Ecogenetic features and functions of solods in transural forest-steppes (within Sverdlovsk Oblast)

Specific ecogenetic features of solods in the forest-steppe zone has been studied, and the role of biotic and abiotic factors of soil formation has been estimated. Differentiation of soil horizons with respect to the physical clay fraction accounts for specific features of their moistening, which is reflected in the ratio of strongly and weakly crystallized forms of iron. Periodic changes in redox conditions results in iron segregation, and a high content of fulvic acids accounts for its eluvial migration. These processes are controlled by soil geochemical barriers.     

Degradation of pentachlorobiphenyl by a sequential treatment using Pd coated iron and an aerobic bacterium (H1)

The reductive dechlorination and biodegradation of 2,2^′4,5,5^′-pentachlorobiphenyl (PCB#101) was investigated in a laboratory-scale. Palladium coated iron (Pd/Fe) was used as a catalytic reductant for the chemical degradation of 2,2^′4,5,5^′-pentachlorobiphenyl, and an aerobic bacteria was used for biodegradation following the chemical reaction in this study. Dechlorination was affected by several factors such as Pd loading, initial soil pH and the amount of Pd/Fe used. The results showed that higher Pd loading, higher dosage of Pd/Fe and slightly acid condition were beneficial to the catalytic dechlorination of 2,2^′,4,5,5^′-pentachlorobiphenyl. In laboratory batch experiments, 2,2^′4,5,5^′-pentachlorobiphenyl was reduced in the presence of Pd/Fe bimetal, which was not further degraded by aerobic bacteria. 2,2^′,4-trichlorobiphenyl (PCB#17), a reduction product from 2,2^′4,5,5^′-pentachlorobiphenyl, was readily biodegraded in the presence of a aerobic bacterial strain. It is suggested that an integrated Pd/Fe catalytic reduction-aerobic biodegradation process may be a feasible option for treating PCB-contaminated soil.     

废钢铁切割加工烟尘的治理

介绍了氧-乙炔火焰切割加工废钢铁产生的烟尘治理系统的设计和系统设备选型,重点介绍了烟尘捕集罩的设计和除尘器、电磁脉冲阀、风机的选型和PLC自动控制以及系统实际运行效果,为废钢铁加工企业治理污染提供一套简单、经济、实用的除尘系统作参考.     

钢铁企业工作场所煤气泄漏扩散规律的研究

以钢铁企业管网煤气泄漏为研究对象,以煤气泄漏扩散规律为研究主题,在确定煤气泄漏相似于浮力射流的基础上,建立煤气泄漏扩散的数学模型。采用CFD软件PHOENICS数值模拟气体泄漏过程的速度场及其浓度分布。在已有煤气泄漏检测系统的基础上,选择性实验模拟煤气泄漏浓度与扩散时间、扩散方向的变化。数值模拟和实验模拟表明,虽然两种方法所得结果存在一定差异,从定性分析角度而言,却能够反映工作场所煤气泄漏后在有限空间内运移扩散的一般规律。     

零价铁-反硝化菌在地下水硝酸盐污染修复中的应用

综述了应用零价铁-反硝化菌复合体系去除地下水中硝酸盐氮污染的研究进展.脱氮技术主要包括物理化学法、化学还原法和生物反硝化法,但单独使用任何一种方法都无法得到令人满意的处理效果.以零价铁在水中厌氧腐蚀所释放的氯气供给微生物进行反硝化,可以同时解决这两种技术单独使用时所存在的弊端.在此复合体系中,主要反应包括产氨、析氢和反硝化,降低脱氮产物中的氨氮比例就要减少产氨反应的发生几率.此外,使用纳米铁代替零价铁和反硝化细菌复合,可以大大提高脱氮反应速率.然而,该技术的研究在国内外尚处于起步阶段,在反应机理、产物控制、条件优化等方面都存在不足,还需要深入研究.     

国外学术界对《巴黎协定》的评价及履约前景分析

2016年《巴黎协定》的正式生效是全球环境治理的重要里程碑,是国际社会在应对气候变化的艰难进程中迈出的重要一步,标志着全球环境治理从此进入履约阶段。本文基于宾夕法尼亚大学智库与公民社会项目(TTCSP)公布的《2015年全球智库指数报告》,选取其中排名前十位的国际环境智库的研究报告和环境领域中代表性学者的相关论文,对国外学术界有关《巴黎协定》履约前景的分析进行了系统梳理,并对此做出简要评述。文章在肯定《巴黎协定》有力推进国际气候治理进程的同时,也指出在新的国际形势之下,尤其是在英国正式启动脱欧进程和特朗普新任美国总统后,其履约过程中更是存在着协定之内和协定之外的众多挑战和不确定性,本文的基本结论如下:首先,协定之内面临着协定缔约方国内批准程序上的挑战;国家自主贡献的实现与发展中国家能力建设;2℃温升目标的实现前景;审评和盘点的效力评估;碳市场机制能否有效运行。其次,协定之外面临着英国脱欧的潜在气候政策变化及影响;美国气候政策的可能变化及其影响。基于对以上智库报告和相关研究论文的分析,笔者对《巴黎协定》的履约前景得出几点看法:(1)正视国际气候合作的机遇与挑战;(2)对具体议题的落实需充满信心;(3)理性冷静看待英美气候政策的可能变化;(4)鼓励环境类国际组织之外的非国家行为体展开通力合作。对此,我们应正视履约中的挑战与不确定性,做好充分的应对之策,确保履约进程的顺利完成。总之,《巴黎协定》的履约前景不容乐观,国际社会任重道远。     

Impact of long‐term pesticide applications on some soil biological parameters

Abstract

The soil oxidative and anaerobic processes, as well as, the microbial biomass were followed during three years in a cotton farm (Tatuí) where the recommended pesticides have been used for several years, and in an experimental field (São Paulo) treated first time with the same pesticides. The oxidative process was monitored by the dehydrogenase (DHA)‐activity using triphenyltetrazolium chloride (TTC) as substrate. The anaerobic process was followed by the iron‐oxide reduction, and the microbial biomass was estimated by the substrate (glucose)‐indiced respiration. Increases in DHA‐activity and in the microbial biomass occurred only in the farm soil, with concomitant decreases in iron‐reduction. In the experimental field soil, the increases in DHA‐activity were followed only by decreases in iron‐reduction. Soil characteristics were the determining factor for different biological parameters after pesticide inputs. All the pesticides produced at least one clear but transient effect.     

Remediation of alachlor and atrazine contaminated water with zero-valent iron nanoparticles

Zero-valent iron nanoparticles (nZVI, diameter < 90 nm, specific surface area = 25 m² g^?1) have been used under anoxic conditions for the remediation of pesticides alachlor and atrazine in water. While alachlor (10, 20, 40 mg L^?1) was reduced by 92–96% within 72 h, no degradation of atrazine was observed. The alachlor degradation reaction was found to obey first-order kinetics very closely. The reaction rate (35.5 × 10^?3–43.0 × 10^?3 h^?1) increased with increasing alachlor concentration. The results are in conformity with other researchers who worked on these pesticides but mostly with micro ZVI and iron filings. This is for the first time that alachlor has been degraded under reductive environment using nZVI. The authors contend that nZVI may prove to be a simple method for on-site treatment of high concentration pesticide rinse water (100 mg L^?1) and for use in flooring materials in pesticide filling and storage stations.     

水热炭化餐厨垃圾制备纳米铁/炭复合材料

以餐厨垃圾中有机组分作为碳源,通过添加铁盐水热炭化制备铁/炭纳米复合材料。考察了不同铁盐(Fe-SO4,FeCl3,Fe(NO3)3)对餐厨垃圾水热炭化物的形貌,以及氮、磷元素的迁移转化的影响;并研究了负载铁的物理、化学性质。实验结果表明,铁盐在水热炭化过程中促进了餐厨垃圾转化生成多种纳米结构。铁的价态是影响复合物形貌的主要影响因素:三价铁离子对大分子有机物的水解和炭化过程有催化作用,从而促进壳核式结构的纳米线及微米球复合物的生成;而亚铁离子则导致可溶性有机物炭化形成空心纳米球结构。负载铁的化学形态主要受阴离子的影响:硝酸铁体系中铁主要以氢氧化物形式沉积、其他阴离子体系则以磷酸盐为主要形态负载。     

铁屑粉煤灰组合处理含磷废水

实验研究了铁屑粉煤灰组合处理含磷废水的除磷效果.通过单因素实验,考查了铁屑粉煤灰质量比、反应时间、pH值和投加量对除磷效果的影响.实验结果表明,该法除磷的最优条件为铁屑和粉煤灰的质量比为2∶1,反应时间为20 min,pH值为6,投加量为20 g/L.在最优实验条件下磷的去除率达到了97.5％.对比了该法和粉煤灰吸附法与传统铁屑法的除磷效果.与单一粉煤灰吸附法和传统铁屑法除磷的结果相比较,铁屑粉煤灰组合除磷的方法具有明显优势.