可见光催化剂BiVO_4 降解废水中直接耐酸大红4BS

以直接耐酸大红4BS模拟染料废水为目标污染物,研究了BiVO_4对直接耐酸大红4BS(简称4BS)的吸附效果以及废水初始质量浓度、废水pH和BiVO_4的加入量对光催化降解效果的影响.实验结果表明:当废水初始质量浓度为40 mg/L、废水pH为6.38、BiVO_4加入量为1.0 g/L时,4BS的降解率可达98.9%;BiVO_4重复使用5次后4BS的降解率可达80.0%以上;COD的变化趋势说明4BS被催化剂吸附和光催化降解的过程是循序渐进的.     

某电镀厂污泥酸浸除杂提磷试验

探讨了武汉某工业园电镀厂污泥酸浸、除杂提磷的工艺及条件。当H2SO4（浓度为72％）用量为4mL/g污泥,在液固比为5：1,常温搅拌浸出时间为1h,用碱液调节浸出液pH为4后沉淀1h,过滤,磷的浸出率为86％,铁的沉淀率达到94．2％,除铁后的浸出液进一步用NH4HCO3净化,并制取磷铵产品,总养分（N＋P2O5）为52％。产品达到国家合格品的标准。     

A failure analysis of fillet joint cracking in an oil storage tank

This paper has studied failure of an oil storage tank. During operation, several cracks were observed at the fillet weldment between reactor shell and annular plates in the bottom of oil storage tank. Extreme stresses in the structure during its operation were determined taking into account shape and geometry imperfections as well as corrosion influence. Both reactor shell and annular plates are made of carbon steel (SM53C). In this study, in order to identify the causes for the fillet weldment cracking, failure analysis such as fractography, tensile test, hardness test, corrosion test(SSRT), chemical analysis was performed. The failure of oil storage tank is the result of the combined and synergistic interaction of mechanical stress and corrosion reactions. Although cracks were initiated by corrosion, failure was generated by propagation of crack caused by stresses concentration. It was recommended that (1) the local stresses be reduced by improved weld toe geometry, and (2) the reinforcement be used in order to avoid failure by stresses concentration.     

再生水做景观用水使用含氯消毒剂消毒的副产物及安全性

再生水消毒后主要作为城市杂用水利用,消毒副产物及其毒性的研究非常重要.在浓度为 5～8 mg/L 的消毒剂(ClO2、HClO)量下,灭菌率能够达到 100%.2 种消毒体系均产生少量ClO2-、ClO3-和CHCl3,对检验用水生生物未产生毒性.适当的选择消毒剂浓度,控制反应条件,能够实现再生水的安全回用.     

基于范例推理的浏阳河隧道风化槽段坍方风险评估

坍方是隧道常见的突发性风险事件.在对已有坍方隧道实例的原因进行了统计分析,并对主要原因进行了力学解释后,进一步应用范例推理方法评估了浏阳河隧道风化槽地段的坍方风险.结果表明:隧道坍方的主要诱因是围岩破碎和降雨,这与断层破碎带处的围岩力学性能差、降水弱化围岩力学性和降低围岩有效应力等有关.浏阳河隧道风化槽地段的范例推理的坍方和梁家山隧道相近,风险为很有可能发生坍方,建议该地段施工中应注重监测信息的反馈并做好超前地质预报.     

Ecotoxicological effects of typical personal care products on seed germination and seedling development of wheat (Triticum aestivum L.)

Biochemical responses of wheat (Triticum aestivum L.) seedlings stressed by two typical personal care products (PCPs) – triclosan (TCS) and galaxolide (HHCB) were experimentally investigated to assess their ecological risks. The results showed that wheat shoot and root elongation was significantly inhibited by 50–250 mg L⁻¹ TCS and HHCB. Wheat roots were sensitive to TCS, while shoots were sensitive to HHCB. The median effect concentration (EC₅₀) of TCS and HHCB based on the inhibition of their sensitive sites were 147.8 and 143.4 mg L⁻¹, respectively. Moreover, the damage of wheat seedlings treated by low concentration of TCS and HHCB during a long period cannot be neglected. After a 21-d exposure, 0.2–3.0 mg L⁻¹ TCS and HHCB treatment caused the damage to the accumulation of chlorophyll (CHL), the synthesis of soluble protein (SP), and the activity of peroxidase (POD) and superoxide dismutases (SOD) in different degree. However, different changing trends of these physiological indexes treated by different PCPs were observed after 7-d to 14-d exposures, especially the activity of POD and SOD. The activity of POD and SOD in wheat leaves and roots decreased with an increase in the concentration of TCS and the exposure time. However, the enzyme activities in wheat leaves treated by 0.2–3.0 mg L⁻¹ HHCB increased after a 14-d exposure, and with the prolongation of exposure time, the enzyme activities significantly decreased. The variations in these physiological indexes of wheat could be considered as good biomarkers of serious stress by TCS and HHCB in the environment.     

水体腐殖酸及其络合物 Ⅱ.蓟运河腐殖酸与汞的络合作用

蓟运河及其入渤海口处水及底泥中的腐殖酸已经提取并且进行了物化表征。本文用凝胶过滤技术研究了它们与汞的络合作用,测定它们对汞的络合容量为0.85—2.10m molHg/gHA(FA)(171.2—420.3mgHg/gHA);计算了腐殖酸汞络合物的表观稳定常数并比较了用各种浓度表示方法所计算的表现稳定常数。另外,合成了蓟运河腐殖酸汞络合物并粗测了其溶解度。根据蓟运河水体中腐殖酸的含量,可以认为,腐殖酸汞是该河中汞的主要存在形态,并且大部分以可溶态存在于表层水及间隙水。     

氨氧化细菌的富集培养及影响因素的研究

采用间歇培养方式,对富集氨氧化细菌的过程进行了研究,并探讨了温度、初始pH值、DO、碱度、进水氨氮浓度对短程硝化作用的影响.实验发现:氨氧化细菌富集完成后,氨氧化速率达到22.8 mg/(L·h),亚硝酸盐积累率在80％左右,氨氧化细菌的数量可提高至富集前的32.6倍.此外,对影响因素的研究发现,当温度30℃、pH=8.5、DO=0.5 mg/L、HCO3-/NH4+-N(摩尔比)=1.67、进水氨氮小于400 mg/L时,有利于实现短程硝化.     

A2/O工艺脱氮除磷的中试试验研究

以某污水处理厂初沉池出水为中试试验A2/O工艺进水,连续运行,考察温度、泥龄、溶解氧、厌氧停留时间对氮磷的去除情况.结果表明,系统硝化功能以20℃为界,低于此温度时系统氨氧化速率(AUR)由10.4mgNH4+;-N/L·h降为8.1 mgNH4+-N/L·h,亚硝酸盐氧化速率(NUR)由6.1 mgNO2--N/L·h降为4.8 mgNO2--N/L·h,氨氮去除率由98.8％降为51.2％.在低温条件下,泥龄由13 d延长至16 d,氨氮去除率升至82.5％.曝气采用固定氧供给模式和非固定氧供给模式对TN去除率影响较大,去除率分别为78.1％和63.8％.厌氧水力停留时间由0.93 h提高至1.86 h,TP去除率由40.5％提高至67.3％,厌氧阶段磷浓缩比由1.36倍提高至4.29倍.     

北京市生活垃圾转运站耗能和排污特征及其影响因素分析

利用实际调研得到的北京市生活垃圾转运站2009～2011年3 a平均数据,从垃圾回收量、渗沥液产量、耗水量、耗电量这4个方面分析北京市生活垃圾转运站耗能排污特征及其影响因素,并对分选转运站及压缩转运站的综合耗能排污情况进行了分析.结果表明,北京市不同生活垃圾转运站的耗能排污情况差别很大,单位垃圾回收垃圾量约为12.9 kg·t-1,单位垃圾渗沥液产量约为5.8～49.0 kg·t-1,单位垃圾耗水量约为40.3～156.7 kg·t-1,单位垃圾耗电量约为1.75～5.60 kWh.t-1.虽然分选转运站综合耗能和排污较多,但分选转运站将部分垃圾回收,使垃圾减量化资源化,并将垃圾分为不同物料运往不同垃圾处理场,实现垃圾的优化处理,减轻了垃圾卫生填埋场的负担,延长填埋场的使用期限.