基于模糊神经网络的污水处理生化除磷过程控制

针对污水处理生化除磷过程中出水总磷难以实时达标的问题,提出了一种基于模糊神经网络(fuzzy neural network,FNN)的出水总磷控制方法。首先,通过分析污水处理生化除磷机理,确定了控制器的操作变量为生化反应池第五分区外部碳源(external carbon, EC)与溶解氧(dissolved oxygen, DO)传递系数。其次,设计了一种基于FNN的出水总磷控制器,采用梯度下降算法更新控制器参数;最后,将基于FNN的出水总磷控制器应用于污水处理过程基准仿真平台(benchmark simulation model No.1,BSM1),实验结果表明,基于FNN的出水总磷控制器能够保证出水总磷的达标排放,具有较好的控制效果。

新型除磷材料在AAO工艺污水处理厂的应用

利用新型除磷材料(钠微米高纯复合铁)替代传统的铝盐、铁盐,在采用AAO工艺的牧屿污水处理厂开展了为期3个月的生产性试验。结果表明,新型除磷材料具有药剂投加量少、高效、缓释、无腐蚀性、不影响出水色度与pH、有助于改善污泥沉降性能等优点,与传统除磷剂相比具有明显的优势,可用于进水总磷浓度高污水处理厂的同步生化除磷需求。

物化/生化法在氧化沟功能提升中的应用

把物化/生化协同除磷技术用于氧化沟功能提升,达到不对原工艺做大的改造的情况下提高磷的去除率。实验结果表明:氧化沟好氧区投加液体聚磷硫酸铁(PPFS)后,对COD、NH4+-N和TN的去除效果略有提升,TP去除率从70%提高到92%,出水TP低于0.5 mg/L,去除效果稳定,最佳投加量为0.05 mL/L(75 mg/L)。能够实现投加少量化学絮凝剂达到出水目标,且对生化污泥没有明显的消极影响。

克拉玛依石化工业园污水处理厂曝气生物滤池工艺除磷效果分析

克拉玛依石化工业园污水处理厂采用气浮、S3D加三级生物滤池工艺,处理后的出水要求达到《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A的标准,即处理后的总磷要求达到0.5 mg/L以下。结合污水处理厂的实际工艺,重点研究了系统的化学除磷和生化混合除磷,对以后类似的工艺运行具有参考意义。

广东某农村小型污水处理站投药除磷研究

介绍了生化除磷的基本原理,分析了小型农村污水处理站总磷不能稳定达标的原因,通过小试展开研究,探索了除磷的最佳药剂、药剂投加的最佳p H值、药剂投加量和合理的投药点。通过对除磷效果影响因素的研究应用,在生化除磷效果不稳定的情况下,可以确保污水厂总磷稳定达标;可广泛运用于污水处理厂的改造和设计中,特别适用于除磷效果不稳定的情况。

氧化沟法城市污水处理厂设计中几个问题的探讨

本文从如何优化一级处理设计，减少占地面积，提高生化除磷效率以及解决好与兄弟专业的配合等几个方面，探讨了工艺专业人员在氧化沟法城市污水处理厂设计中应该注意的地方。并结合设计实践提出了改进措施。

Identification and Metabolic Mechanism of Non-fermentative Short-cut Denitrifying Phosphorus-removing Bacteria

To investigate the characteristics and metabolic mechanism of short-cut denitrifying phospho- rus-removing bacteria （SDPB） that are capable of enhanced biological phosphorus removal （EBPR） using nitrite as an electron acceptor, an aerobic/anoxic sequencing batch reactor was operated under three phases. An SDPB-strain YC was screened after the sludge enrichment and was identified by morphological, physiological, biochemical properties and 16S rDNA gene sequence analysis. Denitrifying phosphorus-removing experiments were conducted to study anaerobic and anoxic metabolic mechanisms by analyzing the changes of chemical oxygen demand （COD）, phosphate, nitrite, poly-fl-hydroxybutyrate （PHB）, and glycogen. The results show that strain YC is a non-fermentative SDPB similar to Paracoccus denitrificans. As a kind of non-fermentative bacteria, the energy of strain YC was mainly generated from phosphorus release （96.2%） under anaerobic conditions with 0.32 mg P per mg synthesized PHB. Under anoxic conditions, strain YC accumulated 0.45 mg P per mg degraded PHB, which produced most of energy for phosphate accumulation （91.3%） and a little for glycogen synthesis （8.7%）. This metabolic mechanism of strain YC is different from that of traditional phosphorus-accumulating organisms （PAOs）. It is also found that PHB, a kind of intracellular polymer, plays a very important role in denitrifying and accumulating phosphorus by supplying sufficient energy for phosphorous accumulation and carbon sources for denitrification. Therefore, monitoring AP/APHB and ANO2 -N/APHB is more necessary than monitoring AP/ACOD, ANO2 -N/ACOD, or AP / ANO2 -N.

A Modified Oxidation Ditch with Additional Internal Anoxic Zones for Enhanced Biological Nutrient Removal

A novel modified pilot scale anaerobic oxidation ditch with additional internal anoxic zones was operated experimentally, aiming to study the improvement of biological nitrogen and phosphorus removal and the effect of enhanced denitrifying phosphorus removal in the process. Under all experimental conditions, the anaero- bic-oxidation ditch with additional internal anoxic zones and an internal recycle ratio of 200% had the highest nutrient removal efficiency. The effluent NH4 -N, total nitrogen （TN）, PO3 -P and total phosphorus （TP） contents were 1.2 mg.L-1, 13 mg.L 1, 0.3 mg.L -1 and 0.4 mg.L-1, respectively, all met the discharge standards in China. The TN and TP removal efficiencies were remarkably improved from 37% and 50% to 65% and 88% with the presence of additional internal anoxic zones and internal recycle ratio of 200%. The results indicated that additional internal anoxic zones can optimize the utilization of available carbon source from the anaerobic outflow for denitrification. It was also found that phosphorus removal via the denitrification process was stimulated in the additional internal anoxic zones, which was beneficial for biological nitrogen and phosphorus removal when treating wastewater with a limited carbon source. However, an excess internal recycle would cause nitrite to accumulate in the system. This seems to be harmful to biological phosphorus removal.

Effect of Return Sludge Pre-concentration on Biological Phosphorus Removal in a Novel Oxidation Ditch

A pilot-scale,pre-anoxic-anaerobic oxidation ditch was used in this study to treat municipal wastewater with limited carbon source.A novel return activated sludge(RAS) pre-concentration tank was adopted for improv-ing the phosphorus removal efficiency and the effects of RAS pre-concentration ratio were studied.Under the opti-mal operational condition,the suspended total phosphorus(STP) and the total phosphorus(TP) removal efficiencies were around 58.9% and 63.9% respectively and the effluent-P was lower than 0.8 mg·L-1.The reason is that with the optimal RAS pre-concentration ratio,nitrate is completely removed with endogenous carbon source and the secondary phosphorus release is strictly restrained in the pre-anoxic tank.Therefore,the anaerobic phosphorus release and the carbon source uptake by phosphorus accumulation organisms(PAOs) in the sludge,which are ex-tremely important to the phosphorus removal process,can be fully satisfied.Furthermore,the oxidation-reduction potential is proved to be suitable for controlling the RAS pre-concentration ratio due to influent fluctuation and varied conditions.The novel modified system is also beneficial for PAO accumulation.

Factors affecting biological denitrifying dephosphatation in anaerobic/anoxic/aerobic sequencing batch reactor

This study was conducted to verify and discuss the denitrifying dephosphatation under different levels of nitrate concentration and retention time of anoxic/aerobic process in a Sequencing Batch Reactor (SBR). The results of tests demonstrated that there were two kinds of phosphorus-accumulating organisms (PAOs) in the biological excess phosphorus removal (BEPR) system. One was non-DNPAOs that could only use oxygen as terminal electron acceptors, the other was denitrifying PAOs (DNPAOs) that could use both nitrate and oxygen as terminal electron acceptors. Phosphorus uptake efficiency could be attained under anoxic period ranging from 28.7%-96.7% in an anaerobic/anoxic/aerobic system. Experimental results showed that nitrate concentration and retention time of anoxic/aerobic process were the key factors affecting the course of denitrifying dephosphatation.

Al^(3+)对序批式生物膜反应器(SBBR)中污泥脱氢酶活性(DHA)和胞外聚合物(EPS)的影响

通过向序批式生物膜反应器(SBBR)中投加氯化铝,研究了化学协同生物除磷过程中Al^(3+)对污泥脱氢酶活性(DHA)、胞外聚合物(EPS)及系统处理效果的影响.结果表明,氯化铝投加量少于0.1 mmol·L^(-1)时,Al^(3+)对微生物的活性有促进作用,多于0.1 mmol·L^(-1)的Al^(3+)对其活性有明显的抑制作用.氯化铝投加量少于0.1 mmol·L^(-1)时,Al^(3+)能够促进EPS中多糖(PS)和蛋白质(PN)的分泌,多于0.1 mmol·L^(-1)的Al^(3+)则只促进多糖的分泌,但对EPS的分泌总量没有影响.Al^(3+)会使污泥的SVI值显著降低,大大改善其沉降性能.MLSS、MLVSS基本上是随着Al^(3+)投加量的增加而增大,MLVSS/MLSS随着投药量的增加先减小后增大再减小.Al^(3+)对COD和TN的去除具有轻微抑制作用,但对TP的去除具有显著的改善作用.当Al^(3+)的投加为0.5 mmol·L^(-1)时,TP的去除效果最好,出水浓度仅为0.44 mg·L^(-1),满足一级A排放标准.此时,TP的去除率为92.7%,比不加药时提升了10.2%.

Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal

The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal （BNR） from municipal wastewater in anaerobic- anoxic-aerobic sequencing batch reactors （SBRs）. Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound （sodium acetate） served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-13-hydroxyalkanoates （PHAs）, and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating or- ganisms （PAOs） and denitrifying phosphorus accumulating organisms （DPAOs） demonstrated that the proportion of DPAOs to PAOs reached 62.6% （Day 86） and 61.8% （Day 65） when using cassava stillage and its anaerobic fer- mentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates （NURs） of the cassava by-products were in the range of 5.49-5.99 g N/（kg MLVSS.h） （MLVSS is mixed liquor volatile suspended solids） and 6.63-6.81 g N/（kg MLVSS.h）, respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes.

Effects of different external carbon sources and electron acceptors on interactions between denitrification and phosphorus removal in biological nutrient removal processes

The effects of two different external carbon sources （acetate and ethanol） and electron acceptors （dissolved oxygen, nitrate, and nitrite） were investigated under aerobic and anoxic conditions with non-acclimated process bi- omass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/（g MLVSS.h） （MLVSS： mixed liquor volatile suspended solids）, respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO2-N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher deni- trification rates were obtained with acetate （1.4 and 0.8 mg N/（g MLVSS.h）） compared to ethanol （1.1 and 0.7 mg N/ （g MLVSS.h）） for both anoxic electron acceptors （nitrate and nitrite）.

膨胀水解-生物流化床工艺中试研究

目前我国中小城镇污水处理厂出水水质标准大都执行一级B标准,如何将现有污水处理厂通过简单技术升级改造,将出水水质升级为一级A标准,是困扰中小城镇污水处理厂的难题。以北京太舟坞污水处理厂作为试验对象,通过对EH-BFB工艺进行中试研究,统计分析试验数据,得出工艺参数,以期寻求污水处理厂最优的升级改造技术,为我国北方地区中小城镇污水厂升级改造提供技术参考。