不同水平低水量运行对AAO工艺的影响

竹园污水处理厂四期工程建成后,进水量可能长期处于设计规模的30％～90％.因此,设置了进水量为设计规模40％和70％的低流量组和高流量组厌氧-缺氧-好氧(anaerobic-anoxic-oxic,AAO)中试反应器,用以模拟典型工况,从而为竹园四期工程和竹园片区的水量调度提供理论依据.在约2倍污泥龄的运行周期中,低流量组和高流量组反应器出水化学需氧量(COD)和氨氮浓度可稳定达到一级A标准;高流量组出水总氮(TN)浓度可稳定达到一级A标准,略优于低流量组;两组出水总磷(TP)浓度均无法达到一级A标准,建议进行深度处理,通过化学除磷达到排放标准.低流量组混合液悬浮固体(mixed liquid suspended solids,MLSS)质量浓度为(1.1±0.7)g/L,污泥体积指数(sludge volume index,SVI)为(68±11)mL/g,均低于正常范围;且外源呼吸耗氧速率(oxygen uptake rate,OUR)仅为0.084 mg/(L·min),远低于高流量组[0.426 mg/(L·min)].因此,推测AAO反应器的进水量长期处于40％设计规模时,对污泥性质可能产生不利影响.     

不同四环素废水处理系统中的抗生素抗性基因研究

通过序批式反应器(SBR)和移动床生物膜反应器(MBBR)两种类型反应器的运行比较了活性污泥和生物膜工艺对不同浓度四环素废水中污染物的去除效果,发现在相同生物量条件下生物膜系统对总氮和四环素的去除效果优于活性污泥系统。基于高通量测序的宏基因组学分析结果表明,活性污泥和生物膜中抗生素抗性基因(ARGs)种类和丰度的差异可能是导致污染物去除效果不同的主要原因。进一步对活性污泥和生物膜中微生物群落结构及其与ARGs的相关性进行分析,证实了微生物群落结构与ARGs组成显著相关,是造成活性污泥和生物膜中ARGs差异的主要原因,进而影响了两种工艺对四环素废水中污染物的去除。     

硫铁耦合中试反应器脱氮除磷效果研究

为实现城市污水处理厂二级出水的深度脱氮除磷,建立了硫铁耦合中试反应器,以污水厂生化出水为处理对象,通过改变进水NO_3~--N含量和水力停留时间(HRT),研究反应器脱氮除磷效果。结果表明,当进水体积流量为150～500 m~3/d(HRT=0.20～0.06 d),NO_3~--N、TP的质量浓度分别20、0.8 mg/L时,反应器出水的NH_4~+-N、NO_3~--N、TP的质量浓度可分别控制在1～5、1、0.3 mg/L,平均TN去除负荷(NRR)为0.08～0.11 kg/(m~3·d),最高可达0.19 kg/(m~3·d);当进水体积流量为150 m~3/d、进水NO_3~--N的质量浓度为30～45 mg/L时,反应器出水的NH_4~+-N、NO_3~--N的质量浓度均维持在1 mg/L以下,平均NRR约为0.17 kg/(m~3·d)。该硫铁耦合中试反应器具有良好、稳定的脱氮除磷能力,受进水负荷冲击影响较小,可为污水厂提标应用提供一定参考。     

HABR工艺在印染废水处理中的应用

采用复合式厌氧折流板反应器(HABR)工艺处理印染废水,考察不同水力停留时间(HRT)下HABR对COD、氨氮、色度等的去除效果。结果表明:在HRT为7、10 h和15 h时,出水COD_(Cr)的去除率均值分别为14.94%、25.6%、31.09%,隔室1的COD_(Cr)去除率最高;HRT为10 h时,出水的可生化性提升最显著,B/C由进水的0.26提高至0.35;随着HRT的增加,出水挥发性脂肪酸(VFA)的浓度不断降低,pH不断升高。此外,反应器进水的氨氮浓度均低于出水的氨氮浓度。GC/MS结果表明,HABR反应器处理后的废水中,有机物种类和含量均显著降低,部分大分子有机物被降解。有机物沿程降解动力学模型拟合较好,各隔室的有机物比降解速率不断降低。     

UASB-絮凝-SBR处理高含量头孢类抗生素废水

采用上流式厌氧污泥床(UASB)-絮凝-序批式活性污泥法反应器(SBR)组合工艺处理高含量头孢类抗生素废水,考察了3个废水处理阶段中的COD去除效果。结果表明,当进水COD为14.3 g/L、容积负荷在14.3 kg/(m.3d)时,UASB反应器的COD去除率稳定在85%左右,出水VFA的浓度在3 mmol/L左右,产气体积流量为17 L/d左右;对UASB出水进行絮凝处理以去除废水中难降解大分子物质,按每1L厌氧出水投加25 mL的PFC和5 mL的PAM后,废水COD由2.279g/L降至1.133g/L,去除率为50.3%;使用SBR处理絮凝后上清液,当反应器负荷为1.2kg/(m.3d)时,出水COD在200 mg/L以下,去除率稳定在80%左右,达到GB 21903-2008中的抗生素类废水排放要求。     

BSBR工艺对城市污水中低浓度磷酸盐的富集优化

采用生物膜序批式反应器（BSBR）在厌氧阶段COD仅为100 mg/L的条件下对模拟废水中的低浓度磷酸盐（2.5 mg/L）实现高效去除和高倍富集。结果表明：好氧出水磷浓度<0.5 mg/L且回收液的磷浓度最高达到了59.53mg/L，磷回收效率为58.63%，碳源消耗（回收每克磷消耗COD的量）为56.27±2.6 mg-P/mg-COD。高通量测序结果表明，当进水磷浓度由10 mg/L降至2.5 mg/L后，变形菌门的丰度从82.1%降至41.9%，拟杆菌门的丰度则从9.6%升至49.1%。在属水平，反应器稳定运行后，生物膜内优势群属主要为Flavobacterium(32.98%)。通过对DO、HRT和好氧厌氧进水体积比的优化，提高溶解氧和延长HRT有利于提高磷回收液浓度和磷回收效率并且降低碳源消耗。     

多级生物膜反应器分段进水方式对脱氮效能影响研究

提出多级生物膜反应器,考察了分段进水方式对反应器处理城镇污水生物脱氮效能的影响.结果表明,分段进水点的数量、流量分配及容积分配对反应器脱氮效能的影响显著,分段进水方式有效地提高了碳源利用率以及反应器脱氮效能.在水温为25℃左右,溶解氧为5mg·L~(-1),挂膜密度为30%,COD负荷为1.2 kg·m~(-3)·d~(-1),总氮负荷为0.22 kg·m~(-3)·d~(-1)的条件下,反应器分段进水方式采用第1级、第3级、第6级分段进水,容积分配比为2:3:4,流量分配比为2:2:1时,可使出水COD为38 mg·L~(-1),出水NH_4~+-N和TN的质量浓度分别为1.5 mg·L~(-1)和11.1 mg·L~(-1),去除率分别为80.8%,95.3%和69.2%,与单点进水方式相比TN去除率提高了8.4%.     

三相内循环生物流化床处理废水的研究

以活性碳和陶瓷颗粒为载体粒子,采用快速排泥挂膜法启动实验,在反应器的运行过程中逐渐加大进气量及进水量,直至出水COD浓度达到一个较低水平.分别考虑了进水COD浓度、空气流量、废水流量、容积负荷四个因素对COD去除率的影响.结果表明:当系统运行到第13 d时,COD的去除率达到了一个较大值,并趋于稳定.     

内循环三相好氧流化床用于废水脱硫

采用内循环好氧反应器处理模拟的含硫废水，以颗粒活性炭为载体，探讨影响反应器效果的主要因素，探求合理的运行参数。研究表明，对于不同的硫化物负荷，总存在一个最佳曝气量，使反应器的处理效率达到92％以上；HRT的减小、进水硫化物浓度的增加会降低硫化物的去除率；增加曝气量会提高反应器的去除能力；进水pH在7．5～8．5变化时对处理效果没有明显的影响；尾气中硫化物损失比率与出水硫化物浓度呈正相关，与进水pH有一定关系：反应器出水呈乳白色浑浊状时，处理效果最好。     

新型分段进水生物脱氮反应器启动策略研究

研究了基于多段进水工艺原理开发的新型分段进水生物脱氮反应器的2种启动模式(模式一为先调整适当HRT,再根据分段配水比进水,模式二根据分段配水比直接配比,然后逐步调整HRT)下的最优启动调控策略。结果表明,在2种模式下,出水SS的质量浓度和TCOD分别均能低于30 mg.L-1和50 mg.L-1,浊度平均去除率均在80%以上,无显著差异。模式一由单一进水口改成分段进水后,平均出水氨氮的质量浓度由11.93 mg.L-1上升至19.51 mg.L-1,平均TN去除率由18.43%上升至49.25%;而模式二的氮素污染物去除性能较稳定,平均氨氮和TN去除率分别为66.15%和54.71%。模式一的污泥含量增长速度要快于模式二,但3个曝气区的污泥含量增长并不均衡,不利于整体反应器的启动驯化。总体而言,新型分段进水生物脱氮反应器建议采用模式二进行启动。     

Preparation and characterization of porous microspheres and applications in controlled-release of abamectin in water and soil

Porous microspheres with different sizes were prepared through solvent evaporation method with ethylcellulose as a matrix material and abamectin as a core material. The abamectin-loaded microspheres were characterized through scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The chemical structure of the microspheres was determined through FTIR. DLS analysis showed that the diameter of the microspheres range from 10 to 100 μm. SEM analysis revealed that the inner structure of the microspheres is characterized by a porous network. TGA revealed that the microspheres are thermally stable below 125 °C. The controlled release of abamectin from the microspheres into water and soil was also investigated. Abamectin was released from microspheres into water through diffusion. The release of abamectin into soil was mainly caused by erosion, a result that was verified through SEM.     

西玛津在甘蔗及土壤中的残留消解动态

为了探明西玛津使用后在甘蔗及其土壤中的残留降解规律,采用气相色谱法研究了西玛津90%水分散粒剂在甘蔗及其土壤中的残留消解降解动态和最终残留实验。结果表明:西玛津在甘蔗和土壤中的降解动态方程分别为Ct=19.157e-0.0587t和Ct=1.689 8e-0.036t,半衰期分别为11.8 d和19.3 d;以1 647 g a.i./hm2和2 470.5 g a.i./hm2的剂量在甘蔗田进行喷雾处理,收获期甘蔗和土壤中的最终残留量分别小于0.01 mg/kg和0.02 mg/kg。     

表面活性剂在宾馆／酒店厨房、餐具保洁中的应用

本文简述了在宾馆／酒店厨房、餐具保洁中应用的表面活性剂的主要类型,并且仅限于对环境及物品的清洁。     

预分解窑窑头和窑尾参数的分析与控制

新型干法水泥是目前水泥行业的发展趋势,中央控制室是新型干法水泥生产线的控制指挥中心。预分解窑系统需要控制的参数较多,综合考虑各参数的变化将有利于窑系统的稳定运行。窑头和窑尾参数是准确判断窑系统运行状况的重要参数,包括窑尾的温度、压力,窑头的温度、压力,窑尾的气体分析等,在操作中应引起操作员的重视。     

高效液相色谱法同时测定蔬菜及水果中的吲哚丁酸和萘乙酸

采用高效液相色谱法,以DiamonsilTMC1(8250mm×4.6mm,5μm)为色谱柱,甲醇∶水∶磷酸为60∶40∶0.35(pH值3~4)作为流动相,检测波长为272nm的条件下测定萘乙酸和吲哚丁酸含量,试验结果表明:在0～50.00mg.L-1范围内线性关系良好,相关系数r吲=0.9998,r萘=0.9998,最低检出浓度为0.025mg.L-1,试样在5.00、10.00、15.00mg.L-13个添加水平下的平均回收率在81.2%~99.4%之间,相对偏差在0.41%~1.61%之间,方法简便,准确。     

Antioxidant activity and hepatoprotective potential of agaro-oligosaccharides in vitro and in vivo

Background  

Agaro-oligosaccharides derived from red seaweed polysaccharide have been reported to possess antioxidant activity. In order to assess the live protective effects of agar-oligosaccharides, we did both in vitro and in vivo studies based on own-made agaro-oligosaccharides, and the structural information of this oligosaccharide was also determined.     

Strength of polymethylmethacrylate in air and in n-propanol

A series of tests was conducted to measure the failure strengths of notched polymethylmethacrylate tensile specimens in air and n-propanol. Tests were conducted on specimens which had been subjected to creep stresses of various magnitudes and for different times. The resulting data indicate that two opposing factors contribute to the fracture strength in n-propanol. The presence of fluid during crack propagation increases the nominal fracture failure stress. Diffusion of the fluid into the polymer produces crazing resulting in the provision of a preferential crack path and consequent lowering of the fracture strength. The former mechanism dominates at small pre-stresses or at short creep times, resulting in an increase in strength in n-propanol over that in air. However, the latter mechanism is dominant at higher creep stresses and longer creep times with a resulting decrease in strength in n-propanol compared to that in air.     

Morphology and microstructure of autoclaved clinker and slag-lime pastes in presence and in absence of silica sand

Development of microstructure in four hydrothermal reactions has been undertaken using scanning electron microscopy. These are clinker, clinker-sand, slag-lime and slag-lime-sand hydrothermal reactions. The microstructure of clinker hydration products displayed crumpled foils and tabular masses of calcium silicate hydrates; few cubic crystals of hydrogarnet appeared only during the initial stage of the reaction. In clinker-sand mixture the C-S-H phase was the only product identified. In slag-lime hydration the microstructure displayed both of the hydrogarnet crystals and the C-S-H phase. The hydration of slag-lime-sand mixture (an optimum composition) was associated with the formation of ill-crystallized tobermorite and crystalline 11A tobermorite as the main products.     

Evaluation and characterization of vector fluids and peroxides in a process of in situ compatibilization of polyethylene and polystyrene

An organic functional silane was found to be the most efficient among several vector fluids in reactive blend compatibilization of the polyethylene (PE) / polystyrene (PS) / peroxide / vector fluid system. This paper involves further analysis of this reactive blending system. Surface tension data was used to calculate spreading coefficients which were compared to the amount of PE-PS copolymer formed during blending. A good correlation between a computed spreading coefficient and the degree of grafting of PS onto PE was found. The results suggest that the pattern of distribution of the vector fluid in PE / PS blends is the key factor leading to effective results. Furthermore, different peroxides were evaluated in PE / PS blends, in order to determine the dependence of PE / PS interfacial grafting reaction on the structure of the peroxide.     

欧盟对农药的重新评定与我国除草剂品种发展

评述了欧盟评定的农药名单中禁用的除草剂品种及我国今后除草剂的开发与使用。