界面化学与水力学作用下的生物炭在砂柱中的迁移特性

通过柱淋溶实验,分别研究不同离子强度或不同流速作用下,生物炭在石英砂柱中的迁移特征及驱动机制.结果表明,淋溶结束时,在高离子强度条件下,生物炭从生物炭层向石英砂柱中迁移的总质量最大,与1号柱(CK)相比,迁移质量提高了62%;主要驱动力为界面化学作用,高离子强度抑制了生物炭内部碱性物质的释放,颗粒表面双电层被压缩,降低了ζ电位,更多生物炭颗粒滞留在不稳定的第二极小势能处,易迁移出炭层.在高流速条件下,生物炭在石英砂柱中径向迁移深度最大,最大迁移深度为3.5—4 cm.主要驱动力为水力学作用,流速的增加,产生的水动力剪切力促使生物炭大聚体分散成小聚体,有利于生物炭随水流向径向深处迁移.     

Combating climate change calls for a global technological cooperation system built on the concept of ecological civilization

Climate change has been considered as the most paramount global environmental problem and the biggest externality throughout the history of human development. Accordingly, the world is facing unprecedented technological innovation and collaborative demands to deal with climate change. In the 2015 Paris Agreement, a long-term vision of technology development and transfer implementation was proposed, and policy and financial support for technological innovation in the area of climate change was advocated. These terms aim to enable developing countries to acquire the necessary technology in the early stage of the technology cycle to address climate change challenge. However, the traditional technological innovation and cooperation mode based on industrial civilization can hardly meet the technical demands of global climate protection. To ensure the continuous development and deployment of technology in a required scale and pace, a new global technical cooperation system is proposed to develop based on the philosophy of ecological civilization. The core contents of this system are supposed be as follows: to implement all-win cooperation targets, adhering to cooperation principles of Eco-man, adopt cooperation content that reflects synergy, pursue cooperation based on mutual trust, encourage participation of multiple actors, and promote sharing of cooperative outputs.     

Screening of Cd tolerant genotypes and isolation of metallothionein genes in alfalfa (Medicago sativa L.)

In order to evaluate Cd tolerance in wide-ranging sources of alfalfa (Medicago sativa) and to identify Cd tolerant genotypes which may potentially be useful for restoring Cd-contaminated environments, thirty-six accessions of alfalfa were screened under hydroponic culture. Our results showed that the relative root growth rate varied from 0.48 to 1.0, which indicated that different alfalfa accessions had various responses to Cd stress. The candidate fragments derived from differentially expressed metallothionein (MT) genes were cloned from leaves of two Cd tolerant genotypes, YE and LZ. DNA sequence and the deduced protein sequence showed that MsMT2a and MsMT2b had high similarity to those in leguminous plants. DDRT-PCR analysis showed that MsMT2a expressed in both YE and LZ plants under control and Cd stress treatment, but MsMT2b only expressed under Cd stress treatment. This suggested that MsMT2a was universally expressed in leaves of alfalfa but expression of MsMT2b was Cadmium (Cd) inducible.     

Toxicity assessment of 45 pesticides to the epigeic earthworm Eisenia fetida

This study was conducted to investigate comparative toxicity of 45 pesticides, including insecticides, acaricides, fungicides, and herbicides, toward the epigeic earthworm Eisenia fetida. Results from a 48-h filter paper contact test indicated that clothianidin, fenpyroximate, and pyridaben were supertoxic to E. fetida with LC(50) values ranging from 0.28 (0.24-0.35) to 0.72 (0.60-0.94) μg cm(-2), followed by carbaryl, pyridaphenthion, azoxystrobin, cyproconazole, and picoxystrobin with LC(50) values ranging from 2.72 (2.22-0.3.19) to 8.48 (7.38-10.21) μg cm(-2), while the other pesticides ranged from being relatively nontoxic to very toxic to the worms. When tested in artificial soil for 14 d, clothianidin and picoxystrobin showed the highest intrinsic toxicity against E. fetida, and their LC(50) values were 6.06 (5.60-6.77) and 7.22 (5.29-8.68) mg kg(-1), respectively, followed by fenpyroximate with an LC(50) of 75.52 (68.21-86.57) mgkg(-1). However, the herbicides fluoroglycofen, paraquat, and pyraflufen-ethyl exhibited the lowest toxicities with LC(50) values>1000 mg kg(-1). In contrast, the other pesticides exhibited relatively low toxicities with LC(50) values ranging from 133.5 (124.5-150.5) to 895.2 (754.2-1198.0) mg kg(-1). The data presented in this paper provided useful information for evaluating the potential risk of these chemicals to soil invertebrates.     

快速高效丙烯酸系吸油树脂的合成及性能研究

采用悬浮聚合法合成了低交联度的丙烯酸系高吸油性树脂。研究了单体配比、交联剂用量及种类、分散剂用量和反应温度等反应条件对树脂吸油性能的影响,并且考察了树脂对4种有机毒物(氯苯、吡啶、硝基苯和甲苯) 的吸油效果。结果表明,吸油5 h后,树脂对氯苯、吡啶、硝基苯及甲苯的最大吸油率分别为37.3、34.1、30.5和23.7 g/g;另外,树脂吸油10 min时,其吸油率即可达到最大吸油率的50%。实验证明,该合成树脂对有机毒物有快速高效的吸附效果,可以应用于污染事故应急处理。     

混凝-碳化污泥吸附深度处理城市污水

针对混凝-碳化污泥吸附对城市污水深度处理的实验研究,结果表明,由城市污水厂剩余污泥经脱水、干化和碳化后所制得的碳化污泥,可通过三氯化铁混凝-碳化污泥吸附联合应用于城市污水深度处理中,处理效果明显优于仅使用碳化污泥吸附或单一采用三氯化铁絮凝剂混凝时的效果,出水各污染物指标可达到一级A标准(GB 18918-2002),其最佳投药量为三氯化铁15 mg/L,碳化污泥5 g/L。     

Nitrous oxide emission from polyculture constructed wetlands: effect of plant species

Loss of nitrogen from the soil-plant system has raised environmental concern. This study assessed the fluxes of nitrous oxide (N2O) in the subsurface flow constructed wetlands (CWs). To better understand the mechanism of N2O emission, spatial distribution of ammonia-oxidizing bacteria (AOB) in four kinds of wetlands soil were compared. N2O emission data showed large temporal and spatial variation ranging from -5.5 to 32.7 mg N2O m(-2) d(-1). The highest N2O emission occurred in the cell planted with Phragmites australis and Zizania latifolia. Whereas, the lower emission rate were obtained in the cell planted with P. australis and Typha latifolia. These revealed that Z. latifolia stimulated the N2O emission. Transportation of more organic matter and oxygen for AOB growth may be the reason. The study of AOB also supported this result, indicating that the root structure of Z. latifolia was favored by AOB for N2O formation.     

微波催化氧化修复技术处理有机氯污染土壤

采用微波催化氧化修复技术处理常州某农药厂有机氯农药污染场地和南通某化工厂有机氯污染场地土壤,考察不同参数条件下实验装置对污染土壤的处理效能。结果表明,在微波功率18kW、微波辐射时间20min、土壤处理量400kg/h、土壤含水率15%、活性炭添加量0.03kg/kg的最佳条件下,实验装置运行稳定,有机氯农药污染土壤中氯丹去除率可达70%左右;有机氯污染土壤中邻二氯苯、石油烃总量、1,2-二氯乙烷、苯酚去除率分别可达到99.98%、91.29%、98.52%、74.74%。研发的污染土壤微波催化氧化修复技术及实验装置对有机氯污染土壤的修复具有一定的普适性。     

生物入侵对生态环境的影响及对策

外来入侵种侵入新的栖息地后,会在该生境所处的生态系统中占据相应的生态位,严重影响当地物种的生存和发展,制约社会经济发展。生物入侵的途径多种多样,生物入侵现状十分严峻。面对这一事实,应采取以预防为主、综合防治的办法,尽量将生物入侵造成的危害降到最低,维护生态平衡,确保生态环境安全。     

高处作业人员位置与生理信号相关性分析

为对高处作业人员位置状态进行识别,加强对高处施工人员作业状态的监控,采用VR技术模拟高处作业,同时利用人-机-环同步平台,采集平地处、一级高处作业(取4 m为例)以及二级高处作业(8 m为例)情景下的6种生理信号数据,运用SPSS软件对生理信号进行数据分析.结果显示,不同高处作业人员对皮电信号(EDA)的时域具有显著性...