pH及表面活性剂对诺氟沙星在海洋沉积物上吸附行为的影响

采用批量平衡法系统考察了pH值和4种表面活性剂对诺氟沙星在海洋沉积物上吸附行为的影响.结果表明,不同pH值下,诺氟沙星在海洋沉积物上的吸附行为均可以较好地用Freundlich等温式拟合.Freundlich常数KF与诺氟沙星的平衡吸附量均随pH值的增大而减小,且在pH值为8.10时,出现最小值;研究发现,pH值为6.01时,诺氟沙星以阳离子交换为主要机制吸附在海洋沉积物上;pH值为8.10时,诺氟沙星在海洋沉积物中的吸附以范德华力、疏水作用、静电作用为主.加入表面活性剂后,其吸附行为能较好地用吸附二级动力学方程拟合.加入表面活性剂对诺氟沙星的平衡吸附量Qe有影响,饱和吸附量Qe由小到大依次为:Qe(Tween80)相似文献   

The “Short Cut” Approach for the Reality of Enhanced Groundwater Contamination

Based on the reality of (a) soil heterogeneity in the vadose zone, (b) enhanced desorption from soil and solubility in water of water insoluble contaminants in the presence of surfactants, and (c) wetting/drying cycles of groundwater recharge (a major cause of fractures formation), a coherent “short-cut” conceptual approach is advanced to account for enhanced groundwater contamination. This is an attempt to close the gap between theory, lab simulations and conventional modelling-based predictions, and observed higher concentrations and more rapid arrival times of contaminants reaching groundwater. Recent data concerning chloride ion and non-ionic surfactants concentrations in aquifers and groundwater wells, combined with previous results concerning the concentrations of tritium, chlorides, metals, organic hydrocarbons and surfactants in the unsaturated and saturated zones of Israel's aquifers, are accounted for in terms of the “short-cut” approach. The contradiction between predictions of groundwater contamination made with conventional, deterministic, homogeneous models and the actual observed behavior of contaminants in soils and aquifers is thus explaind. The “short cut” approach should not be perceived as a better type of model to guide modelling. Rather, it is a proposal for a conceptual change from the realistically invalid, but commonly accepted, conventional “buffer-protective soil/long-term groundwater contamination” to the “short cut” conceptual model to explain the enhanced groundwater contamination actually observed. Although the validity of the proposed approach is strongly supported by the data here presented for the case of Israel (serving as an illustrative case study), selected results and conclusions drawn from studies conducted worldwide suggest its general applicability and usefulness. A major conclusion evolved from the “short-cut” conceptual model is that contemporary groundwater management policies, based on the current perception of groundwater contamination processes and their modelling, may result in an irreversible detrimental effect on the environmental situation in the long run. In any case, prevention, rather than correction/remediation, is strongly recommended as the strategy of choice for rational long-term management of groundwater resources.     

亚甲蓝比色法测定水中阴离子表面活性剂的方法探讨

采用亚甲蓝比色法测定水中阴离子洗涤剂是目前较为简便、迅速、准确可靠又经济的测定方法。样品经中速定性滤纸过滤除去悬浮物后，加入酚酞试剂经酸碱中和后直接加入亚甲蓝显色液，用三氯甲烷分次萃取，该实验相对偏差，工作曲线、相关系数均达到了方法所规定的要求。     

有机物料及表面活性剂对植物修复菲污染土壤的影响

采用盆栽试验方法,研究了外源有机物料及表面活性剂加入菲污染土壤后黑麦草对土壤中菲的修复作用.结果表明,有机物料(绿肥和猪粪堆肥)施入土壤后,黑麦草地上部和地下部的生物量比对照增加了13.54～24.18%,而表面活性剂(T80、SDS、CTAB)的加入却降低了黑麦草的生物量;结果还显示,有机物料和表面活性剂加入都可以提高植株体内菲的含量,但植株吸收积累菲的量占土壤菲总损失量的比例不足0.1%.本研究表明,植物从土壤中吸收菲不是植物修复菲污染土壤的主要机制.     

改性粉煤灰处理含阳离子表面活性剂废水的研究

以粉煤灰作为吸附剂 ,研究了含阳离子表面活性剂CTMAB为 2 0～ 12 0mg L的模拟废水去除CTMAB的一般规律。研究结果表明 ,以CaO为改性剂改性的粉煤灰对含阳离子表面活性剂废水具有良好的吸附性能 ,在含CTMAB浓度为 2 0～ 12 0mg L ,改性粉煤灰用量每 2 0 0mL为 2 0～ 2 5g,粒径范围 2 0 0～ 180目 ,pH为 12～ 13的实验条件下 ,CTMAB的去除率最高可达 98%以上     

Biodegradation of synthetic surfactants by river microorganisms

Ｂｉｏｄｅｇｒａｄａｔｉｏｎｏｆｓｙｎｔｈｅｔｉｃｓｕｒｆａｃｔａｎｔｓｂｙｒｉｖｅｒｍｉｃｒｏｏｒｇａｎｉｓｍｓ￥ＨｉｄｅａｋｉＭａｋｉ；ＫｅｎｒｏｕＴｏｋｕｈｉｒｏ；ＹａｓｕｈｉｒｏＦｕｊｉｗａｒａ；ＭｉｃｈｉｈｉｋｏＩｋｅ；ＫｅｎｊｉＦｕｒｕｋ...     

表面活性剂及水溶性有机物对菲生态毒性的影响

采用室内培养试验及化学试验研究了表面活性剂及水溶性有机物(DOM)对土壤中菲对小麦的生态毒性的影响.结果表明,绿肥和猪粪堆肥DOM具有具有类似表面活性剂的表面活性性质,且猪粪堆肥的表面活性较大;在本试验条件下,DOM对菲对小麦的生态毒性有减轻作用,而表面活性剂对菲生态毒性有增加的趋势;当DOM和表面活性剂共存时,菲的生态毒性则比DOM单独作用时的结果强,而弱于表面活性剂单独作用的结果.     

LAS和AE对水生植物损伤的显微和亚显微结构观察

利用透射电镜研究了阴离子型表面活性剂LAS和非离子型表面活性剂AE对水生植物水绵、水浮莲的损伤作用.观察发现,在LAS处理液中,水绵细胞壁外层被溶解而消失,载色体的规则螺旋缠绕结构被打乱,集结成团.细胞膜与细胞壁部分分离.水浮莲细胞出现质壁分离,细胞膜部分解体,细胞质中有许多空腔,液泡增大,叶绿体变形;在AE处理液中,水绵细胞壁外层被溶解,细胞膜消失,载色体和造粉核解体,分散于整个由细胞壁内层构成的空腔中.水浮莲细胞膜部分解体,染色质浓缩,核膜逐渐解体,叶绿体和线粒体解体,液泡消失,被细胞质充填.可以推断:LAS和AE对水生植物损伤的机理不同,AE以溶解为主,LAS则除溶解外,所带电荷引起蛋白质构象改变也是主要因素之一.     

溴甲酚绿－溴化十六烷基吡啶光度法测定水中阴离子表面活性剂

建立溴甲酚绿（ＢＣＧ）－溴化十六烷基吡啶（ＣＰＢ）光度法测定水中阴离子表面活性剂的方法。实验表明，最适合的ｐＨ范围为５．５－９．０，λｍａｘ＝６１４ｎｍ，在８６μｇＣＰＢ存在下，十二烷基苯磺酸钠（ＳＤＢＳ）和十二烷基硫酸钠（ＳＤＳ）分别在０－８０μｇ／１０ｍｌ和０－７５μｇ／１０ｍｌ范围内符合比耳定律，其表观摩尔吸光系数分别为２．９×１０４和３．１×１０４Ｌ·ｍｏｌ－１·ｃｍ－１。用此法测定了河水和生活废水中的阴离子表面活性剂，相对标准偏差＜３．０％，样品加标平均回收率为９９．３％。     

表面活性剂清洗法在污染土壤修复中的应用

探讨了表面活性剂清洗法对土壤中芳烃类污染物的清除作用,并对常州市染化厂原址污染现场土壤样品进行了清洗研究．研究表明,表面活性剂对土壤中的芳烃类污染物有很好的去除效果,十二烷基苯磺酸钠溶液对土壤中苯酚、硝基苯洗脱率分别达９３．９７％ 和７８．７４％ ．对污染现场土壤样品中主要污染物的洗脱率达９０％ 以上