微絮凝-超滤工艺处理微污染水源水的中试研究

进行了微絮凝．超滤工艺处理微污染水源水的中试研究。试验结果表明：在微絮凝-超滤工艺中，相同混凝剂投加量（相同金属摩尔浓度）下铁盐比铝盐的混凝效果好；微絮凝-超滤工艺的最佳絮凝时间为120s左右；最佳混凝剂投加量为2．2mg／L（以Fe计）。微絮凝-超滤工艺在改善出水水质和缓解膜污染方面均优于直接超滤工艺。微絮凝-超滤工艺的出水水质均符合建设部《城市供水水质标准》（CJ／T206-2005）要求。     

化学生物絮凝与化学絮凝工艺处理城市污水--加药量对污染物去除效果的影响

化学生物絮凝工艺是利用将化学和生物协同絮凝作用处理污水的强化一级新工艺.试验通过在不同加药量情况下化学生物絮凝和化学絮凝工艺的中试试验对比研究,得出在相同加药量条件下,化学生物絮凝污染物去除效率均优于化学絮凝工艺10%～20%.在70 mg/L液体聚合氯化铝铁复配0.5 mg/L PAM的加药条件下,化学生物絮凝工艺经过30 min的水力停留时间,在进水CODCr为100～260 mg/L,TP为2～4 mg/L,SS为80～150 mg/L,NH3-N为10～25 mg/L条件下,出水CODCr、TP、SS、NH3-N满足城镇污水处理厂污染物排放二级标准.     

微絮凝-超滤工艺处理微污染水源水的中试研究

进行了微絮凝-超滤工艺处理微污染水源水的中试研究.试验结果表明:在微絮凝-超滤工艺中,相同混凝剂投加量(相同金属摩尔浓度)下铁盐比铝盐的混凝效果好;微絮凝-超滤工艺的最佳絮凝时间为120 s左右;最佳混凝剂投加量为2.2 mg/L(以Fe计).微絮凝-超滤工艺在改善出水水质和缓解膜污染方面均优于直接超滤工艺.微絮凝-超滤工艺的出水水质均符合建设部<城市供水水质标准>(CJ/T206-2005)要求.     

生物絮凝-AAAO中试系统污染物去除特性及反硝化除磷菌的培养

为降低污水处理成本并实现出水稳定达标,采用中试规模生物絮凝-AAAO工艺处理城镇生活污水,并模拟生物絮凝污泥厌氧消化所产生的碳源,用于强化反硝化除磷菌(DPAO)驯化效果。实验结果表明:生物絮凝系统抗冲击负荷能力较强,化学需氧量(COD)、总氮(TN)和总磷(TP)平均去除率可达67.23%、 27%与68.93%。将模拟厌氧消化后产生的碳源投加至厌氧池促进DPAO的驯化后,AAAO系统对COD、TN和TP去除率分别提升31.53%、37.67%和26.37%,反硝化吸磷率最高可达62.97%,二沉池出水COD、TN均满足一级A出水标准,TP可低于0.30 mg·L-1。生物絮凝-AAAO工艺脱氮除磷效果较好,可为污水处理厂节能降耗运行奠定基础并有望得到广泛应用。     

基于多级神经网络模型的厌氧氨氧化系统参数预测

厌氧氨氧化菌生长条件复杂、影响因素多,其工艺系统运行控制复杂,为解决上述问题,研究构建了1个多级神经网络预测模型,以提高SBBR单级自养脱氮厌氧氨氧化系统出水总氮去除率预测精度,并确定了系统工程应用的关键控制参数。一级神经网络模型通过灰色关联度分析,对影响出水总氮去除率的关键性指标进行预测;二级神经网络模型基于一级模型增加数据维度,并通过改进粒子群算法优化网络、借鉴遗传算法变异的思想扩大搜索范围,提高了出水总氮去除率的预测精度。多级神经网络模型预测结果表明,其总氮去除率平均相对误差为0.54%,相对误差为5.76%,均方根误差为1.132 1,预测数据基本上与实际值相符;与其他预测模型相比较,该模型表现出较优的预测精度。进一步分析发现,通过控制工艺系统的曝气量调节出水亚氮浓度,是保证工艺反应的稳定和实现厌氧氨氧化工艺工程应用的有效控制方式。     

低碳排放的生物絮凝中试系统污染物去除特性及污泥EPS变化

用中试规模生物絮凝工艺处理含化学絮凝剂的生活污水,分别研究了HRT和进水SS对生物絮凝系统污染物去除特性、剩余污泥产量、污泥特性和温室气体排放的影响。结果表明:生物絮凝系统对COD、TN和TP有较好的去除效果,且污染物去除效果受进水SS影响较大;生物絮凝系统平均污泥产量和平均有机物产量最高可达53.63 kg·d~(-1)和21.14 kg·d~(-1);污泥胞外聚合物EPS浓度和PN/PS均与有机负荷呈反比;化学絮凝剂通过影响PN/PS和EPS浓度,可间接影响污泥的沉降性能;生物絮凝系统与AAO工艺相结合,可降低50.12 g·m~(-3)温室气体的排放。因此,生物絮凝工艺可为污水处理厂节能降耗运行奠定基础,有望得到广泛应用。     

生物预处理后给水沉淀池生物污泥回流净水效果的研究

针对季节性氨氮和有机微污染水源,通过回流生物预处理后沉淀池生物污泥至絮凝池,进行常规生物强化处理。不同污泥回流比工况的中试实验表明,污泥回流比宜在1.5%～5%之间选取,回流比再加大,生物强化效应不会增加;相比不回流工况27.6%的CODMn平均去除率,在污泥回流比为1.5%、3%和5%的运行工况下,沉淀池出水相对于预处理出水CODMn的平均去除率分别为44.5%、44.1%和45.5%;同时,在1.5%～5%之间选取污泥回流比,絮凝剂投加量减少了17 mg/L,并且沉淀池出水浊度降低,氨氮去除率也有提高。     

一体式膜生物反应器处理生活污水的中试研究

采用中试规模（1.8m^3／d）的缺氧-好氧膜生物反应器（A／OMBR）对城市污水处理回用进行了试验研究。试验结果表明，该工艺处理效果优良，系统对COD、氨氮、浊度、总氮、总磷去除率较高，COD、氨氮出水浓度分别为7～39 mg/L、0～1.31mg／L。出水水质优于城市杂用水水质标准（GB／T18920-2002）。     

白龙港水质净化厂污水化学-生物联合絮凝试验研究

为有效降低污水对长江人海口的污染,针对白龙港水质净化厂的水质状况,采用化学-生物联合絮凝工艺,对污水处理效果进行了研究,结果表明,与单独生物絮凝吸附工艺相比,化学-生物联合絮凝吸附工艺可以承受更高的水力负荷,并可节省部分药剂消耗量和污泥处理成本.     

生物脱氮除磷活性污泥系统复合模拟方法

为避免繁琐的参数校核工作,提出了活性污泥2 d号模型(ASM2d)和人工神经网络(ANNs)相结合的复合模拟方法。考察了复合方法在某污水处理厂生物脱氮除磷工艺中的应用情况。研究表明,ANNs能够准确地模拟出水实测值与未经校核的ASM2d机理模型的估计值之间的差值。利用Levenberg-Marquardt算法,对出水氨氮、总氮和总磷分别建立网络结构为5-12-1、5-8-1和5-8-1的ANNs子模型,将这些子模型输出同ASM2d机理模型输出相加便得到复合模型输出。复合模型估计值对前10.4 d(ANNs子模型训练数据时段)出水氨氮、总氮和总磷浓度的拟合平均绝对百分比误差分别为0.267、0.055和0.048;其对后2.6 d(ANNs子模型测试数据时段)出水氨氮、总氮和总磷浓度的预测平均绝对百分比误差分别为0.332、0.083和0.069。均方根误差、平均绝对误差等评价指标也表明复合模型能够给出合理的模拟结果。     

光助Fenton氧化、化学絮凝法联合处理R盐废水的研究

采用光助Fenton氧化、化学絮凝法联合处理生物难降解的R盐废水,考察了不同反应条件对处理效果的影响.试验结果表明,光助Fenton氧化、化学絮凝法联合处理废水,两者之间存在协同作用,可以提高处理效果,降低处理成本.在最佳试验条件下,R盐废水经光助Fenton氧化、化学絮凝法联合处理后,COD去除率可达90%以上.     

光助Fenton氧化、化学絮凝法联合处理R盐废水的研究

采用光助Fenton氧化、化学絮凝法联合处理生物难降解的R盐废水,考察了不同反应条件对处理效果的影响。试验结果表明,光助Fenton氧化、化学絮凝法联合处理废水,两者之间存在协同作用,可以提高处理效果,降低处理成本。在最佳试验条件下,R盐废水经光助Fenton氧化、化学絮凝法联合处理后,COD去除率可达90%以上。     

新型氧化-混凝剂处理染料废水研究

根据染料废水的特点 ,研究了自制产品新型氧化 混凝剂处理染料废水的情况 ,探索了药剂用量、pH值等因素对COD、色度去除率的影响。试验表明 ,当pH >10、“染清”氧化 混凝剂的加入量万分之三左右、絮凝时间 6min、静置沉淀3 5min时 ,该药剂对染料废水具有良好的效果 ,COD和色度的去除率最高分别可达 97%和 86% ,从而证明该方法对于染料废水的处理是可行的。该处理工艺设备简单 ,系统运行稳定 ,操作方便 ,成本低     

Prediction of Flue Gas Composition of an Incinerator Based on a Nonequilibrium-Reaction Approach

A nonequilibrium-reaetion model is developed to predict the flue gas composition of an incinerator for solid waste combustion and gasification. The model may also be effectively utilized to predict the composition of exit gas from the primary chamber of an incinerator where invariably substoichiometrie combustion conditions exist The model assumes that the drying and pyrolysis of waste occurs in sequence followed by combustion of devolatilized gas and residue separately. The model is applied to the combustion of pine wood, and the flue gas compositions are computed as a function of operating parameters such as temperature (1100 to 1500 K), initial moisture content (0 to 40 percent), and percentage excess air (up to 100 percent). The model is extended to include substoichiometric combustion (to simulate the gasification process without steam injection) to compare its predictions with the available experimental data. The general agreement of theory and experiment is good.     

Appropriate combination of physico-chemical methods (coagulation/flocculation and ozonation) for the efficient treatment of landfill leachates

An integrated technique consisted of ozonation and coagulation/flocculation processes was studied, aiming to provide an efficient method for the treatment of stabilized/biologically pre-treated leachates, in order to reduce the organic pollutants' content to concentration values lower than the corresponding limits, imposed by the legislation. Leachates were collected from a municipal landfill site; samples containing around 1000 mg l(-1) COD and BOD(5)/COD ratio about 0.17 were treated by using two different processes or combinations between them, i.e. ozonation, coagulation-flocculation, ozonation followed by coagulation/flocculation and coagulation/flocculation followed by ozonation. The application of single ozonation resulted to the efficient removal of color and organic loading, due to the respective oxidation, induced by ozonation; however, COD values lower than 200 mg l(-1) could be only achieved after prolonged reaction times and for high ozone production rates. The coagulation of leachate samples was studied by the addition of ferric chloride or poly-aluminum chloride agents at various dosages. Maximum COD removal rates (up to 72%) were achieved by the addition of 7 mM Fe, or of 11 mM Al respectively. However, final COD values higher than 200 mg l(-1) were obtained indicating the requirement of an additional treatment step. Pre-ozonation followed by coagulation/flocculation was not found to be an efficient treatment approach for this aim, but coagulation/flocculation followed by ozonation, was proved to be an efficient process for the reduction of COD to lower than 180 mg l(-1).     

EPA site demonstration of BioTrol aqueous treatment system

BioTrol's pilot scale, fixed-film biological system was evaluated, under the EPA's SITE program, for its effectiveness at removing pentachlorophenol from groundwater. The demonstration was performed in the summer of 1989 at a wood preserving site in New Brighton, Minnesota. The system employs indigenous microorganisms amended with a specific pentachlorophenol-degrading bacterium. Groundwater from a well on the site was fed to the system at 1, 3, and 5 gpm with no pretreatment other than pH adjustment, nutrient addition, and temperature control. Each flowrate was maintained for about two weeks while samples were collected for extensive analyses. At 5 gpm, the system was capable of eliminating about 96 percent of the pentachlorophenol in the groundwater and producing effluent with pentachlorophenol concentrations of about 1 ppm. At the lower flows (1 and 3 gpm) removal was higher (about 99 percent) and effluent pentachlorophenol concentrations were well below 0.5 ppm. The system consistently produced a completely nontoxic effluent at all three flowrates. Review of other data provided by BioTrol indicates that the process is also effective on other hydrocarbons, including solvents and fuels. The system appears to be a compact and cost-effective treatment for contaminated wastewaters requiring minimal operating attention once acclimated.     

Application of dynamic models to estimate greenhouse gas emission by wastewater treatment plants of the pulp and paper industry

Greenhouse gas (GHG) emission in wastewater treatment plants of the pulp-and-paper industry was estimated by using a dynamic mathematical model. Significant variations were shown in the magnitude of GHG generation in response to variations in operating parameters, demonstrating the limited capacity of steady-state models in predicting the time-dependent emissions of these harmful gases. The examined treatment systems used aerobic, anaerobic, and hybrid—anaerobic/aerobic—biological processes along with chemical coagulation/flocculation, anaerobic digester, nitrification and denitrification processes, and biogas recovery. The pertinent operating parameters included the influent substrate concentration, influent flow rate, and temperature. Although the average predictions by the dynamic model were only 10 % different from those of steady-state model during 140 days of operation of the examined systems, the daily variations of GHG emissions were different up to ±30, ±19, and ±17 % in the aerobic, anaerobic, and hybrid systems, respectively. The variations of process variables caused fluctuations in energy generation from biogas recovery by ±16, ±17, and ±14 % in the three examined systems, respectively. The lowest variations were observed in the hybrid system, showing the stability of this particular process design.     

Performance Evaluation of Integral and Analytical Plume Rise Algorithms

The purpose of this study was to evaluate the performance of current regulatory algorithms for predicting plume rise for refinerytype sources (short stacks and a wide range of source conditions) and the performance of new or alternate algorithms which may provide better estimates. To meet the objectives, five plume rise algorithms were statistically evaluated against ten field and laboratory plume rise data bases. Two forms of the Briggs plume rise equations were tested because they are almost exclusively used in current EPA regulatory models. Two modified Briggs equations were tested to assess how simple modifications can Improve the accuracy of the estimates. The fifth algorithm was a numerical solution to the basic equations for conservation of mass, momentum, and energy often referred to as an Integral plume rise algorithm. This algorithm was selected because It handles the wide range of source and atmospheric boundary-layer conditions that affect trajectories of plumes from refinery stacks.

Ten independent plume rise data bases were assembled that covered a wide range of source and meteorological conditions. From the data bases, a total of 107 different data sets were obtained and each data set included plume rise observations versus downwind distance for one source and meteorological condition. Each model was run for each data set and the root-mean-square and mean error between model and observation was computed for use in statistically evaluating model performance.

The statistical evaluation of the algorithms showed that the rms error (considering all data bases) for the Integral plume rise algorithm was approximately 30 percent less than the errors for all other algorithms tested. This difference was significant at the 95 percent confidence level. The results suggest that improved plume rise estimates in regulatory models applied to refineries and other appropriate sources could be achieved to reduce costs and improve ambient air quality estimates through the use of an integral plume rise algorithm.     

A feasibility study on the predictive emission monitoring system applied to the Hsinta power plant of Taiwan Power Company

The continuous emission monitoring system (CEMS) can monitor flue gas emissions continuously and instantaneously. However, it has the disadvantages of enormous cost, easily producing errors in sampling periods of bad weather, lagging response in variable ambient environments, and missing data in daily zero and span tests and maintenance. The concept of a predictive emission monitoring system (PEMS) is to use the operating parameters of combustion equipment through thermodynamic or statistical methods to construct a mathematic model that can predict emissions by a computer program. The goal of this study is to set up a PEMS in a gas-fired combined cycle power generation unit at the Hsinta station of Taiwan Power Co. The emissions to be monitored include nitrogen oxides (NOx) and oxygen (O2) in flue gas. The major variables of the predictive model were determined based on the combustion theory. The data of these variables then were analyzed to establish a regression model. From the regression results, the influences of these variables are discussed and the predicted values are compared with the CEMS data for accuracy. In addition, according to the cost information, the capital and operation and maintenance costs for a PEMS can be much lower than those for a CEMS.