固相微萃取技术及其在环境中的应用

通过论述当前的萃取技术的发展,提出了固相萃取技术的概念.详细的论述了固相微萃取技术的特点、萃取头的选择、在环境中的应用以及该技术的发展方向,说明了固相萃取技术在环境有机分析中有广阔的前景,是有机前处理的技术的发展方向.     

土壤中铜的形态及其转化

本文报告了使用连续提取方法研究加铜培育的黄棕壤、水稻土、红壤、砖红壤中铜的形态,并初步考察了土壤酸度、氧化还原状况等因素对铜形态的影响,对铜在不同矿物之间结合形态的转化进行了模拟。     

萃取在含盐有机废水焚烧处理中的应用

提出并研究了萃取-焚烧工艺在蒸发残液焚烧处理中的应用.以乙酸乙酯为萃取剂,水油体积比为5时,将含30 g·L-1氯化钠、1 g·L-1对硝基苯酚的模拟废水剧烈振荡1min,静置10 min后进行萃取,一级萃取效率和二级萃取效率分别为97.12%和99.89%.随着水油比的升高,一级萃取效率和二级萃取效率都有所下降,但是经过二级萃取之后,有机物的萃取率均在99.00%以上.废水中的氯化钠对萃取效率有提高作用,当氯化钠浓度从60g·L-1升高到200 g·L-1时,一级萃取效率和二级萃取效率分别从94.76%和99.82%上升到97.53%和99.92%.正辛醇的萃取效率较乙酸乙酯低.经过萃取脱盐的有机相,蒸发回收有机溶剂后得到有机物残渣,有机物残渣与有机废水蒸汽一起进入流化床焚烧炉进行焚烧处理;当焚烧炉的温度从700℃提高到850℃时,有机废水蒸汽单独焚烧的焚烧效率从86.34%上升到99.96%,而有机废水蒸汽和有机残渣混合焚烧时的焚烧效率则从90.16%上升到99.99%.     

多种微塑料提取方法在中国典型土壤中的应用

为探究我国典型区域土壤中微塑料的提取及成分鉴定方法,通过人工模拟微塑料的方法,评估了水+油（T1）、饱和NaCl溶液+油（T2）、饱和NaCl溶液（T3）这3种处理方法对4种典型区域土壤（黑土、黄土、红土和紫土）中4种类型微塑料[聚对苯二甲酸乙二酯（polyethylene terephthalate,PET）、聚丙烯（polypropylene,PP）、聚苯乙烯（polystyrene,PS）和聚乙烯（polyethylene,PE）]的检测效果.结果表明：①T3处理下土壤中微塑料提取率随微塑料密度的增大而降低,对PP、PE、PS的提取率均大于86.67%,而PET的提取率仅为0%~13.30%;②T1和T2处理下,黑土、黄土和紫土中4种微塑料的提取率均为86.67%~100.00%,但微塑料表层残留的油会影响傅里叶变换红外光谱（FTIR）对微塑料成分性质的鉴定,配合无水乙醇清洗后,PE和PS鉴定效果仍不佳;③T1和T2处理下红土中PET的提取率分别为56.60%和50.00%,T3处理下红土中PET、PE和PP的提取率分别为3.33%、10.00%和56.67%.结果表明,黄土、黑土和紫土中4种微塑料采用T1和T2提取效果均较好,但需配合无水乙醇进行清洗,T3处理会导致对密度>1 g·cm^-3微塑料PET的漏测;红土中微塑料的提取方法有待进一步探索研发.     

乳状液膜提取废汞触媒浸出液中的汞及 乳状液破乳

采用乳状液膜法分离提取废汞触媒浸出液中的Hg~(2+)。考察了影响乳状液膜体系分离富集汞的主要因素,并对分离提取后的乳液相进行了破乳研究。分离提取实验结果表明:乳状液膜体系的最佳配方为流动载体磷酸三丁酯体积分数10%、表面活性剂失水山梨糖醇脂肪酸酯体积分数4%、膜溶剂磺化煤油体积分数86%、内水相HCl溶液浓度0.10mol/L、油相与内水相的体积比1∶1;在乳状液与外水相的体积比为1∶10的条件下Hg~(2+)提取率达78.50%。破乳实验结果表明:加热破乳、离心破乳、加热离心联合破乳3种方法的破乳率分别为29.0%,54.0%,85.7%;采用加热离心联合法破乳后,Hg~(2+)富集倍数达8.5。     

反胶团萃取技术的影响因素与应用

反胶团是一种新型提取分离技术,具有防止生物大分子失活、变性等优良特性.综述了反胶团的原理、含水率、pH、表面活性剂、助表面活性剂、离子浓度、萃取时间等因素对反胶团萃取的影响及反胶团的应用.     

Heavy metal content and distribution in surface sediments of the Seyhan River, Turkey

Chemical fractionation of seven heavy metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) was studied using a modified three-step sequential procedure to assess their impacts in the sediments of the Seyhan River, Turkey. Samples were collected from six representative stations in two campaigns in October 2009 and June 2010, which correspond to the wet and dry seasons, respectively. The total metal concentrations in the sediments demonstrated different distribution patterns at the various stations. Cadmium was the only metal that was below detection at all stations during both sampling periods. Metal fractionation showed that, except for Mn and Pb, the majority of metals were found in the residual fraction regardless of sampling time, indicating that these metals were strongly bound to the sediments. The potential mobility of the metals (non-residual fractions) is reflected in the following ranking: Pb > Mn > Zn > Cu > Ni > Cr in October 2009 and Mn > Pb > Zn > Cu > Ni > Cr in June 2010. The second highest proportion of metals was bound to organic matter/sulfides, originating primarily from anthropogenic activities. Non-residual metal fractions for all stations were highest in June 2010, which may be linked to higher organic matter concentrations in the sediment samples with 1.40% and 15.1% in October 2009 and June 2010, respectively. Potential sediment toxicity was evaluated using the Risk Assessment Code (RAC). Based on RAC classification, Cd and Cr pose no risk, Cu and Ni pose low risk, Pb and Zn were classified as medium risk metals, while the environmental risk from Mn was high. In addition, based on the sediment quality guidelines (SQG), the Seyhan River can be classified as a river with no, to moderate, toxicological risks, based on total metal concentrations.     

聚环氧琥珀酸对污泥中铅的萃取研究

以上海市桃浦污水厂污泥为对象,研究了易生物降解的聚环氧琥珀酸(PESA)对污泥中重金属Pb的萃取作用,重点考察了萃取体系的pH值和萃取剂PESA的用量对重金属Pb萃取的影响.研究发现,PESA对污泥中的重金属Pb具有较好的萃取效果,形态分析结果表明,被PESA萃取的锌主要来自水溶态、酸溶态、可还原态和可氧化态4种形态.当萃取体系的pH=4且PESA与污泥中重金属总量的摩尔比为4∶1时,Pb的萃取效率可达73%.实验结果还表明,萃取体系的pH值和PESA用量是影响污泥中Pb萃取的重要因素.随着萃取体系pH值的降低,Pb的萃取效率总体呈现逐渐下降的趋势;随着PESA用量的增加,Pb的萃取效率逐渐提高,且对体系pH值的依赖性减小.     

“热洗+助溶剂萃取”技术处理含油污泥的应用

为解决大量堆存的含油污泥可能造成的环境隐患问题,新疆油田公司针对含油污泥无害化、资源化技术进行探索研究。采用"热洗+助溶剂萃取"工艺技术处理,使含油污泥中矿物油含量从处理前的8%～30%降低至处理后的0.3%以下,满足GB 4284—84《农用污泥中污染物控制标准》的要求,有效回收了石油资源,减少环境污染,装置运行能耗成本为62.55元/t,具有运行费用低、操作简便的特点,为油田规模化、产业化处理含油污泥提供借鉴。     

污泥胞外聚合物的提取方法及其对污泥脱水性能的影响

采用7种不同方法提取污泥胞外聚合物(EPS),并研究污泥不同层EPS剥离前后对污泥脱水性能的影响.结果表明,甲醛+NaOH和2%EDTA提取法对污泥中紧密结合的胞外聚合物(tightly bound extracellular polymeric substances,TB-EPS)提取效率最高,总固体(SS)中的EPS提取量分别为128.9 mg.g-1和42.38 mg.g-1,但提取后细胞破裂严重,不能代表污泥EPS的真实含量,不宜采用.加热法较为温和,提取效率较高,总SS中EPS产量为21.97 mg.g-1.污泥剥离黏液层(Slime层)、松散结合的胞外聚合物(loosely bound extracellular polymeric substances,LB-EPS)和TB-EPS层后污泥的脱水性能大幅度改善,其中Slime层EPS含量越高污泥的脱水性能越差,当污泥EPS大量地释放到溶液中即Slime层时污泥的CST值大幅度升高,污泥的脱水性能变差.石湖墟和昂船舟污泥初始的毛细吸水时间(CST)为132.9 s和229.9 s,当剥离Slime层时这2种污泥的CST值分别为80.8 s和79.4 s,脱水性能得到明显改善.