高效聚合氯化铝对超滤膜污染影响的中试研究

针对某水厂以超滤为核心的短流程水处理工艺,在通过聚氯乙烯(PVC)超滤膜之前选择不同投加量(5、10、15和20 mg/L)的高效聚合氯化铝(HPAC)对长江下游原水进行混凝处理。通过跨膜压差(TMP)增长趋势、CODMn的去除率以及混凝后的水质,可知HPAC的最优投加量为15 mg/L。在此投加量下,运用体积排阻色谱法分析原水、膜前水、膜后水中各相对分子质量有机物的变化,可以发现混凝去除有机物的效果要优于超滤截留的。继而将HPAC与另外4种常用混凝剂:硫酸铝(分析纯)、氯化铁(化学纯)、聚合氯化铝(PAC)、聚合硫酸铁进行对比,结果表明,在它们各自最优投加量下,HPAC能够更有效地减缓超滤膜TMP的增长率,从而降低膜污染。因此,认为HPAC是与PVC超滤合金膜契合效果最佳的混凝剂。     

循环式超声强化光催化降解双酚A

设计了一种循环式超声强化光催化反应器,以TiO2作为光催化剂,研究了超声功率、TiO2加入量、循环液流速和空气流量对双酚A(BPA)降解效果的影响。实验结果表明:超声与光催化过程在循环式超声强化光催化反应器中实现了较好的协同效应;在初始BPA质量浓度为20.0mg/L、超声功率为600W、TiO2加入量为7g/L、循环液流速为4.05×10-2m/s、空气流量为200mL/min的条件下,反应150min后,BPA降解率可达90.5%,溶液中剩余BPA质量浓度仅为1.8mg/L,反应240min后TOC去除率可达84.5%。     

建筑垃圾再生利用存在的问题与对策

通过深入分析目前建筑垃圾再生利用存在的问题,有针对性地提出:政府在法律法规上给予再生产业扶持是建筑垃圾资源化再生利用的条件,民众理念更新是建筑垃圾再生利用的基础,建立有利于跟踪管理的再生产业链是建筑垃圾再生利用的关键.提出的对策旨在促进建筑垃圾资源化再生利用有序快速发展.     

Green manure plants for remediation of soils polluted by metals and metalloids: Ecotoxicity and human bioavailability assessment

Borage, white mustard and phacelia, green manure plants currently used in agriculture to improve soil properties were cultivated for 10 wk on various polluted soils with metal(loid) concentrations representative of urban brownfields or polluted kitchen gardens. Metal(loid) bioavailability and ecotoxicity were measured in relation to soil characteristics before and after treatment. All the plants efficiently grow on the various polluted soils. But borage and mustard only are able to modify the soil characteristics and metal(loid) impact: soil respiration increased while ecotoxicity, bioaccessible lead and total metal(loid) quantities in soils can be decreased respectively by phytostabilization and phytoextraction mechanisms. These two plants could therefore be used for urban polluted soil refunctionalization. However, plant efficiency to improve soil quality strongly depends on soil characteristics.     

诱导结晶工艺中诱品载体的选择与改性

以含铜废水为处理对象,重点考察了诱晶载体的表面性质及表面负荷对诱导结晶过程的影响。结果表明,在工艺启动初期,白云石以及碱式碳酸铜为诱晶载体时,铜的去除率在90％以上,石英砂对铜的去除率较低,但石英砂经表面改性后对铜的去除效率亦可达90％以上。在运行稳定后,几类诱导载体对铜的去除率皆能稳定在95％,说明诱晶载体的表面性质对诱导结晶工艺的影响主要在于反应启动初期,选择与目标结晶产物结构、成分相同或相似的诱晶载体有利于诱导结晶过程的进行。此外,研究结果还表明,诱晶载体表面负荷对结晶过程影响较大,诱导结晶除铜工艺中载体表面负荷不宜高于0．054gCu／（m2·d）。     

In vitro activity of antimicrobial agents against Legionella isolated from environmental water systems: first results from Turkey

We evaluated the in vitro activity of antimicrobial agents against Legionella obtained from hotel and hospital water systems in three different regions of Turkey. Sixty-five Legionella strains (Legionella pneumophila serogroup 6 [n?=?32], L. pneumophila serogroup 1 [n?=?27], L. pneumophila serogroup 3 [n?=?2], and Legionella spp. [n?=?4]) were tested against levofloxacin, ciprofloxacin, clarithromycin, azithromycin, and rifampicin. The minimum inhibitory concentration (MIC) values of each antimicrobial agent for these strains was determined by the microdilution method using buffered yeast extract medium supplemented with 0.1% ketoglutarate broth. L. pneumophila ATCC 33152, Staphylococcus aureus ATCC 29213, and Escherichia coli ATCC 25922 were used as controls. Minimum inhibitory concentration values were in the following ranges: clarithromycin 0.001–0.5 mg/L, azithromycin 0.001–0.5 mg/L, levofloxacin 0.001–0.5 mg/L, ciprofloxacin 0.001–0.125 mg/L, and rifampicin 0.001– 0.5 mg/L. The MIC₉₀ for rifampicin, levofloxacin, ciprofloxacin, azithromycin, and clarithromycin were 0.015, 0.125, 0.06, 0.125, and 0.06 mg/L, respectively. To the best of our knowledge, this is the first study to determine in vitro activities of antimicrobial agents against Legionella species in Turkey. Rifampicin had the lowest MIC₉₀ value. It would seem that azithromycin and clarithromycin exhibit good activity as well as levofloxacin and ciprofloxacin against Legionella isolated from environmental water systems in Turkey.     

Effect of humic deposit (leonardite) on degradation of semi-volatile and heavy hydrocarbons and soil quality in crude-oil-contaminated soil

In order to investigate the bioremedial potential of humic deposit (leonardite), the effects of the treatments of leonardite and a commercial bioaugmentation agent on the degradation of a variety of petroleum hydrocarbons (C13–C31) and soil enzyme activities (urease acid-alkaline phosphatase and dehydrogenase) were tested within a soil incubation experiment lasting 120 days. Experimentally crude-oil-contaminated soil (2.5%) was regulated to a C:N:P ratio (100:15:1; Oilcon), amended with 5% of leonardite and regulated to the same C:N:P ratio (Oilcon-L) or mixed with a commercial bioaugmentation product (Oilcon-B), respectively. In the short period of incubation (60 days), Oilcon and Oilcon-B treatments showed higher hydrocarbon degradations, whereas Oilcon-L showed higher hydrocarbon degradation over Oilcon and Oilcon-B treatments in the long-term (120 days). Applying contaminated soil with leonardite increased urease (LSD, 4.978, *P?<?0.05) and dehydrogenase (LSD, 0.660, *P?<?0.05) activities. However, acid and alkaline phosphatase activities showed no certain inclination between different treatments. Dehydrogenase seemed to be more related to hydrocarbon degradation process. Overall results showed that leonardite enhanced biodegradation of petroleum hydrocarbons and also stimulated soil ecological quality measured as soil enzyme activities.     

学龄儿童肺功能水平影响因素的研究

用逐步回归分析方法对与室内、外空气污染和机体状况等有关的因素对广州市学龄儿童肺功能 (FVC、FEV1 、PEFR和 FEF2 5～ 75 )水平的影响进行研究。结果提示 ,影响肺功能水平的主要因素是内因 ,身高的影响最明显 ,呼吸系统疾病或症状发生与肺功能水平下降有关 ;室外空气污染使肺功能水平下降 ,SO2 、NOx 和 PM2 .5 的影响明显 ,PM2 .5 的影响明显大于 PM1 0 和 TSP;居室或厨房通风不良、家庭烹饪用不洁燃料对儿童肺功能的生长不利 ;被动吸烟对女性儿童肺功能有不利影响。对各种影响因素 ,PEFR和 FEF2 5～ 75 比 FVC和 FEV1 更为敏感     

Biosorption properties of Cd(II), Pb(II), and Cu(II) of extracellular polymeric substances (EPS) extracted from Aspergillus fumigatus and determined by polarographic method

Extracellular polymeric substances (EPS) were extracted from Aspergillus fumigatus using cationic exchange resin technique. The EPS were mainly composed of polysaccharide and low quantities of protein and nucleic acid. Biosorption of Cd(II), Pb(II), and Cu(II) of EPS was investigated as a function of pH using differential pulse polarography and the Ruzic model. Results showed that the EPS biosorption capacity determined using either the direct titration curves i?=?f(C _M) or the method proposed by Ruzic (Analytica Chimica Acta 140:99–113, 1982) were coincident. Cu(II) had the highest affinity with EPS followed by Pb(II) and Cd(II). The total number of binding sites for Cu(II) and Cd(II) increased with pH in the range of 4.0–7.0. Similar trend was observed for Pb(II) at pH?4.0–5.0, while precipitates were observed at pH?6.0 and 7.0. The conditional binding constants of these three metals displayed low levels of fluctuation with pH and ranged from 4.02?±?0.02 to 5.54?±?0.05.