水力旋转填料生物接触氧化处理城市污水的研究

通过对中试规模的新型水力旋转填料生物接触氧化法处理城市污水的试验研究,利用新型填料的独特构型,增强反应器的传质性能,探讨了接触氧化池对COD、NH+4-N的去除,及水力停留时间、气水比、温度对处理效果的影响。试验结果表明在水力停留时间为2~2.5h,气水比为(7~8)∶1,进水COD、NH4+-N浓度分别为130.1~366.5mg/L、11.3~19.2mg/L的条件下,两者的平均去除率为75.9%、65.4%,出水COD、NH4+-N浓度均已达到国家二级排放标准;气水比和水力停留时间对接触氧化池处理效果的影响较为明显;低温下接触氧化池对有机物、氨氮的去除仍具有较好的效果。     

三相生物流化床处理啤酒废水

通过三相生物流化床处理啤酒废水的实验研究,探讨曝气量和水力停留时间对处理效果的影响,确定最佳曝气量为0.25 m³/h,最佳水力停留时间为1.5 h。在该实验条件下,COD_cr平均去除率在85％以上,生物浓度高达28.31 mg/L,生物膜活性强,同时反应器具有较强的抗冲击负荷能力。     

ABR反应器结构对水力特性的影响

ABR反应器的结构决定了反应器的流态, 从而控制着可能达到的处理效率.为进行反应器结构优化设计, 首次研究了ABR的下、上向流室宽度比、折流板底端距底板距离和折流板折角等结构参数与ABR水力特性之间的关系.厌氧折流板反应器ABR的典型结构由一系列相同结构单元串联组成.反应器的水力特性可通过研究单个单元的水力特性推知.采用停留时间分布RTD (residence time distribution)方法研究了反应器各结构参数的变化对一个5.2 5L的ABR单元清水水力特性的影响.结果表明: ABR的死区较小, 远低于其他厌氧生物反应器; 流态接近理想推流式; 下、上向流室宽度比不宜过小, 最佳值为1∶3;折流板底端距底板距离与死区在本试验所取范围内(1~ 5cm)成正比关系; 折流板折角以50°左右为佳.      

SMBR中污染物处理效率随污泥浓度变化的数学模型

以一体式膜生物反应器(SMBR)对生活污水进行处理,研究不同水力停留时间(HRT)条件下污泥浓度对有机物去除率的影响,并对所得试验数据进行曲线拟合,建立有机物去除率与污泥浓度的数学模型。试验结果表明:在溶解氧(DO)浓度为2.0～3.0mg/L的条件下,HRT为3h、2h和1h时,有机物去除率(η)随着污泥浓度的增大而增大,但当污泥浓度增大到6000mg/L时,η增大趋势逐渐减小,并趋于稳定。有机物去除率与污泥浓度的数学模型表明:有机物去除率(η)与水力停留时间(τ)、进水COD浓度(S_o)和污泥负荷率(N_s)等主要运行参数有关,并可以通过调节运行参数τ、S_o和N_s来达到所需要的COD去除率。     

硝化载体选择试验研究

实验结果表明,以活性炭和甲壳素为悬浮载体的生物反应器,进水中NH3-N质量分数为50mg/L,水力停留时间为20h,投加量分别为8.93g/L、2.71g/L时,氨氮去除率接近于100%,为适宜的硝化细菌生长载体.     

贝壳填料酸化反应器预处理生活污水试验

在中国沿海一带,海产品废弃物贝壳多数进行废弃处理,成为潜在的环境隐患,对其进行废物资源化利用将是很好的选择.利用贝壳做填料,通过98 d的小试研究,考察了厌氧固定膜反应器在18～25 ℃条件下的运行效果.在水力停留时间分别为4 h、8 h和12 h的条件下,考察了反应器处于酸化段对污染物的处理效能.运行期间获得了较高的TP去除率,水力停留时间4 h、8 h和12 h对应的平均COD去除率分别为55.0%,58.0%和58.9%,平均TP去除率分别为16.90%,25.95%和27.43%.在试验条件下,贝壳释放的碱度足以调节系统的pH值,水力停留时间8 h和12 h对应的出水pH值较进水增加11.6%和16.5%.试验结果表明,贝壳是一种理想的酸化反应器微生物附着和生长载体,从技术和经济角度,水力停留时间设定为8 h较佳.     

新型一体化水族箱对养鱼循环水中三氮的去除实验

针对目前我国养鱼水处理器体积大、易生物堵塞、氨氮或亚硝酸盐氮积累等问题,设计了水族箱与水处理器一体化设备,采用物理过滤+生物降解+活性炭吸附工艺对养鱼水进行处理后循环利用;研究了不同工况条件下,水温、水力停留时间(HRT)、曝气量、曝气频率对养鱼水中三氮(NH4+、NO3-、NO2-)去除效果的影响。实验结果表明:水处理器污泥产量低,不易堵塞;当水温为25℃、曝气量为1.5 L/min、水力停留时间为1.5 h时,采用曝气频率0.5运行,NH4+、NO3-、NO2-皆未检出,即NH4+去除率大于97.5%,NO3-去除率大于96%,NO2-去除率大于98.7%。     

复合生物反应器处理城市污水的试验研究

为了提高城市污水的处理效率、降低运行成本,进行了复合生物反应器处理城市污水的试验研究,从曝气停留时间、有机负荷率、气水比等3个方面研究了试验运行的最佳条件和控制参数.试验结果表明,利用该工艺方法处理城市污水在有机负荷率高达2.44 kgCOD/kgMLSS*d的条件下,停留时间1.5～2 h,气水比(2.5～3)∶1,可使出水COD去除率达80%以上.该方法强化了混合液的物相传质速率.     

异波折板多段两相厌氧城市污水处理工艺试验研究

提出了异波折板多段两相厌氧城市污水处理工艺。通过反应器内异波折板的结构设计、液相流速设计和系统内生物相的分段调控,在提高传质效率的同时,使不同种群微生物的生化活性得到明显改善,有机污染物去除效率显著提高。实验结果表明,当水力停留时间大于10 h时,COD的去除率可达90%以上,而且受温度影响很小。     

褐铁矿与石英砂作为反硝化生物滤池填料的比较

近年来铁氧化物在废水处理及其他环境污染控制领域中的应用得到了广泛关注。本文研究了石英砂和褐铁矿作为填料时的反硝化生物滤池的启动以及在不同水力停留时间下的反硝化脱氮性能。结果表明,褐铁矿为填料的反硝化生物滤池更容易启动并达到稳定状态。维持反硝化生物滤池的运行条件在p H 7.50±0.15和温度22±3℃,进水中的化学需氧量浓度和NO3--N浓度分别为400 mg/L和100 mg/L,当水力停留时间为4 h时,两个反应器中NO3--N的去除率均在99%以上;当HRT缩短为1 h时,以褐铁矿为填料的生物滤池中NO3--N的去除率依然保持在98%以上,而以石英砂为填料的生物滤池中NO3--N的去除率仅为83.25%,并且出水中检测到NO2--N,其最大浓度为0.9 mg/L。实验结果表明褐铁矿是一种良好的反硝化生物滤池填料。     

Treatment of domestic wastewater using upflow anaerobic sludge blanket reactor

This paper presents the findings of the study on treatment of domestic wastewater using a laboratory scale Hybrid Upflow Anaerobic Sludge Blanket (HUASB) reactor. The reactor with a working volume of 5.9 L and plastic cut rings as packing media was operated at varying Hydraulic Retention Time (HRT) for a period of 110 days. While the COD removal varied from 75–86%, the BOD removal was in the range of 70–91%. Methane content in the biogas was 62±3%. VFA levels fluctuating between 100 and 186 mg/L (as acetate) did not pose operational problems such as souring of the reactor. During the treatment, nutrient levels exhibited an increasing trend. HUASB system could be designed with very short HRT of 3.3 hours, which will reduce the treatment cost significantly. It appears to be a promising alternative for the treatment of domestic wastewater in developing countries like India     

潜流构建湿地氮素转化运移的理论模型研究

构建湿地中氮素的主要存在形态为有机氮和无机氮,无机态氮主要包括氨态氮和硝态氮两种形态。一方面,这些氮素之间通过矿化、氨同化、硝化、反硝化、吸附交换、植物吸收等物理、化学及生物学过程相互联系并相互转化;另一方面在构建湿地污水处理系统中,从进水到出水,这些不同形态的氮素又随多孔介质中的饱和流发生运移。根据氮素的转化机理和溶质运移理论,以构建湿地中氮素的溶质运移模型为基础,将氮素转化的机理过程作为源汇项包括到基本模型中,由不同形态氮素的运移转化模型相联合形成构建湿地中氮素转化运移的理论模型系统。根据文献调研,给出模型系统参数的参考值,并简要介绍了模型系统的计算机语言求解方法。该模型为深入研究构建湿地中污水脱氮综合机理提供工具,其结果为以脱氮为目的的构建湿地的设计提供科学参考。     

Evaluation of moving-bed biofilm sequencing batch reactor (MBSBR) in operating A<Superscript>2</Superscript>O process with emphasis on biological removal of nutrients existing in wastewater

In this study, the performance of moving-bed biofilm sequencing batch reactor in operating the anaerobic/anoxic/oxic (A²O) process for treatment of wastewaters containing nitrogen and phosphorous was evaluated. For this purpose, a pilot system with two bench-scale sequencing batch reactors with a total volume of 30 L and functional volume of 10 L was used. The installation was elaborated using plexiglass, in which 60% of the functional volume consisted of PVC suspended carriers (Kaldnes K3) with a specific surface area of 560 m²/m³. The independent variables used in this study were hydraulic retention time (HRT) (1.5, 2, 2.5, 3, and 3.5 h) and the initial organic load (300, 500, 800, 1000 mg O₂/L). The results showed impressive performance in the case of an initial organic load of 300 mg O₂/L and HRT of 3 h with maximum removal of COD and TN, respectively, by 95.1 and 89.8%. In the case of an initial organic load of 1000 mg O₂/L and HRT of 3.5 h, the maximum total phosphorus removal was 72.3%. Therefore, according to the analysis of data obtained by different HRTs, it was revealed that the system of A²O has greater efficiency in removing organic matter from wastewater in the shortest possible time.     

Denitrification of nitrate-contaminated groundwater using biodegradable snack ware as carbon source under low-temperature condition

A considerable increase in nitrate concentration in groundwater has been observed in many countries. This research focuses on nitrate removal using biodegradable snack ware (BSW) as both carbon source and biofilm support for denitrifiers. The denitrification efficiency of a laboratory-scale denitrification reactor packed with BSW was examined in a low-temperature condition. The nitrate removal efficiency supported by BSW decreased to approximately 40% at 12°C from nearly 100% at 25°C with 50?mg/L of nitrate-nitrogen in the influent and 2?h of hydraulic retention time (HRT). The complete nitrate removal was obtained when nitrate-nitrogen concentration was no more than 15?mg/L at 2?h of HRT and at 12°C. If the initial concentration of nitrate-nitrogen was 50?mg/L, 5?h of HRT was needed for the complete nitrate removal. Nitrite concentration in the treated water decreased evidently as HRT was increased from 2 to 5?h, or as nitrate-nitrogen concentration in the influent decreased to 15?mg/L from 50?mg/L. It was observed that varying HRT and nitrate concentration in the influent had no noticeable effect on dissolved organic carbon content in the effluent under the experimental conditions. This study indicated that the complete nitrate removal could be achieved readily even at 12°C using BSW as carbon source by changing HRT or the initial concentration of nitrate in the influent, which has some useful implications in environmental engineering practice.     

中温UBF与UASB两相厌氧系统处理垃圾渗滤液的实验研究

针对石碑岭垃圾场渗滤液水质特性,采用以高效生物陶粒为填料的UBF反应器作酸化相,以UASB反应器作甲烷相的两相厌氧系统进行了处理垃圾渗滤液的实验研究.实验结果表明:在系统进水CODCr和BOD5质量浓度分别为3 887 mg/L和819 mg/L,UBF与UASB的HRT分别控制在10.3 h和61.7 h时,CODCr和BOD5总去除率分别为85.4%和90.1%,UBF酸化率达42.9%,BOD5/CODCr比值由0.21提高到0.39.     

Treatment of polluted river water by a new constructed wetland

A new constructed wetland was built to purify one polluted river in Taiwan, and this study was conducted to evaluate the treatment efficiency of the wetland. Due to the very limitation of available budget, several water quality items, which were stipulated by Taiwan’s Environmental Protection Administration for rivers, in the influent and effluent of wetland were analyzed and evaluated. These items included water temperature, pH, DO, BOD₅, TSS, and NH₄ ⁺-N. The results showed that the average removal rates of total (unfiltered) BOD₅, TSS and NH₄ ⁺-N were 36.9 %, 71.8 % and 47.1%, respectively. With the HRT more than 3.4 days, the wetland could treat the polluted river water effectively. Longer HRT in this wetland appeared no obvious improvement on the removal rate of TSS or NH₄ ⁺-N. However, BOD removal rate increased while the HRT (Hydraulic Retention Time) increased to about 5 days. In this wetland, the calculated mean first-order reaction rate constant (k_T) for BOD₅ was 0.15/day with a standard deviation of 0.13/day and for NH₄ ⁺-N was 0.24/ day with a standard deviation of 0.18/day. It is also concluded that there is a linear proportional relationship between BOD concentrations in the effluent of wetland and its influent mass loading rates, with the coefficient of determination (R²) of 0.6511. Similar result was seen for NH₄ ⁺-N as well, with the coefficient of determination (R²) of 0.5965. TSS removal rate was found to be linearly proportional to its influent mass loading rate, with the coefficient of determination (R²) of 0.4875.     

Treatment of septic tank effluent using moving-bed biological reactor: kinetic and biofilm morphology

Septic tanks are very commonly used wastewater collection systems throughout the world, and especially in rural areas. In this study, the use of moving-bed biological reactors (MBBR) for the treatment of septic tank effluent (STE) was examined. The study was conducted in two phases. In Phase I, the performance of septic tanks from four projects working under different operational conditions and with different service lives was followed to determine the parameters that required further treatment. In Phase II, four specially designed continuous flow pilot-plant MBBRs and one laboratory-scale batch reactor were tested for their efficiency in treating STE. Experiments were carried out at various temperatures (8–25 °C) and with different hydraulic retention times (HRTs). MBBR effectively reduced STE’s nutrients and chemical oxygen demand by 90 and 85 %, respectively, over 180 days of operation. The average ammonia removal rate at 25 °C increased from 0.279 to 0.540 kg N/m³ when the reactor HRT changed from 5.7 to 13.3 h. Under these conditions, the ammonia removal kinetics were successfully correlated with a theta model with an average θ value of 1.054. The biofilm morphology showed a stable and global biomass coverage (>70 %) and a high percentage of live cells. A thinner biofilm was observed when the MBBR operated at high temperatures. The results of this study showed that MBBR is a promising technology for post-treatment of septic tank effluent.     

Modelling of moving bed biofilm reactor (MBBR) efficiency on hospital wastewater (HW) treatment: a comprehensive analysis on BOD and COD removal

Performance of moving bed biofilm reactor system for a real hospital wastewater (HW) was experimented, modelled, and optimized using response surface methodology. Prior to conducting laboratory tests, design of the experiments was evaluated to minimize any prediction error. Statistical analyses demonstrated the models’ validity and adequacy for anticipation of the removal of BOD and COD by the process. The models predictions (with desirability of 0.98) were found to be in very good agreement with confirmative experiments results. The results indicated that under convenient operating conditions of the studied variables (packing rate 70%, HRT 24 h, and MLSS 3000 mg/L), the removal efficiencies for BOD and COD were 97.8 and 95.6%, respectively. Moreover, kinetics of the biological process showed that removal of organic matters for the tested wastewater adheres to modified Stover–Kincannon model with a correlation coefficient of 0.998. Ratio of BOD to COD of 0.6 (optimal range for biological treatment normally is >0.5) suggests acceptable efficiency of the reactor for decomposing organic load. A high overall efficiency of the process and fulfilling the related standards make this system an appropriate option for treating HDW.     

The hydraulic retention time on the particle removal efficiency by <Emphasis Type="Italic">Daphnia magna</Emphasis> filtration on treated wastewater

The study of low-cost techniques for the tertiary treatment of wastewater is of global interest; above all low-energy techniques that do not require the use of chemicals. In this study, a wastewater treatment technology based on the filtration by a zooplanktonic population (Daphnia magna) is studied in controlled laboratory and mesocosm experiments for different hydraulic retention times (HRT). The efficiency of the treatment is evaluated in terms of particle removal efficiency. From laboratory experiments, HRT over 12 h and Daphnia concentrations above 50 individuals l^?1 guarantee a particle removal efficiency greater than 30 %. However, low HRT of 6 h would require Daphnia concentrations above 70 individuals l^?1 in order to obtain a particle removal efficiency of 20 %. The minimum removal efficiency of 2 % was for HRT = 3 h, independent of the Daphnia concentration. In the mesocosm, the growth of Daphnia individuals enhanced Daphnia magna filtering rates and higher removal efficiencies than those in the laboratory for the same HRT range. In the mesocosm experiments E. coli concentrations were reduced to a maximum of 2 logarithmic units. A balance equation model is proposed to predict particle removal efficiencies for varying HRT.     

Influence of hydraulic retention time on heterotrophic biomass in a wastewater moving bed membrane bioreactor treatment plant

Wastewater treatment using moving bed membrane bioreactor technology was tested with real urban wastewater at a pilot plant, combining moving bed treatment as a biological process with hybrid biomass (suspended and fixed) and the advantages of a membrane separation system. The evolution of the kinetic constants of the hybrid biomass and organic matter removal were studied in a pilot plant under different operational conditions, by varying hydraulic retention time (HRT), mixed liquor suspended solids (MLSS) and temperature, and considering the attached biomass of the carrier and the dispersed biomass of the flocs to reproduce real treatment conditions. The rates of organic matter removal were 97.73 ± 0.81 % of biochemical oxygen demand (BOD₅), 93.44 ± 2.13 % of chemical oxygen demand (COD), 94.41 ± 2.26 % of BOD₅ and 87.62 ± 2.47 % of COD using 24.00 ± 0.39 and 10.00 ± 0.07 h of HRT, respectively. The influence of the environmental variables and operational conditions on kinetic constants was studied; it was determined that the most influential variable for the decay coefficient for heterotrophic biomass was HRT (0.34 ± 0.14 and 0.31 ± 0.10 days^?1 with 10.00 ± 0.07 and 24.00 ± 0.39 h of HRT, respectively), while for heterotrophic biomass yield, this was temperature (0.61 ± 0.04 and 0.52 ± 0.06 with 10.00 ± 0.07 and 24.00 ± 0.39 h of HRT, respectively). The results show that introducing carriers in an MBR system provides similar results for organic matter removal, but with a lower concentration of MLSS.