 5.3?days comprising 2.5?days in the first stage and 2.8?days in the second stage, and solids retention time of 25?days in the first stage consistently met the criteria despite wide variations in influent characteristics. Very high COD and BOD5 removal efficiencies of 97.2 and 99.8% were observed in the first stage, with an observed yield of 0.14?gVSS/gCOD. A modular approach for the quantification of simultaneous nitrification denitrification (SND) in the first-stage MBR was developed and verified experimentally. The model indicated that on average, 21% of the influent nitrogen was removed by SND and predicted nitrogen loss with an accuracy of 72%. Complete nitrification of the residual organic nitrogen and ammonia was achieved in the second-stage MBR.     

Simultaneous Removal of Nitrogen and Phosphorous from Municipal Wastewater Using Continuous-Flow Integrated Biological Reactor

A pilot-scale experiment was carried out to study the simultaneous removal of nitrogen and phosphorous from municipal wastewater by an innovative continuous-flow integrated biological reactor (CIBR) process. A three-phase separator was used in the CIBR process, which not only saved energy consumption of sludge returning, but also solved the sludge–gas separating problem. The optimal working condition was 2?h aeration, 1?h agitation, and 1?h settling, with an energy consumption of 0.23?kW?h/m3. The average removal of chemical oxygen demand (COD), ammonia nitrogen (NH4+–N), total nitrogen (TN), and total phosphorus (TP) under the optimal conditions were 72.87, 75.23, 61.25, and 68.25%, respectively. The distributing rules of dissolved oxygen, pH, mixed liquid suspended solid, COD, NH4+–N, NO3?–N, TN, and TP in each phase of CIBR was studied. It was indicated that the appropriate condition was created for the simultaneous removal of nitrogen and phosphorus in the integrated reactor. The study demonstrated the feasibility of using CIBR process for simultaneous removal of nitrogen and phosphorus at the average temperature 12.2°C.     

Simultaneous Nitrogen and Phosphorus Removal from High-Strength Industrial Wastewater Using Aerobic Granular Sludge

Aerobic granular sludge technology was applied to the simultaneous nitrogen and phosphorus removal from livestock wastewater that contains high concentrations of nitrogen and phosphorus (TN: 650?mg/L; TP: 125?mg/L). A lab-scale sequencing batch reactor was operated in an alternating anaerobic/oxic/anoxic denitrification mode. Granular sludge was first formed using synthetic wastewater. When livestock wastewater was diluted with tap water, the shape and settleability of aerobic granular sludge were maintained even though livestock wastewater contained suspended solids. Simultaneous nitrification, denitrification, and phosphate uptake were observed under an aerobic condition. However, when nondiluted livestock wastewater was used, the diameter of granular sludge and the denitrification efficiency under an oxic condition decreased. When the concentrations of nitrogen and phosphorus in wastewater increased, hydraulic retention time (HRT) increased resulting in a decrease in selection pressure for granular sludge. Therefore, the sustainment of granular sludge was difficult in livestock wastewater treatment. However, by applying a new excess sludge discharge method based on Stokes’ law, the shape of granular sludge was maintained in spite of the long HRT (7.5?days). To select large granular sludge particles, excess sludge was discharged from the upper part of settled sludge because small particles localized there after settling. Finally, excellent nitrogen and phosphorus removal was accomplished in practical livestock wastewater treatment. The effluent concentrations of NH4–N, NOx–N, and PO4–P were <0.1, 1.4, and 1.2?mg/L, respectively.     

Biotransformation of Carbon Tetrachloride and Anaerobic Granulation in a Upflow Anaerobic Sludge Blanket Reactor

Carbon tetrachloride (CT) in a synthetic wastewater was effectively degraded in a 2?l upflow anaerobic sludge blanket reactor during the granulation process by increasing the chemical oxygen demand (COD) and CT loadings. The effect of operational parameters such as influent CT concentrations, COD, CT loading, food to mass (F/M) ratio, and specific methanogenic activity (SMA) were also detected during granulation. Over 97% of CT was removed at 37°C, at a COD loading rate of 10?g/L?day. Chemical oxygen demand and CT removal efficiencies of 92 and 88% were achieved when the reactor was operating at CT and COD loading rates of 17.5?mg/L?day and 12.5?g/L?day, respectively. This corresponds to an hydraulic retention time of 0.28?day and an F/M ratio of 0.57?g?COD/g?volatile?suspended?solids?(VSS)?day. In 4?weeks, the seed sludge developed the CT degrading capability that was not very sensitive to shocks. The granular sludge cultivated had a maximum diameter of 2.5?mm and SMA of 1.64?g?COD/g?VSS?day. Glucose biodegradation by CT acclimated anaerobic granules was expressed with competitive inhibition. However the competitive inhibition was not significant since the competitive inhibition coefficient (Ki) was as high as 18.72?mg/L. Kinetic coefficients of k (maximum specific substrate utilization rate), Ks (half velocity coefficient), Y (growth yield coefficient), and b (decay coefficient) were determined as 0.6/day, 1.1?mg/L, 0.23?g?VSS/g glucose-COD, and 0.01/day, respectively, based on growth substrate glucose–COD during CT biotransformation. The CT was treated via biodegradation and this contributed to 89% of the total removal. The removal contributions from biomass adsorption, abiotic transformation, and volatilization were negligible. Adsorption and volatilization accounted for only 0.8 and 0.5% of the total removal, respectively.     

Performance of Nitrogen-Removing Bioretention Systems for Control of Agricultural Runoff

This research evaluated nitrogen-removing bioretention systems for control of nutrients, organics, and solids in agricultural runoff. Pilot-scale experiments were conducted with bioretention systems incorporating aerobic nitrification and anoxic denitrification zones with sulfur or wood chips as denitrification substrates. Varying hydraulic loading rates (HLRs), influent concentrations, and wetting and drying periods were applied to the units during laboratory and two seasons of field tests with dairy farm runoff. Total N removal efficiencies greater than 88% were observed in both units with synthetic storm water. In first-season field tests, moderate removal efficiencies were observed for chemical oxygen demand (46%), suspended solids (69%), total phosphorous (TP) (66%), and total N (65%). During the second season, operational changes in the farm resulted in lower organic, solids, and nutrient loadings resulting in improved effluent quality, especially for suspended solids (81% removal) and total N (82% removal). The systems were not hydraulically overloaded even at 20 times the normal HLR.     

不同pH下好氧颗粒污泥的稳定性

为考察好氧颗粒污泥（AGS）对不同pH环境下的耐受力，研究了不同pH废水（pH分别为3、4、5、10、11、12）下AGS的稳定性变化规律.在酸性环境中，AGS的理化特性随pH下降而变差（胞外聚合物（EPS）含量由102.5 mg/g下降到76.43 mg/g MLSS，比耗氧速率（SOUR）由17.94 mg O₂/（g MLSS·h））下降到16.19 mg O₂/（g MLSS·h）），pH为3和4时均出现不同程度的污泥上浮，对污染物的去除效果也呈下降趋势，但COD和TP的去除率维持在80 %以上.在碱性环境中，AGS出现了明显的上浮及解体.随着pH的增大，AGS的理化特性不断恶化（EPS由93.27 mg/g MLSS上升到178.45 mg/g MLSS，SOUR由6.81 mg O₂/（g MLSS·h））下降到4.30 mg O₂/（g MLSS·h））.同时，AGS对污染物的去除能力急剧下降，对COD、TN、TP的去除率均下降到50 %以下.研究结果表明AGS在酸性环境中有较强的耐冲击负荷能力，而碱性环境对AGS有较大的抑制作用.