Cyhalofop‐p‐butyl mobility and distribution of residues in soil at various depths

This study was conducted to evaluate cyhalofop‐p‐butyl mobility in a sandy loam soil and subsequent distribution of residues at various depths under field conditions. Soil samples were taken from 0 to 150 cm depths at 3–90 d after rains in lysemeter of 1 and 2 m depths. Cyhalofop‐p‐butyl application at two rates and subsequent precipitation had a significant impact on soil, physico‐chemical properties and herbicide mobility. Precipitation caused substantial mobility of cyhalofop‐p‐butyl in the soil and 1.1–7.6 μg L^?1 of cyhalofop‐p‐butyl was found in leachates. Cyhalofop‐p‐butyl residues in the leachates were probably due to preferential flow through the soil. Cyhalofop‐p‐butyl residues were detected in significant amounts from the soil up to 10 d, later, residues were found below the detection limit but its three transformation products viz., cyhalofop acid, diacid, and phenol were detected.     

Sustainability through system transformation: lessons from Finnish efforts

This special issue of the Journal of Cleaner Production addresses system transformation by examining progress, stumbling blocks and opportunities for sustainable consumption and production in a specific country, Finland, set within a global context. The articles present and analyse top-down policy efforts, bottom-up efforts by municipalities, activities by companies and actions by consumers. They provide material for discussions on the shift from sustainability planning to enhancing system transformation, on the implications of globalisation for system boundaries, on the transformation of complex systems, on learning processes and on methods of assessing transitions. Without providing a singular solution, the articles show that issues of sustainability should be explored in different ways within different contexts, and experimented with. There is a continuous need for transformations and reflexive learning, since conditions are likely to become very different, not least due to climate change. The notion of change and transformation will be high on the agenda of the Rio+20 conference, as will similar efforts to promote large-scale transformations of consumption and production.     

三相内循环流化床光催化反应器及其光辐射传递规律

提出并建立了三相内循环流化床光催化反应器 ,对其内部光辐射传递规律进行了研究 .结果表明 ,在气固相共同作用下(通气量>0.3m³/h) ,光强的径向分布服从指数衰减规律 ,与Rose公式中通过均匀悬浊介质时的光强分布规律一致 .光辐射能的数值受初始光强 .催化剂颗粒浓度和液层厚度的共同影响 .通气量只影响床层流化状态 ,对光强分布影响可以忽略 .对罗丹明B的光催化降解实验表明 ,三相内循环流化床的光催化效率高于传统的悬浆式反应床 ,本系统的最佳催化剂浓度为10～12g/L .     

城市区域臭氧浓度变化的研究

通过中尺度气象模式和高分辨化学模式的耦合,研究广州地区O3的时空分布及其变化特征.结果表明,近地层上O3的分布与地面源排放的分布有非常好的对应关系,并且呈现出多中心分布;O3浓度随时间变化有很好的日变化周期,模拟结果与实测对比有较好的一致性;对单站O3浓度随高度的变化趋势的分析表明,对流层低层O3的日变化幅度较大.      

Ammonia abatement and its impact on emissions of nitrous oxide and methane—Part 2: application for Europe

Agriculture is an important source of NH₃, which contributes to acidification and eutrophication, as well as emissions of the greenhouse gases CH₄ and N₂O. Because of their common sources, emission reduction measures for one of these gases may affect emissions of others. These interrelations are often ignored in policy making. This study presents an analysis of the effects of measures to reduce NH₃ emissions on emissions of N₂O and CH₄ from agriculture in Europe. The analysis combines information from the NH₃ module of the Regional Air pollution INformation and Simulation (RAINS) model for Europe with the IPCC method for national greenhouse gas inventories. The IPCC method for estimating agricultural emissions of N₂O and CH₄ is adjusted in order to use it in combination with the RAINS database for the European agricultural sector. As an example, we applied the adjusted method to the agricultural sector in the Netherlands and found that application of several NH₃ abatement options may result in a substantial increase in N₂O emissions while the effect on CH₄ emissions is relatively small. In Part 2 of this paper we focus on the resulting emissions for all European countries for 1990 and 2010.     

Real-world emission characteristics of carbonyl compounds from agricultural machines based on a portable emission measurement system

Emissions of carbonyl compounds from agricultural machines cannot be ignored. Carbonyl compounds can cause the formation of ozone (O₃) and secondary organic aerosols, which can cause photochemical smog to form. In this study, 20 agricultural machines were tested using portable emission measurement system (PEMS) under real-world tillage processes. The exhaust gases were sampled using 2,4-dinitrophenylhydrazine cartridges, and 15 carbonyl compounds were analyzed by high-performance liquid chromatography. Carbonyl compound emission factors for agricultural machines were 51.14–3315.62 mg/(kg-fuel), and were 2.58 ± 2.05, 0.86 ± 1.07 and 0.29 ± 0.20 g/(kg-fuel) for China 0, China II and China III emission standards, respectively. Carbonyl compound emission factor for sowing seeds of China 0 agricultural machines was 3.32 ± 1.73 g/(kg-fuel). Formaldehyde, acetaldehyde and acrolein were the dominant carbonyl compounds emitted. Differences in emission standards and tillage processes impact ozone formation potential (OFP). The mean OFP was 20.15 ± 16.15 g O₃/(kg-fuel) for the China 0 emission standard. The OFP values decreased by 66.9% from China 0 to China II, and 67.4% from China II to China III. The mean OFP for sowing seeds of China 0 agricultural machines was 25.92 ± 13.84 g O₃/(kg-fuel). Between 1.75 and 24.22 times more ozone was found to be formed during sowing seeds than during other processes for China 0 and China II agricultural machines. Total carbonyl compound emissions from agricultural machines in China was 19.23 Gg in 2019. The results improve our understanding of carbonyl compound emissions from agricultural machines in China.     

Ecotoxicological assessment of doxycycline in soil

Doxycycline has been used in continually increasing quantities for mass treatment of food animals because of its greater bioavailability relative to older tetracyclines. The study presented in this paper was undertaken to investigate the degradation rate of the tetracycline derivative in manure-amended soil. In the present experiment, following composting, the doxycycline-contaminated manure was applied to agricultural land, and a field study was performed to investigate the degradation rate of doxycycline in soil. By the end of the 20-week sampling period, about 20 %, 33 % and 18 % of the initial doxycycline concentrations could be measured in soil samples taken at three different soil depths. The calculated half-life of doxycycline in the soil was 66.5, 76.3 and 59.4 days at depths of 0 cm, 25 cm and 50 cm, respectively. The potential effect of doxycycline on soil microbial activity was demonstrated by the nitrogen transformation test performed in compliance with the Organisation for Economic Co-operation and Development (OECD) Guideline No. 216. On day 28, the following nitrate concentrations of the control soil sample were found in the soil samples treated with different amounts of doxycycline: 76.9 %, 53.0 %, 65.6 %, 59.7 % and 77.1 %.     

国土空间用途管制的改革逻辑及其规划响应路径

在完善生态文明制度体系、推进国家治理体系和治理能力现代化的宏观背景下,系统梳理土地用途管制制度起源、实施特点、成效与不足,重点解析土地用途管制向国土空间用途管制转型的改革逻辑及其对国土空间规划的具体要求,为完善国土空间规划体系提供借鉴。研究结果表明：（1）土地用途管制制度突出强调对耕地的保护,以新增建设用地为主要管控对象,建立了土地用途分类—规划—计划—审批—监管的完整管控链条,在保护耕地、保障粮食安全、倒逼节约集约用地和提高依法依规用地意识等方面取得了较好成效,但仍存在覆盖范围不全、管制刚性过强、生态用地管制乏力等不足。（2）国土空间用途管制以生态文明建设为逻辑起点,通过单一地类保护向空间统筹转型、地类管制向空间管控转型、指标传导为主向指标与分区相结合转型、底线约束向约束与引导并重转型,构建面向全过程、多样化的管制规则体系,完善空间传导机制,进而实现所有国土空间全要素统一管制。（3）面对国土空间用途管制的时代需求,国土空间规划改革应在系统性、整体性的规划管控指标体系、覆盖全域、上下衔接的规划分区体系、底线约束与激励引导相结合的规划实施弹性机制以及“全链条”管理机制等方面做出积极响应,进而实现不同层级国土空间规划和用途管制的统筹协调管控。     

Water resource conservation promotes synergy between economy and environment in China’s northern drylands

•Considering evenness provides a more accurate assessment of sustainable development. •Water resource conservation drives industrial transformation. •Synergy between economic development and environmental protection is achieved. •Regional collaboration over water could promote sustainable development in drylands. Water resource availability is the major limiting factor for sustainable development in drylands. Climate change intensifies the conflicting water demands between people and the environment and highlights the importance of effective water resource management for achieving a balance between economic development and environmental protection. In 2008, Inner Mongolia, typical dryland in northern China, proposed strict regulations on water exploitation and utilization aimed at achieving sustainable development. Our study is the first to investigate the effectiveness and performance of these long-standing water conservation regulations. Our analyses found that the regulations drove industrial transformation, evidenced by the decreasing proportion of environmentally harmful industries such as coal and steel, and the increasing proportion of tertiary industries (especially tourism). Following industrial transformation, economic development decoupled from industrial water consumption and subsequently led to reduced negative environmental impacts. Based on these results, adaptive strategies were developed for 12 cities by revealing and integrating their development pathways and relative status in achieving sustainable development. Integration and cooperation between cities were proposed, e.g., a water trade agreement between eastern Inner Mongolia (an economically underdeveloped region with relatively abundant water resources) and central Inner Mongolia (an economically developed region with high water stress). Such an agreement may enable the holistic achievement of sustainable development across regions. By integrating the findings of our research, our study presents a reproducible framework for water-management-based sustainable development strategies in drylands.     

二氧化锰氧化降解五氯酚

以二氧化锰为氧化剂,研究了pH 4.12的水溶液中五氯酚氧化降解的反应动力学,并讨论了反应溶液的pH对反应动力学的影响.结果表明,五氯酚对二氧化锰的氧化作用具有较强的反应感受性.在pH一定和二氧化锰充分过量的条件下,随着反应的进行,五氯酚的降解速度变慢,遵循的不是简单的准一级反应动力学而是复合的反应动力学.此外,随溶液pH由3.5升高6.6,五氯酚的降解速度发生显著地下降.运用溶剂萃取和气质联用仪的分析方法,检测到2个主产物和1个次产物.其中,次产物是由四氯-1,4-氢醌与四氯儿茶酚组成的混合物;2个主产物是由五氯酚氧自由基偶合而成的二聚体,且是同分异构体.在观测到的表面反应动力学和降解产物的基础上,提出了五氯酚被二氧化锰氧化降解的反应流程图.