AAO工艺低氧条件下的运行及其模拟

利用厌氧-缺氧-好氧(AAO)工艺探讨了在好氧池低溶解氧(DO)浓度条件下的水质指标变化情况.结果表明,当好氧池DO浓度从2.00 mg·L~(-1)降低到1.00 mg·L~(-1)和0.50 mg·L~(-1)时,系统仍然具有良好的除磷脱氮效果,出水水质指标均满足我国《城镇污水处理厂污染物排放标准》(GB 18918-2002)中的一级A标准.在此基础上,基于Bio Win 4.1软件建立了AAO工艺的活性污泥模型,对模型参数进行了灵敏度分析,并利用动态模拟对模型参数中的聚磷菌吸收乙酸或丙酸的聚羟基烷酸(PHA)产率系数(YP/PHA,seq)、聚磷菌好氧氧化PHA的储磷率(YP/PHA,aerobic)、氨氧化菌的最大单位生长速率(μmax,A)和亚硝酸盐氧化菌的最大单位生长速率(μmax,N)进行了校验.此外,对系统的曝气能耗进行了模拟评估,结果表明,与好氧池DO浓度为2.00 mg·L~(-1)时相比,好氧池DO浓度为1.00 mg·L~(-1)和0.50 mg·L~(-1)时的空气流量可分别节省23.8%和38.1%,氧转移效率可分别提高7.2%和11.7%.     

氮和氧同位素示踪伊洛河河水硝酸盐来源及转化过程

河流硝酸盐(NO^-₃)浓度及氮和氧同位素组成(δ¹⁵N-NO^-₃和δ¹⁸O-NO^-₃)可以辨识河水NO^-₃受自然过程和人为输入的影响,但流域不同土地利用方式对河水NO^-₃来源及转化过程的影响尚不明确,特别是山区人为输入对河水NO^-₃的影响仍不清楚.选择土地利用空间异质性显著的伊河和洛河作为研究对象,借助水体水化学组成,氢氧同位素(δD-H₂O和δ¹⁸O-H₂O)、δ¹⁵N-NO^-₃和δ¹⁸O-NO^-₃,辨识不同土地利用方式影响下河水NO^-₃来源及...     

基于经济普查引入EGSS统计框架的可行性分析

环境货物和服务部门(EGSS)统计框架是由欧盟统计署研究制定的、用于收集和整理环境产品与服务相关统计数据的方法,已经被联合国统计署纳入"环境经济统计体系(SEEA)"中,成为一项国际统计标准。中国的经济普查工作在数据采集方式上与EGSS具有较好的一致性,本文主要对我国的经济普查与EGSS统计框架进行比较研究,探索从经济普查表核算EGSS数据的方法和思路。结果表明:经济普查可作为常规统计口径核算EGSS数据的一个切入点,但是需要在数据连续性、行业小类划分、统计的经济指标范围方面进行衔接融合;基于经济普查数据引进EGSS统计框架可采取分阶段推进方式。     

对加快推进我国矿山生态修复的思考

绿色矿山建设是矿业领域践行"绿水青山就是金山银山"的重要体现。本文从矿山生态修复的内涵到外延，从问题识别到任务措施，从单一治理修复目标到生态系统功能修复目标，从矿山生态修复系统到与经济社会发展系统相结合等多个方面，系统地梳理矿山生态修复的解决路径，围绕矿业绿色发展提出一系列建议。     

大气自净能力指数的气候特征与应用研究

为了定量地评估污染气象条件对空气污染的作用并实现对空气污染潜势的预报,本文在城市大气污染数值预报系统（CAPPS）预报原理的基础上,定义了大气自净能力指数,并分别给出了采用气象站观测资料和通过数值模拟计算大气自净能力指数的方法.基于气象站观测资料的全国大气自净能力指数分析计算表明,全国大气自净能力最差的地区分布在四川盆地和新疆塔里木盆地,大气自净能力最强的地区分布在青藏高原、蒙古高原、云贵高原、以及东北平原和三江平原、山东半岛和海南岛;1961~2017年,京津冀、长三角和珠三角地区的大气自净能力指数呈下降的变化趋势,全年低自净能力日数呈上升的变化趋势.采用大气自净能力指数评估2014年北京APEC会议期间大气污染防控效果,表明在11月8~10日极端不利扩散气象条件发生时,减排措施使北京市空气质量AQI平均降低77%,使京津冀平原地区11个城市的空气质量AQI平均降低37%.基于国家气候中心月动力延伸气候预测模式（DERF2.0）的预报产品和中尺度模式（WRF）,建立了可以预测全国未来40d逐日大气自净能力指数的延伸期-月尺度大气污染潜势预测系统,回报实验表明,在大多数情况下可以提前15d预报出大气重污染过程;月尺度的大气重污染过程预报效果更大程度上取决于月动力延伸气候预测模式（DERF2.0）的预报准确率.     

北京城区大气干沉降的水溶性离子特征

为了解北京城区大气干沉降中水溶性离子的化学组成与时间变化特征,连续进行了4年多的干沉降采样与分析.结果表明,在222个有效干沉降样品中,存在不同程度的阴离子缺失. SO42-与Ca2+分别是含量最丰富的阴、阳离子组分,其次是NO3-和NH4+. SO42-、NO3-和NH4+呈现相似的季节变化特征,即其浓度在夏季最高,冬季最低. 干沉降基本呈中性,其pH值月变化幅度小,但季节变化明显,夏季低而春季高.     

Synthesis, crystal structure, photodegradation kinetics and photocatalytic activity of novel photocatalyst ZnBiYO4

ZnBiYO₄ was synthesized by a solid-state reaction method for the first time. The structural and photocatalytic properties of ZnBiYO₄ were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and UV-Vis diffuse reflectance. ZnBiYO₄ crystallized with a tetragonal spinel structure with space group I41/A. The lattice parameters for ZnBiYO₄ were a = b = 11.176479 Å and c= 10.014323 Å. The band gap of ZnBiYO₄ was estimated to be 1.58 eV. The photocatalytic activity of ZnBiYO₄ was assessed by photodegradation of methyl orange under visible light irradiation. The results showed that ZnBiYO₄ had higher catalytic activity compared with N-doped TiO₂ under the same experimental conditions using visible light irradiation. The photocatalytic degradation of methyl orange with ZnBiYO₄ or N-doped TiO₂ as catalyst followed first-order reaction kinetics, and the first-order rate constant was 0.01575 and 0.00416 min^-1 for ZnBiYO₄ and N-doped TiO₂, respectively. After visible light irradiation for 220 min with ZnBiYO₄ as catalyst, complete removal and mineralization of methyl orange were observed. The reduction of total organic carbon, formation of inorganic products, SO₄^2- and NO₃^-, and evolution of CO₂ revealed the continuous mineralization of methyl orange during the photocatalytic process. The intermediate products were identified using liquid chromatography- mass spectrometry. The ZnBiYO₄/(visible light) photocatalysis system was found to be suitable for textile industry wastewater treatment and could be used to solve other environmental chemical pollution problems.     

北京首都机场绿色滑行时间估算

采用北京首都机场2014年实际CDM地面放行数据确定航空器的污染物排放量与离场排队飞机数量和落地滑入飞机数量的强关联性,构建包含这两个解释变量为影响因素的多元线性回归模型,用以估算几种常见机型在首都机场地面运行时的最小污染物排放量和绿色滑行时间。对比实际污染物排放量与最小污染物排放量,得出首都机场离场地面污染物排放量远远超过最小污染物排放量。     

贵州喀斯特山区生态环境脆弱性及其生态整治

贵州是我国喀斯特地貌最发育的省份之一,属典型的生态环境脆弱区通过对人口容量、生物生产力与生物量、敏感性和承灾能力等4个方面的分析阐述了贵州喀斯特山区生态环境脆弱性的基本特征,探讨了喀斯特脆弱环境形成的自然因子和人类活动因子的影响机理,根据我国西部大开发中生态建设的要求,提出了贵州喀斯特山区脆弱生态环境的整治对策．     

Low-carbon transition of iron and steel industry in China: Carbon intensity, economic growth and policy intervention

As the biggest iron and steel producer in the world and one of the highest CO₂ emission sectors, China's iron and steel industry is undergoing a low-carbon transition accompanied by remarkable technological progress and investment adjustment, in response to the macroeconomic climate and policy intervention. Many drivers of the CO₂ emissions of the iron and steel industry have been explored, but the relationships between CO₂ abatement, investment and technological expenditure, and their connections with the economic growth and governmental policies in China, have not been conjointly and empirically examined. We proposed a concise conceptual model and an econometric model to investigate this crucial question. The results of regression, Granger causality test and impulse response analysis indicated that technological expenditure can significantly reduce CO₂ emissions, and that investment expansion showed a negative impact on CO₂ emission reduction. It was also argued with empirical evidence that a good economic situation favored CO₂ abatement in China's iron and steel industry, while achieving CO₂ emission reduction in this industrial sector did not necessarily threaten economic growth. This shed light on the dispute over balancing emission cutting and economic growth. Regarding the policy aspects, the year 2000 was found to be an important turning point for policy evolution and the development of the iron and steel industry in China. The subsequent command and control policies had a significant, positive effect on CO₂ abatement.