Immobilization of activated sludge using improved polyvinyl alcohol （PVA） gel

The microbial immobilization method using polyvinyl alcohol(PVA)gel as an immobilizing material was improved and used for entrapment of activated sludge.The oxygen uptake rate(OUR)was used to characterize the biological activity of immobilized activated sludge.Three kinds of PVA-immobilized particles of activated sludge,that is,PVA-boric acid beads,PVA-sodium nitrate beads and PVA-orthophosphate beads were prepared,and their biological activity was compared by measuring the OUR value.The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media (containing 250 mg/L COD and 25 mg/L NH_4~ -N).The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation.With respect of the bioactivity and the mechanical stability,the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization.     

Hydrogen generation from polyvinyl alcohol-contaminated wastewater by a process of supercritical water gasification

Gasification of polyvinyl alcohol(PVA)-contaminated wastewater in supercritical water(SCW)was investigated in a continuous flow reactor at 723-873 K,20-36 MPa and residence time of 20-60 s.The gas and liquid products were analyzed by GC/TCD,and TOC analyzer.The main gas products were H_2,CH_4,CO and CO_2.Pressure change had no significant influence on gasification efficiency. Higher temperature and longer residence time enhanced gasification efficiency,and lower temperature favored the production of H_2. The effects of KOH catalyst on gas product composition were studied,and gasification efficiency were analyzed.The TOC removal efficiency(R_(TOC)),carbon gasification ratio(R_(CG))and hydrogen gasification ratio(R_(HG))were up to 96.00%,95.92% and 126.40% at 873 K and 60 s,respectively,which suggests PVA can be completely gasified in SCW.The results indicate supercritical water gasification for hydrogen generation is a promising process for the treatment of PVA wastewater.     

Copper biosorption on immobilized seaweed biomass： Column breakthrough characteristics

The biosorption of copper by the brown seaweed Sargassum baccularia,immobilized onto polyvinyl alcohol(PVA)gel beads, was investigated with fixed-bed experiments.Laboratory-scale column tests were performed to determine breakthrough curves with varying flow rates and feed concentrations.A theoretical fixed-bed model,known as the Bohart-Adams equation,was evaluated in simulating the experimental breakthrough curves.The Bohart-Adams model qualitatively predicted the breakthrough trends.PVA- immobilized seaweed biomass beads were amenable to efficient regeneration with aqueous solution containing the chelating agent ethylenediaminetetraacetic acid(EDTA).The biosorbent retained most of its original uptake capacity over three cycles of use.The excellent reusability of the biosorbent could lead to the development of a viable metal remediation technology.     

基于灰色理论的特种设备安全事故预测研究

应用灰色理论,借助于EXCEL及MATLAB软件工具,并以我国近年实际数据为基础,对我国“十二五”期间特种设备安全事故的绝对死亡人数和万台设备死亡人数进行了预测.结果表明,基于灰色理论的特种设备事故的死亡人数和万台设备死亡人数的模拟值和真实值较吻合,预测模型精度检验为好；预测指标可为特种设备安全政策制订和科学监管决策提供依据及参考.     

纳氏比色法测定氨氮的改进

减少显色剂中ＨｇＣｌ２，ＫＩ的含量，以聚乙烯醇做胶体稳定剂，显著提高了显色剂的稳定度和显色的稳定度，以ＫＯＨ和酒石酸做缓冲液，保持恒定的显色碱度，同时也隐蔽了金属离子的干扰，从而大大降低了空白吸光度和检测限。废水予处理，通过条件实验，确定了稀释比，稀释水样用絮凝沉淀法或蒸馏法处理，蒸馏时用磷酸盐缓冲液，并降低硼酸吸收液的浓度，提高了回收率。     

松花江哈尔滨段水环境质量评价及污染源解析

为全面了解松花江流域哈尔滨段的水质污染状况,根据2015年松花江流域哈尔滨段丰水期、平水期和枯水期的水质监测数据,采用主成分分析（PCA）对水质污染现状进行综合评价,并根据主成分分析计算得到的相关数据进行APCS-MLR（绝对主成分多元线性回归分析）,量化主成分对各污染物的贡献率.在评价过程中,充分利用ArcGIS软件对不同断面水质状况进行可视化表征,展现水环境质量的空间特征,更加直观地表达水质的区域差异性.结果表明:松花江哈尔滨段水体的主要污染物包括COD_Cr、TN和NH₃-N,丰水期第1主成分对其贡献率分别为69.97%、69.18%、74.23%,平水期为22.91%、22.21%、37.57%,枯水期为83.77%、83.60%、83.09%;6个断面中,朱顺屯断面的水质优于其他断面的水质,上游水质优于下游水质;研究水体水质总体上表现为丰水期优于枯水期.研究表明,污染物主要受到生活污水和该江段沿岸石化、汽车和造纸企业工业废水排放的影响.污染物主要来源于阿什河口内和呼兰河口内断面,干流水体水质优于支流水体.      

介孔ZnO负载Fe-Cu-Zr复合催化剂用于催化燃烧降解乙酸丁酯

采用醇热法制备了有序球状介孔ZnO负载Fe-Cu-Zr复合催化剂,应用BET、SEM、XRD、XPS等对不同物质的量比催化剂进行了表征,研究了催化降解乙酸丁酯的活性及其影响因素,并推测了降解机理.结果表明,铁铜锆复合催化剂颗粒均匀,分散性较好,孔径大部分小于50 nm,比表面积为46~68 m²·g^-1.各活性成分能够共存和协同发挥作用,铁、铜、锆离子吸附在氧化锌晶胞内,粒子间量子作用力促使晶胞表面积略有变大.锆能够提高3种活性成分间的作用力,可以调节表面电子密度,促使结合能向低的方向偏移,增强催化剂的氧化还原能力.随着锆比例的增大,催化剂的活性也随之增强;随着初始浓度、空速、相对湿度的增加,乙酸丁酯降解效率均有所下降.在乙酸丁酯初始浓度为2590 mg·m^-3、空速为9000 h^-1的工况下,ZnO-3M催化剂降解乙酸丁酯的T₅₀为116 ℃,T₉₀为200 ℃,270 ℃时CO₂转化率达96%,具有良好的低温催化活性和稳定性.乙酸丁酯催化氧化主要中间产物为少量的低级酸和低碳醇,最后被彻底氧化成CO₂和H₂O.     

机械设备无泄漏设计

机械设备在运行中的泄漏，是当前环境污染的源头之一。从泄漏与污染、泄漏与密封的关系。提出绝对密封技术。用述了磁力传动与密封原理，分析了无泄漏设计的应用与发展前景。建议推广绿色产品-磁力泵、全封闭阀门及反应设备。     

PSA application for a PCB detoxification plant

 Polychlorinated biphenyls (PCBs), a type of persistent organic pollutants (POPs), are considered to be endocrine disrupters. According to the Stockholm Convention on POPs, PCB detoxification is being accelerated globally. We have developed an environmentally sound chemical PCB detoxification plant using the ultraviolet ray/catalyst method. The purpose of this paper is to check the design methodology for the PCB detoxification plant by the application of probabilistic safety analysis. First, possible hazardous events were determined; second, the weakest points in these hazardous events were established; and third, the impact when failures arise at the weak points in the system were studied. We clarified the preventive measures as follows. To prevent PCBs leaking into the environment, select leak-tight valves for the piping containing PCBs, and reduce the number of valves. To prevent fire or explosions due to leaks of an inflammable mixture, select leak-tight valves, reduce the number of valves installed in the piping, and improve the reliability of the suppression tank in the isopropyl alcohol (IPA) recovery unit. Received: February 27, 2001 / Accepted: June 17, 2002     

具有共轭结构的CDPVA/ZnO复合光催化剂的制备及其可见光催化性能

CDPVA是一种具有共轭多烯序列的聚乙烯醇(PVA)衍生物。通过低温热处理法制备了CDPVA/ZnO复合光催化剂。表征结果显示,PVA经低温热处理后形成了具有一定共轭结构的CDPVA并包覆于纳米ZnO颗粒表面,提高了光催化剂的可见光响应能力,有效促进了光生空穴和电子的分离。当PVA与纳米ZnO的质量比为1∶100时,CDPVA/ZnO的可见光催化活性最高;在催化剂投加量为0.5 g/L、初始罗丹明B质量浓度为4 mg/L、可见光照射50 min的条件下,罗丹明B降解率为97.51%,明显优于纯纳米ZnO;CDPVA/ZnO循环使用9次后仍保持较高的罗丹明B降解率,表明CDPVA的包覆有效抑制了纳米ZnO的光腐蚀,提高了光催化剂的稳定性。