交替曝气及外投碳源强化自养硝化颗粒污泥脱氮效果研究

探索了在交替曝气序批式反应器(SBR)中的缺氧段外投有机碳源提高自养硝化颗粒污泥(ANGS)脱氮效果,为离子型稀土矿山废水高效脱氮提供技术支持。首先,探索各影响因素(外投碳源浓度、曝气量及曝停比)对总无机氮(TIN)去除率的影响,确定它们适宜的范围。然后,利用响应曲面法(RSM)耦合出最佳工况点,即：COD投加量=600 mg/L,曝气量=0.6 L/min,曝停比=9∶21。此工况下2 h缺氧段ANGS对TIN去除率的预测值为69.39%,实测值为(68.52±3.35)%。应用双倒数法,拟合求解最佳工况下ANGS对氨氮、亚硝态氮及硝态氮的基质降解动力学方程,发现ANGS对硝态氮的亲和性最好,亚硝氮居中,对氨氮亲和性最差。最后,探索了典型周期试验中各污染物的变化规律,探究出外源硝化反硝化对TIN去除的贡献率为85%,而内源硝化反硝化占比为15%。研究结果表明,通过交替曝气并外投有机碳源具有高效脱氮并降低运行成本的潜力。     

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%。     

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...     

交替A/O工艺处理养猪废水脱氮研究

采用交替A/O工艺处理养猪废水.进行硝化菌与反硝化菌的培养、驯化;交替阶段厌氧和好氧段各自运行的最佳时间的确定;交替A/O工艺对NH3-N、TN、NO3-N的去除情况以及交替A/O工艺对养猪废液脱氮机理的研究.结果表明,A段运行2.5 h,O段运行时间为2 h,交替13.5 h即3个交替过程后,NH3-N的去除率为60.44%,总氮去除率为56.37%,NO3-N去除率22.35%.交替A/O工艺脱氮的去除率突破了传统A/O工艺脱氮的去除率的理论限制,对脱氮机理理论研究有重大的贡献.     

生活污泥用于焦化废水处理的培养驯化

介绍了用生活污水厂的干污泥做菌种,进行焦化废水处理的培养驯化过程。采用连续曝气、间歇进水的方式对污泥进行驯化,通过调整温度、pH值、磷酸三钠和萄葡糖的投加量等工艺参数,32d内使污泥恢复了活性并完全适应了焦化废水环境,使废水中酚的去除率达到99.8%以上,CODcr去除率达到60%以上。     

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。     

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.     

新型TMT-硫酸铁固定剂对重金属污染土壤的修复研究

以新型TMT（三巯基均三嗪三钠盐）-硫酸铁复配混合物为化学固定剂,考察了其对湖南郴州某重金属污染土壤中铅、镉、砷的固定效果.结果表明,单一使用TMT（含15 %（质量分数）TMT的水溶液）为固定剂时,土壤中的有效态铅、镉去除率高于60 %,但对砷没有固定效果.使用TMT-硫酸铁复配固定剂时,控制硫酸铁投加量为35.7 g/kg,TMT投加量为0.1 L/kg时,有效态铅、镉去除率达到90 %以上.随着土壤含水量的增加,土壤中有效态铅、镉的含量显著降低.当控制硫酸铁投加量为35.7 g/kg,TMT投加量为0.04 L/kg,控制土壤含水量至田间持水量的70 %,固定60 d,有效态铅、镉的去除率在80 %以上,有效态砷的去除率可达到60 %.      

高浓度氨氮-重金属复合废水资源化处理试验及工程研究

针对高浓度氨氮-重金属复合废水,采用HSJ脱氨-资源化回收技术-电化学组合工艺,研究分析了废水pH、进料流量、进塔温度对脱氨-资源化回收系统脱除氨氮的影响、废水pH、电流密度、电解时间对电化学去除重金属的影响及整套系统运行稳定性。结果表明:当pH=12,进塔温度=95℃、进料流量=8 m3/h、蒸汽流量=1.2 m3/h时,HSJ脱氨-资源化回收技术氨氮去除率>99%,出水氨氮稳定低于15 mg/L。当pH=9、电流密度=40 A/m2、电解时间=40 min时,电化学系统出水中铅、锑去除率>99%,出水中铅、锑稳定小于0.5 mg/L。HSJ脱氨-资源化回收技术-电化学组合工艺处理高浓度氨氮-重金属复合废水具有良好的运行稳定性。     

Stimulating Biological Nitrification via Electrolytic Oxygenation

The feasibility of electric current prompted aerobic biodegradation of NH4+–N in an attached growth bioreactor system is demonstrated. Nitrification was induced at electric current densities of 1.25 and 2.5?mA/cm2 and with pure oxygen supplied at a rate equivalent to 1.25?mA/cm2 when the bioreactor was operated in batch mode at 6 days detention time. About 84% (27?mg/L)?NH4+–N loss was observed at the end of each detention period during all three experimental conditions, indicating that the electric current did not negatively impact the rate of nitrification. Nitrite accumulation was observed during the initial stages of nitrification experiments with 1.25?mA/cm2 current intensity, but nitrite did not accumulate during the other two sets of nitrification experiments. A mathematical model formulated to obtain the rates of biological reactions showed that rates of NH4+–N removal are similar for all aeration conditions. Abiotic experiments showed that NH4+–N was not removed electrolytically and via stripping, confirming that NH4+–N disappearance is due to biological activity.     

好氧颗粒污泥的培养及处理低碳氮比废水效果

采用"搅拌-曝气-搅拌"间歇曝气运行模式,探索好氧颗粒污泥(AGS)在低碳氮比(1～6)废水中的形成规律及其对污染物的降解效果,旨在为低碳氮比污水的高效处理提供技术支持.当进水碳氮比为1～2.25时,接种污泥表现出明显的不适应,污泥量及颗粒化率增长缓慢,化学需氧量(COD)、总无机氮(TIN)及总磷(TP)的去除率较低...     

Nitrification∕Denitrification in Intermittent Aeration Process for Swine Wastewater Treatment

A continuous-flow intermittent aeration (IA) process has been studied for nitrogen removal from anaerobically digested swine wastewater with high ammonium content. High nitrogen removal efficiency of average 91% total Kjeldahl nitrogen and 92% NH4-N was achieved in an IA system with an alteration of 1-h aeration and 1-h nonaeration. Nitrification and denitrification were found to be responsible for the nitrogen removal in the system. Nitrite and nitrate in the effluent were less than 1.0 mg∕L and 8.0 mg∕L, respectively. The specific nitrification and denitrification rates of the single-sludge IA culture were determined through batch experiments as 2.79–3.70 mgNO3-N∕g volatile suspended solids-h and 0.59–1.03 mgNO3-N∕g volatile suspended solids-h, respectively. In the IA process, the aeration period created favorable conditions for nitrifying bacteria (dissolved oxygen = 4–6 mg∕L and oxidation-reduction potential = 80–100 mV), while the nonaeration period provided good environment for denitrifying bacteria (dissolved oxygen < 1 mg∕L and oxidation-reduction potential as low as 0 mV). Ammonia volatilization in the IA process was negligible (<0.008%). Denitrification activity in the IA process prevented nitrate from accumulation and significant pH change in the system, which is critical for nitrogen removal from swine wastewater with high ammonium content.     

钢铁企业的焦化废水短程生物脱氮的研究

铁碳电池预处理－厌氧－好氧－缺氧多级SBR法处理焦化废水取得了良好的COD、氨氮脱除效果。在SBR反应器中创造条件，既保证了亚硝化反应的顺利进行，同时又保证了生成的亚硝酸盐与NH4^＋及有机物发生反应实现共同降解，亚硝酸盐与NH4^ 的反应弥补了反亚硝化过程中碳源的不足。系统运行稳定，氨氮浓度大于600mg/L时，却除率大于95％。该方法成本低，处理效果较好。     

Acetate Limitation and Nitrite Accumulation during Denitrification

Nitrite accumulated in denitrifying activated sludge mixed liquor when the carbon and electron source, acetate, was limited. If acetate was added to obtain a carbon-to-nitrogen (C:N) ratio in the range of 2:1 to 3:1, nitrate was completely consumed at the same rate with no nitrite accumulation, indicating that nitrate concentration controlled the respiration rate as long as sufficient substrate was present. However, when acetate was reduced to a C:N ratio of 1:1, while nitrate continued to be consumed, >50% of the initial nitrate-nitrogen accumulated as nitrite and 29% persisted as nitrite throughout an endogenous denitrification period of 8–9 h. While nitrite accumulated during acetate-limited denitrification, the specific nitrate reduction rate increased significantly compared with the rate when excess acetate was provided as follows: 0.034 mg-NO3-N∕mg-mixed liquid volatile suspended solids∕h versus 0.023 mg-NO3-N∕mg-mixed liquid volatile suspended solids∕h, respectively. This may be explained by nitrate respiration out-competing nitrite respiration for limited acetate electrons. Complete restoration of balanced denitrification and elimination of nitrite accumulation during denitrification required several weeks after the C:N ratio was increased back to 2:1.     

Application of the Nitritation and Anammox Process into Inorganic Nitrogenous Wastewater from Semiconductor Factory

The first full-scale nitritation and anaerobic ammonium oxidation (Anammox) processes for an inorganic wastewater of semiconductor factory were installed and performances were evaluated. Existing facilities of conventional nitrification and denitrification were retrofitted to a combination of the nitritation and Anammox process. Novel nitritation method, selective acceleration of ammonia oxidation by high concentration of inorganic carbon, was evaluated in full-scale aeration tank with carrier material. The ammonia conversion rate of the nitritation reactor was in the range of 0.27–0.48?kg?NO2-N/m3?day after start-up period, and stable nitritation was achieved for over 10 months. In an Anammox reactor, on-site cultivation of anammox bacteria was performed, and the most plausible reason for slower nitrogen conversion at the beginning was oxygen contamination into the reactor. After minimizing influence of oxygen contamination, design loading was achieved within 3 months of operation. After start-up period, stable Anammox reactions are maintained for over 10 months. The nitrogen removal rate after start-up period was in the range of 1.04–3.29?kg?N/m3?day. In combination with conventional denitrification process, soluble nitrogen in the final effluent was reduced below 8 mg/L.     

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.     

The anaerobic oxidation of ammonium

From recent research it has become clear that at least two different possibilities for anaerobic ammonium oxidation exist in nature. 'Aerobic' ammonium oxidizers like Nitrosomonas eutropha were observed to reduce nitrite or nitrogen dioxide with hydroxylamine or ammonium as electron donor under anoxic conditions. The maximum rate for anaerobic ammonium oxidation was about 2 nmol NH4+ min-1 (mg protein)-1 using nitrogen dioxide as electron acceptor. This reaction, which may involve NO as an intermediate, is thought to generate energy sufficient for survival under anoxic conditions, but not for growth. A novel obligately anaerobic ammonium oxidation (Anammox) process was recently discovered in a denitrifying pilot plant reactor. From this system, a highly enriched microbial community with one dominating peculiar autotrophic organism was obtained. With nitrite as electron acceptor a maximum specific oxidation rate of 55 nmol NH4+ min-1 (mg protein)-1 was determined. Although this reaction is 25-fold faster than in Nitrosomonas, it allowed growth at a rate of only 0.003 h-1 (doubling time 11 days). 15N labeling studies showed that hydroxylamine and hydrazine were important intermediates in this new process. A novel type of hydroxylamine oxidoreductase containing an unusual P468 cytochrome has been purified from the Anammox culture. Microsensor studies have shown that at the oxic/anoxic interface of many ecosystems nitrite and ammonia occur in the absence of oxygen. In addition, the number of reports on unaccounted high nitrogen losses in wastewater treatment is gradually increasing, indicating that anaerobic ammonium oxidation may be more widespread than previously assumed. The recently developed nitrification systems in which oxidation of nitrite to nitrate is prevented form an ideal partner for the Anammox process. The combination of these partial nitrification and Anammox processes remains a challenge for future application in the removal of ammonium from wastewater with high ammonium concentrations.     

VFA Production in Thermophilic Aerobic Digestion of Municipal Sludges

Volatile fatty acids (VFA) are a principal carbon substrate used in biological nutrient removal processes, and an increase in their concentration can enhance process performance. In the autothermal thermophilic aerobic digestion (ATAD) of primary sludge, a reduction in both aeration and retention time had been reported to enhance VFA production. However, smaller wastewater treatment plants, which are suitable for ATAD, often combine sludge in a single digestion process for convenience. Consequently, research was undertaken to determine if a mixture of primary and secondary sludge would increase VFA production, compared to primary sludge alone, in the first stage of ATAD. Secondary sludge was predicted to further enhance VFA production by providing the required substrate “prepackaged” in the correct ratios. The results illustrated that the incorporation of secondary sludge into the primary sludge feed resulted in increased production and accumulation of VFA. The greatest production and accumulation were produced with the digestion of 100% secondary sludge. In addition, analysis of nutrient species confirmed that the mixing of primary and secondary sludge, as well as the ATAD of mixed and secondary sludge, results in the release of stored phosphorus and an increase in ammonia nitrogen.     

Nitrogen Removal Using Combined Ultracompact Biofilm Reactor-Packed Bed System

A predenitrification system consisting of an ultracompact biofilm reactor (UCBR) and a packed bed column was used for removing nitrogen from synthetically simulated wastewater. The UCBR column was maintained under aerobic conditions to favor nitrification process, while the packed bed column was operated under an anoxic environment for denitrification process. A peristaltic pump was used to recycle fluid between the anoxic-packed bed and aerobic-UCBR columns to facilitate nitrogen removal. Five recycle ratios (R) were investigated, namely, 3, 4, 5, 6, and 10. The highest average total nitrogen (TN) removal rate was achieved at R = 4. The NH4+–N, TN, and chemical oxygen demand (COD) removal rates at this R were 0.56±0.05?kg NH4+–N/m3/day, 0.39±0.09?kg TN/m3/day, and 1.83±0.18?kg COD/m3/day, respectively. It was noted that poor nitrification in the UCBR was accompanied by a corresponding reduction in overall TN removal efficiency. This observation suggested that nitrification process was the limiting step for TN removal in this setup. Thus, the performance of this predenitrification system could be enhanced by optimizing the performance of the nitrification process.