糖脂类生物表面活性剂去除污染含水层中石油烃的研究

研究了糖脂类生物表面活性剂对石油烃的增溶,并将其用于污染含水层中石油烃的去除。结果表明:石油烃溶解度随着糖脂类生物表面活性剂浓度的增大而增大,糖脂类生物表面活性剂质量浓度为1 200mg/L时,石油烃溶解度达10 077.7mg/L;界面张力随着糖脂类生物表面活性剂浓度的增加而减小,糖脂类生物表面活性剂质量浓度为1mg/L时,界面张力为34.3mN/m,糖脂类生物表面活性剂质量浓度为800mg/L时,界面张力为5.2 mN/m。采用糖脂类生物表面活性剂对污染含水层进行清洗处理,在固液比(质量体积比)为1g∶2mL的体系中,糖脂类生物表面活性剂质量浓度为3 000mg/L,120r/min、10℃下振荡12h,石油烃去除率达70.82%。污染含水层柱冲洗结果表明,糖脂类生物表面活性剂质量浓度分别为1 200、3 000mg/L时,10倍孔隙体积的表面活性剂冲洗后,分别从污染砂样中去除41.81%和63.30%的石油烃。     

表面活性剂CMC对石油烃污染土壤的增溶

研究了表面活性剂羧甲基纤维素钠(carboxyl methyl cellulose,CMC)对土壤中石油污染物的增溶作用。通过批实验,对比研究了CMC和十二烷基苯磺酸钠SDBS 2种表面活性剂的增溶效果,探究了CMC浓度、pH、盐度及回用次数对土壤中石油烃增溶效果的影响。研究结果表明,当CMC浓度为0.5%,增溶时间为24 h时,对TPHs浓度为17 695 mg·kg~(-1)的污染土样,TPHs洗脱率高达60%以上。碱性环境有利于石油烃的洗脱,酸性体系会抑制石油烃的洗脱;增溶作用随盐度的增大而显著增大。在利用CMC对污染土壤进行增溶洗脱时,对于TPHs高浓度污染土壤,可以选择将其洗脱液回用1次或者2次;对于TPHs较低浓度污染土壤,可以选择将其洗脱液回用于较高浓度的污染土壤。     

微米Cu／Fe对污染土壤洗脱液中有机氯农药的降解

以表面活性剂TritonX-100（TX-100）为洗脱剂，某有机氯农药（organochlorinepesticides，OCPs）污染场地土壤为对象，七氯、氯丹和灭蚁灵为目标污染物，研究微米Cu／Fe双金属对污染土壤洗脱液中OCPs的降解效果。考察了洗脱液中OCPs初始浓度、洗脱液pH值、微米零价铁加入量和cu负载量对Cu／Fe去除OCPs效果的影响。结果表明，微米Cu／Fe可以有效的去除土壤洗脱液中目标污染物。当微米零价铁加入量为1．0g（25g／L），cu负载量为1．0％，洗脱液pH值为6．89时，Cu／Fe对2号土壤洗脱液中七氯、γ-氯丹、α-氯丹和灭蚁灵的去除效果最好，去除率分别为100．0％、99．3％、80．8％和71．1％。洗脱液中OCPs初始浓度越低，微米零价铁加入量越大，Cu／Fe对OCPs去除率越高；偏酸性条件有利于Cu／Fe对γ-氯丹和灭蚁灵的去除，而α-氯丹在中性条件下去除效果最好；1号土壤和2号土壤洗脱液的最佳铜负载量分别为2．O％和1．0％。     

矿化垃圾修复石油污染土壤的影响因素及污染物的去除机制

利用矿化垃圾对石油污染土壤进行修复研究,以期在低成本、易操作、修复效果好的前提下达到以废治废的目的。分别研究了矿化垃圾与石油污染土壤的混合比例、土壤含盐量、含油量和含水率对矿化垃圾修复石油污染土壤的影响,并通过3D-EEM(三维荧光)和GC-MS(气相-质谱)技术分析了体系石油污染物的去除特性。结果表明:矿化垃圾对石油污染土壤具有较好的修复效果,在矿化垃圾与石油污染土壤的混合比例为6:4、土壤不添加盐分、含油量为4%、含水率为30%的条件下,运行94 d后土壤中石油去除率最高可达58.61%;同时,基于3D-EEM分析发现土壤中石油类物质的荧光峰位置在处理前后均出现在Ex/Em=300 nm/330 nm处,其去除率为44.89%,表明矿化垃圾床对三环及其同系物和单环及其同系物的芳烃去除效果较好;另外,基于GC-MS技术分析得出,经矿化垃圾修复后,土壤中石油总去除率为66.57%,除正十八烷去除率(19.84%)较低外,其他烷烃的去除率均高于56.8%。     

混合型乳化液膜萃取分离处理工业化纤废水

为了去除工业化纤废水中的水溶性污染物,采用混合型乳化液膜法对废水样品进行了处理,以紫外吸收值和COD去除率为指标。结果表明,不同的表面活性剂、废水浓度、反应时间、液膜组成及处理工艺(包括内相酸浓度、油水比、乳水比)等对处理效果都会产生影响;其中T-152是最合适的表面活性剂,当体系pH=4,油内比为1∶1,乳水比为1∶3,废水初始COD为1 000 mg/L左右,表面活性剂的量:溶剂煤油的量:膜固定剂(TOA)三者体积比为5∶25 000∶1时,搅拌处理30 min,废水中紫外吸收光谱的最强吸收峰红移且峰强减小,COD的去除率达到96.5%,出水COD小于100 mg/L;处理后,废水的色度和浊度均得到显著降低,去除率达到98%以上,达到了排放要求。     

老化石油污染土壤的清洗处理

以华北油田老化长达1年以上的石油污染土壤为研究对象,采用自行选配的清洗剂对该污染土壤进行了一次清洗和二次清洗处理.实验结果表明,一次清洗后,污染土壤样品的含油率从26.34%～29.90%降到6.34%～7.84%,洗油率达80.06%～81.06%;经二次清洗处理后,污染土壤样品的含油率从26.34%～29.90%降到4.05%～4.85%,洗油率达88.06%～88.19%.在一次清洗和二次清洗的基础上,通过模拟实验确定了洗油污水回用的最佳回用率为80%,最佳加药质量浓度为0.4 g/L,该条件下污水的最终产生量也较少.按照该参数对华北油田的石油污染土壤进行了清洗实验,洗油率达79.20%～80.51%.     

表面活性剂对黄土中石油污染物的解吸影响研究

研究了用表面活性剂去除黄土中柴油类污染物。选用阴离子活性剂十二烷基苯磺酸钠和十二烷基硫酸钠（LAS和SDS）和阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）对污染的土壤进行解吸实验，表明阴离子表面活性剂浓度从0.1%增加到1.0%时，其柴油的去除率可达20％，而阳离子表面活性剂去除作用不甚明显。利用摩尔增溶比MSR值求得LAS和SDS的logKm值为4.552和3.630，这和理论的计算值很接近。     

电吸附对水中盐类、氨氮、COD的去除效果分析

电吸附技术作为高效、环境友好型的除盐、除氨氮技术，可应用与水的深度处理领域内。为了使污水回用达到工业用水的水质标准，对电吸附去除水中盐类、氨氮、COD的效果进行分析，结果表明，电吸附设备处理不同氨氮浓度的废水，对中低浓度的氨氮去除效果稳定，当进水氨氮浓度低于20 mg/L时，处理后出水氨氮浓度低于5 mg/L，COD浓度小于25 mg/L，达到回用标准；随着进水盐浓度的增大电吸附处理效果逐渐变差，在电导率低于2 500 μS/cm时除盐率在75%左右，氨氮去除率达到70%左右，COD去除率达到60%左右。经电吸附处理后的低氨氮浓度废水，TDS、氨氮浓度均可达到工业回用水标准。     

工艺参数对表面活性剂洗涤修复PAHs污染土壤的影响

采用土壤洗涤(soil-washing)技术,分别用TritonX-100和Tween-80为强化洗涤剂研究了搅拌强度、洗涤时间、表面活性剂浓度、液固比、温度和间歇搅拌6个工艺参数对PAHs污染土壤洗涤效果的影响。通过一系列烧杯搅拌实验得到最佳洗涤工艺参数。TritonX-100和Tween-80的最佳洗涤时间分别是30 min和60 min,其他工艺参数最佳条件均相同。分别是搅拌强度为250 r/min,表面活性剂浓度为5 g/L,液固比为10∶1,温度为室温和连续搅拌。在此最佳工艺参数条件下,污染土中PAHs的残留率<10%,基本上满足目标污染物的修复目标。应用表面活性剂强化洗涤技术修复PAHs污染土壤是合理和可行的。     

泡沫分离法去除废水中的Cr(Ⅲ)离子

以绿色表面活性剂酪蛋白为起泡剂,采用间歇式泡沫分离法去除废水中高浓度Cr(Ⅲ)离子,考察了pH值、空气流量、酪蛋白的添加量、搅拌速度和装液体积5个因素对Cr(Ⅲ)离子去除率的影响。结果表明:当Cr(Ⅲ)离子初始浓度为100 mg·L~(-1)、处理时间为1.5 h时,最佳分离工艺条件为pH=9.5、空气流量0.75 L·min~(-1)、4 g·L~(-1)的酪蛋白的添加量25 m L、搅拌速度800 r·min~(-1)、装液体积1 500 m L,去除率可达99.78%;在最佳工艺条件下,用常规表面活性剂十二烷基苯磺酸钠(SDBS)代替酪蛋白进行对比实验,酪蛋白可以使废水中Cr(Ⅲ)离子去除率提高1.73%。酪蛋白是一种环境友好型物质,作为绿色生物表面活性剂适用于泡沫分离工艺中。     

Crude oil contaminated soil washing in air sparging assisted stirred tank reactor using biosurfactants

This study investigated the removal of crude oil from soil using air sparging assisted stirred tank reactors. Two surfactants (rhamnolipid and sodium dodecyl sulfate, SDS) were tested and the effects of different parameters (i.e. temperature, surfactant concentrations, washing time, volume/mass ratio) were investigated under varying washing modes namely, stirring only, air sparging only and the combination of stirring and air sparging. The results showed that SDS removed more than 80% crude oil from non-weathered soil samples, whilst rhamnolipid showed similar oil removal at the third and fourth levels of the parameters tested. The oil removal ability of the seawater prepared solutions were better than those of the distilled water solutions at the first and second levels of temperature and concentration of surfactant solutions. This approach of soil washing was noted to be effective in reducing the amount of oil in soil. Therefore we suggested that a field scale test be conducted to assess the efficiency of these surfactants.     

应用表面活性剂-生物柴油微乳液去除污染土壤中多环芳烃

针对修复焦化厂高浓度多环芳烃污染土壤高成本的现实,采用以非食用性植物油、生物柴油、表面活性剂及其乳化合成的微乳液为淋洗剂,比较不同淋洗剂的淋洗效果。结果表明乳化合成的微乳液对焦化厂土壤中多环芳烃的总去除率高于单独使用表面活性剂为淋洗剂对土壤中多环芳烃的总去除率,说明生物柴油及植物油与表面活性剂乳化形成的微乳液对原污染土壤中的多环芳烃具有显著的增溶作用。1%TW-80和2.5%TW-80对土壤中多环芳烃总去除率分别为11%和14%;以2.5%TW-80为原料乳化合成的微乳液的淋洗去除率较以1%TW-80为原料乳化合成的微乳液高,总去除率分别为15%～30%和11%～18%;以生物柴油为原料乳化合成的微乳液的淋洗去除率较以植物油为原料乳化合成的微乳液高,分别为17%～30%和15%～23%,且对多环芳烃的去除率与其辛醇水分配系数(logKow)呈线性相关关系。     

The influence of defoamer on removal of PAHs in soil washing

The use of surfactants during soil washing process can create massive foam, which has a negative impact on the effective use of equipment. A series of tests was conducted to evaluate the defoaming performance of three defoamers and to investigate the influence on removal of polycyclic aromatic hydrocarbons (PAHs) during enhanced soil washing by the addition of the defoamer. Results showed that polydimethylsiloxane oil, which is the most common biomaterial used in commercial antifoaming and defoaming agents, has the best defoaming performance. With the addition of 0.1% polydimethylsiloxane oil, the removal ratios of total 16 PAHs (ΣPAHs) increased up to 53.48% and 75.92% when washing time was 5 min and 30 min, respectively, compared with the removal ratios of 44.12% and 67.28% with Triton X-100 solution only. This indicated that the proper selection of defoamer not only solves massive foaming problem but also brings out a positive influence on PAH removal during the soil washing process.

Implications: Three kinds of defoamers (kieselguhr, dodecanol, and polydimethylsiloxane oil) were collected to destroy the foam produced by Triton X-100. Among those defoamers, the polydimethylsiloxane (PDMS) oil has the best defoaming performances. The surface tension of the Triton X-100 solution with the addition of PDMS was lower. The addition of PDMS could improve the removal ratio of ΣPAHs during soil washing. That may be attributed to the addition of the nonionic surfactant Tergitol NP-10 as the emulsifier in the defoamer. After all, the results do not provide any indication of the influence on the solubilization micelles. It is thus questionable whether other components of PDMS oil could improve the PAH solubilization.     

Surfactant-enhanced release of carbaryl and ethion from two long-term contaminated soils

The potential of five nonionic surfactants, Triton X-100, Brij35, Ethylan GE08, Ethylan CD127, and Ethylan CPG660 for enhancing release of carbaryl and ethion from two long-term contaminated soils was evaluated using the batch method. Incorporation of the surfactants into soils enhanced the release of both pesticides to various extents, which could be related to the type of pesticides and type and the amount of surfactants added. Release of ethion was dramatically enhanced by aqueous concentrations of surfactants above their critical micelle concentration values. This was attributed to solubility enhancement through incorporation of the highly hydrophobic compound within surfactant micelles. A concentration of 10 g L(-1) of various surfactants released >70% of the total ethion from the soil irrespective of the surfactant. For carbaryl, the surfactants were effective at low concentrations and dependence on concentration was lower than in the case of ethion. The ethylan surfactants (GE08, CD127, and CPG660) had a higher potential than Triton X-100 and Brij35 for releasing the pesticides. However, there was still a significant portion of carbaryl (11% of the total) and ethion (17% of the total) left in the soil. Our study also showed that there must be an optimal concentration of each surfactant to maximize the mass transfer of pesticides. At some threshold concentration level, additional surfactant started to inhibit the mass transfer of solute from the soil into the water. The results suggested that surfactants could help remediation of soils polluted by pesticides. The choice of surfactant should be made based on the properties of pesticides.     

胶团强化超滤法(MEUF)去除废水中氯苯的研究

研究了3种单一表面活性剂十二烷基硫酸钠(SDS)、十六烷基三甲基溴化铵(CTMAB)、聚氧乙烯失水山梨脂肪酸酯醇醚(TW80)和混合表面活性剂TW80-SDS对氯苯(CB)的强化超滤,以期为有机废水胶团强化超滤技术提供参考。结果表明,进料液静置时间对去除率无显著影响,而振荡时间在1 h后对去除率影响不大。氯苯的去除率随进料液中表面活性剂浓度的增大而增大,单一的表面活性剂对氯苯的去除效果顺序为TW80CTMABSDS,且表面活性剂对氯苯的去除效果与表面活性剂的临界胶束浓度值(CMC)、亲水-亲油平衡值(HLB)呈负相关。阴-非混合表面活性剂TW80-SDS对氯苯的去除效果明显强于单一的SDS,且去除率随着非离子表面活性剂质量分数的增加而增加。渗透通量随着进料液中表面活性剂浓度的增加而下降,单一表面活性剂种类对渗透通量的影响顺序为SDSTW80CTMAB,混合表面活性剂中随着非离子表面活性剂质量分数的增加而渗透液的渗透通量越低。     

Solubilization of DNAPLs by mixed surfactant: reduction in partitioning losses of nonionic surfactant

Efforts to remediate the dense nonaqueous phase liquids (DNAPLs) by mobilizing them face with risks of driving the contaminants deeper into aquifer zones. This spurs research for modifying the approach for in situ remediation. In this paper, a novel solubilization of DNAPLs by mixed nonionic and anionic surfactant, Triton X-100 (TX100) and sodium dodecylbenzene sulfonate (SDBS), was presented and compared with those by single ones. Given 1:40 phase ratio of DNAPL:water (v/v) and the total surfactant concentration from 0.2 to 10gl(-1), mixed TX100-SDBS at the total mass ratios of 3:1, 1:1 and 1:3 exhibited significant solubilization for the DNAPLs, trichloroethene (TCE), chlorobenzene (CB) and 1,2-dichlorobenzene (1,2-DCB). The solubilization extent by mixed TX100-SDBS was much larger than by single TX100 and even larger than by single SDBS at the ratios of 1:1 and 1:3, respectively. TX100 partitioning into the organic phase dictated the solubilization extent. The TX100 losses into TCE, CB and 1,2-DCB phases were more than 99%, 97% and 97% when single TX100 was used. With SDBS alone, no SDBS partitioned into DNAPLs was observed and in mixed systems, SDBS decreased greatly the partition loss of TX100 into DNAPLs. The extent of TX100 partition decreased with increasing the amount of SDBS. The mechanism for reduction of TX100 partition was discussed. TX100 and SDBS formed mixed micelles in the solution phase. The inability of SDBS to partition into DNAPLs and the mutual affinity of SDBS and TX100 in the mixed micelle controlled the partitioning of TX100 into DNAPL phase. The work presented here demonstrates that mixed nonionic-anionic surfactants would be preferred over single surfactants for solubilization remediation of DNAPLs, which could avoid risks of driving the contaminants deeper into aquifers and decrease the surfactant loss and remediation cost.     

Solubilization and biodegradation of phenanthrene in mixed anionic-nonionic surfactant solutions

The effects of mixed anionic-nonionic surfactants, sodium dodecyl sulfate (SDS) mixed with Tween80 (TW80), Triton X-100 (TX100) and Brij35 respectively on the solubility enhancement and biodegradation of phenanthrene in the aqueous phase were investigated. The efficiency of solubilization and biodegradation of phenanthrene in single-, and mixed-surfactant solutions were also compared. The critical micellar concentrations (CMCs) of mixed surfactants were sharply lower than that of sole SDS. The degree of solubility enhancements by the mixed surfactants followed the order of SDS-TW80>SDS-Brij35>SDS-TX100. Synergistic solubilization was observed in the mixed surfactant solutions, in which the molar ratios of SDS to nonionic surfactant were 1:0, 9:1, 7:3, 5:5, 3:7, 1:9 and 0:1 while the total concentration of surfactants was kept at 5.0 and 10.0 mM, respectively. SDS-Brij35 exhibited more significant degree of synergistic solubility enhancement for phenanthrene. The mixed surfactants exhibited no inhibitory effect on biodegradation of phenanthrene. Substantial amounts of the solubilized phenanthrene by mixed surfactants were completely degraded by phenanthrene-degrading microorganisms within 96 h. The results suggested that anionic-nonionic surfactants would improve the performance of remediation of PAH-contaminated soils.     

Benzene removal from waste water using aqueous surfactant two-phase extraction with cationic and anionic surfactant mixtures

A novel separation technique known as an aqueous surfactant two-phase (ASTP) extraction is a promising method to remove organic contaminants from wastewater. When cationic and anionic surfactants are mixed at certain surfactant concentrations and compositions, the solution separates into two immiscible aqueous phases. One is the surfactant-rich and the other is the surfactant-dilute phase. The organic contaminants will solubilize into the surfactant aggregates and concentrate in the small volume surfactant-rich phase. The other phase contains only small amount of surfactants and contaminants as the treated water. Most ASTP studies have used nonionic surfactants above the cloud point. Mixtures of anionic and cationic surfactants can also exhibit aqueous-aqueous phase separation and can be used in the ASTP extraction process. The phase behavior and performance of ASTP extraction using cationic surfactant dodecyltrimethylammonium bromide (DTAB) and anionic surfactant alkyldiphenyloxide di-sulfonate (DPDS) to extract benzene from wastewater was investigated in batch experiments. It was found that phase separation only occurs over a narrow range of molar ratios of DTAB:DPDS from 1.6:1 to 2.4:1. In this study, a 2:1 molar ratio of DTAB:DPDS at which there is no net charge in the surfactant aggregates show the highest extraction efficiency and lowest critical micelle concentration value with greatest synergism (highest negative values of the micellar interaction parameter). At a total surfactant concentration of 50mM, the benzene partition ratio is 48 and 72% of the benzene is extracted into the surfactant-rich phase solution in a single stage extraction, which is superior performance compared to ASTP extraction using nonionic surfactants.     

洗车废水处理技术现状与展望

洗车废水中含有泥砂、油乳化液、有机物及洗涤剂类污染物质。在分析中 ,对洗车废水的水质进行了分类 ,并针对不同的水质 ,对国内的大型洗车场的处理工艺和小型洗车行的洗车废水回用工艺进行了介绍和分析 ,对国外采用膜工艺处理洗车废水的相关研究也进行了简要的介绍 ,同时提出了洗车废水的污泥处理问题。从社会、经济效益来看 ,洗车废水回用是必然趋势。现行的洗车废水回用处理工艺回用率低、处理效果不理想 ,采用高效、简单、实用、经济的原则进行设计 ,满足社会对洗车水回用的需求是未来洗车废水处理技术发展的要求