基于职能控制下的环境保护和管理措施

当今世界面临的环境危机使人类认识到人必须和环境和谐发展。环境保护人人有责,企业应做好环境保护的事前和过程的控制,要用新的理论技术充实环保管理的内容,强化环境控制职能。本文用环境工程、系统工程、控制论的原理和方法探讨研究企业在环保管理中如何强化控制职能的理论和方法,为企业在"环境和发展"所面临的挑战中采取相应的管理对策抛砖引玉。     

页岩气增产采出水处理方法研究

针对页岩气增产采出水易起泡,难以平稳蒸发脱盐的问题,利用"预处理+多效蒸发"处理方法,对井站两种不同性质的采出水进行中试,连续监测各工艺单元处理后水质及蒸发出水水质。结果表明:通过破乳混凝、催化氧化、电荷中和及除硬等步骤,能够完全消除泡排水起泡性;中试稳定运行7d,两种泡排水蒸发出水水质稳定,COD浓度<55mg/L,NH4^+-N浓度<18mg/L,满足GB 8978-1996《污水综合排放标准》一级标准;Cl^-浓度<21mg/L,满足DB 51/190-1993《四川省水污染物排放标准》要求。     

Persistent free radicals in humin under redox conditions and their impact in transforming polycyclic aromatic hydrocarbons

• Regulation of redox conditions promotes the generation of free radicals on HM. • HM-PFRs can be fractionated into active and inactive types depending on stability. • The newly produced PFRs readily release electrons to oxygen and generate ROS. • PFR-induced ROS mediate the transformation of organic contaminants adsorbed on HM. The role of humic substance-associated persistent free radicals (PFRs) in the fate of organic contaminants under various redox conditions remains unknown. This study examined the characterization of original metal-free peat humin (HM), and HM treated with varying concentrations of H₂O₂ and L-ascorbic acid (VC) (assigned as H₂O₂-HM and VC-HM). The concentration of PFRs in HM increased with the addition of VC/H₂O₂ at concentrations less than 0.08 M. The evolution of PFRs in HM under different environmental conditions (e.g., oxic/anoxic and humidity) was investigated. Two types of PFRs were detected in HM: a relatively stable radical existed in the original sample, and the other type, which was generated by redox treatments, was relatively unstable. The spin densities of VC/H₂O₂-HM readily returned to the original value under relatively high humidity and oxic conditions. During this process, the HM-associated “unstable” free radicals released an electron to O₂, inducing the formation of reactive oxygen species (ROS, i.e., ^•OH and ^•O₂⁻). The generated ROS promoted the degradation of polycyclic aromatic hydrocarbons based on the radical quenching measurements. The transformation rates followed the order naphthalene>phenanthrene>anthracene>benzo[a]pyrene. Our results provide valuable insight into the HM-induced transformation of organic contaminants under natural conditions.     

青藏高原东部过渡区水环境中全氟化合物的分布特征

为探究高原过渡区水环境中全氟化合物(perfluorinated compounds,PFCs)的污染状况,以青藏高原东部过渡区典型高山峡谷区、若尔盖草原湿地区为研究区,应用固相萃取结合高效液相色谱-电喷雾负电离源串联质谱的方法对研究区内的降雪样品、河水和草原湿地地表径流样品中的全氟化合物进行测定.降雪样品中平均∑PFCs浓度为6266 pg·L~(-1),共检出11种PFCs,其中PFBA含量最高,表明该地区的大气中存在着以PFBA为主的PFCs污染.河水样品中检测到7种PFCs,高山峡谷区河水样品中ΣPFCs浓度范围为272—2244 pg·L~(-1),若尔盖草原湿地区河水样品中ΣPFCs浓度范围为727—5149 pg·L~(-1),远低于我国东部地区及长江黄河下游区域.若尔盖草原湿地地表径流样品检测出11种PFCs,∑PFCs浓度范围为5837—13720 pg·L~(-1),高于当地河水中PFCs的浓度,表明地表径流是当地河水中PFCs不可忽略的非点源污染源.运用熵值法得到青藏高原东部过渡区河水中PFOA、PFOS及PFBA的风险值均远低于参考值,未达到对生态环境具有风险的水平.     

China’s industrial gray water footprint assessment and implications for investment in industrial wastewater treatment

Industrial wastewater is the largest contributor of toxic pollutants and third-largest contributor of nutrients to bodies of water in China, and understanding the characteristics of such pollution is important for water pollution control. In this study, the industrial gray water footprint (GWF) of each industry sector in China’s 31 provinces in 2015 was calculated to identify the pollution characteristics of industrial wastewater discharge and determine how to efficiently allocate investment to pollution reduction. We show that the total industrial GWF of China was 300 billion m³ in 2015 and that the major pollutants were petroleum pollutant (PP), ammonia nitrogen (NH₃-N), volatile phenol (VP), and chemical oxygen demand (COD). The water pollution level (WPL) was higher than 1 in Ningxia, Shanxi, Hebei, Tianjin, Shanghai, Henan, and Shandong, indicating that industrial pollution exceeded the carrying capacity of local water bodies in these seven regions. Given equivalent total investment, a scenario that takes the total reduction of the industrial GWF weighted by the WPL in each region as the investment target can better allocate funds to control industrial wastewater pollution in regions with high WPLs relative to a scenario in which investment targets the reduction of the unweighted total industrial GWF. For further industrial GWF reduction in regions with high WPLs, it is crucial to adjust the industrial structure and to upgrade relevant technologies.

     

基于Factsage的金属硫化矿尘爆炸过程产物分析*

为研究金属硫化矿尘爆炸的过程与产物,预防与控制其粉尘发生爆炸,在20 L爆炸球中开展金属硫化矿尘爆炸试验,发现存在磁黄铁矿含量越高爆炸产物颜色越红的现象。为揭示这一现象的本质,应用XRD对爆炸产物进行分析,基于Factsage软件模拟计算黄铁矿矿尘与磁黄铁矿矿尘爆炸过程。结果表明:产物中含有的Fe2O3是主要致色原因;最终产物除固体Fe2O3外还存在气体SO2,SO3,反应中间过程主要固体产物为Fe2(SO4)3;在磁黄铁矿与黄铁矿含硫量相同或质量相同时,Fe2O3的生成量磁黄铁矿较黄铁矿多,且磁黄铁矿含硫量越多Fe2O3生成量越多,模拟计算结果与试验现象一致,研究结果可为分析金属硫化矿尘爆炸过程提供理论与数据支撑。     

环境监测信息化建设的问题分析与对策建议

环境监测信息化是环境管理现代化的重要手段,信息化建设是监测现代化的重要组成部分。基于当前环境监测信息化建设的现状,分析了建设过程中经常存在的"信息孤岛"、系统失衡、进度延期等问题,提出了建设初期做好IT规划、实施阶段重视项目管理的对策和建议,并依据监测站的实践经验对实施要点加以阐述。解决好这些问题,将推动环境监测信息化建设工作更加高效合理地进行,提升监测信息化程度,对提高环境管理和环境决策的水平具有重要意义。     

Impact of Cloud on Net Ecosystem CO2 Exchange of Alpine Meadow in Tibetan Plateau

Meteorological elements and CO2 fluxes over alpine meadow ecosystem were observed continuously from 2004 to 2005in Damxung Alpine Meadow Flux Station,China Flux Network.Based on the eddy covariance CO2 fluxes and meteorological data obtained,the relationships among the CO2 fluxes,the cloud amount,and the meteorological factors in alpine meadow ecosystem were explored and analyzed.Some conclusions can be drawn from the discussion with previous researches as following:(1)the cloud amount can affect the net ecosystem CO2 exchange(NEE)of alpine meadow on Tibetan Plateau;(2)the soil temperature sensitive to the cloud amount,is a major environmental controlling factor for NEE,and closely relates to the maximum of NEE.In the morning period with large cloud amount,the NEE reaches its maximum when the clearness index ranges from 0.5 to 0.7; yet in the afternoon it comes to the maximum with the index from 0.2 to 0.35.The span of soil temperature covers from 12 to 15℃ as the NEE at its highest;(3)the scatterplots between NEE and photosynthetic available radiation(PAR)was a significant inverse triangle in the clear day,two different kinds of concave curves in the cloudy day,and strongly convergent rectangular hyperbola in the overcast day.These differences were controlled by the changes of light radiation and soil temperature.     

危险废物回转式流化冷渣多段焚烧系统焚烧特性研究

危险废物的处理和处置是摆在我国各级市政府面前的紧迫任务。然而我国已经运行的危险废物焚烧装置普遍存在回转窑挂壁结渣、热灼减率偏高和污染排放超标等问题,作者通过将回转窑和流化床特点相结合的方法提出了一种新型危险废物回转式流化冷渣多段焚烧处置装置。该装置采用回转窑(一燃室)、二燃室和流化床结合的热解-流化焚烧工艺,特别是采用控制窑头温度避免了回转窑挂壁结渣;采用流化冷渣装置延长未燃烬渣的焚烧时间,解决了热灼减率偏高问题;水冷式烟气急冷装置可以将烟气温度从1 100℃降到200℃,防止了二恶英的尾部低温再生成。该系统运行稳定可靠,可以处理医疗垃圾和大多数的固态和液态危险废物,实现了烟气污染物尤其是二恶英排放达到国家标准的目标。同时对该系统运行时窑头温度分布、二燃室炉膛出口氧量变化、回转窑和炉膛升温特性、燃烧室外壁温度分布等几方面运行数据都进行了详细的介绍,为危险废物焚烧炉的运行提供了宝贵的经验数据。     

餐厨垃圾中典型组分的裂解液化特征研究

利用实验室规模的实验装置管式加热炉进行餐厨垃圾热解实验,实验分析了反应温度对餐厨垃圾热解产物分布的影响,米饭、白菜、猪肉、塑料和纸5种原料在最佳温度下可实现热解油质量产率的最大化,分别为45.02%、24.55%、61.19%、73.77%和24.86%。其中,米饭和白菜热解油含水率较高,可达到30%~40%,将含水率降到15%后,测定热值分别为25.51 MJ/kg和17.75 MJ/kg。塑料和纸混合热解时,塑料热解过程的放热效应可缩小纸的热解温度区间,增加热解油产量。红外光谱分析厨余热解油包含多种含氧有机物。通过气质联用仪(GC-MS)分析塑料热解油和塑料与纸混合热解油在180℃以下蒸馏出的液相产物,主要组分为烷烃和烯烃,从成分和热值分析,与汽油、柴油相近。