城市自来水管网中挥发性有机物的空间分布特征

分析了中国2座沿海城市(S市和L市)自来水管网中挥发性有机物(VOCs)的赋存状态,对检出的VOCs进行了健康风险评价,并探讨了检出VOCs在城市自来水管网中的分布规律.在本文选取的47种VOCs目标化合物中,所研究的2座城市自来水管网中共检出16种VOCs,在2市共同检出的VOCs为11种,以卤代烃类化合物为主,其中又以三卤甲烷类VOCs(一溴二氯甲烷、二溴一氯甲烷和三溴甲烷)的检出率最高(92%~100%).在浓度水平上,除一溴二氯甲烷和二溴一氯甲烷外,其他检出VOCs在2市自来水管网中的最大浓度均未超过我国《生活饮用水卫生标准(GB 5749-2006)》中相关化合物的限值.一溴二氯甲烷和二溴一氯甲烷在2座城市自来水管网中不仅浓度水平超标(限值分别为60μg·L-1和100μg·L-1),而且其致癌风险值(LCR)也处于不可接受的水平(10-4),二者应当被给予足够的重视或被列为2市自来水管网中优先控制的污染物.此外,本研究还选择了8种检出率大于90%的VOCs,探讨了它们在S市自来水管网中的空间分布规律,结果表明,所研究的VOCs(除甲苯外)在该市自来水管网中的浓度都随管网输送距离的增加而逐渐降低.     

Floc structure and membrane fouling affected by sodium alginate interaction with Al species as model organic pollutants

Membrane filtration combined with pre-coagulation has advantages in advanced wastewater treatment. As a model of a microbial polysaccharide, research on the effect of sodium alginate(SA) on alum hydrolysis has been rare; therefore, it is necessary to gain insight into the interface interaction between SA molecules and Al species, and the role SA plays during floc formation. In this study, the interaction mechanism between SA and Al species has been investigated, by evaluating the effect of SA on floc characteristics and membrane fouling during coagulation–ultrafiltration with different Al species coagulants(AlCl3 and preformed Al13). Al 2 p X-ray photoelectron spectroscopy(XPS) confirmed that the complexation of ligands and Al species strongly affects the reaction pathways for Al hydrolysis and the final nature of the flocs, as Al13 can be decomposed into octahedral precipitates when SA is added. The presence of SA can affect floc properties, which have important impacts on the characteristics of the cake layer and membrane fouling. Due to the bridging ability of SA, the floc strength increased by about 50% using Ala, which was much better than preformed Al13, with a percentage increase of only about 6%. Moreover,the recovery factor of HA-flocs was decreased from 96% to 43% with SA addition of 0.5 mg/L.It was concluded that SA can affect the characteristics of the cake layer and membrane fouling through participating in the formation of primary flocs and altering the Al hydrolysis pathway.     

中国未来氟氯化碳(CFC)的生产和消费变化趋势

本文首先分析了中国履行《蒙特利尔议定书》控制CFC的生产和消费的履约目标，回顾了中国历史上CFC的生产和消费，最后提出了中国未来CFC的生产和各相关行业的消费计划。中国将在2010年前淘汰CFC生产和消费，2005-2010年间预计生产CFC共52450t ODP，消费48320t；2005-2010年期间，生产和消费计划量分别从《议定节》限定的目标低15744吨和35700t，现有CFC生产和消费淘汰计划相对安全，而替代品的发展将是保障CFC淘汰目标实现的关键之一。     

城市生态景观项目环评中应重点关注的问题

近年来,许多城市趋向于建设一些集商业、居住、休闲、旅游、生态于一体的生态景观区.这类项目具有建设内容丰富、建设范围大、建设周期长等特点.对这类项目进行环境影响评价时,在环境影响因素识别的基础上,应重点关注其与城市规划的符合性、景现环境的可接受性、施工期的环境影响和保护、运营期的环境影响和保护这四个问题.     

生物流化床工艺处理生活污水实验的灰色关联分析

采用灰色关联分析理论，阐述了生物流化床工艺处理生活污水实验的灰色关联分析方法，给出了其算法并编制了相关的程序，对实验中的主要条件：填料填充量、水力停留时间及污泥回流比对污水COD、NH3－N去除率的影响程度进行了研究，结果表明各因素的影响强弱顺序依次为：水力停留时间＞污泥回流比＞填料填充量。分析结果对生物流化床反应器的实际运行具有指导意义。     

水中腐殖酸的O_3氧化与其生物可降解性实验研究

分析探讨了水中DBPs的重要先质———腐殖酸的臭氧化机理 ,采用O3氧化作为生物预处理 ,可以提高腐殖酸的生物降解能力。实验研究表明O3氧化 +生物流化床组合工艺下HA的UV- 2 50 和CODMn的去除率与单独生物处理相比 ,预臭氧化后水中有机物生物降解能力可提高30 %左右。     

利用水泥迴转窑处理可燃性危险废物

本文评述了国外利用可燃性危险废物作为生产水泥燃料的经验技术，说明这是一项既可处理危险废物，又回收废物资源的成功之举。结合我国具体情况，指出它将是我国进行区域性集中处理某些可燃性危险废物的有效之路。     

Effects of nitrite on phosphate uptake in anaerobic-oxic process

An anaerobic-oxic (A/O) biological phosphorus removal reactor was operated to study the effect of nitrite on phosphate uptake. The phosphorus uptake profile was determined under different operating conditions. The results indicated that in addition to oxygen and nitrate (DPB_Na, nitrate denitrifying phosphorus removal), to some extent, nitrite could also serve as an electron acceptor to achieve nitrite denitrifying phosphorus removal (DPB_Ni). The quantity and rate of phosphorus uptake of DPB_Ni, however, were evidently lower than that of DPB_Na. The experiment results revealed that nitrite would bring toxic action to phosphate-accumulating organisms (PAOs) when NO₂ ⁻-N ⩾ 93.7 mg/L. The nitrite existing in the anoxic reactor made no difference to the quantity and rate of denitrifying phosphorus removal, but it could reduce the consumption of nitrate. Moreover, the data showed that the aerobic phosphate uptake of DPB_Ni was lower than that of anaerobic phosphorus-released sludge in a traditional A/O process. However, there was not much difference between these two kinds of sludge in terms of the total phosphorus uptake quantity and the effluent quality. Translated from Environmental Science, 2006, 27(4): 701–703 [译自: 环境科学]     

Zn2+对棉铃虫N-乙酰-β-D-氨基葡萄糖苷酶活力与性质的影响

以棉铃虫蛹为材料,经分离纯化获得棉铃虫N乙酰βD氨基葡萄糖苷酶制剂;研究了Zn2 对棉铃虫N乙酰βD氨基葡萄糖苷酶(EC3.2.1.14)活力与性质的影响.结果表明,Zn2 对酶活力有抑制作用,酶活力丧失一半的Zn2 浓度(IC50)为1.3mmol/L.进一步研究Zn2 的抑制作用动力学,发现Zn2 对该酶的抑制作用是一种可逆过程,抑制机理表现为竞争型,抑制常数KI为1.158mmol/L.Zn2 不会影响酶的酸碱稳定性,但有Zn2 存在时,在30～40范围内,酶是稳定的,温度高于50℃后,随着Zn2 浓度的增加,酶的温度稳定性也相对增加.图5参10     

苏云金芽胞杆菌菌株WB9编码活性因子的基因分析

采用PCR—RFLP及PCR技术对苏云金芽胞杆菌新分离菌株WB9的ICP、VIP、几丁质酶和肠毒素4种活性因子的编码基因进行了分析．结果表明，该菌株含有编码ICP的cry1Aa、cry1Ab、cry1Cb、cry1Fa和cry1GaS个cry1基因型，编码Vip3A蛋白的vip3A基因以及编码3种肠毒素的hblA、bceT和entS基因；不含编码几丁质酶的基因．将vip3A、hblA、bceT和entS基因PCR产物回收纯化后直接测序，经在线的BLAST软件进行同源性分析，前两个基因片段与Bt已公布基因序列的相应片段同源性分别为99％和96％～98％，bceT基因片段与蜡质芽孢杆菌bceT相应片段同源性为97％．