Effects of water hardness and existence of adsorbent on toxic surface tension of surfactants for aquatic species

We have studied the effectiveness of surface tension on surfactants risk assessment. gamma(tox) was defined as surface tension at a point where acute aquatic toxicity of a surfactant emerges. Oryzias latipes, Daphnia magna, and Podocopida were used for acute aquatic toxicity test of 7 surfactants and 3 detergents. Gamma(tox)values were plotted on surface tension curves, and the effect of water hardness on toxicity and surface tension were examined. Results showed that gamma(tox) varies greatly by kind of surfactant or detergent. Therefore, aquatic toxicity cannot only be explained by surface tension. The change of aquatic toxicity with varying water hardness, however, could be explained by the change of surface tension. Aquatic toxicity of LAS (Linear Alkylbenzene Sulphonate) increased and aquatic toxicity of SOAP decreased with an increase of water hardness, but both gamma(tox), values were constant. Aquatic toxicity was decreased by an addition of mud soil as adsorbent into surfactant solution. The toxicity change can be explained by the surface tension since gamma(tox) value of solution with and without mud soil were equal. These results showed that the change of aquatic toxicity of a surfactant caused by water property, such as water hardness, could be explained by the change of surface tension.     

Effects of surface activity on aquatic toxicity of binary surfactant mixtures

The purpose of this study was to discuss the effects of surface activity on the aquatic toxicity of binary surfactant mixtures comprising anionic, nonionic, and cationic surfactants. Surface tension was measured to determine the cmc (critical micelle concentration), and acute aquatic toxicity tests were conducted on Daphnia magna to obtain 24h-EC(50) (24h 50% effective concentration). TU (toxic unit) was calculated to evaluate the toxicity of the mixture. Most of the surfactant mixtures showed no synergistic increase in the aquatic toxicity. The mixture of anionic/nonionic surfactants showed synergistic interfacial activity with decreasing cmc, but the toxicity did not increase. The surface tension of the mixture at 24h-EC(50) (γ(tox)), which was used as an indicator of the toxic concentration, decreased considerably and TU was >1, indicating decreased toxicity. γ(tox) of the anionic/anionic surfactant mixture decreased when tested with hard water (hardness of 625 ppm). γ(tox) could not be used as a toxic indicator for the anionic/cationic surfactant mixtures because they showed aquatic toxicity before their surface tension began to decrease.     

N-十二烷基天冬氨酸钠的性能

用Wilhelmy法对实验室制备的氨基酸表面活性剂N-十二烷基天冬氨酸钠(NDASPS)的表面张力进行了测定,发现25℃,pH=6~10时,其CMC为1.127~3.382 mmol/L,γCMC为32.47~39.32 mN/m,高pH对表面性能影响较大。应用性能研究表明,不同硬水中,钙皂分散性在pH=7时均为最优(钙皂分散指数为2%),渗透性随pH的增加而减小,两者均好于LAS和OAB;产品在pH=8时对油酸的乳化性优于LAS和OAB;去污性和泡沫性几乎不受水硬度的影响,当m(NDASPS)∶m(LAS)=1∶2时,其去污值达到66.09%,该质量比为1∶1时,其水溶液的表面张力达到27.08 mN/m。     

十二烯基琥珀酸淀粉酯的表面性质研究

以直链十二烷基苯磺酸钠（LAS）为参照样,研究了十二烯基琥珀酸淀粉酯（DDSS）表面活性剂的表面张力、硬水稳定性、发泡力及泡沫稳定性等理化特性。结果表明：DDSS具有较好的表面活性,其临界表面张力（γcm）c和临界胶束浓度（cmc）分别为27.786 mN/m和0.49 g/L。DDSS在硬水中具有更好的稳定性,但发泡力和泡沫稳定性较低。DDSS在日化领域具有广泛的应用前景。     

Interactions between LAS and nonionic surfactants

Physicochemical interactions between linear alkylbenzene sulfonate (LAS) and various linear alcohol nonionics (NI) have been investigated. The effect of adding nonionic to LAS on critical micelle concentration (cmc), surface tension, water hardness sensitivity and detergency performance depends on both hydrophobe and hydrophile structure. The addition of low levels of a lauryl range-high EO nonionic surfactant significantly lowers cmc and causes the formation of micelles containing predominantly nonionic molecules. These mixed micelles improve hard water performance by acting as a sink for LAS and free calcium. Nonionic surfactant enhances LAS hard water performance by preventing the loss of LAS via Ca(LAS)₂ precipitation, not by its own soil removal capabilities. Nonionic surfactant acts as a micelle promotion agent, while LAS remains responsible for surface and interfacial properties. Presented at the AOCS meeting in May 1984 in Dallas, Texas.     

双直链烷基二苯甲烷双磺酸盐的合成与性能

以二苯甲烷、系列长链脂肪酰氯(月桂酰氯、豆蔻酰氯、棕榈酰氯)和氯磺酸为主要原料,合成了3个阴离子双子表面活性剂———双直链烷基二苯甲烷双磺酸钠盐(DSDM)。通过硅胶层析法分离提纯了中间产品,并采用核磁共振氢谱对其结构进行表征,采用质谱对最终产品的结构进行了表征,证明所得产物即为目标产物。测定了DSDM的相关性能,结果表明,C12-DSDM在25℃时,CMC和γCMC分别为1.452 mmol/L和38.49 mN/m;C14-DSDM、C16-DSDM的油水界面张力均受温度和硬度的影响;C14-DSDM不受盐度的影响;C16-DSDM受盐度影响较大;C14-DSDM、C16-DSDM复配体系可达到9.44×10-3 mN/m的超低界面张力。     

直链烷基苯磺酸镁的温和作用和应用性能（英）

对直链烷基苯磺酸镁盐（ＬＡＳ２ Ｍｇ） 与钠盐水溶液中诸多性质的对比做了大量研究。例如， 表面张力、临界胶束浓度、比电导、粘度、溶解性、生物降解性、毒性及耐硬水性等。同时， 对ＬＡＳ２ Ｍｇ 的其它性能如Ｚｅｉｎ 试验（ 一种皮肤刺激性试验） ， 润湿性及在盥洗用品和餐具洗涤剂中的应用性能也进行了测试。镁盐的一些特殊性质及其在洗涤剂和化妆品领域中新的应用的可能性得到了证实或确认。     

壬基酚聚氧乙烯醚丙基磺酸钠的表面活性及应用性能

研究了硬水和油田水中壬基酚聚氧乙烯醚丙基磺酸钠(NPSO-5)水溶液的表面活性及应用性能,并与常用表面活性剂LAS、AOS和AES进行比较;考察了添加脂肪醇对NPSO-5体系泡沫性能的影响和NPSO-5在NaOH水溶液中的润湿性能及硬水溶液中的润湿乳化性能。结果表明,水硬度从0 mmol/L增加到80 mmol/L,NPSO-5的临界胶束浓度(CMC)从2.06×10-4 mol/L降低到7.8×10-5 mol/L;NPSO-5相对于LAS和AOS具有较强的抗硬水能力,且在硬水中具有较高的起泡能力和稳泡性能,添加脂肪醇在一定程度上改变了液膜吸附层的结构,进一步提高了体系的泡沫性能;在NaOH质量分数达12%时,NPSO-5仍然具有良好的润湿性能。     

沥青质模型油/MD膜驱剂溶液的界面张力

从MD膜驱剂与原油界面活性组分沥青质模型油的界面张力出发,考察了作用时间、水相pH、MD膜驱剂质量浓度、盐浓度、沥青质含量、芳香度、温度等对模型油/水界面张力的影响,并根据扩散控制机理解释了动态界面张力初期过程,进一步揭示了MD膜驱油技术的机理。结果表明,沥青质模型油/MD膜驱剂溶液的界面张力先随时间增加而降低,约15min后达到平衡,达到平衡之前的过程基本上符合扩散控制过程;MD膜驱剂的加入并不能改变pH对模型油/水界面张力的影响趋势;在所考察的条件范围内,沥青质模型油/水溶液的界面张力不随MD膜驱剂质量浓度增加而改变,其值约为19 65mN/m;NaCl对界面张力的影响不明显;沥青质质量浓度从0增加到1000mg/L时,模型油/水和模型油/MD膜驱剂溶液的界面张力分别从23 4mN/m和22 0mN/m逐渐下降至20 0mN/m和18 8mN/m;温度从25℃升高到45℃时,模型油/水溶液的界面张力降低;但芳香度从0增加到100%时,其界面张力均从21 0mN/m增加至31 5mN/m。MD膜驱剂是表面非活性物质,在驱油时不存在低界面张力提高采收率的机理。     

两种油溶性磺酸盐与重烷基苯磺酸盐复配体系的界面性能

以十二烷为油相,比较了二烷基苯磺酸盐（DAS）与α-烯烃磺酸钠（C2024AOS）两种不同结构的油溶性表面活性剂与重烷基苯磺酸盐（HABS）复配体系的界面张力.结果表明,具有苯环结构的DAS和直链型C2024AOS本身界面张力均较高.但与HABS/LAS二元体系复配之后,DAS与HABS之间在降低界面张力方面存在明显的协同效应（固定HABS与DAS质量比为3∶1,LAS含量为20％时,DAS/HABS/LAS三元体系界面张力可以达到3.28×10-3 mN/m;固定LAS含量为30％,DAS与HABS质量比为1∶1时,界面张力可以达到1.85×10-3 mN/m）,而C2024AOS与HABS之间不存在明显的协同效应.     

Ecotoxicological Assessment of Mixtures of Ether Carboxylic Derivative and Amine-Oxide-Based Non-ionic Surfactants on the Aquatic Environment

The purpose of this study was to discuss the effect of the chemical structure of anionic and non-ionic surfactants and surface activity on toxicity. Single and binary mixtures of three ether carboxylic derivative surfactants and three amine-oxide-based non-ionic surfactants were used. Toxicity was determined using three test organisms: freshwater crustaceans (Daphnia magna), luminescent bacteria (Vibrio fischeri), and microalgae (Selenastrum capricornutum). The toxicity of surfactants is related to the hydrophobic alkyl chain, the degree of ethoxylation, and the critical micelle concentration of surfactants. Relationships found agreed with the fact that the lower toxicity is shown by the shorter alkyl chain. There is a strong relation between surface activity and toxicity: the toxicity increased as the CMC of the surfactant or mixtures of surfactants decreased. Commercial products are formulated using surfactants mixtures, so it is important to know their behavior using an easily measured property: the least toxic mixtures were formed by the surfactants having lower individual toxicity. Around the CMC, our data show a synergism for the binary mixtures. The results have given rise to a classification of the different surfactants and their mixtures according to the organism test, as safe, harmful or toxic. V. fischeri was in general the most sensitive microorganism to the toxic effect of the surfactants, followed by Daphnia magna, while Selenastrum capricornutum was more tolerant. These results can be useful for selecting technically efficient surfactants and their mixtures with a lower ecotoxicity on the aquatic environment.     

Novel fluorinated surfactants for enhanced oil recovery in carbonate reservoirs

Novel surfactant‐polymer (SP) formulations containing fluorinated amphoteric surfactant (surfactant‐A) and fluorinated anionic surfactant (surfactant‐B) with partially hydrolyzed polyacrylamide (HPAM) were evaluated for enhanced oil recovery applications in carbonate reservoirs. Thermal stability, rheological properties, interfacial tension, and adsorption on the mineral surface were measured. The effects of the surfactant type, surfactant concentration, temperature, and salinity on the rheological properties of the SP systems were examined. Both surfactants were found to be thermally stable at a high temperature (90 °C). Surfactant‐B decreased the viscosity and the storage modulus of the HPAM. Surfactant‐A had no influence on the rheological properties of the HPAM. Surfactant‐A showed complete solubility and thermal stability in seawater at 90 °C. Only surfactant‐A was used in adsorption, interfacial tension, and core flooding experiments, since surfactant‐B was not completely soluble in seawater and therefore was limited to deionized water. A decrease in oil/water interfacial tension (IFT) of almost one order of magnitude was observed when adding surfactant‐A. However, betaine‐based co‐surfactant reduced the IFT to 10^?3 mN/m. An adsorption isotherm showed that the maximum adsorption of surfactant‐A was 1 mg per g of rock. Core flooding experiments showed 42 % additional oil recovery using 2.5 g/L (2500 ppm) HPAM and 0.001 g/g (0.1 mass%) amphoteric surfactant at 90 °C.     

十二烷基甘油醚羧酸盐的性能研究

文章测定了十二烷基甘油醚羧酸盐阴离子表面活性剂的一系列性能,结果显示同AEO7、LAS相比,它的γcmc较低,为24.07 mN/m,具有良好的降低表面张力性能,泡沫高度5 min后仍维持58 mm,稳泡性较好,对苯的增溶能力为130 ml/mol,润湿、乳化、钙皂分散性能均较好。     

长链脂肪醇聚氧乙烯醚丙酸盐的合成与性能

以脂肪醇聚氧乙烯醚、丙烯酸甲酯、氢氧化钠为主要原料,经过加成、皂化反应,合成脂肪醇醚丙酸盐(AEP)。采用IR、质谱对产物结构进行了表征,证明所得产物即为目标产物。测定了AEP的相关性能,结果表明,C12AEP在25℃时,CMC和γCMC分别为0.236 mmol/L和26.63 mN/m;采用稳态荧光法以芘(Py)为荧光探针,测定C12AEP的胶束栅栏层的微极性,较一般表面活性剂小;AEP与甜菜碱(B)复配体系界面张力受硬度、盐度及复配比例的影响较大,C18AEP与甜菜碱(B)复配体系可达到3.98×10-3mN/m的超低界面张力,可适用于石油的三次开采。     

木质素两性表面活性剂的合成及表面物化性能

以十二烷基二甲基叔胺、环氧氯丙烷为原料,合成了中间体(2,3-环氧丙基)十二烷基二甲基氯化铵(DMAC),再与磺化木质素(SL)酚羟基反应,合成了木质素两性表面活性剂LAS。通过正交实验确定了最佳合成条件:以丙酮为溶剂,n(SL)∶n(DMAC)=1∶1.1,反应时间3h,pH=12,反应温度55℃,产物中氮质量分数达2.25%。通过元素分析、傅立叶变换红外光谱、UV,确证了目的产物结构。测定产物的临界胶束质量浓度CMC为3g/L,γCMC为21.11mN/m,HLB值为10。表明所合成的木质素两性表面活性剂具有较高的表面活性。     

岔30断块S/P二元复合驱实验研究

针对华北岔30断块90℃高温、地层水矿化度18765.1 mg/L的特点,筛选得到了石油磺酸盐CDS-1与疏水缔合聚合物HNT201-3二元复合体系。0.05%CDS-1/HNT201-3二元复合体系与原油的界面张力可降到10^-2mN/m数量级;当HNT201-3浓度为1250mg/L时,复合体系的表观粘度为23.7 mPa.s。非均质岩心（模拟油层非均质变异系数和平均空气渗透率）驱油试验结果表明,注入驱油体系0.3PV、后续保护段塞0.1PV（聚合物HNT201-3浓度1250mg/L）时,可比水驱提高采收率19.73%OOIP。     

Effects of sewage treatment on textile effluent

Textile effluent is discharged to sewer with little or no destructive treatment. In investigating the effects of sewage treatment on textile effluent we aim to establish the biodegradability of the effluent and the reduction in toxicity exerted on aquatic organisms resulting from standard sewage treatment. Using three separate samples of effluent, the initial toxicity was tested using the aquatic invertebrate Daphnia magna. The samples were biodegraded following the Zahn-Wellens method and then retested. Results showed relatively good biodegradability but negligible toxicity reduction. The ‘hard COD’, or non-degradable, portion of the effluent, which appears to be responsible for exerting toxicity, is not altered by this treatment method.     

Preparation of polyaniline montmorillonite clay composites for the removal of diethyl hexyl phthalate from aqueous solutions

The work presents the synthesis of polyaniline functionalized montmorillonite (PANI/MMT) clay composites and evaluation of their performance as an adsorbent for the mitigation of toxic diethyl hexyl phthalate (DEHP) from water. The formation of composite was confirmed by different analytical techniques such as FTIR, zeta potential analysis, XRD, SEM, and AFM. The adsorption capacity of PANI/MMT was superior to MMT. DEHP followed partition mechanism on PANI/MMT whereas MMT favored surface adsorption mechanism. The performance of PANI/MMT for DEHP removal was unaffected by the change in pH of solution, change in salinity, and hardness contents in aqueous system and consecutive adsorption desorption cycles compared to MMT. Furthermore, both PANI/MMT and MMT exhibited greater adsorption capacities as compared to the previously published work and showed satisfactory performance in real water samples.     

驱油阴/两性表面活性剂复配体系协同效应研究

针对某油藏A区块,利用阴离子/两性表面活性剂的协同作用,进而达到油水超低界面张力,且两性表面活性剂十二烷基甜菜碱在浓度为0.1%~0.5%的范围内,降低油水界面张力的效果达到10~(-2) mN/m数量级,在加入阴离子表面活性剂的条件下,复配体系可以使油水界面张力达到超低界面张力。通过探讨表面活性剂的总浓度以及复配比对油水界面张力的影响,最终得到阴离子/两性表面活性剂复配体系可在较高矿化度和较低的浓度(0.4%)范围内达到10~(-3) mN/m的超低界面张力,并在此基础上对两者的协同作用进行分析。     

Characterizations of surfactant synthesized from Jatropha oil and its application in enhanced oil recovery

Surfactants are frequently used in chemical enhanced oil recovery (EOR) as it reduces the interfacial tension (IFT) to an ultra‐low value and also alter the wettability of oil‐wet rock, which are important mechanisms for EOR. However, most of the commercial surfactants used in chemical EOR are very expensive. In view of that an attempt has been made to synthesis an anionic surfactant from non‐edible Jatropha oil for its application in EOR. Synthesized surfactant was characterized by FTIR, NMR, dynamic light scattering, thermogravimeter analyser, FESEM, and EDX analysis. Thermal degradability study of the surfactant shows no significant loss till the conventional reservoir temperature. The ability of the surfactant for its use in chemical EOR has been tested by measuring its physicochemical properties, viz., reduction of surface tension, IFT and wettability alteration. The surfactant solution shows a surface tension value of 31.6 mN/m at its critical micelle concentration (CMC). An ultra‐low IFT of 0.0917 mN/m is obtained at CMC of surfactant solution, which is further reduced to 0.00108 mN/m at optimum salinity. The synthesized surfactant alters the oil‐wet quartz surface to water‐wet which favors enhanced recovery of oil. Flooding experiments were conducted with surfactant slugs with different concentrations. Encouraging results with additional recovery more than 25% of original oil in place above the conventional water flooding have been observed. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2731–2741, 2017