介质阻挡放电协同Ag/Al_2O_3对NO_x脱除的影响

为有效去除发电厂烟气中产生的NOx,利用介质阻挡放电(DBD)产生低温等离子体并结合催化剂Ag/Al2O3进行烟气脱硝实验,研究了在加入乙烯的条件下,平均负载量、催化温度和装置的布置方式对NOx脱除的影响。结果表明,随着负载的增多,NO脱除率呈现先增大后减小的趋势,5种负载量中最佳为1.76%;随着催化温度的升高,NO脱除率同样呈现先增大后减小的趋势,最佳的催化温度为150℃左右;3种不同布置方式对NO和NOx脱除有明显差别,单独催化剂在NO和NOx的脱除率都比较低;单独介质阻挡放电NO脱除率很高,但是NOx很却很低;而两者结合在NO和NOx都达到了很好的效果。     

河北省祖山风景区崩塌灾害特征与防治对策研究

以祖山为例,阐述了崩塌地质灾害的机理、特征和现状,并利用传递系数法对崩塌稳定性进行了计算和评价,采用削方卸载、修建抗崩塌挡土墙、构筑排水沟与格构等工程设施的防治对策及工程措施,取得了预期的效果。     

国家海洋生态环境保护“十四五”战略路线图分析

2018年,国家海洋生态环境管理体制重组,为系统推进海洋生态环境质量改善奠定了基础。本文基于美丽中国建设的战略目标,在分析海洋生态环境保护现状、问题以及形势的基础上,提出坚持陆海统筹、区域联动、分区防控和精准治理的原则,建议协同推进"污染防治、生态修复、风险防范、能力建设、国际合作"五大领域任务,重点建设"法律规范、空间管控、标准规范、目标责任、许可管理"五大体系,最终实现"十四五"国家海洋生态环境保护目标。     

浅谈我国推行排污许可制度难点及对策

我国排污许可制度推行已有二十余年,但由于在政策设计层面、技术支撑层面及配套保障层面尚有不足之处,排污许可制度在推行过程中遇到很多阻碍,排污许可制度的应用范围、实施效果和改革举措实际落地都还不尽如人意,依然处于难以推广的境地。本文基于对以上各层面存在问题的深入分析,进而指出目前阻碍排污许可制度推行的难点问题及具体成因,其中难点问题主要包括专项法律法规缺失、管理要求落地难、各方权责落实难、多套数据并行、排放标准滞后、部分行业标准缺失、与环境目标未建立响应关系、管理方式落后、数据支撑和人员配备不足等方面。根据前述问题的论证,本文相应提出了推进排污许可制度改革的各项对策措施,并建议排污许可制度应形成上下联动的工作格局,进一步夯实技术支撑基础和完善配套保障措施,以期助力排污许可制度各项改革举措的实际落地,更好地推进排污许可制度的有效实施,建立系统完整、权责清晰、监管有效的管理格局,最终实现排污许可"一证式"管理模式。     

A study on the reaction characteristics of vanadium-impregnated natural manganese oxide in ammonia selective catalytic reduction

This study investigated the effect of adding vanadium (V) to natural manganese oxide (NMO) in ammonia (NH3) selective catalytic reduction (SCR). The addition of V to NMO decreased the catalytic activity at low temperatures by blocking the active site. However, the enhancement of catalytic activity was achieved by controlling NH3 oxidation at high temperatures. From the NH3 temperature programmed desorption and oxygen on/off test, it was confirmed that the amount of Lewis acid site and active lattice oxygen of the catalyst affects the catalytic performance at low temperature.     

不同因素对人工湿地基质脱氮除磷效果的影响

在人工配制的污水中投入一定量的基质,不同条件下振荡培养,评价沸石、炉渣和陶瓷滤料3种基质在不同因素影响下对氨氮(NH4+-N)和总磷(TP)的吸附能力。结果表明,不同吸附时间时,沸石对NH4+-N的吸附效果最好,陶瓷滤料对TP的吸附效果最好;进水浓度对沸石吸附NH4+-N的影响较大,其吸附量随进水浓度的增大而增大,进水浓度对炉渣和陶瓷滤料吸附NH4+-N及炉渣吸附TP影响不大;3种基质对NH4+-N和TP的吸附量均是随吸附剂量的增加而降低,要达到较好的去污效果,应根据实验结果考虑基质投入量;pH值对沸石吸附NH4+-N影响显著,pH值6～7范围内吸附效果最好,pH值8～12的碱性条件有利于基质对TP的吸附。     

Fate of caffeine in mesocosms wetland planted with Scirpus validus

Uptake, accumulation and translocation of caffeine by Scirpus validus grown in hydroponic condition were investigated. The plants were cultivated in Hoagland’s nutrient solution spiked with caffeine at concentrations of 0.5–2.0 mg L^?1. The effect of photodegradation on caffeine elimination was determined in dark controls and proved to be negligible. Removal of caffeine in mesocosms without plants showed however that biodegradation could account for about 15–19% of the caffeine lost from solutions after 3 and 7 d. Plant uptake played a significant role in caffeine elimination. Caffeine was detected in both roots and shoots of S. validus. Root concentrations of caffeine were 0.1–6.1 μg g^?1, while the concentrations for shoots were 6.4–13.7 μg g^?1. A significant (p < 0.05) positive correlation between the concentration in the root and the initial concentrations in the nutrient solution was observed. The bioaccumulation factors (BAFs) of caffeine for roots ranged from 0.2 to 3.1, while BAFs for shoots ranged from 3.2 to 16.9. Translocation from roots to shoots was the major pathway of shoot accumulation. The fraction of caffeine in the roots as a percentage of the total caffeine mass in solution was limited to 0.2–4.4% throughout the whole experiment, while shoot uptake percentage ranged from 12% to 25% for caffeine at the initial concentration of 2.0 mg L^?1 to 50–62% for caffeine at the initial concentration of 0.5 mg L^?1. However, a marked decrease in the concentration of caffeine in the shoots between d-14 and d-21 suggests that caffeine may have been catabolized in the plant tissues subsequent to plant uptake and translocation.     

我国三大城市群城镇化水平对碳排放的影响

在新型城镇化进程深入推进的背景下,选择我国城镇化发展水平较高的京津冀、长三角和珠三角三大城市群为研究对象,利用STIRPAT模型分析了三大城市群城镇化水平与碳排放之间的关系。结果表明：三大城市群城镇化水平与碳排放之间呈现出先下降后上升的“正U型”曲线关系;经济发展与碳排放之间存在着“倒U型”的曲线关系;人口总量和能源强度对碳排放存在显著的正向影响,产业结构对碳排放影响较小。在城镇化发展早期加快城镇化发展速度,而在城镇化发展到一定阶段后,控制人口规模,降低能源强度,均可实现减少二氧化碳排放的目标。     

财政分权对环境污染的空间效应

利用2006—2017年我国30个省级行政单位的面板数据,采用空间计量模型对财政分权与环境污染之间的关系进行实证分析,并通过效应分解分别计算出财政收入分权和财政支出分权对环境污染的直接效应、空间溢出效应和总效应。模型估计的结果表明:①财政收入分权与财政支出分权通过直接效应和空间溢出效应两种途径对环境污染产生显著影响,但收入分权与支出分权对环境污染的空间效应具有异质性。②财政收入分权对环境污染具有显著的负向直接效应和负向空间溢出效应,影响系数分别为-5.429和-17.572。提高财政收入分权度不仅有利于减轻本省份环境污染,也对邻近省份的环境污染起到抑制作用。而财政支出分权对环境污染具有显著的负向直接效应和正向的空间溢出效应,影响程度分别为-3.345和1.173。提高财政支出分权虽然有利于减少本省份污染的排放,但在一定程度上引起省际的污染外溢效应,提高邻近省份的污染程度。③从总效应来看,财政收入分权和财政支出分权对环境污染均呈现出显著的负向相关性,影响程度分别为-23.001和-2.172。提高财政分权可降低环境污染水平,有利于环境质量提升。④通过构建不同空间权重矩阵,检验模型的稳健性,结果表明模型估计是稳健可靠的。根据分析结论,可能的启示与建议有:①合理划分中央政府和地方政府之间的财政事权和支出责任,在提高财政支出分权度的同时提高地方政府财政收入分权度,充分发挥地方政府环境治理的积极性和主动性。②继续加大生态环境保护力度,完善绿色经济考核机制,引导地方政府加大对污染治理和环境改善的支出水平及效率。     

Gauging the environmental efficiency with ecological compensation in presence of missing data using data envelopment analysis

Environment, Development and Sustainability - The ecological compensation mechanism is regarded as the direction for the future management of the ecological environment of the river basin, which...