Assessment of mobile and potential mobile trace elements extractability in calcareous soils using different extracting agents

• DTPA and NH₄OAc, HNO₃ and EDTA, and MgCl₂ and NH₄NO₃ had similar behavior. • In NH₄OAc, DTPA, and EDTA, the possibility of re-adsorption of trace elements is low. • CaCl₂ may be more suitable than other extracts in calcareous soils. Understanding trace elements mobility in soils, extracting agents, and their relationships with soil components, are essential for predicting their movement in soil profile and availability to plants. A laboratory study was conducted to evaluate extractability of cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), and zinc (Zn) from calcareous soils utilizing various extracting agents to be specific CaCl₂, DTPA, EDTA, HNO₃, MgCl₂, NaNO₃, NH₄NO₃, and NH₄OAc. Cluster analysis indicated that DTPA and NH₄OAc, HNO₃ and EDTA, and MgCl₂ and NH₄NO₃ extracting agents yielded comparative values, whereas NaNO₃ and CaCl₂ have shown different behavior than other extracting agents for all studied trace elements. The speciation of extracted trace elements in solutions indicated that in the CaCl₂, NaNO₃, NH₄NO₃, and MgCl₂ extracting agents most extracted Cd, Co, Ni, Zn, and part of Cu were as free ions and may be re-adsorbed on soils, leading to lower extractability, whereas, in the case of HNO₃ extracting agent, the likelihood of re-adsorption of trace elements may be little. The results of speciation of trace elements using NH₄OAc, DTPA, and EDTA extracting agents showed that Me-(Acetate)₃^–, Me-(Acetate)₂(aq), Me(DTPA)³⁻, Me(EDTA)²⁻, and MeH(EDTA)^– complexes dominated in solutions indicating that the extracted trace elements may not be re-adsorbed on soils, leading to higher extractability. The results of this study are useful for short and long-term evaluations of trace elements mobility and further environmental impacts.     

制革废水中丙烯酸类鞣剂的膜分离特征

针对3种丙烯酸类鞣剂超滤(UF)、反渗透(RO)分离参数进行了实验研究,探索其在废水深度处理中膜去除的可行性,研究结果表明,3种鞣剂在分离参数:浓度为200 mg/L,超滤的操作压力(P UF)为0.11 MPa,反渗透的操作压力(P RO)为0.4 MPa的条件下UF-RO分离,效果最好。其次,丙烯酸类鞣剂对膜通量影响较大,导致产生的清液较少,所以用UF、RO处理含有这类物质的制革废水时,应尽可能对废水进行预处理。最后,丙烯酸类鞣剂分子中含有极性较强的基团时,粒径分离效果不同。     

破络合剂对化学镀镍废水处理的影响

采用不同的破络合剂处理化学镀镍废水,探讨了CaO、CaCl2和BaCl2 3种破络合剂处理化学镀镍废水时,对Ni2＋去除率的影响,同时对CaO联合BaCl2处理化学镀镍废水进行了研究。实验结果表明,CaO、CaCl2和BaCl2的使用量分别为3.0、6.0和4.5 g/L时,Ni2＋去除率分别为32%、19%和99.9...     

植物化学杀雄研究进展

介绍了化学杀雄剂诱导植物雄性不育的变化,回顾了化学杀雄杂种优势利用研究的进展,阐述了化学杀雄杂种优势利用的特点,以及化学杀雄剂的设计思路和常用的化学杀雄剂。     

Soil phytoremediation from the breakdown products of the chemical warfare agent, yperite

A plant-based bioremediation (phytoremediation) strategy has been developed and shown to be effective for the clean-up of soil contaminated by the breakdown products of the chemical warfare agent (CWA), yperite. The method involves exploiting the plant growth hormone, indole-3-acetic acid (IAA), to intensify the phytoremediation. For determination of the yperite breakdown products, gas chromatography is used. Soil and plant samples were analysed with a gas chromatograph fitted with an atomic emission detector. The method of standard-free determination was employed to identify sulphur-containing substances (SCSs). A series of soil tests was conducted, which showed that the level of SCSs decreased 4, 8, and more than 20-fold compared with that found in contaminated soil. This decrease was dependent upon the IAA concentrations used for plant treatment. The treated plants accumulated 2.7 to 2.9-fold larger amounts of the SCSs than did the untreated plants. Owing to its simplicity, environmental safety and inexpensiveness, the method can be recommended for the restoration of soil fertility in areas of storage and destruction of blister CWAs.     

两性高分子水处理剂的研究进展

本文综述了近年来国内外两性高分子水处理剂的研究进展,并对今后的研究工作提出了一些建议.     

基于过氧化物的消毒技术研究进展

对环境友好消毒技术需求的增长,推动了过氧化物消毒技术的快速发展,并已被广泛应用于反化学和生物恐怖袭击、化生灾害处置、环境污染治理等领域.在综述了过氧化物消毒剂α亲核取代/氧化消毒反应机制研究进展的基础上,介绍了以过氧化物为活性组分的水基消毒溶液、消毒泡沫、消毒乳液、消毒凝胶、消毒气雾、自消毒材料、纳米材料催化消毒技术等典型消毒体系.针对现有过氧化物消毒技术消毒效率偏低、对个别毒剂消毒效果不理想的缺点,建议在过氧化物消毒技术研究中,加强消毒反应机制、多相体系界面相互作用研究,开发新型催化剂、多功能表面活性剂、自消毒材料和消毒剂缓蚀技术,以实现真正的绿色消毒.     

热水介质＋脱附破乳组剂处理高凝固点油泥的条件研究

通过热水介质添加脱附破乳组剂的方法,研究了辽河油田公司沈阳采油厂油泥分离的相关条件。通过油泥的组分分析、热水介质温度实验、处理时间实验、脱附破乳组剂浓度实验,确定了热水介质添加脱附破乳组剂实现油泥分离的条件:脱附破乳组剂浓度为15.0 g/L、洗涤温度50℃、洗涤时间大于5 min。     

Protective effect of weak pulsed magnetic fields on early ontogeny of tugun Coregonus tugun (Pallas) under conditions of chronic oil pollution

The state of internal organs in tugun larvae was analyzed histologically in the intact (control) group, the group treated with a water-soluble oil fraction (WSOF) in fivefold excess over the maximum allowable concentration, and the group exposed in a weak pulsed magnetic field at the stage of hatching, prior to treatment with WSOF. Larvae of the second group had severe pathologies of inner organs that caused 100% mortality before the age of 15 days, but no pathomorphological changes in the organs of larvae and juvenile fish of the third group were revealed for up to 40 days. Probable causes of high resistance to the toxic agent in fish of the experimental group are discussed.     

螯合剂在植物修复重金属污染土壤中的应用

向土壤中添加螯合剂促进植物对重金属的吸收是目前一项比较有发展前景的土壤修复技术。本文通过对植物修复技术的机理和特点,即对超累积植物对重金属的富集机理及植物修复技术的局限性的讨论,介绍了螯合剂在植物修复重金属污染土壤中的应用,其中详细介绍了螯合剂强化植物修复技术的机理、螯舍剂的使用方式,以及它的外部影响条件。最后对螯合剂在植物修复重金属污染土壤应用中存在的问题进行了讨论,并对未来螯合刺在该领域的研究重点进行了展望。