关于重点排污单位名录制定和使用过程中存在的问题及建议

2017年11月,原环境保护部办公厅发布《关于印发重点排污单位名录管理规定(试行)的通知》,对重点排污单位的基本管理要求和筛选条件作出了详细规定。重点排污单位是国家重点监控企业的替代和延续,成为当前排污许可制度尚未完全成熟阶段环境管理的重要抓手。重点排污单位名录聚焦影响环境质量的主要污染物、排污大户和重大风险源,由设区的市级地方人民政府生态环境主管部门确定,有利于压实地方环保责任。在名录制定和使用过程中存在着部分指导性文件存疑、名录重点不突出、部分重点排污单位无法安装自动监测设备、不能满足新的环境监管需求、名录更新时间滞后、缺少罚则等问题,本文就此进行了深入分析并提出了几点建议。     

Effect of potential HONO sources on peroxyacetyl nitrate (PAN) formation in eastern China in winter

As an important secondary photochemical pollutant, peroxyacetyl nitrate (PAN) has been studied over decades, yet its simulations usually underestimate the corresponding observations, especially in polluted areas. Recent observations in north China found unusually high concentrations of PAN during wintertime heavy haze events, but the current model still cannot reproduce the observations, and researchers speculated that nitrous acid (HONO) played a key role in PAN formation. For the first time we systematically assessed the impact of potential HONO sources on PAN formation mechanisms in eastern China using the Weather Research and Forecasting/Chemistry (WRF-Chem) model in February of 2017. The results showed that the potential HONO sources significantly improved the PAN simulations, remarkably accelerated the RO_x (sum of hydroxyl, hydroperoxyl, and organic peroxy radicals) cycles, and resulted in 80%–150% enhancements of PAN near the ground in the coastal areas of eastern China and 10%–50% enhancements in the areas around 35–40°N within 3 km during a heavy haze period. The direct precursors of PAN were aldehyde and methylglyoxal, and the primary precursors of PAN were alkenes with C > 3, xylenes, propene and toluene. The above results suggest that the potential HONO sources should be considered in regional and global chemical transport models when conducting PAN studies.     

引入分形维数的混凝动力学方程数值求解

运用Smoluchowskj基本原理,建立了引入絮凝体分形维数的混凝动力学模型.该模型在絮凝过程中考虑了不同时刻形成的絮凝体中引入的初始颗粒数目和空隙率,并以此来推求不同时刻形成的絮凝体所对应的分形维数.采用有限差分法对建立的混凝动力学模型进行了数值计算.结果表明,初始颗粒的结构特征和碰撞效率是影响絮凝体粒径分布的主要因素.初始颗粒的分形维数和碰撞效率越大,絮凝体粒径分布越宽泛,大尺寸的颗粒所占的份额越多.同时计算结果表明,絮凝体的分形维数有随其粒径增大而逐渐降低的趋势,其原因是絮凝体的成长粒径与絮凝体中所包含的初始颗粒增长速度不成比例.以腐殖酸为混凝对象,采用硫酸铝作为混凝剂进行混凝实验,并以其初始絮凝条件作为数值计算初始条件,研究表明数值计算分析结果和模拟结果吻合较好.     

Simulation of three-stage operating temperature for supersaturation water-based condensational growth tube

In order to realize accurate dynamic control of supersaturation and to study condensation growth characteristics of nanoparticles through different levels of super saturation,a series of parametric analyses and systematic comparisons between two-stage and three-stage operating temperature designs were simulated with COMSOL Multiphysics.The simulation results showed that the three-stage operating temperature did not change peak supersaturation compared with two operating temperatures,and the three-stage operating temperature was superior in decreasing the amount of water vapor and the temperature,thus lowering particle loss and variation in detection and collection.The peak supersaturation level increased by 0.3 as the flow rate increased from 0.6 to 2.0 L/min,but the supersaturation peak moved from 0.0027 z0 to 0.08 z0(i.e.,the growth time and the final size decreased by 40%).Peak supersaturation increased as the temperature difference increased or the temperature difference window was shifting left,and minimum activation size decreased.Shifting the 70℃temperature difference window from 9℃,79℃-1℃,71℃for the condenser and initiator temperatures resulted in peak supersaturation in the centerline being above 5.8,and the activation size changed as low as 1 nm.Experiments with flow rates varying by a factor of 2.5(from 0.6 to 1.5 L/min) resulted in a final size decrease of 43%(from 3.2 to 1.8 μm),and experimental results of outlet particle size distributions were equivalent with theoretical analysis as the operating temperature was changed.     

石化化工建设项目环境影响评价技术要点

石化化工行业是国民经济的重要组成部分,同时具有工艺复杂,涉及大量危险化学品,环境风险高、危害大等特征,其环境影响评价技术难度较大。产业政策、规划符合性和总图布置、选址合理性;工程分析;环境风险评价;污染防治措施等内容是石化化工项目环境影响评价的核心。本文对这几个方面环境影响评价技术要点进行了系统总结,为今后相关项目环评工作提供借鉴和参考。     

源分类生物有机垃圾及其各组分甲烷潜能实验研究

研究了一种实验室范围内源分类生物有机垃圾制取甲烷潜能的方法.37℃条件下,添加20 g新鲜物料和300 mL来自于沈阳市污水处理厂接种体.于3个平行反应器中进行为期50 d的厌氧消化实验,通过气相色谱定期检测甲烷气体的浓度.在37℃条件下,BMW及其各组分厌氧消化产气速率为:淀粉>BMW>蛋白质>食用油>脂肪>纸,BMW、淀粉、蛋白质、食用油、脂肪和纸最终甲烷化潜能(CH4/VS)分别为:218.15、209.11、194.20、238.86、257.82和131.41 mL/g,其厌氧生物降解率分别为:67.73%、72.88%、65.84%、78.38%、74.11%和47.98%.     

呼和浩特市交通要道氮氧化物浓度监测与分析

为获知呼和浩特市交通要道氮氧化物（NOx）污染现状,采用短期暴露扩散采样法,于2010年3月21至4月24日,在呼和浩特市区交通要道设置IN个采样点,对氮氧化物进行了监测并分析。实验结果为四个采样点的N0x浓度日平均值为0．012—0．14mg·m^-3,表明呼和浩特市交通要道附近氮氧化物浓度存在超标现象,有关职能部门应采取有效措施,防治NOx污染的发生。     

Risk-based siting considerations for LNG terminals – Comparative perspectives of United States & Europe

Siting regulations and industrial standards for liquefied natural gas (LNG) terminals are evolving along different paths within Europe and the United States (U.S.). The 49 Code of Federal Regulations (CFR), Part 190 continues to delineate the United States process to adopt and revise safety regulations pertaining to LNG terminals and peak shaving plant sitting.¹ Embodied in these regulations are rich legal and regulatory traditions that are unique to the U.S. perspective. For example, the public is encouraged to petition existing regulations and to comment on regulatory proposals. Litigation within the U.S. court system is another means by which industry and the public may seek regulatory change. This approach promotes public involvement in governmental oversight and creates a distinctive obligation and accountability for U.S. regulatory agencies, which uniquely shape technical, safety, risk mitigation, and societal risk perspectives for siting LNG terminals.European traditions shape siting regulations for LNG terminals as well. Though American siting guidance includes references to the National Fire Protection Association’s NFPA 59A and 49 CFR, Part 193, European developers also apply the guidance within EN 1473 – a risk-based case-by-case analysis directive.^{2, 3 and 4} The NFPA 59A standard is applied for a basis to examine property line spacing as they pertain or may relate to off-site hazard impacts. The European approach applies the assessment and suitability of code compliance and the application of accepted engineering practices. In addition the approach incorporates the application of empirical risk assessments and computational modeling to reach an understanding of risk exposures. European policies set limits on the population’s cumulative exposure to facility risks and require LNG facility developers not to exceed established risk criteria.This paper describes how the U.S. and Europe site LNG terminals, identifies key differences in their risk-based approaches, and explains why these differences exist. This discussion also examines historical precedents that have influenced regulations and approval processes for siting LNG terminals within each continent.     

城市旅游发展的动力:理论分析与案例研究

20世纪80年代之初，深圳和珠海旅游发展的内外部条件极为类似，但是20年来两个城市旅游的发展模式却完全不同。本文研究发现：城市旅游发展取决于需求结构和相对优势两个因素的共同作用。基于旅游体验本质的需求结构的变化，决定了同一类型的旅游城市具有相似的变化规律；不同类型的旅游城市变化规律差异较大。另一方面，城市旅游驱动机制决定了相对优势的变化，旅游驱动机制演变轨迹的不同正是建成各个城市旅游目的地旅游发展模式差别的主因。由此可见，城市旅游要实现可持续发展就必须用随外部环境的变化（主要是需求结构的变化），适时培育和转变驱动机制。     

重金属防控区域整治进展及“十三五”思路研究

文章总结性提出我国138个防控区域"十二五"期间实践的3种类型防控模式,对防控区域总体成效和经验进行了阐述,分析了当前防控区域深入推进过程中面临的主要问题,并从导向管理、目标管理、监控管理等方面,提出了"十三五"防控区域深入管理4个方面的建议。