厌氧序批式反应器快速启动的影响因素述评

厌氧序批式反应器是第三代新型高速厌氧反应器,其快速启动运行规律的研究相对较少。总结了目前国内外关于ASBR快速启动的研究进展情况,并结合试验成果,论述了ASBR快速启动的影响因素,包括运行方式、搅拌、种泥类型、投加物、反应器构型等方面,以及当前研究中存在的问题。     

Biodegradation of novel amino acid derivatives suitable for complexing agents in pulp bleaching applications

The biodegradability of four novel diethanolamine derivative complexing agents was examined by using two biodegradation tests standardised by OECD (301B and 301F). Ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) were employed as reference substances. Biodegradation of the new complexing agents was studied both with unacclimated and acclimated inocula as well as by simulating wastewater treatment in sequencing batch reactors (SBRs). These new complexing agents were of technical grade, and therefore, the results are only indicative but these new compounds hold promise for use as complexing agents in the pulp and paper industry.The novel complexing agents were not readily biodegradable but they showed slight biodegradation. Around 10-30% degradation was found in the SBR where degradation was followed by measurement of concentration. Moreover the novel complexing agents did not have any negative impact on reactor performance as measured by chemical oxygen demand reduction. In the standardised biodegradation tests at best around 50% degradation was observed with the acclimated inoculum and in the prolonged test whereas EDTA and DTPA exhibited no biodegradation. The elevated degradation in acclimated sludge indicates that the water treatment plant microbes are capable of decomposing these molecules under favourable conditions. The total concentration of novel complexing agents decreased slightly during biodegradation tests, while the EDTA and DTPA concentrations remained stable.     

Anaerobic biodegradability and treatment of grey water in upflow anaerobic sludge blanket (UASB) reactor

Feasibility of grey water treatment in an upflow anaerobic sludge blanket (UASB) reactor operated at different hydraulic retention time (HRT) of 16, 10 and 6h and controlled temperature of 30 degrees C was investigated. Moreover, the maximum anaerobic biodegradability without inoculum addition and maximum removal of chemical oxygen demand (COD) fractions in grey water were determined in batch experiments. High values of maximum anaerobic biodegradability (76%) and maximum COD removal in the UASB reactor (84%) were achieved. The results showed that the colloidal COD had the highest maximum anaerobic biodegradability (86%) and the suspended and dissolved COD had similar maximum anaerobic biodegradability of 70%. Furthermore, the results of the UASB reactor demonstrated that a total COD removal of 52-64% was obtained at HRT between 6 and 16 h. The UASB reactor removed 22-30% and 15-21% of total nitrogen and total phosphorous in the grey water, respectively, mainly due to the removal of particulate nutrients. The characteristics of the sludge in the UASB reactor confirmed that the reactor had a stable performance. The minimum sludge residence time and the maximum specific methanogenic activity of the sludge ranged between 27 and 93 days and 0.18 and 0.28 kg COD/(kg VS d).     

Effect of backwashing on perchlorate removal in fixed bed biofilm reactors

The influence of backwashing on biological perchlorate reduction was evaluated in two laboratory scale fixed bed biofilm reactors using 1- or 3-mm glass beads as support media. Influent perchlorate concentrations were 50 microg/L and acetate was added as the electron donor at a concentration of 2 mg C/L. Perchlorate removal was evaluated at various influent dissolved oxygen (DO) concentrations. Complete perchlorate removal was achieved with an influent DO concentration of 1mg/L resulting in bulk phase DO concentrations below the detection limit of 0.01 mg/L. The influence of increasing influent DO concentrations for 12 h periods was evaluated before and after individual backwash events. Partial perchlorate removal was achieved with an influent DO concentration of 3.5 mg/L before a strong backwash (bulk phase DO concentrations of approximately 0.2mg/L), while no perchlorate removal was observed after the strong backwash at the same influent DO level (bulk phase DO concentrations of approximately 0.8 mg/L). The immediate effect of backwashing depended on influent DO concentrations. With influent DO concentrations of 1 mg/L, strong backwashing resulted in a brief (<12 h) increase of effluent perchlorate concentrations up to 20 microg/L; more pronounced effects were observed with influent DO concentrations of 3mg/L. Daily weak backwashing had a small and, over time, decreasing negative influence on perchlorate reduction, while daily strong backwashing ultimately resulted in the breakdown of perchlorate removal with influent DO concentrations of 3 mg/L.     

Application of a three-component competitive adsorption model to evaluate and optimize granular activated carbon systems

A recently developed kinetic model for granular activated carbon (GAC) adsorbers (COMPSORB-GAC) that quantitatively describes the adsorption of trace organic contaminant in the presence of competing natural organic matter (NOM) was applied to evaluate the performance of different GAC system configurations: conventional fixed-bed adsorbers, layered upflow carbon adsorbers (LUCA), and moving-bed adsorbers (with few or many bed sections). COMPSORB-GAC separately tracks the adsorption of three components: a trace compound, a strongly competing NOM fraction that reduces trace compound equilibrium capacity, and a pore-blocking NOM fraction that reduces kinetics. Performance was simulated for various design criteria and with model parameters derived for two natural waters with significantly different NOM concentrations. For the range of simulated conditions and with baseline performance defined by a fixed-bed adsorber, LUCA generally reduced carbon usage rates (CURs) by 15-35%. A 2-section and a 16-section moving-bed reactor reduced baseline CURs by 20-30% and 45-55%, respectively. Projected CURs for the water source with a relatively high NOM concentration were 2-3 times higher for all reactor configurations and indicated that NOM preloading would cause performance deterioration in deep GAC beds, which highlights the importance of source water quality. These results show how COMPSORB-GAC can be used in a comprehensive, site-specific optimization of GAC systems to ensure robust system performance and to balance capital and operating costs.     

基于MABR的压裂返排液处理及微生物群落研究

压裂返排液含有多种复杂有机物,毒性高、盐度高以及可生化性差。设计了1个三级MABR系统用于压裂返排液的处理,该系统在最适宜运行参数下表现出优异的除碳脱氮性能,出水经过芬顿试剂处理后满足污水综合排放二级标准。MABR系统对COD、NH⁺₄-N和TN的去除率分别达到79.30%、96.06%和75.61%。微生物分析表明MABR生物膜富集了丰富的功能菌群,Proteobacteria(变形菌门)、Bacteroidetes(拟杆菌门)是生物膜中的优势菌群。阐明了MABR处理压裂返排液的技术可行性,为MABR在处理相关废水中的应用奠定了基础。     

气升式反应器在L-苯丙氨酸发酵产酶过程中的应用

针对L 苯丙氨酸的酶法制备体系 ,研究了内循环和外循环气升式反应器在L 苯丙氨酸产酶发酵过程中的应用。实验发现 ,与标准机械搅拌罐相比 ,采用气升式反应器发酵产酶 ,转氨酶酶活分别提高了 2 0 %和 1 0 % ,产酶周期也相应缩短。     

乳化液膜法提取废水中柠檬酸膜配方的研究

利用恒界面反应器，考察了流动载体，流动载体浓度，表面活性剂浓度。内相试剂浓度。制乳转速，油内比等因素对提取率的影响。用正交试验法设计实验。结果表明：在恒界面情况下，载体采用3%（V/V）三正辛胺（TOA），表面活性剂采用3%（V/V）span80。内相采用浓度为15%（W/V）Na2CO3，油内比Roi为1：1，制乳转速n=2000r/min是该实验液膜体系的较佳配方。     

有机氯化物动态光催化反应器数学模型

根据光催化反应的特点,采用工业常用的管式圆柱(环)型反应器,建立外循环悬浮态光催化反应器系统。以氯代愈创木酚光催化降解为例,采用中心有限差分法对模型进行离散化,并用积分追赶法、四阶龙格-库塔单步积分法进行计算;用Matlab软件进行微分方程的求解。再用Origin软件描绘出反应器内光强分布和浓度分布的三维立体图。结果表明,紫外光强的辐射随着径向远离光源而逐渐减弱;反应器中无因次浓度分布沿着轴向(水流方向)逐渐降低,沿径向(远离光源方向)浓度逐渐增大。     

厌氧处理宣纸檀皮蒸煮黑液

采用酸化预处理和厌氧折流工艺对宣纸生产中产生的高浓度檀皮蒸煮黑液进行处理研究.结果表明:预处理主要是进行水解和酸化,改善废水水质;厌氧折流反应器(ABR)是处理的主要单元,当进水COD浓度为7 250～8 500mg/L,ABR的水力停留时间为24h,容积负荷为9.2kg COD/(m3@d)时,ABR反应器对COD的去除率超过80%;两相厌氧处理可作为好氧处理的预处理段.