膜生物反应器用于城市污水处理与回用的试验研究

采用规模为40m^3／d的膜生物反应器对城市污水处理回用进行了试验研究．试验结果表明：膜生物反应器具有较强的抗冲击负荷能力，活性污泥对污染物的去除起主要作用，膜分离对维持稳定的出水起重要作用．膜生物反应器出水稳定，水质良好，优于生活杂用水水质标准(CJ25．1—89)．     

Comparison of nutrients degradation in small scale membrane bioreactors fed with synthetic/domestic wastewater

Two membrane bioreactors were operated with biological phosphorus removal, carbon degradation and denitrification to check how comparable and representative they were compared to full-scale plants. One was fed with synthetic municipal wastewater and was switched from pre- to post-denitrification without carbon dosing. The influent of the second plant was drawn from a separate sewer. This plant worked the whole time with post-denitrification without carbon dosing. The synthetic wastewater was designed to achieve a realistic COD:TN:TP ratio and tested for long time biodegradability. The eliminations were >94% (COD) and >97% (TP) for both plants. This was within the range of commercial plants, as well as the TN elimination for the pre-denitrification of plant I (>75%). The eliminations of TN for post-denitrification were above 80% for both plants despite the high influent concentrations and the missing carbon source for post-DN. A calculation of the nitrification rates gave values similar to those found in literature (1-6 mgN/(gMLVSSh)). A comparison of the denitrification showed expected rates for pre-denitrification (7.5 mgN/(gMLVSSh)) for plant I. The values (on average 1.8 mgN/(gMLVSSh)) for post-denitrification in plant II were higher than endogenous denitrification rates which are commonly reported as 0.2-0.8 mgN/(gMLVSSh). The rates for post-denitrification in plant I were only slightly higher than endogenous ones (0.9 mgN/(gMLVSSh)).     

Degradation characteristics of secondary effluent of domestic wastewater by combined process of ozonation and biofiltration

The performance of the combined process of ozonation and biofiltration was studied for treating the secondary effluent from sewage treatment plant. It was found that COD, NH(3)-N, and TOC were removed from 40-52, 10-19, and 9-13 mg/L in the raw water to 18-23, 0.5-1.5, and 7-8.5 mg/L in the effluent water (removal efficiency were 58, 89, and 25%, respectively), respectively, with an ozone dose of 10 mg/L (0.7-1.1 mg O(3)/(mg TOC) and 0.2-0.25 mg O(3)/(mg COD)), and contacting time of 4 min. Under the operation conditions, ozonation enhanced the biodegradability of the organics in the secondary effluent, as illustrated by increasing biodegradable dissolved organic carbon (BDOC) value from 0.8-1.1 mg/L in the raw water to the 2.0-2.7 mg/L in the effluent water. Meanwhile, the percentage of the organics with molecular size less than 1k Da in the secondary effluent increased from 52.9 to 72.6%. The experimental results supported the expectation that the combined process of O(3)/Biofiltration might enhance the overall treatment efficiency of secondary effluent treatment.     

用集成膜过程对含油废水进行资源化回收利用处理

采用电渗析与超滤、微滤相结合的集成膜过程对含油废水进行了资源化回收利用处理,并对该工艺中电渗析脱盐过程的各项运行参数与分离效果之间的关系进行了讨论.在此基础上,为进一步改善出水水质,还对不同材料的超滤、微滤膜去除废水CODCr的效果作了相应的实验比较.     

A/O-MBR强化脱氮除磷优化控制研究

采用A/O-MBR脱氮除磷工艺对生活污水进行小试试验,通过改变回流策略来强化营养物的去除效果.试验结果表明,间歇回流的运行方式并没有对系统的硝化效果产生影响,全程硝化率达到了99.4%;与连续回流的运行模式相比,TP的去除率明显提高,由57.98%上升到81.5%,出水由2.13 mg/L降到了0.98 mg/L;TN的去除率由于在缺氧池的停留时间变短而有所下降,由77.4%下降至66.3%,出水由10.9 mg/L上升至15.8 mg/L;有机污染的去除率受回流模式的影响较小,去除率稳定在91.9%左右.     

膜生物反应器脱氮除磷工艺处理城市污水的工程应用

为强化城市污水脱氮除磷,研发了厌氧/缺氧/好氧/缺氧-膜生物反应器(A2/O/A-MBR)新工艺,并建设了设计处理规模为2万m3/d实际工程.对该工程的长期监测表明,出水C()D、TN、NH4+-N和TP的平均浓度分别为20.6、6.67、1.05、0.19 mg/L,优于《城镇污水处理厂污染物排放标准》中的一级A标准...     

传统帘式和海藻式MBR法处理印染废水的研究

采用帘式与海藻式两种膜在一定的污泥条件下(如MLSS,pH,SV等),对印染废水各项污染物质的去除效果和膜运行过程进行研究,探索两种膜组件的各自优缺点.实验结果表明:帘式膜对污染物质的去除效果比藻式的好,而藻式膜的抗膜污染性则较好.     

Decolorization and COD reduction of UASB pretreated poultry manure wastewater by electrocoagulation process: a post-treatment study

The performance of electrocoagulation (EC) technique for decolorization and chemical oxygen demand (COD) reduction of anaerobically pretreated poultry manure wastewater was investigated in a laboratory batch study. Two identical 15.7-L up-flow anaerobic sludge blanket (UASB) reactors were first run under various organic and hydraulic loading conditions for 216 days. Effects of operating parameters such as type of sacrificial electrode material, time of electrolysis, current density, initial pH, and electrolyte concentration were further studied to optimize conditions for the post-treatment of UASB pretreated poultry manure wastewater. Preliminary tests conducted with two types of sacrificial electrodes (Al and Fe) resulted that Al electrodes were found to be more effective for both COD and color removals than Fe electrodes. The subsequent EC tests performed with Al electrodes showed that optimal operating conditions were determined to be an initial pH of 5.0, a current density of 15mA/cm(2), and an electrolysis time of 20min. The results indicated that under the optimal conditions, about 90% of COD and 92% of residual color could be effectively removed from the UASB effluent with the further contribution of the EC technology used as a post-treatment unit. In this study, the possible acute toxicity of the EC effluent was also evaluated by a static bioassay test procedure using guppy fish (Lebistes reticulatus). Findings of this study clearly indicated that incorporation of a toxicological test into conventional physicochemical analyses provided a better evaluation of final discharge characteristics.     

Spray drying of a poorly water-soluble drug nanosuspension for tablet preparation: formulation and process optimization with bioavailability evaluation

Spray drying experiments of an itraconazole nanosuspension were conducted to generate a dry nanocrystal powder which was subsequently formulated into a tablet formulation for direct compression. The nanosuspension was prepared by high pressure homogenization and characterized for particle-size distribution and surface morphology. A central composite statistical design approach was applied to identify the optimal drug-to-excipient ratio and spray drying temperature. It was demonstrated that the spray drying of a nanosuspension with a mannitol-to-drug mass ratio of 4.5 and at an inlet temperature of 120?°C resulted in a dry powder with the smallest increase in particle size as compared with that of the nanosuspension. X-ray diffraction results indicated that the crystalline structure of the drug was not altered during the spray-drying process. The tablet formulation was identified by determining the micromeritic properties such as flowability and compressibility of the powder mixtures composed of the spray dried nanocrystal powder and other commonly used direct compression excipients. The dissolution rate of the nanocrystal tablets was significantly enhanced and was found to be comparable to that of the marketed Sporanox®. No statistically significant difference in oral absorption between the nanocrystal tablets and Sporanox® capsules was found. In conclusion, the nanosuspension approach is feasible to improve the oral absorption of a BCS Class II drug in a tablet formulation and capable of achieving oral bioavailability equivalent to other well established oral absorption enhancement method.