Ionic composition of submicron particles (PM1.0) during the long-lasting haze period in January 2013 in Wuhan, central China

In January 2013, a long-lasting severe haze episode occurred in Northern and Central China; at its maximum, it covered a land area of approximately 1.4 million km². In Wuhan, the largest city in Central China, this event was the most severe haze episode in the 21st century. Aerosol samples of submicron particles (PM_1.0) were collected during the long-lasting haze episode at an urban site and a suburban site in Wuhan to investigate the ion characteristics of PM_1.0 in this area. The mass concentrations of PM_1.0 and its water-soluble inorganic ions (WSIIs) were almost at the same levels at two sites, which indicates that PM_1.0 pollution occurs on a regional scale in Wuhan. WSIIs (Na⁺, NH₄⁺, K⁺, Mg²⁺, Ca²⁺, Cl^-, NO₃^- and SO₄^2-) were the dominant chemical species and constituted up to 48.4% and 47.4% of PM_1.0 at WD and TH, respectively. The concentrations of PM_1.0 and WSIIs on haze days were approximately two times higher than on normal days. The ion balance calculations indicate that the particles were more acidic on haze days than on normal days. The results of the back trajectory analysis imply that the high concentrations of PM_1.0 and its water-soluble inorganic ions may be caused by stagnant weather conditions in Wuhan.     

重金属抗性解磷细菌的磷溶解特性研究

从湖南省湘西州花垣县的铅锌矿表层土壤中,筛选出两株具有重金属抗性和解磷特性的细菌T PSB1和T PSB2.通过16S rRNA基因序列比对,分别鉴定为嗜麦芽寡养单胞菌(Stenotrophomonas maltophilia)和唐菖蒲伯克霍尔德菌(Burkholderia gladioli).T PSB1和T PSB2在含有难溶性无机磷液体培养基中,其上清液的可溶性磷含量最高分别达到了402.9 mg·L-1和589.9 mg·L-1;在难溶性有机磷固体和液体培养基中,固体平板上均出现解磷圈,而液体培养基上清液中,可溶性磷含量也分别达到了2.97 mg·L-1和4.69 mg·L-1.另外,两株细菌对重金属Zn2+的抗性最高,在其浓度为2000 mg·L-1固体和液体培养基条件下均可以生长,磷溶解浓度分别为114.8 mg·L-1和125.1 mg·L-1.而在含铬和铅的浓度为1 000 mg·L-1的液体培养基中,两株细菌同样表现出重金属抗性.在Pb2+浓度为1000 mg·L-1的液体培养基中,磷溶解浓度分别达到了57.9 mg·L-1和71.7 mg·L-1;而在Cr2+浓度为1000 mg·L-1的培养基中磷溶解浓度分别为60.1 mg·L-1和98.4 mg·L-1.     

东莞市大气亚微米粒子PM1及其中水溶性无机离子的污染特征

2011年8月—2012年7月期间,利用中流量(100 L·min-1)大气采样器对东莞市A和B两点(A:生活区,B:工业区)进行PM1、PM1~2.5、PM2.5~10采样,并定量分析颗粒物上F-、Cl-、NO-3、SO2-4、NH+4、Na+、K+、Ca2+、Mg2+等9种水溶性无机离子.分析结果显示,工业区B点的细粒子污染较生活区A点严重,B点PM1质量浓度年均值为48μg·m-3,其浓度是A点的1.2倍.A、B两点PM1对PM2.5和PM10的质量贡献率无明显差异,平均贡献率分别高达69%和45%.二次离子SO2-4、NO-3、NH+4及与燃烧行为有关的K+、Cl-等5种离子在细粒子PM1上富集,这5种离子对PM1质量的贡献率分别为18.82%~19.76%、4.98%~5.47%、3.98%~4.12%、2.03%~2.27%和3.39%~3.78%.而其他4种离子,Ca2+、Mg2+、F-和Na+积聚在粗粒子PM2.5~10上.PM10/PM2.5/PM1三种粒子中,PM1粒子酸性值AE/CE(阴离子当量浓度/阳离子当量浓度)比值和硫转化率SOR、氮转化率NOR值均是最高.     

优势微生物菌群消减有机污泥作用效果分析

本文阐述用优势微生物菌群消解有机污泥的作用效果及原因,指出了优势菌群的构成类别和消解特点。实验结果表明,污泥消解率可达到55%,且过程对出水水质不产生负面影响,水质指标均符合GB18918-2002要求。     

成都市城区大气细颗粒物水溶性离子污染特征

为了解成都市城区大气细颗粒物水溶性离子污染特征,在成都市城区四季采集PM2.5有效样品共计102个,测得颗粒物质量浓度以及水溶性离子质量浓度(NH4+、Ca2+、Na+、Mg2+、K+、F-、NO3-、SO42-、Cl-),并分析其浓度变化特征,重点关注二次无机离子的污染特征及形成影响.结果表明,成都市城区水溶性离子与...     

硫化矿物中无机盐及重金属离子溶出的影响因素探讨

基于浸泡试验,在不同的时间、温度、酸碱度、固液比等条件下研究硫化矿物中无机盐和重金属离子的溶出反应,得到影响该溶出反应的重要因素,为实际矿业生产过程中硫化矿物的堆放和处理提供了理论依据.     

贵阳市区大气降水中有机酸的研究

利用ICS-90常规离子色谱结合RFC-30型淋洗液在线发生器,对贵阳市区大气降水中的小分子有机酸进行了系统研究。测得贵阳市降水中的有机酸主要以甲酸[质量分数为(0.2-4.5)×10-6]、乙酸[质量分数为(0.6-5.3)×10-6]、草酸[质量分数为(0.1-4.9)×10-6]为主,其次是乳酸和丙酮酸,及少量丙酸和甲烷磺酸;有机酸对降水自由酸平均贡献为23.2%,占总阴离子的1.4%;通过比较贵阳市区有机酸前后二十年的变化,得出现阶段可能至少有近1/2乙酸和3/4甲酸来源于人类的活动,这说明有机酸人为源是其来源的重要组成部分。     

用膨润土处理油田污水的研究进展

介绍了膨润土的基本特性及其存油田污水处理中的研究情况。天然膨润土经改性后,可吸附去除油田污水中的油、烃类衍生物、注聚残留聚合物及表面活性剂;负载金属氧化物的改性膨润土可对光催化氧化产生协同效应,提高光催化氧化油田污水中有机物的能力;在高压下将膨润土制成薄膜,对油田污水中的无机离了有一定的截留去除作用。     

TiO_2/EP光催化降解水体中微污染磺胺嘧啶的研究

制备了膨胀珍珠岩(EP)为载体的TiO2催化剂(TiO2/EP),对使用较为广泛的抗生素磺胺嘧啶(SDZ)进行了光催化降解研究,探讨了TiO2的负载量、溶液的初始浓度、初始pH、无机离子(HCO3-、SO42-和Cl-)和腐殖酸(HA)对SDZ降解效果的影响。结果表明:SDZ的光催化降解符合一级反应动力学方程;当TiO2最佳负载量为20 wt%,SDZ浓度为5 mg/L,pH=6.7,紫外光照射强度为1 000μW/cm2,反应时间为45 min时,SDZ的降解率达到96%;HCO3-在低浓度时能促进SDZ的光催化降解,高浓度时促进作用不明显;SO42-和Cl-对SDZ的光催化降解有轻微的抑制作用;HA对SDZ光催化降解有显著的抑制作用,浓度越高,抑制作用越强。UV-TiO2/EP是一种去除水体中微污染SDZ的有效方法。     

Factors Influencing Prymnesium parvum Population Dynamics During Bloom Initiation: Results from In-lake Mesocosm Experiments1

Roelke, Daniel L., Leslie Schwierzke, Bryan W. Brooks, James P. Grover, Reagan M. Errera, Theodore W. Valenti, Jr., and James L. Pinckney, 2010. Factors Influencing Prymnesium parvum Population Dynamics During Bloom Initiation: Results from In-Lake Mesocosm Experiments. Journal of the American Water Resources Association (JAWRA) 46(1):76-91. DOI: 10.1111/j.1752-1688.2009.00392.x Abstract: The alga Prymnesium parvum forms large fish-killing blooms in many Texas lakes. In some of these lakes, however, P. parvum occurs but does not develop blooms. In this study, we investigated factors that may influence bloom initiation by conducting a series of in-lake experiments involving mixing of waters from Lake Whitney, which has a history of P. parvum blooms, with waters from Lake Waco where no blooms have occurred. In all experiments, the addition of Lake Waco waters resulted in a poorer performance of P. parvum. Various experimental treatments and field data show that differences in grazing, pathogens, nutrients, and salts between the two lakes were not likely factors that contributed to this observation. Industrial and agricultural contaminants, allelochemicals and algicidal chemicals were not measured as a part of this research. However, anthropogenic contaminants other than nutrients were not observed at levels exceeding water quality standards in Lake Waco in recent years. On the other hand, nuisance cyanobacteria are common in Lake Waco, where Microcystis sp. and Anabaena sp. were abundant during the initiation of our experiments, both taxa are known to produce chemicals with allelopathic properties. In addition, the emergent field of algal-heterotrophic bacteria interactions suggests that chemicals produced by heterotrophic bacteria should not be overlooked. Further research focusing on the chemical interactions between cyanobacteria and P. parvum, as well as the potential role of algicidal bacteria, in the initiation of P. parvum blooms is necessary, as it may be important to the management of these blooms.