衡阳市区和衡山背景站臭氧浓度变化规律的对比分析

选取衡阳市区和衡山背景站臭氧自动监测数据,分析两地的臭氧污染特征。对空气质量的优良率情况、臭氧作为首要污染物的变化情况、臭氧浓度的日变化特征、典型时段的浓度变化特征、臭氧浓度的月际变化特征和臭氧与PM_(2.5)的关联情况等进行了分析。结果表明,多云及阴雨天气时,衡阳市区的臭氧浓度日变化幅度大于衡山背景站。夏季,衡阳市区和衡山背景站的臭氧浓度的日变化特征规律差异较大,臭氧浓度分布比较分散,前者为典型的单峰形,后者则波动平缓。冬季,日变化幅度不大,但衡阳市区的臭氧浓度明显低于衡山背景站。衡山背景站和衡阳市区的臭氧基本同步变化,但日均值高于衡阳市区。     

典型地区农用地污染调查及风险管控标准探讨

针对《土壤污染风险管控标准——农用地土壤污染风险管控标准》(GB 15618—2018),提出以土壤中全量浓度筛选值和管控值作为衡量农用地土壤污染风险管控的标准,对湖南省部分稻田农用地土壤及点对点稻米样品中镉、铅、砷、汞的总量和有效态浓度及稻米中含量进行监测,根据重金属总量浓度分为低风险、中风险、高风险3组。结果显示:(1)土壤及稻米中镉含量基本为随着风险级别的升高而增加,铅、砷在土壤和稻米中含量无规律性结果,汞监测结果均为未检出。(2)低风险组稻米镉超标率为12. 0%,高风险组稻米镉达标率为33. 3%,表明利用总量浓度对农用地土壤潜在风险进行分组存在一定的局限性。(3)依据4种重金属在土壤中总量及稻米(早稻)中含量情况,对风险级别进行调整并综合判断:有58个样品为低风险组,占样品总数的68. 2%,超标率为零;有15个样品为中风险组,占样品总数的17. 7%,超标率为80. 0%;有12个样品为高风险组,占样品总数的14. 1%,超标率为100. 0%。调整后评价结果与上述标准的划分目标更接近,能够提高上述标准的准确性和实用性。     

The application of system dynamics in different practices of a waste management system

The continuous increase in waste generation warrants global management of waste to reduce the adverse economic, social, and environmental impact of waste while achieving goals for sustainability. The complexity of waste management systems due to different waste management practices renders such systems difficult to analyze. System dynamics (SD) approach aids in conceptualizing and analyzing the structure, interactions, and mode of behavior of the complex systems. The impact of the underlying components can therefore be assessed in an integrated way while the impact of possible policies on the system can be studied to implement appropriate decisions. This review summarizes various applications of SD pertinent to the waste management practices in different countries. Practices may include waste generation, reduction, reuse/recovery, recycling, and disposal. Each study supports regional-demanding targets in environmental, social, and economic scopes such as expanding landfill life span, implementing proper disposal fee, global warming mitigation, energy generation/saving, etc. The interacting variables in the WMS are specifically determined based on the defined problem, ultimate goal, and the type of waste. Generally, population and gross domestic product can increase the waste generation. An increase in waste reduction, source separation, and recycling rate could decrease the environmental impact, but it is not necessarily profitable from an economic perspective. Incentives to separate waste and knowledge about waste management are variables that always have a positive impact on the entire system.

     

Simultaneous removal of cyanobacterial blooms and production of clean water by coupling flocculation with a rotary drum filter

Environmental Science and Pollution Research - A mechanical harvesting technology based on coupling flocculation with a rotary drum filter (RDF, 35-μm) was applied to remove cyanobacterial...     

高烈度地震区隧道软硬围岩交接段刚柔并济抗减震技术研究*

为提高高烈度地震区隧道抗震性能，以某铁路隧道为研究背景，分析3种抗减震措施下隧道不同监测点隧道拱顶沉降、边墙收敛、衬砌结构PGA及最小安全系数，通过对比分析得到最优抗减震措施。结果表明:相比于工况1，工况2隧道拱顶沉降减小10.54%~81.10%，边墙收敛减小13.92%~78.77%，衬砌结构PGA减小31.42%~72.02%，最小安全系数增加18.04%~66.13%；相比于工况1，工况3结构拱顶沉降减小3.04%~18.02%，边墙收敛减小4.70%~32.00%，PGA增加13.95%~27.48%，最小安全系数增加7.49%~30.99%；工况4即“减震层+SFRC衬砌”刚柔并济法，相比于工况1，隧道拱顶沉降减小18.46%~83.98%，结构边墙收敛减小17.54%~85.47%，PGA减小30.00%~69.98%，最小安全系数增加47.95%~83.56%；4种工况抗减震性能由高到低依次为:工况4＞工况2＞工况3＞工况1。研究结果可为隧道软硬围岩交接段抗震设防提供理论参考。     

A comprehensive review on green buildings research: bibliometric analysis during 1998–2018

Environmental Science and Pollution Research - Buildings account for nearly 2/5ths of global energy expenditure. Due to this figure, the 90s witnessed the rise of green buildings (GBs) that were...     

A comparison analysis of the decoupling carbon emissions from economic growth in three industries of Heilongjiang province in China

Environmental Science and Pollution Research - Growing environmental pressure urges China to develop in a sustainable and low carbon way, and thus China strives to achieve a carbon peak by 2030 and...     

长江经济带数字产业化与产业数字化的耦合协调分析

数字产业化与产业数字化是数字经济的"双重向度",其耦合协调程度对于优化数字经济发展结构具有重要意义.揭示与阐述数字产业化与产业数字化的耦合机理,建立评价两者耦合协调度的理论模型,设计评价两者耦合协调状况及趋势的指标体系,运用长江经济带11省市2013～2018年的面板数据,实证分析长江经济带数字产业化与产业数字化的耦合协调度.结果表明:长江经济带数字产业化水平和产业数字化水平稳步提升,总体耦合协调度区域差异明显,存在数字产业化滞后产业数字化的趋势.从加快推进新型数字产业发展、以"新基建"助力传统产业数字化转型、为区域间数字经济协调发展和区域内数字化转型构建更好制度体系、加强数字人才培养和激励等方面,提出促进我国数字产业化与产业数字化融合发展的政策建议.     

Lithium extraction from salt lake brines with high magnesium/lithium ratio: a review

Environmental Chemistry Letters - The demand for lithium is growing rapidly with the increase in electric vehicles, batteries and electronic equipments. Lithium can be extracted from brines, yet...     

汉江与嘉陵江源区黄土的风化成土强度及其在土壤系统分类中的归属

以汉江源区(李家河村)和嘉陵江源区(杨家山村)黄土剖面为研究对象,对其粒度、元素组成、团聚体等进行分析与对比,探究两地土壤成土强度与系统分类归属.结果表明两江源区的土壤风化成土特征级类明显不同:(1)两地土壤团聚体主要分布在0.25～1 mm范围内,但汉江源区(LJH)土壤上部的大团聚体含量R0.25值(83.73％)、平均重量直径MWD值(2.17)和几何平均直径GMD值(1.11)均大于嘉陵江源区(YJS)的土壤(其R0.25值为69.81％,MWD和GMD值分别为1.06、0.47),团聚体稳定性更强,而剖面中下部则相反,土体稳定性弱于后者;(2)嘉陵江源区土壤的风化程度仅达到低等向中等强度过渡阶段,与其相比,汉江源区土壤的钾钠比值和残积指数较高、硅铝铁率和淋溶系数较低,钙、钠等易溶元素风化淋失更强,产生的富铝黏土矿物更多,达到中等风化强度,故后者风化成土强度远大于前者;(3)在土壤系统分类中,汉江源区黄土母质发育的土壤可归为斑纹简育湿润淋溶土,嘉陵江源区土壤可归为普通钙积干润淋溶土.