3种表面活性剂对有机氯农药污染场地土壤的增效洗脱修复效应

以有机氯农药生产企业工业场地污染土壤为对象,研究Tween80、TritonX-100和SDS这3种表面活性剂对土壤中氯丹(α-氯丹和γ-氯丹)、灭蚁灵、七氯、硫丹(α-硫丹和β-硫丹)的增溶洗脱效应.结果表明,3种表面活性剂对土壤中的有机氯农药均具有一定的增效洗脱作用,且洗脱去除率随表面活性剂添加量升高而逐渐增加.3种表面活性剂对土壤中氯丹、硫丹和七氯的去除率明显高于灭蚁灵,TritonX-100对灭蚁灵的去除率明显高于SDS和Tween80.Tween80和TritonX-100添加量为10g·L-1、SDS添加量为8.50g·L-1时,对土壤中4类有机氯农药的总去除率最高,分别为32.8％、59.7％和60.1％.对于该类污染场地土壤,选择10g·L-1 TritonX-100溶液在50℃条件下振荡5min时洗脱效果最好.     

乳化微米Fe/Cu降解有机氯农药污染土壤过程中微生物群落变化特征

利用磷脂脂肪酸(phospholipids fattyacids,PLFAs)法,以杭州某农药厂六六六(HCH)和滴滴涕(DDT)污染土壤为例,研究了空白(对照组)、还原铁粉、微米Fe/Cu和微米Fe/Cu+5 mmol·L~(-1)TX-100这4种处理对土壤中微生物群落结构的影响。结果表明:在105 d的研究时间内,微米Fe/Cu+TX-100组细菌生物量显著降低,可能的原因是TX-100具有一定的毒性,破坏了细胞膜的功能和结构;各组真菌/细菌生物量之比均呈上升趋势,微米Fe/Cu+TX-100组比值最大;表面活性剂TX-100对革兰阴性菌有抑制作用,还原铁粉组革兰阴性菌略有增加,微米Fe/Cu组革兰阳性菌与革兰阴性菌显著增加。还原铁粉组革兰阳性菌/革兰阴性菌比值较小,说明还原铁粉的加入改善了土壤的营养状况,而其他几组营养胁迫较强。还原铁粉和微米Fe/Cu+TX-100这2种修复方式对土壤通气有明显促进作用。各处理组微生物总生物量高于对照组,表明处理过程有助于恢复污染土壤的生态功能。通过对不同处理组PLFAs进行主成分分析,发现微米Fe/Cu与微米Fe/Cu+TX-100处理组后期原生动物明显增加。     

非离子表面活性剂强化白腐菌及其粗酶液对有机氯农药的降解

有机氯农药曾在世界范围内被广泛用于农业害虫的防治,为利用表面活性剂增效修复技术去除环境中的有机氯农药污染,研究了3种非离子表面活性剂(Tween 80、Tween 20和Triton X-100)对4种典型有机氯农药(4,4’-DDT、狄氏剂、艾氏剂和七氯)在水相中的增溶作用,对白腐菌Phlebia acanthocystis TMIC34875生长的影响以及对该菌株、胞外及胞内酶降解有机氯农药的强化效果.增溶试验结果表明,3种非离子表面活性剂可明显增加各有机氯农药的水溶解度,其增溶能力大小顺序为Tween 80>Tween 20>Triton X-100.Tween 80在低浓度(0.05、0.1和0.2 gL-1)下会促进白腐菌在PDB培养基中的生长,使其生物量增加;而高浓度(0.5和1.0 gL-1)的Tween 80则对菌株的生长产生一定的抑制作用.在0.05-0.5 g L-1浓度范围内,Tween 80可强化菌株对有机氯农药的降解效果,且降解率随着Tween 80浓度的增加而增加.降解强化效果在Tween 80浓度为0.5 gL-1时达到最佳,4,4’-DDT、狄氏剂、艾氏剂和七氯的降解率相比对照分别提高了6.70%、6.37%、10.94%和7.21%.Tween 80同样可促进胞内酶和胞外酶对4种有机氯农药的降解,尤其是对胞外酶降解的强化作用,在1.0 gL-1的Tween 80溶液中,有机氯农药的降解率提高了10%左右.可见,在农药污染环境的生物修复技术中,应用Tween 80等非离子表面活性剂来提高修复效率是可行的.     

雷州半岛典型区域土壤有机氯农药污染探查研究

在雷州半岛典型区域共采集了74个表层土壤和4个剖面土壤,对土壤中有机氯农药残留及分布状况进行了研究。结果表明:有机氯农药检出率为100%,其中∑HCH(六六六)和∑DDT(滴滴涕)质量分数范围分别在nd～65.93μg·kg-1和0.04～52.00μg·kg-1之间,同国内外同类报道相比处于较低水平;按土壤中有机氯农药17种成分质量分数所占的比重排序,前五名分别为P,P'-DDE、β-HCH、硫丹硫酸盐、硫丹Ⅱ、艾氏剂;按不同利用类型土壤中有机氯残留质量分数由大到小排序为菜地→水田→果园→甘蔗地;有机氯农药残留质量分数随土壤深度的增加呈下降趋势,耕层(0~20cm)的有机氯农药残留质量分数都高于底下层次。     

氯丹和灭蚁灵污染场地土壤对陆生生物的毒性效应

为向污染土壤的监测、生态毒理诊断及修复提供方法和数据,以氯丹、灭蚁灵污染场地土壤为供试土壤,测定了氯丹、灭蚁灵复合污染对蚯蚓的急性毒性效应以及对小麦、小白菜、玉米和水稻4种植物种子发芽率和根伸长抑制率的影响.结果表明,蚯蚓对本场地污染响应十分敏感,处理d 3高浓度组开始出现死亡,此后死亡率随污染物浓度增大而上升,d 14部分高浓度组死亡率达到100%;同一浓度下,氯丹和灭蚁灵对4种植物种子根伸长抑制率均显著大于对种子发芽的抑制率,植物的根生长比种子发芽对有机污染物的毒性更为敏感.4种植物种子对污染场地土壤的敏感性为小麦>小白菜>水稻>玉米.氯丹和灭蚁灵对蚯蚓的毒性要大于对这几种植物的毒性,蚯蚓对氯丹和灭蚁灵的响应更加敏感.因此,蚯蚓作为指示生物,其急性毒性试验可作为氯丹和灭蚁灵污染场地的诊断指标,诊断周期以14 d为宜.     

成都城区蔬菜地土壤中农药残留及其分布特征

采用GC-ECD检测、GC/MS-MS确证的方法对成都城区14个区县蔬菜地土壤中23种有机氯农药（OCPs）进行分析,以揭示OCPs的残留现状及其分布特征。结果表明,OCPs残留水平在不同区县间差异很大,变化范围20.18～104.33μg.kg-1之间,近郊区县（双流、龙泉驿、郫县、新都、温江）远低于边缘区县。被检出的18种OCPs中,DDTs、HCHs检出率最高（100%）,残留水平为16.11～99.51、1.31～9.34μg.kg-1,分别占OCPs残留总量质量分数的87.68%、8.15%;六氯苯（HCB）次之（90%）;灭蚁灵、环氧七氯、硫丹Ⅰ和γ-氯丹也有不同程度的检出（44.29%～47.14%）,主要分布在近郊区县;艾氏剂、狄氏剂、异狄氏剂、毒杀芬的检出率较低（32.86%～37.14%）,多分布于彭州、都江堰、大邑、崇州等地。土壤中OCPs的各种异构体、代谢物变化规律显示,DDTs、HCHs残留主要源于早期的使用或大气输入,但不排除金堂、青白江、新津地区近期可能有新的DDTs输入,崇州、彭州、都江堰、大邑地区可能有HCHs输入。     

Pd-Fe/C催化氯酚还原脱氯-氧化联合降解

以Pd和Fe为活性金属组分通过沉积沉淀法制备了负载型Pd-Fe/C双金属催化剂,针对氯酚类污染物进行催化还原脱氯和催化氧化的连续降解处理.通过ICP-MS、XRD和TEM对催化剂进行表征,证实0.5%Pd-0.5%Fe/C催化剂中活性金属组分Pd和Fe在载体表面分散性最好,催化剂比表面积达到718.8 m~2·g~(-1).在温和条件下,以水作为反应介质,研究了负载型Pd-Fe/C催化剂对4-氯苯酚(4-CP)和2,4-二氯苯酚(2,4-DCP)的连续降解过程和反应条件,以及催化剂的重复使用情况.考察了Pd和Fe的负载量及p H值对催化剂活性的影响,得到了最佳反应条件,以0.5%Pd-0.5%Fe/C为催化剂,20 min内完成4-CP和2,4-DCP的催化还原脱氯,产物都为苯酚;之后加酸调节pH=5,并加入H2O2继续进行催化氧化,苯酚被彻底降解为H_2O和CO_2,而且转化率在60 min内可以达到97.5%以上,从而实现4-CP和2,4-DCP的彻底降解.     

高分辨气相色谱/高分辨质谱法测定南极样品中有机氯农药

建立了同位素稀释-高分辨气相色谱/高分辨质谱法(HRGC/HRMS)测定南极土壤、苔藓和地衣样品中23种有机氯农药的分析方法.样品经冷冻干燥、研磨处理后用正己烷∶二氯甲烷(1∶1,V∶V)混合溶剂进行加速溶剂萃取(ASE),萃取液经硅胶-氧化铝层析柱和C18小柱净化后,进HRGC/HRMS检测分析.样品中目标物定量采用平均相对响应因子法,6点标准曲线响应因子的相对标准偏差(RSD)≤20%,方法的线性范围为0.4—800μg·L-1,回收率在62%—101%之间.实际样品分析结果表明,23种OCPs的加标回收率为40%—100%,在土壤、苔藓和地衣样品中的检出限(LODs)分别为0.024—5.01、0.2—12.2、0.020—13.7 pg·g-1,可以满足南极环境样品中有机氯农药的检测分析.     

镍/铁和铜/铁双金属降解四氯乙烯的研究

选用镍 /铁和铜 /铁双金属对四氯乙烯 (PCE)进行脱氯试验 .结果表明 ,双金属系统对四氯乙烯有明显的脱氯作用 ,且脱氯反应符合准一级反应动力学方程 ,双金属在降解PCE的过程中 ,无三氯乙烯 (TCE)、二氯乙烯 (DCE)和氯乙烯 (VC)等中间产物形成 ,与零价铁系统相比 ,双金属系统对PCE的降解速率有明显提高 ,尤其是Ni/Fe双金属 ,反应速率常数kSA从 0 1 2 89ml·m- 2 ·h- 1 提高到 0 3697ml·m- 2 ·h- 1 ,Cu/Fe双金属的反应速率常数kSA为 0 2 2 79ml·m- 2 ·h- 1 .无论是哪种反应介质 ,在制备过程中干燥与否对脱氯速率都有很大的影响     

我国重点流域地表水中29种农药污染及其生态风险评价

针对我国重点流域水体,包括长江流域、黄河流域、太湖流域、松花江流域、黑龙江流域、东江流域、南水北调中线和东线等,分析了29种农药(18种有机氯农药、6种有机磷农药、3种三嗪类农药、1种酰胺类和1种取代杂环类农药)在流域地表水中浓度,并使用风险商的方法进行了生态风险评价。结果显示,在27个采样点地表水样中一共检出9种农药,包括α-六六六、α-氯丹、γ-氯丹、西玛津、阿特拉津、乙草胺、扑草净、敌敌畏和噁草酮。其中,阿特拉津、乙草胺、扑草净、噁草酮和敌敌畏的检出率分别为100.0%,74.1%,59.3%,37.0%和33.3%;α-六六六、α-氯丹、γ-氯丹和西玛津均只有1~2个采样点检出。阿特拉津在各采样点浓度范围为7.0 ng·L-1~1 289.5 ng·L-1;乙草胺浓度范围为未检出(ND)~579.9 ng·L-1;扑草净浓度范围为ND~104.2 ng·L-1;噁草酮浓度范围为ND~32.6 ng·L-1;敌敌畏的浓度范围为ND~204.5 ng·L-1。研究发现,阿特拉津在太湖流域、黑龙江流域和松花江流域具有潜在生态风险;乙草胺在松花江流域有潜在生态风险;噁草酮在长江流域、太湖流域、松花江流域和黑龙江流域有潜在生态风险;敌敌畏在长江流域、黄河流域和东江流域具有潜在生态风险。上述4种需要重点关注的水体污染物中,仅阿特拉津和敌敌畏被列入地表水环境质量标准(GB3838-2002),但都没有保护水生生物或保护水生态的标准。     

Chemical poison and regeneration of SCR catalysts for NOx removal from stationary sources

Selective catalytic reduction (SCR) of NO_x with NH₃ is an effective technique to remove NO_x from stationary sources, such as coal-fired power plant and industrial boilers. Some of elements in the fly ash deactivate the catalyst due to strong chemisorptions on the active sites. The poisons may act by simply blocking active sites or alter the adsorption behaviors of reactants and products by an electronic interaction. This review is mainly focused on the chemical poisoning on V₂O₅-based catalysts, environmental-benign catalysts and low temperature catalysts. Several common poisons including alkali/alkaline earth metals, SO₂ and heavy metals etc. are referred and their poisoning mechanisms on catalysts are discussed. The regeneration methods of poisoned catalysts and the development of poison-resistance catalysts are also compared and analyzed. Finally, future research directions in developing poisoning resistance catalysts and facile efficient regeneration methods for SCR catalysts are proposed.     

食蚊鱼(Gambusia afinis)cat、gapdh和gst基因的克隆及其在生态毒理学中的应用

根据Ensembl、Genbank登录的鱼类cat、gapdh和gst基因的CDS序列设计普通PCR扩增引物,寻找食蚊鱼的cat、gapdh和gst基因的c DNA片段,并根据定量引物设计要求设计出相应的SYBR Green I荧光定量RT-q PCR引物,建立了食蚊鱼cat、gapdh和gst基因的SYBR Green I荧光定量RT-q PCR方法。该方法在104~108数量级范围内有良好线性关系(R=0.999~1.000);熔解曲线显示扩增产物特异性良好,均为单一峰值;质粒标准品最高浓度与最低浓度的批内试验变异系数与批间试验变异系数均低于2%。利用该方法监测和评价环境污染物对水生生物的影响,选择了水体中常见典型药物污染物——双氯芬酸,研究其对食蚊鱼抗氧化基因表达的影响。结果表明,雌性食蚊鱼暴露在不同浓度双氯芬酸钠(0.005、0.05、0.5和5 mg·L-1)24 h后,其肝脏cat、gapdh和gst的mRNA呈现显著变化,相对于对照组,在低浓度0.005 mg·L-1时,cat与gst mRNA的表达量均有极显著上升(p0.01),而其它浓度均极显著下降(p0.01)。试验表明该方法具有快速、精确、灵敏度高的优点,可为利用该类小型鱼类的原位污染物的生物监测和生态毒理评价提供有力的技术支持。     

Simultaneous removal of NOx and chlorobenzene on V2O5/TiO2 granular catalyst: Kinetic study and performance prediction

• A V₂O₅/TiO₂ granular catalyst for simultaneous removal of NO and chlorobenzene. • Catalyst synthesized by vanadyl acetylacetonate showed good activity and stability. • The kinetic model was established and the synergetic activity was predicted. • Both chlorobenzene oxidation and SCR of NO follow pseudo-first-order kinetics. • The work is of much value to design of multi-pollutants emission control system. The synergetic abatement of multi-pollutants is one of the development trends of flue gas pollution control technology, which is still in the initial stage and facing many challenges. We developed a V₂O₅/TiO₂ granular catalyst and established the kinetic model for the simultaneous removal of NO and chlorobenzene (i.e., an important precursor of dioxins). The granular catalyst synthesized using vanadyl acetylacetonate precursor showed good synergistic catalytic performance and stability. Although the SCR reaction of NO and the oxidation reaction of chlorobenzene mutually inhibited, the reaction order of each reaction was not considerably affected, and the pseudo-first-order reaction kinetics was still followed. The performance prediction of this work is of much value to the understanding and reasonable design of a catalytic system for multi-pollutants (i.e., NO and dioxins) emission control.     

壬基酚在蛋白核小球藻和大型溞体内的富集与传递

为探究壬基酚(nonylphenol,NP)在水生生物中的富集传递效应,选择以蛋白核小球藻(Chlorella pyrenoidosa)和大型溞(Daphnia magna)为研究对象,开展蛋白核小球藻对NP的富集效应实验,及NP在蛋白核小球藻和大型溞体内的传递效应实验。研究结果表明,NP对蛋白核小球藻的96 h半数效应浓度(96 h-EC50)为3.13 mg·L~(-1),对蛋白核小球藻的生长和叶绿素含量的影响呈现明显的剂量-时间效应。NP对大型溞的48 h半数效应浓度(48 h-LC50)为37.41μg·L~(-1),属于高毒类化合物。蛋白核小球藻暴露于0.05 mg·L-1NP 4 h后,其生物富集系数(BCF)为5 144.93,富集量为252.2μg·g~(-1),在12 h内对NP的生物富集系数(BCF)最高达12 053.64,富集量为1 181.73μg·g~(-1)。以0.05 mg·L-1NP中暴露4 h后的蛋白核小球藻为饵料投喂大型溞7 d后,大型溞体内NP富集量最高达3.6μg·g~(-1)。0.05 mg·L~(-1)NP直接暴露组大型溞暴露10 d后,大型溞体内NP富集量最高达4.02μg·g~(-1)。蛋白核小球藻对NP具有较强的富集能力,能够通过摄食过程将NP传递到大型溞,经传递的NP能够显著抑制大型溞的生长、繁殖、摄食等生命活动。论文为评估NP在水生生态系统中的污染风险和富集传递效应提供了一定的参考依据。     

Identification of Illex coindetii, I. illecebrosus and I. argentinus (Cephalopoda: Ommastrephidae) throughout the Atlantic Ocean; by body and beak characters

Shortfinned squid species of the genus Illex support commercial fisheries throughout the Atlantic Ocean and Mediterranean Sea. Previous identification of interspecific and intraspecific populations by morphological and size-at-maturity studies have not provided conclusive results. We analysed morphometric body and beak variables (24 characters) in three species of the genus (I. coindetii, I. illecebrosus and I. argentinus), using a geographic and seasonal series of 33 populations for 1,500 specimens of I. coindetii, I. illecebrosus and I. argentinus. Residuals of the regression between each morphometric body and beak variable and mantle length were used as input in a stepwise discriminant analysis. Species discrimination by body and hectocotylus characters required at least eight variables and resulted in high correct-classification percentages for I. coindetii and I. argentinus (75% and 90%, respectively), whereas the best identification resulted from beak characters (83% correctly classified). Size of the suckerless basal arm, sucker-bearing length and beak lateral wall discriminated best among I. coindetii from northern Iberia, northwest Iberia (year-1996) and Ireland in the Atlantic and western Mediterranean versus middle and eastern Mediterranean samples. Canadian shelf and American samples were discriminated from Canadian slope I. illecebrosus. Winter/shelf and winter/slope samples of I. argentinus seemed to form a single biological group separated from Falkland Island, 46°S/autumn spawners and 46°S/1996 specimens along the Patagonian Shelf. No significant sexual or maturity polymorphism was obtained. Discriminant analysis optimised population diagnosis on a morphometric basis of interest in fisheries strategies. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00227-002-0796-7.     

立方体和八面体微/纳米氧化亚铜对大型水蚤(Daphnia magna)的氧化胁迫和生理损伤

为了实现特定的功能和应用,越来越多不同结构特性的纳米材料逐渐被人们精确合成。一些研究指出纳米材料的物理化学特性能够显著影响纳米材料对水生生物的毒性作用,但是对于不同特性的纳米氧化亚铜的毒性研究依然比较缺乏。本研究制备了2种不同形貌和结构的微/纳米氧化亚铜(micro/nano-Cu_2O)晶体,通过对大型水蚤(Daphnia magna)进行72 h的急性暴露实验,测定了大型水蚤体内还原型谷胱甘肽(GSH)的含量以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和钠/钾腺苷三磷酸酶(Na+/K+-ATPase)的活性变化。结果表明在2种不同特性的微/纳米氧化亚铜暴露体系中,大型水蚤体内Cu的积累量差别不大,但是不同结构的micro/nano-Cu_2O对大型水蚤抗氧化酶活性和钠/钾腺苷三磷酸酶活性影响存在差别。与立方体相比,八面体micro/nano-Cu_2O能够暴露更多的{111}面,并且其原子排列使其具有较高的表面能量,因此更容易在大型水蚤肠道内诱导产生活性氧(ROS)及溶出更多Cu2+,对大型水蚤产生更强的氧化胁迫和膜损伤。     

Separation/degradation behavior and mechanism for cationic/anionic dyes by Ag-functionalized Fe3O4-PDA core-shell adsorbents

● PDA-Fe₃O₄-Ag was made by hydrothermal and oxidation self-polymerization method. ● PDA-Fe₃O₄-Ag had great magnetic separation performance. ● PDA-Fe₃O₄-Ag had good adsorption and degradation performance for ionic dyes. ● PDA-Fe₃O₄-Ag showed NR and MO degradation potential of 91.2% and 87.5%, respectively. High-performance adsorbents have been well-studied for the removal of organic dye pollutants to promote environment remediation. In this study, an Ag nanoparticle-functionalized Fe₃O₄-PDA nanocomposite adsorbent (PDA-Fe₃O₄-Ag) was synthesized, and the adsorption/separation performance of commonly used cationic and anionic organic dyes by the PDA-Fe₃O₄-Ag adsorbent were assessed. Overall, PDA-Fe₃O₄-Ag exhibited a significantly higher adsorption capacity for cationic dyes compared to anionic dyes, the highest of which was more than 110.0 mg/g (methylene blue (MB)), which was much higher than not only the adsorption capacities of the anionic dyes in this study but also other dye adsorption capacities reported in the literature. The dye adsorption kinetics data fitted well to both the pseudo second-order kinetics model and the Langmuir isotherm model, suggesting a monolayer-chemisorption-dominated adsorption mode. Thermodynamics analysis indicated that the adsorption process was both endothermic and spontaneous. Furthermore, the PDA-Fe₃O₄-Ag adsorbent achieved high photodegradation removal rates of the dyes, especially neutral red (NR) and methyl orange (MO), which were 91.2% and 87.5%, respectively. With the addition of PDA-Fe₃O₄-Ag, the degradation rate constants of NR and MO increased from 0.08 × 10⁻² and 0 min⁻¹ to 2.11 × 10⁻² and 1.73 × 10⁻² min⁻¹, respectively. The high adsorption and photocatalytic degradation performance of the PDA-Fe₃O₄-Ag adsorbent make it an excellent candidate for removing cationic and anionic dyes from the industrial effluents.     

铯对印度芥菜和菊苣植物螯合肽和金属硫蛋白含量的影响

以133Cs作为污染源,溶液培养印度芥菜和菊苣幼苗,研究植物螯合肽(phytochelatins,PCs)、金属硫蛋白(metallothionein,MT)等含巯基肽类物质与Cs+胁迫毒理的内在联系。采用改良水培法培养印度芥菜和菊苣长至两片真叶,置于含铯[ρ(Cs~+)0~200 mg·L~(-1)]的营养液中培养一段时间后取样,测定幼苗地上部和根系生物量,采用火焰原子吸收分光光度法测定Cs~+富集量,5,5’-二六硝基苯甲酸(DTNB)比色法测定PCs和MT含量。结果显示:随着Cs~+浓度[ρ(Cs+)25~200 mg·L~(-1)]增加,印度芥菜和菊苣地上部和根系生物量显著降低(P0.05),印度芥菜的生物量降低幅度小于菊苣;Cs~+的富集量均显著增加,印度芥菜对Cs~+富集量大于菊苣,印度芥菜地上部、菊苣根系分别是Cs~+的主要蓄积部位;非蛋白巯基肽类(non-protein thiol,NPT)、植物螯合肽(PCs)、谷胱甘肽(glutathione,GSH)和金属硫蛋白(MT)含量变化均呈现先升后降的趋势,均表现为根系地上部,印度芥菜菊苣。当ρ(Cs~+)100 mg·L~(-1)时NPT、PCs、GSH和MT达最大值。结果表明,菊苣对Cs~+处理敏感,印度芥菜具有较强的吸收和转运Cs~+的能力,Cs~+处理诱导合成PCs、GSH和MT含量显著增加,这是印度芥菜对Cs~+耐性较强的主要原因。