低温对螺旋升流式反应器系统营养物去除效果的影响及其流态释因

结合螺旋升流式反应器（spiral up-flow reactor,SUFR）的流态特点,分析低温（8-20℃）对SUHt系统处理效果的影响。结果表明,该系统COD和TN处理效果虽然随着温度的降低有所下降,但是COD及TN去除率仍分别达到86％、70％以上,TP的去除率一直在92％以上。流态模拟结果表明,SUFR系统中单元反应器的推流流态容积利用率为59％。     

低温对螺旋升流式反应器系统营养物去除效果的影响及其流态释因

结合螺旋升流式反应器(spiral up-flow reactor,SUFR)的流态特点,分析低温(8～20℃)对SUHt系统处理效果的影响.结果表明,该系统COD和TN处理效果虽然随着温度的降低有所下降,但是COD及TN去除率仍分别达到86%、70%以上,TP的去除率一直在92%以上.流态模拟结果表明,SUFR 系统中单元反应器的推流流态容积利用率为59%.这说明SUFR系统反应器内螺旋流形成的以活塞流为主要特征的复合流态有助于减轻低温对污水处理的负影响.该系统具有更宽的温度适宜范围.     

螺旋对称流厌氧反应器常温下的运行特性

螺旋对称流厌氧反应器（SSSAB）的最高有机负荷能在中温条件下（35℃）可达361.5kgCOD/（m³·d）,然而在常温条件下（10～30℃）其运行性能及污泥特征尚不明确,需进一步探究。以分段组合式厌氧反应器（TCAB）和升流式厌氧污泥床反应器（UASB）为参比,在常温下,以相同的操作条件研究了SSSAB的运行性能和污泥特征。实验结果表明：SSSAB的COD平均去除率（88%）高于TCAB和UASB（80%和78%）,SSSAB的一级反应动力学常数为5.4d^-1,高于TCAB的3.6d^-1和UASB的2.2d^-1。SSSAB内颗粒污泥宏观上相比于TCAB及UASB轮廓清晰、黑亮密实,且SSSAB颗粒污泥表面微观上较为粗糙,存在许多孔道。SSSAB颗粒污泥的胞外聚合物（EPS）总量高于TCAB及UASB,为底物的质量传递创造了条件,SSSAB颗粒污泥EPS的蛋白质（PN）/多糖（PS）较低,更有利于维持高污泥强度和优良的沉降性能。相比于UASB,SSSAB厌氧颗粒污泥凝聚性的分布更优,且其凝聚性波动更小。     

2套组合折流板反应器系统处理生活污水的启动运行

以厌氧污泥为种泥,采用2套填充不同填料的兼氧-厌氧组合ABR为反应器,考察了填充不同填料组合系统处理生活污水的启动运行。结果表明,当温度在25～35℃时,进水体积流量约为0.40 m3/d、HRT为24 h时,连续运行65 d后,组合单元中2种填料表面均形成一层均匀而致密的深褐色菌膜;稳定运行时,填充悬浮球型填料的组合ABR和填充组合填料的ABR对生活污水中COD的平均去除率分别为66.5%和70.1%,对SS的平均去除率分别为90.9%、92.0%,出水COD和SS含量均达到GB 18918-2002二级排放要求,且填充组合填料的系统对COD、SS、TN及TP的去除率效果均优于填充悬浮球填料的系统。     

六箱一体式反应器水力流态及其脱氮除磷性能

采用有效容积为312L的模型对六箱一体式活性污泥反应器的流态特征及其脱氮除磷性能进行了试验研究。结果表明,周期性交替进水方式增强了反应器系统流态的完全混合性,在工艺上表现为通过反向进水完成混合液以及部分污泥回流。反应器具有良好的去除氮磷的性能,对NH3-N、COD、TN、TP的平均去除率分别为89％、75％、74％、90％,出水水质达到GB18918-2002中的一级标准。     

三维上流式反应器床层流动和返混特性

采用内径为280 mm的上流式反应器,以空气模拟气相、甘油和水混合溶液模拟渣油。用3种不同粒径的氧化铝球形工业催化剂颗粒为填充颗粒,考察了不同模拟物系的颗粒粒径、颗粒密度、液相黏度、不同床层的高径比和不同操作条件对上流式反应器内床层压降及其波动、床层轴向返混的影响规律。得到模拟工业运行物系和操作条件的上流式反应器床层总压降关联式,相对误差在12%以内。床层总压降均随床层高径比、颗粒密度和液相黏度增加而增大,但随颗粒粒径的增大而减小,床层压降波动随表观气速增加而增大。填充颗粒粒径越小、颗粒密度越小、高径比越大,床层内轴向返混越严重;床层内压降和轴向返混均随表观气速的增加而增大。     

Sequencing batch reactor system for nutrient removal: ORP and pH Profiles

The sequencing batch reactor (SBR) process is known for its flexibility to meet a wide range of treatment needs, including nutrient removal. However, information related to the operational stability of SBR nutrient removal systems and control parameters to adjust the cyclic duration is sparse. Consequently, this study was undertaken to identify process parameters (pH and oxidation reduction potential) that could be useful for monitoring and real-time control purposes. In general, the system achieved removal efficiencies of 91, 98 and 98%, respectively, for Chemical Oxygen Demand, total nitrogen and phosphate at the solids retention time of 10 days, with a cyclic duration of 6 h. Shock loadings of nitrogen (20 mg dm⁻³ of NH−N, four cycles) exhibited little impact on effluent quality, except for a higher nitrate content. Activated sludge settled well throughout the entire study period. Several significant points associated with different reactions within SBR cycle, e.g. end of nitrification, end of phosphate release and completion of phosphate uptake, were identified in pH profiles. Slope changes in pH profiles (dpH/dt, or d²pH/dt²) were found to better represent the corresponding biological reactions. The application of these significant points in pH profiles as real time control parameters appears promising.     

污水处理活性污泥法流态分析

阐述了活性污泥法的两种流态,分析比较了推流式和完全混合式曝气池的池型、曝气方式、水力特征、各自的特点和存在问题、反应内在规律、去除率、适用水质等,从理论上证明了同样的污水水质若达到同样的处理效果,则推流式曝气池的动力学负荷、体积处理负荷均大于完全混合式;推流式曝气池需氧量小于完全混合式;推流式曝气池比完全混合式曝气池经济。     

污泥固体停留时间对实时控制生物脱氮SBR中亚硝酸盐积累的影响

In this study,four sequencing batch reactors(SBR),with the sludge retention time(SRT)of 5,10,20 and 40 d,were used to treat domestic wastewater,and the effect of SRT on nitrite accumulation in the biological nitrogen removal SBR was investigated.The real-time control strategy based on online parameters,such as pH,dissolved oxygen(DO)and oxidation reduction potential(ORP),was used to regulate the nitrite accumulation in SBR. The model-based simulation and experimental results showed that with the increase of SRT,longer time was needed to achieve high level of nitritation.In addition,the nitrite accumulation rate(NAR)was higher when the SRT was relatively shorter during a 112-day operation.When the SRT was 5 d,the system was unstable with the mixed liquor suspended solids(MLSS)decreased day after day.When the SRT was 40 d,the nitrification process was significantly inhibited.SRT of 10 to 20 d was more suitable in this study.The real-time control strategy combined with SRT control in SBR is an effective method for biological nitrogen removal via nitrite from wastewater.     

Enhanced biological nutrient removal in modified carbon source division anaerobic anoxic oxic process with return activated sludge pre-concentration☆

A pilot-scale modified carbon source division anaerobic anoxic oxic (AAO) process with pre-concentration of returned activated sludge (RAS) was proposed in this study for the enhanced biological nutrient removal (BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60%and 50%, respectively, with an inner recycling ratio of 100%under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L?1 with a removal efficiency of 63%and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.     

Biological nutrient removal in a sequencing batch reactor using ethanol as carbon source

BACKGROUND: When organic matter is limiting for biological nutrient removal (BNR) from wastewater, external organic carbon can be added to a wastewater treatment plant (WWTP). This increases the overall treatment cost, so the choice of substrate is critical. The effect of using ethanol as the carbon source for BNR is investigated. RESULTS: The results clearly showed that using ethanol as a carbon source is a promising strategy for removing nutrients from wastewater. Effluent concentrations of 3.0 mg total nitrogen (TN) L^?1 (96% N removal efficiency) and 0.05 mg phosphate (P‐PO₄) L^?1 (99.9% P removal efficiency) were obtained. Furthermore, tests performed in order to identify the carbon source used by polyphosphate‐accumulating organisms (PAOs) showed that the phosphorus release/carbon uptake ratio using ethanol (0.41 mmol P mmol^?1 C) was slightly lower than that with acetate (0.50 mmol P mmol^?1 C) but close to that with propionate (0.42 mmol P mmol^?1 C). CONCLUSION: Therefore, taking into account the results presented for ethanol‐acclimatised biomass and the fact that the cost of ethanol is lower than that of acetate or propionate, ethanol can be considered as an alternative carbon source if one is needed in a WWTP. Copyright © 2007 Society of Chemical Industry     

污泥转移SBR工艺中EPS对生物除磷的作用

采用新型强化生物除磷工艺--污泥转移SBR处理合成废水,探讨胞外聚合物（EPS）在工艺强化除磷过程中的作用。当污泥转移量为0、15%及30%时,污泥中的EPS含量分别为（108.14±9.68）mg·（g MLSS）^-1、（128.17±1.45）mg·（g MLSS）^-1和（123.35±22.98）mg·（g MLSS）^-1;工艺的除磷率分别为82.14%±0.85%、96.35%±1.25%及98.99%±0.98%,反应末端EPS中TP含量占污泥中TP的比重分别为27.9%±2.55%、57.23%±2.33%和63.88%±2.87%。此外,污泥中EPS在该工艺的好氧吸磷过程中吸磷量分别为（2.04±0.32）mg·（g MLSS）^-1、（5.90±0.38）mg·（g MLSS）^-1和（6.00±0.52）mg·（g MLSS）^-1,在污泥吸磷量中的贡献率均达到90%以上。研究结果表明：污泥转移SBR工艺中随着污泥转移量的增大有利于提高EPS中的磷含量,从而提升了工艺的除磷性能,EPS在该工艺的吸磷过程中起主要作用。但污泥转移对污泥中EPS含量影响不显著。     

废水生物脱氮除磷工艺的进展与评述

针对传统生物脱氮除磷工艺存在的一些不足,即微生物的混合培养,泥龄,碳源和回流污泥中的硝酸盐问题,概要介绍了双循环两相生物处理(BICT)工艺,厌氧/缺氧和硝化(A2N)工艺,BCFS工艺,分段进水BNR工艺,厌氧-往复好氧组合式工艺等几种近年来针对这些问题提出的改进工艺,并从处理工艺的原理、流程和应用于实际工程尚需进一步研究的问题等方面对这些工艺进行了比较和评述。