Source apportionment of wintertime secondary organic aerosol during the California regional PM10/PM2.5 air quality study

The UCD/CIT air quality model with the Caltech Atmospheric Chemistry Mechanism (CACM) was used to predict source contributions to secondary organic aerosol (SOA) formation in the San Joaquin Valley (SJV) from December 15, 2000 to January 7, 2001. The predicted 24-day average SOA concentration had a maximum value of 4.26 μg m^?3 50 km southwest of Fresno. Predicted SOA concentrations at Fresno, Angiola, and Bakersfield were 2.46 μg m^?3, 1.68 μg m^?3, and 2.28 μg m^?3, respectively, accounting for 6%, 37%, and 4% of the total predicted organic aerosol. The average SOA concentration across the entire SJV was 1.35 μg m^?3, which accounts for approximately 20% of the total predicted organic aerosol. Averaged over the entire SJV, the major SOA sources were solvent use (28% of SOA), catalyst gasoline engines (25% of SOA), wood smoke (16% of SOA), non-catalyst gasoline engines (13% of SOA), and other anthropogenic sources (11% of SOA). Diesel engines were predicted to only account for approximately 2% of the total SOA formation in the SJV because they emit a small amount of volatile organic compounds relative to other sources. In terms of SOA precursors within the SJV, long-chain alkanes were predicted to be the largest SOA contributor, followed by aromatic compounds. The current study identifies the major known contributors to the SOA burden during a winter pollution episode in the SJV, with further enhancements possible as additional formation pathways are discovered.     

The permeability of dredged material-bentonite backfills

Environmental Science and Pollution Research - Extensive attention has been paid to the treatment and disposal of dredged material, and there is a need to clarify the feasibility of recycling...     

Effective cleanup of oil contamination on bio-inspired superhydrophobic surface

Environmental Science and Pollution Research - The oil-water separation is a popular issue and the removal of oil from bulk water is also meaningful especially in oil spill incident, which not only...     

随身自动空气净化处理器的研究

随身自动空气净化器,采用了活性炭、光催化技术相结合的空气过滤装置.空气污染传感器与单片机组成空气质量监测电路,当空气污染超标时,产生语音提示,液晶屏显示空气质量的等级,自动(或手动)控制引风机工作,供给个人清新无污染的空气.     

Medium optimization for the production of anti-cyanobacterial substances by Streptomyces sp. HJC-D1 using response surface methodology

Bioremediation using isolated anti-cyanobacterial microorganism has been widely applied in harmful algal blooms (HABs) control. In order to improve the secretion of activated anti-cyanobacterial substances, and lower the cost, a sequential optimization of the culture medium based on statistical design was employed for enhancing the anti-cyanobacterial substances production and chlorophyll a (Chl a) removal by Streptomyces sp. HJC-D1 in the paper. Sucrose and KNO₃ were selected as the most suitable carbon and nitrogen sources based on the one-at-a-time strategy method, and sucrose, KNO₃ and initial pH were found as major factors that affected the anti-cyanobacterial ability of the isolated stain via the Plackett–Burman design. Based on the response surface and canonical analysis, the optimum condition of culture medium was obtained at 22.73 g l^-1 of sucrose, 0.96 g l^-1 of KNO₃, and initial pH 8.82, and the Chl a removal efficiency by strain HJC-D1 increased from 63?±?2 % to 78?±?2 % on the optimum conditions.     

有机污染物的光催化降解过程中的分析技术进展

本文对有机物的光催化降解动力学研究 ,降解产物的鉴定、定量检测等过程中所使用的一些分析技术和手段 ,尤其是在有机物的光降解机理研究中羟自由基的检测技术和方法进行了综述     

不同共代谢基质对四氯乙烯的厌氧生物降解研究

用驯化好的厌氧污泥对葡萄糖、乳酸盐和醋酸盐作为电子供体时四氯乙烯(PCE)的降解进行研究。实验结果表明,PCE是通过还原脱氯发生生物降解的。实验的回归结果表明,反应均符合一级动力学反应速率,常数的大小依次为k乳酸>k葡萄糖>k醋酸。表明乳酸盐作为电子供体时PCE的降解速率较快,说明在实验条件下乳酸盐是最合适的电子供体。并且在整个实验过程中由共代谢基质提供的电子供体不是PCE降解的限制因素。     

不同酶强化污泥为燃料微生物燃料电池特性对比分析

采用单室无膜悬浮阴极微生物燃料电池(MFC),对比分析了蛋白酶和淀粉酶强化剩余污泥为燃料的MFC(ESMFC)产电特性、酶特性和污泥减量化效果。研究表明,投加蛋白酶的ESMFC最大功率密度比对照组增加106.2%,投加淀粉酶时ESMFC最大功率密度比对照组增加48%。蛋白酶作用主要体现在投加后的前12小时,而淀粉酶作用时间则较长,为投加后的前144小时,但在运行前期,由于高温作用,导致系统内的酶活性较强,投加的淀粉酶作用则不明显。投加蛋白酶的系统内TCOD、TSS和VSS去除率分别为82%、65%和85%,而投加淀粉酶的系统内TCOD、TSS和VSS去除率分别达到86%、67%和88%。此研究对于ESMFC中外加酶的选择具有一定意义。     

改性甘蔗渣对Cu^2＋和Zn^2＋的吸附机理

研究了均苯四甲酸二酐（PMDA）和乙二胺四乙酸二酐（EDTAD）改性甘蔗渣对重金属离子Cu^2＋和Zn^2＋的吸附性能,包括吸附动力学和吸附等温线。结果表明,改性后的甘蔗渣对重金属离子Cu^2＋和Zn^2＋的吸附容量有显著提高,对Cu^2＋和Zn^2＋吸附等温线均符合Langmuir方程,吸附为单分子层吸附。根据Langmuir方程,PMDA和EDTAD改性甘蔗渣对Cu^2＋的吸附量分别为60．21和33．45mg／g,对Zn^2＋的吸附量分别是70．53和36．53mg／g。两种改性甘蔗渣对两种金属离子的吸附在30min内均可完成,用准二级吸附动力学方程模拟动力学过程得到较好的线性相关性。以EDTA溶液为洗脱剂对吸附Cu^2＋和Zn^2＋的改性甘蔗渣进行洗脱再生,再生的吸附剂可反复使用。     

废旧冰箱拆解及聚氨酯泡沫放置的一氟三氯甲烷释放量研究

研究了废旧冰箱聚氨酯(PUR)泡沫中所含的一氟三氯甲烷(CFC-11)总量,并对冰箱箱体切割过程、金属板剥离过程和PUR泡沫破碎后常温放置时的CFC-11释放量进行了测定。结果表明,PUR泡沫所含CFC-11总量占PUR泡沫质量的20.06%;箱体切割和金属板剥离过程中的CFC-11释放量分别占PUR泡沫中CFC-11总量的0.75%和2.32%;常温放置到第15天时,0.5、1.0、4.0、8.0 mm 4种粒径PUR泡沫颗粒的CFC-11累计释放量分别占PUR泡沫所含CFC-11总量的4.75%、5.25%、5.42%、6.50%,均高于箱体切割、金属板剥离过程中的CFC-11释放量。