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101.
Lab-scale experiments of in situ chemical oxidation (ISCO), were performed on soil contaminated with 100 mg kg(-1) of atrazine (CIET). The oxidant used was hydrogen peroxide catalysed by naturally occurring minerals or by soluble Fe(II) sulphate, added in aqueous solution. The oxidation conditions were: CIET:H2O2=1:1100, 2 PV or 3 PV reaction volume, Fe(II):H2O2=0, 1:22, 1:11. Stabilized (with KH2PO4 at a concentration of 16 g l(-1)) or non-stabilized hydrogen peroxide was used. The pH of the reagents was adjusted to pH=1 with sulphuric acid, or was not altered. Results showed that the addition of soluble Fe(II) increased the temperature of the soil slurry and the use of stabilized hydrogen peroxide resulted in a lower heat generation. The treatment reduced the COD of the soil of about 40%, pH was lowered and natural organic matter became less hydrophobic. The highest atrazine conversion (89%) was obtained in the conditions: 3 PV, Fe(II):H2O2=1:11 with stabilized hydrogen peroxide added in two steps. The stabilizer only increased H2O2 life-time significantly when soluble Fe(II) was added. Results indicate as preferential degradation pathway of atrazine in soil dechlorination instead of dealkylation. 相似文献
102.
通过改进WRF-CMAQ模型中非均相反应模块,定量研究了2017年夏季和冬季海盐与含氮气体非均相反应对我国山东沿海地区大气O3浓度的影响.模拟结果表明,考虑海盐气溶胶非均相反应后,山东沿海地区夏季O3小时浓度增加了0.2×10-9~6.6×10-9(0.5%~15.5%),冬季增加了0.8×10-9~15.3×10-9(1.7%~27.4%),ClNO2在夏季和冬季分别增加了100×10-12~250×10-12,300×10-12~650×10-12;夏季O3浓度增加主要集中在山东东部,而冬季O3的增加则覆盖了山东大部分地区,表明海盐非均相反应对冬季O3的影响强度及范围均明显高于夏季.海盐非均相反应引起的O3浓度增加主要发生在日间,特别是8:00~16:00.该反应对渤海及南黄海大气O3浓度也有影响,且在这些海域生成的O3可通过4条传输路径影响山东沿海地区,甚至可影响到济南、菏泽等山东中西部地区(距离山东东部海岸线~350km);海洋大气中O3的传输可造成山东东部沿海O3浓度升高0.2×10-9~15.3×10-9,山东中西部O3升高0.3×10-9~6.2×10-9. 相似文献
103.
104.
Environmental sustainability in manufacturing is nowadays an urgent and remarkable issue and the main concerns are related to more efficient use of materials and energy.In sheet metal forming processes there is still a lack of knowledge in this field mainly due to the need of a proper modelling of sustainability issues and factors to be taken into account. The aim of this paper is mainly to underline the state of the art from a forming point of view about the sustainability contributions offered in any phase of a product life cycle. Actually, a lack in terms of comprehensive contributions is present in the technical literature, thus, the authors try to give a sort of holistic vision aimed to provide basic guidelines in order to help in identifying the possible solutions with regard to all the phases of a forming product life cycle. The main attention was paid to sheet metal forming technologies. The paper gives an overview of the main topics concerning sheet metal forming problems related to energy and resource efficiency with the aim to stress the principal contributions which may derive from such processes to environmental performances of manufacturing. 相似文献
105.
采用液膜萃取—酸析沉降—络合萃取组合工艺对有机磷阻燃剂生产废水进行预处理.最佳工艺条件为:液膜萃取时,液膜油相(表面活性剂与煤油的混合液)与内水相(H2SO4溶液)的体积比2∶1、乳化液膜与废水的体积比1∶8、废水pH 13.0,硫酸体积分数10%、煤油中表面活性剂质量浓度30 g/L、液膜萃取时间 15 min;酸析沉降时,废水pH l.0,酸析沉降时间30 min;络合萃取时,络合萃取剂(烷基叔胺N235与煤油的混合液)中烷基叔胺N235体积分数30%,络合萃取剂与废水的体积比1∶4,废水pH l.0,络合萃取时间30 min.在此最佳处理条件下,废水COD总去除率可达93%,吡啶去除率达99.9%以上,总磷去除率可达97%,BOD5/COD提高至0.32,有利于后续生化处理. 相似文献
106.
采用催化超临界水氧化技术处理焦化废水.实验结果表明:升高反应温度、增加反应压力、延长反应时间可提高废水中氨氮去除率;在反应时间为60 s、反应压力为30 MPa、反应温度为460℃的最佳实验条件下,未加入催化剂时的氨氮去除率为53.7%,加入催化剂后,氨氮去除率大幅提高,以MnO2为催化剂时氨氮去除率为86.9%,以CuSO4为催化剂时氨氮去除率为92.4%. 相似文献
107.
镉和乙草胺对少根紫萍的毒性效应 总被引:3,自引:0,他引:3
联合毒性实验在水环境污染评价中非常重要.本文以少根紫萍(Spirodela Oligorrhiza)为研究对象,研究了重金属Cd和除草剂乙草胺对少根紫萍生长的单一毒性和联合毒性效应.实验结果表明:Cd、乙草胺及对少根紫萍的96h-IC50分别为4.77mg/L和6.95mg/L,在浓度1:1的情况下,Cd与乙草胺共存对少根紫萍的96h-IC50为1.41mg/L,采用Marking相加指数法求得相加指数AI为1.00,大于零,为协同作用.同时,随着Cd、乙草胺处理浓度的增加,少根紫萍叶绿素a的浓度下降,其中Cd对叶绿素a的影响大于乙草胺,复合污染对叶绿素a的影响明显大于单一污染,也表现为协同作用.另外,本文还对少根紫萍生长抑制试验进行了探讨,建议使用植物体数和重复间的偏差作为衡量试验质量的指标. 相似文献
108.
Leo S. Morf Rolf Gloor Olaf Haag Melanie Haupt Stefan Skutan Fabian Di Lorenzo Daniel Böni 《Waste management (New York, N.Y.)》2013,33(3):634-644
In Switzerland many kinds of waste, e.g. paper, metals, electrical and electronic equipment are separately collected and recycled to a large extent. The residual amount of municipal solid waste (MSW) has to be thermally treated before final disposal. Efforts to recover valuable metals from incineration residues have recently increased. However, the resource potential of critical elements in the waste input (sources) and their partitioning into recyclable fractions and residues (fate) is unknown. Therefore, a substance flow analysis (SFA) for 31 elements including precious metals (Au, Ag), platinum metal group elements (Pt, Rh) and rare earth elements (La, Ce, etc.) has been conducted in a solid waste incinerator (SWI) with a state-of-the-art bottom ash treatment according to the Thermo-Re® concept. The SFA allowed the determination of the element partitioning in the SWI, as well as the elemental composition of the MSW by indirect analysis. The results show that the waste-input contains substantial quantities of precious metals, such as 0.4 ± 0.2 mg/kg Au and 5.3 ± 0.7 mg/kg Ag. Many of the valuable substances, such as Au and Ag are enriched in specific outputs (e.g. non-ferrous metal fractions) and are therefore recoverable. As the precious metal content in MSW is expected to rise due to its increasing application in complex consumer products, the results of this study are essential for the improvement of resource recovery in the Thermo-Re® process. 相似文献
109.
110.
合成了一种高吸附容量的磁性生物炭负载Mg-Fe水滑石复合材料(L-BC),并用于去除水中的Cd2+和Ni2+。表征结果表明,采用浸渍联合热解法成功制备了磁性生物炭(M-BC),水热合成法成功地将Mg-Fe水滑石负载在M-BC上。动力学研究结果表明,Cd2+和Ni2+吸附符合伪二级动力学模型,化学吸附为速率控制步骤。等温吸附研究结果表明,L-BC对Cd2+和Ni2+的吸附符合Langmuir模型,为单分子层化学吸附,最大吸附量分别为263.156 mg/g和43.291 mg/g。吸附机理主要为Mg-Fe水滑石层间CO32-和表面羟基与Cd2+和Ni2+产生表面共沉淀。L-BC具有良好的吸附和重复利用性能,是一种很有前景的去除Cd2+和Ni2+的吸附材料。 相似文献