不同生物接触氧化方法对藻类的去除效果比较及其途径分析

比较了3种生物接触氧化法对富营养化水源水中藻类的去除效果，探讨其去除藻类的途径。试验结果表明：淹没式曝气生物陶粒滤池（I型）在4-6m/h过滤速度条件下，对藻类总数的去除效率稳定，平均为70%左右；采用YDT弹性立体填料的中心导流筒曝气生物接触氧化法（Ⅱ型）与直接微孔曝气生物接触氧化法（Ⅲ型），在试验初期对藻类总数的去除率较低，平均去除率分别为60.2%、51.6%。但随着生物膜厚度的增加，试验后期对藻类的去除效果逐步得到提高，平均达70%以上。生物膜对藻类的生物絮凝、吸附、生物膜的脱落沉降等是生物接触氧化法去除藻类的主要途径。     

加强城市环境风险管理,促进和谐社会建设

针对我国目前非正常死亡长期据高不下现状,分析了小尺度环境安全问题成因特点,提出用加强城市环境风险管理作为对策,并具体讨论了环境安全标准、环境安全责任、环境安全立法、环境安全经济、环境安全管理、环境安全科研等相关问题。     

Combined effect of tributyltin and benzo[a] pyrene on the levels of sex hormone and vitellogenin in female Sebastiscus marmoratus

Tributyltin（TBT）, an organometal used as an antifouling biocide, has been reported to induce masculinization of fish. Benzo [a]pyrene （BaP）, a widespread carcinogenic polycyclic aromatic hydrocarbon, has been reported that its microsomal metabolites can produce an estrogenic response when tested in vitro. This study was therefore designed to examine the potential in vivo influence of TBT, BaP and their mixture on sex hormone levels in serum of Sebastiscus marmoratus, which were given 2 separate intraperitoneally （ip） injections（a single injection every 7 d） of TBT（0.5, 1, 5 and 10 mg/kg）, BaP（0.5, 1, 5 and 10 mg/kg）, or both in combination（0.5, 1, 5 and 10 mg/kg）; control fish received olive oil vehicle only. Six days after the 2nd injection, serum samples were collected and analyzed for sex hormone levels and alkali labile protein phosphorus （ALPP）, which is related to the yolk precursor protein vitellogenin. The pollutants at all doses significantly reduced serum testosterone, estradiol and ALPP content after 2 injections compared with the corresponding controls. The reduction of the estradiol levels should be response for the decrease of the vitellogenin levels. The results in the present study suggested that aromatase seems not the major target acted by TBT and BaP in fish. This study demonstrated that TBT or BaP exposure both inhibit the reproductive potential in female Sebastiscus marmoratus. Combined effect of TBT and BaP on the serum testosterone, estradiol and ALPP was not antagonism from the anticipation.     

水稻烤田期间N2O排放及其影响因素

水稻田间实验研究了烤田期间的土壤温度、Eh、含水量和裂缝基本性质,矿质态氮以及与氮有关的酶活性的演变规律,及其对N2O排放的影响.试验表明,在水稻分蘖期间烤田,N2O有一个排放高峰,其最高值可达75.6μg·m-2·h-1.在排放高峰后,即使继续烤田,N2O的排放值也将降低.N2O排放与尿素氮肥的施用量没有明显关系.裂缝的生成,改变了N2O的日排放规律.随着烤田时间的延长,脲酶和羟胺还原酶活性呈波动变化,硝酸还原酶活性递减,亚硝酸还原酶活性极低.硝酸还原酶活性与N2O排放之间没有显著相关性.土壤中的脲酶活性与N2O日排放通量呈显著的线性正相关.在烤田期间,NO-3含量呈增加趋势.土壤中的硝态氮含量与N2O排放通量之间呈显著正线性关系.土壤中的铵态氮含量与N2O排放通量之间呈显著负线性相关.     

沸石在水处理中的应用

本文介绍了中国沸石的种类及其分布概况，以产自甘肃省白银市的斜发沸石为研究对象，对其化学组成及分子晶格形式作了较为详尽的阐述，经实验室检测出其化学组成及物化指标，且对沸石作为吸附剂、离子交换剂、催化剂处理废水的作用机理进行了深入的探讨，对于天然沸石改性进行了实验研究，得出采用氯化钠溶液对天然沸石改性的效果比较理想，改性溶液的最佳浓度为0．9mol/L。研究沸石在沸水处理领域中的应用，分析了沸石处理各类废水的机理，并对沸石处理废水的前景进行了展望。     

On-line optical determination of floc size of Fe(Ⅲ) coagulants

This study investigated the floc aggregation, average floc size, floc size variance and floc growth velocity when ferric chloride （FeCl3） and polyferric chloride （PFC） were used to treat the simulated water samples. The factors including coagulant dose, ionic strength and solution pH, which affect the floc aggregation, were studied. Experiments were carried out in a bench-scale reactor using photometric dispersion analyzer （ PDA）. Results showed that there were great differences between the floc aggregation of PFC and FeCl3. The average floc size and fioc growth velocity of PFC were much larger than those of FeCl3. Compared with FeCl3, PFC gave a better coagulation performance in wider range of pH, dosage and ionic strength. It was also found that the coagulation efficiency of PFC did not depend on average floc size but on floc growth velocity.     

Sorption of pyrene on two paddy soils and their particle-size fractions

In the present study, the sorption of pyrene on two kinds of bulk paddy soils, Gleyic Stagnic Anthrosols, and Ferric accumulic Stagnic Anthrosols as well as their particle-size fractions was investigated. The sorption isotherms fitted well with Freundlich equation. For both soils, the clay fraction（ 〈 2μm） and coarse sand fraction（2000-250μm） had higher sorption capacity than fine sand fraction（250-20 μm） and silt fraction（20-2 μm）. The IogKoc values obtained of each soil and its particle-size fractions were similar, proving that SOM content was a key factor affecting pyrene sorption. The Kd values showed a significant correlation with contents of dithionite-extractable Fe in both paddy soils and a good relationship with CEC in Gleyic Stagnic Anthrosols, indicating possible effects of surface properties of particle-size fractions on the sorption of pyrene.     

谈双鸭山市气象特征及地形特征对空气质量的影响

双鸭山市采暖期污染较重是因为采暖期燃煤量大、低矮分散的面源多的缘故,同时气象因素及地形特征对空气质量的影响也起着相当大的作用,采用2005年空气质量监测数据,进行双鸭山市气象特征及地形特征对空气质量影响分析,得出空气较稳定的取暖期和具有山风、谷风、局地环流的地形特征是形成双鸭山市空气污染的主要原因之一,并针对地形特征及气象特征对双鸭山市空气质量的影响提出空气污染治理措施.     

采用钙钛矿型催化剂(La0.8K0.2Cu0.05Mn0.95O3)同时催化去除NOx和碳烟的研究

将钙钛矿型催化剂与碳烟均匀混合后置于固定床连续流动反应体系中,利用程序升温反应技术,在模拟柴油机尾气的情况下对同时催化去除氮氧化物(NOx)和碳烟的反应进行了实验研究.通过改变含Cu原料的用量,得到不同Cu取代量的催化剂La0.8K0.2CuxMn1-xO3,性能评价结果表明,La0.8K0.2Cu0.05Mn0.95O3催化剂的综合性能较好,碳烟的起燃温度及NO向N2的最大转化率分别为280℃和58.0%.采用该催化剂,进一步考察了进气中NO浓度、O2浓度、进气总流量及催化剂与碳烟的接触状况对反应的影响.研究结果表明,进气中NO浓度、O2浓度、气体总流量和催化剂与碳烟之间的接触状况对NO的去除率的影响比较明显,而对碳烟起燃温度的影响较小.O2浓度从5%变为7.5%时,碳烟的起燃温度及最大NO转化率分别从280℃和53.8%变为270℃和96.7%.碳烟与催化剂松散接触时,碳烟的起燃温度及最大NO转化率分别为290℃和48.4%,紧密接触时分别为275℃和70.4%.而进气中NO浓度、气体总流量的变化对碳烟的燃烧基本上没有影响,虽然NO的转化率有明显变化,但生成的N2总量基本不变.     

外控电势对Ch-1菌株生长及Cr(Ⅵ)还原的影响

为进一步优化Ch-1菌株对碱性含铬废水的处理及铬渣的解毒效果,以细菌总数和6价铬的还原率为指标,详细考察了外控电位对Ch-1菌株生长及Cr(Ⅵ)还原的影响.结果表明,电极材料对细菌生长及其活性有一定的影响,不锈钢电极和铂电极体系对细菌生长及活性的影响基本相同,而采用石墨电极细菌的培养效果欠佳.静态培养和动态培养Ch-1菌株时,Cr(Ⅵ)的最终还原率与初始Cr(Ⅵ)浓度无关,24h时Cr(Ⅵ)的还原率均达到了100%;但就还原过程而言,动态培养对Cr(Ⅵ)的还原速率明显优于静态培养,外控电势能够增强或抑制Ch-1菌株的生长及活性,0～-900 mV的负电位可以促进细菌的生长,而400 mV以上的正电势对Ch-1菌株的生长有抑制作用.在-800～ 200 mV的电势范围内,Ch-1菌株还原6价铬的能力得到增强,在此范围外其还原能力受到抑制.