常规净水工艺对猛水蚤的去除机理及效果

为实现对桡足类生物泄露风险的高效控制,以猛水蚤为研究对象,开展了常规净水工艺对桡足类生物的去除作用机理及效果研究,重点研究了猛水蚤去除与絮体颗粒形态特性关系和在石英砂滤床的分布规律.结果表明:优化操作条件下,混凝沉淀和过滤对猛水蚤去除率均可达99%,最佳工况包括快速搅拌300 r/min(1min)、中速搅拌150 r/min(5min)和低速搅拌75 r/min(5min),聚合氯化铝(PAC)投加量10 mg/L,沉淀时间0.5h,滤速9m/h,过滤周期1d.混凝对猛水蚤的去除效率主要决定于猛水蚤与絮体的有效吸附,絮体颗粒粒径越大、分形维数越低,猛水蚤去除率越高;过滤水冲刷携带引起的被动迁移,是导致猛水蚤穿透砂滤池的主要原因,适当降低滤速和缩短过滤周期,控制猛水蚤被动迁移规模,可以达到提高猛水蚤去除率效果.     

基于Miseq的好氧反硝化菌源水脱氮的种群演变

为了研究好氧反硝化菌源水脱氮过程中水体微生物群落的演变,利用Miseq高通量测序法对投菌和对照两系统水体样本的微生物信息进行统计,并对两组样品进行了优化序列统计,OTU分布统计和分类学分析的基础分析;以及细菌群落结构,PCA,Rank-Abundance,Hcluster,Specaccum和OTU分布的高级分析.结果显示,投加贫营养好氧反硝化菌的源水系统的氮素得到有效去除,脱氮效果明显;层次聚类和主成分分析显示两系统内的群落结构发生变化,投菌系统与对照系统主要表现为变形菌和拟杆菌门;细菌主要门类和水质参数的相关性分析得出,水质指标对两系统群落变化作用明显;与此同时,投菌系统中有关氮循环的细菌有上升的变化过程. Miseq高通量测序研究源水脱氮过程的微生物种群演变可行,为研究原位生物脱氮过程的水体微生物群落演变提供技术支撑.     

缺氧/好氧电化学膜-生物反应器强化脱氮效果及抗污染性能研究

研究了外加电压下电化学A/O-MBR的污染物去除效果和抗污染性能,分析了抗污染性能提高的原因.结果显示,外加2V电压时系统对COD和总氮的平均去除率分别为89.4%、92.2%,不加电压时COD和总氮的去除率分别为87.6%、77.3%,表明外加电压能够显著提高A/O-MBR的脱氮处理效果;研究同时发现,外加2V电压时,导电膜的平均运行周期为38d,相比不加电压时（平均26d）,运行周期有所延长.污染物与导电膜之间的静电排斥作用和H₂O₂的原位清洗作用是系统抗污染性能提升的主要原因.     

Removal of elemental mercury by KI-impregnated clay

This study described the use of clay impregnated by KI in gas phase elemental mercury (Hg^o) removal in flue gas. The effects of KI loading, temperature, O₂, SO₂ and H₂O on Hg^o removal were investigated using a fixed bed reactor. The Hg^o removal efficiency of KI-clay with 3% KI loading could maintain at a high level (approximately 80 %) after 3 h. The KI-clay demonstrated to be a potential adsorbent for Hg^o removal when compared with activated carbon based adsorbent. O₂ was found to be an important factor in improving the Hg^o removal. O₂ was demonstrated to assist the transfer of KI to I₂ on the surface of KI-clay, which could react with Hg^o directly. NO and SO₂ could slightly improve Hg^o removal, while H₂O inhibited it greatly. The results indicated that after adsorption, most of the mercury escaped from the surface again. Some of the mercury may have been oxidized as it left the surface. The results demonstrated that the chemical reaction primarily occurred between KI and mercury on the surface of the KI-clay.     

Wastewater-nitrogen removal using polylactic acid/starch as carbon source: Optimization of operating parameters using response surface methodology

The use of PLA/starch blends for nitrogen removal was achieved. The influence of different operating parameters on responses was verified using RSM. The conditions for desired responses were successfully optimized simultaneously. Blends material may have a promising application prospect in the future. Nitrogen removal from ammonium-containing wastewater was conducted using polylactic acid (PLA)/starch blends as carbon source and carrier for functional bacteria. The exclusive and interactive influences of operating parameters (i.e., temperature, pH, stirring rate, and PLA-to-starch ratio (PLA proportion)) on nitrification (Y₁), denitrification (Y₂), and COD release rates (Y₃) were investigated through response surface methodology. Experimental results indicated that nitrogen removal could be successfully achieved in the PLA/starch blends through simultaneous nitrification and denitrification. The carbon release rate of the blends was controllable. The sensitivity of Y₁, Y₂, and Y₃ to different operating parameters also differed. The sequence for each response was as follows: for Y₁, pH>stirring rate>PLA proportion>temperature; for Y₂, pH>PLA proportion>temperature>stirring rate; and for Y₃, stirring rate>pH>PLA proportion>temperature. In this study, the following optimum conditions were observed: temperature, 32.0°C; pH 7.7; stirring rate, 200.0 r·min^-1; and PLA proportion, 0.4. Under these conditions, Y₁, Y₂, and Y₃ were 134.0 μg-N·g-blend^-1·h^-1, 160.9 μg-N·g-blend^-1·h^-1, and 7.6 × 10³ μg-O·g-blend^-1·h^-1, respectively. These results suggested that the PLA/starch blends may be an ideal packing material for nitrogen removal.     

Simulation of long-term nutrient removal in a full-scale closed-loop bioreactor for sewage treatment: an example of Bayesian inference

In this study, the performance of nitrogen and phosphorus removal in a full-scale closed-loop bioreactor (oxidation ditch) system was simulated using the ASM2d model. Routine data describing the process for two years were compiled for calibration and validation. To overcome the identifiability problem, the classic Bayesian inference approach was utilized for parameter estimation. The calibrated model could describe the long-term trend of nutrient removal and short-term variations of the process performance, showing that the Bayesian method was a reliable and useful tool for the parameter estimation of the activated sludge models. The anoxic phosphate uptake by polyphosphate accumulating organisms (PAO) contributed 71.2% of the total Poly-P storage, which reveals the dominance of denitrifying phosphorus removal process under the oxygen limiting conditions. It was found that 58.7% of the anoxic Poly-P storage and denitrification by PAO in the reactor was achieved in the aerated compartment, implying that the PAO’s anoxic activity was significantly stimulated by the low dissolved oxygen (DO) level in this compartment due to the oxygen gradient caused by brush aerator.     

不同有机物对厌氧氨氧化耦合反硝化的影响

通过连续试验和血清瓶批式试验研究了不同种类有机物对厌氧氨氧化耦合异养反硝化脱氮性能的影响.结果表明,从TN去除率来看,对耦合反应器的影响:苯甲酸钠<邻苯二酚<间苯二酚<丙酸钠<乙酸钠;苯甲酸钠、邻苯二酚、间苯二酚、丙酸钠和乙酸钠对厌氧氨氧化菌的影响很小.苯酚反硝化菌能利用苯甲酸钠、邻苯二酚、间苯二酚、丙酸钠和乙酸钠作为电子供体进行反硝化.不同有机物对苯酚反硝化菌的影响不同,进而影响苯酚反硝化菌与厌氧氨氧化菌之间的协同和竞争关系.苯甲酸是苯酚降解过程中可能的中间产物.     

低低温电除尘器灰硫比计算及中国煤种分析

低低温电除尘技术是电除尘新技术,不仅可以提高电除尘器的除尘效率,改善电除尘器对煤种的适应性,还可除去烟气中大部分的SO3,已经成为日本燃煤电厂烟气治理的主流。烟气的灰硫比(D/S)是低低温电除尘器选型设计中的一个重要参数,是电除尘器是否会受到低温腐蚀的评判标准。对烟气灰硫比的定义,计算公式的推导,中国几种代表性煤种的灰硫比,以及灰硫比与腐蚀和提效幅度的关系作了深入的分析。为我国低低温电除尘器的研究和应用推广提供参考。     

铁活化过二硫酸盐湿法氧化去除一甲胺恶臭气体

CH₃NH₂(一甲胺)作为一种重要的工业原料而被大量使用,其嗅阈值低,具有刺鼻的鱼臭味,是一种典型的恶臭气体. 选取PS(过二硫酸盐)作为氧化剂,采用湿法吸收氧化去除CH₃NH₂. 在探讨CH₃NH₂的吸收性能的基础上,比较了4种方式〔Fe2+活化PS、CA(柠檬酸)螯合Fe2+活化PS、Fe0活化PS、CA联合Fe0活化PS〕对CH₃NH₂湿法氧化去除效果的影响. 结果表明:CH₃NH₂ 气体在酸性条件下易溶于水;单独用Fe2+或Fe0活化PS处理CH₃NH₂时,Fe0活化后的去除效果明显优于Fe2+;然而,在联合使用螯合剂CA之后,Fe2+活化的去除效果反而优于Fe0. CA螯合Fe2+的CH₃NH₂去除率由单独Fe2+活化时的32%升至64%,Fe0活化与CA联合Fe0活化去除率均提升至40%. 究其原因,可能是由于不同活化方式下Fe2+释放速率不同所致,释放速率直接影响了Fe2+的存在时间,Fe2+活化PS速率对于氧化去除效果有影响,并最终影响CH₃NH₂的脱除.      

覆膜滤料特性实验研究

覆膜滤料是降低微细颗粒物排放,降低大气环境中PM2．5浓度源头的净化技术之一。对氟美斯（FMS ）针刺毡为基布覆膜滤料,进行了表面微观结构电镜扫描,同时,进行了这种滤料的阻力实验测试和分级效率测试。表面电镜扫描结果显示,覆膜呈微孔且直径为0．5μm左右的多层铰链结构。实验结果表明,覆膜滤料周期性清灰后阻力为1200 Pa ,万次老化实验后覆膜滤料阻力是1163．3 Pa;在过滤风速为1．4 m／min时,滤料对PM2．5的过滤效率高于99％。实验结果对使用覆膜滤料的布袋除尘器设计具有一定指导意义。