城市污水处理选址决策及程序设计

在分析影响城市污水处理场选址的自然及经济因素的基础上,利用层次分析方法构造选址模型.讨论了决策方法及利用计算机进行排序的程序设计步骤,并在IBM-PC机上对实际问题进行了计算.     

Studies on the causes of forest decline in Nanshan,Chongqing

Nanshan is located in the south suburb of Chongqing, Sichuan province in China. It is about 10 km from the city of Chongqing. There are about 2000 ha of forest, mainly Masson pines (Pinus massoniana Lamb) which have exhibited decline since the beginning of the 1980s. Surveys of stands estimated that 85% of Masson pines are injured. Symptomology of Masson pines includes tip necrosis of needles, thin crown, reduced needle length, premature abscission, branch dieback, reduced radial growth. The foliage of broadleaf treesRobinia pseudoacacia L,Quercus dentata Thunb,Eucalyptus robusta Sm,Erythrina variegata var. orientalis (L) Merr,Faulownia fortunei (Seem) Hemsl,Rosa chinensis Jacq, also displayed necrotic lesions, both marginal and interveinous, most are brown or bleached. Foliage symptoms are similar to that produced in laboratory fumigation experiments with gaseous air pollutants SO₂ or HF. The foliage injury intensity is related to the distance from the city. Forest in some localities furthest from the city exhibit approximately normal growth.Three monitoring sites had been selected in Nanshan forest area. At two sites pine trees were severely damaged. At another site they showed little damage. Atmospheric SO₂ and fluoride concentrations had been examined. The average value of SO₂ and fluoride concentrations at the two former sites were much higher than that at the latter site. The injury intensity was consistent with an increase in the concentrations of SO₂ and fluoride. The sulphur and fluoride contents of tree leaves were also monitored. Sulphur contents of pine needles at the two former sites were generally more than that at the latter. The same tendency is observed in broadleaf trees. Higher levels of fluoride had been found in foliage of injured trees compared to unijured trees.Chongqing is also an acid rain region. The yearly average pH value of precipitation approaches to 4.0, and the frequency 100%. The pH values of acid rain at the three sites in Nanshan region are 4.17, 4.20, and 4.38 respectively. The difference is not significant. Also no significant difference in soil pH among the three sites is observed. It is suggested that acid rain and the acidification of soil are not implicated in the decline of Masson pines in Nanshan region.     

Monitoring atmospheric nitrous oxide background concentrations at Zhongshan Station, east Antarctica

At present,continuous observation data for atmospheric nitrous oxide(N_2O) concentrations are still lacking,especially in east Antarctica.In this paper,nitrous oxide background concentrations were measured at Zhongshan Station(69°22′25″S,76°22′14″E),east Antarctica during the period of 2008–2012,and their interannual and seasonal characteristics were analyzed and discussed.The mean N_2O concentration was 321.9 n L/L with the range of 320.5–324.8 n L/L during the five years,and it has been increasing at a rate of 0.29% year-1.Atmospheric N_2O concentrations showed a strong seasonal fluctuation during these five years.The concentrations appeared to follow a downtrend from spring to autumn,and then increased in winter.Generally the highest concentrations occurred in spring.This trend was very similar to that observed at other global observation sites.The overall N_2O concentration at the selected global sites showed an increasing annual trend,and the mean N_2O concentration in the Northern Hemisphere was slightly higher than that in the Southern Hemisphere.Our result could be representative of atmospheric N_2O background levels at the global scale.This study provided valuable data for atmospheric N_2O concentrations in east Antarctica,which is important to study on the relationships between N2 O emissions and climate change.     

区域次生环境风险评价方法研究

针对化工园区内各装置次生环境风险进行了系统研究,建立了一套区域次生风险识别方法,并且以成品油储罐区和7万吨苯抽提装置为例对研究区燃爆类风险源和泄漏类风险源分别进行次生环境风险分析,识别化工园区内对环境有潜在威胁的风险源,结果表明：有8个危险源存在次生风险事故,且对可能发生的次生事故类型进行分析,为化工园区的次生环境风险的监控和防范提供了依据。     

N2O emission from a combined ex-situ nitrification and in-situ denitrification bioreactor landfill

A combined process comprised of ex-situ nitrification in an aged refuse bioreactor (designated as A bioreactor) and in-situ denitrification in a fresh refuse bioreactor (designated as F bioreactor) was constructed for investigating N₂O emission during the stabilization of municipal solid waste (MSW). The results showed that N₂O concentration in the F bioreactor varied from undetectable to about 130 ppm, while it was much higher in the A bioreactor with the concentration varying from undetectable to about 900 ppm. The greatly differences of continuous monitoring of N₂O emission after leachate cross recirculation in each period were primarily attributed to the stabilization degree of MSW. Moreover, the variation of N₂O concentration was closely related to the leachate quality in both bioreactors and it was mainly affected by the COD and COD/TN ratio of leachate from the F bioreactor, as well as the DO, ORP, and NO₃^?-N of leachate from the A bioreactor.     

功率超声场作用下水溶液中甲苯的降解机理

研究密闭体系功率超声场中甲苯的超声降解过程,并探讨降解机理及反应历程.甲苯的降解效率受辐射时间影响较大,降解过程符合拟一级反应,通常处理40min后可以获得90%～95%的去除率,而溶液中饱和气体种类等也产生一定的影响.经pH、紫外和SMPE-GC-MS等分析,以及发光氨与自由基反应现象,证实甲苯的超声降解以自由基降解为主,主要中间降解产物为苯甲醛、联甲苯、邻苯二甲酸二丁脂等,最终产物为二氧化碳和水.     

Evaluation of accelerated dechlorination of p,p'-DDT in acidic paddy soil

The reductive dechlorination and behavior of p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) was investigated in a paddy soil. Treatment with 5% (w/w) metallic iron (Fe(0)) resulted in sharp decrease of p,p'-DDT, whereas there was no extra effect when 2% (w/w) aluminum sulfate (Al(2)(SO(4))(3)) was added to the Fe(0) treatment. These results suggest that Fe(0) could effectively promote the reductive dechlorination of p,p'-DDT and its metabolites while Al(2)(SO(4))(3) did not show any effect on those processes. Furthermore, p,p'-DDT and its daughter compounds inhibited holistic soil respiration greatly at first but could be metabolized by certain species of indigenous microorganisms after a period of adaptation time in the soil. When treated with Fe(0), the polluted soil produced much less CO(2) while the addition of Al(2)(SO(4))(3) counteracted its negative effect to much extent.     

国内外石油化工行业事故预警预防管理对比研究

介绍了发达国家在事故调查、分析、研究、预警和预防管理方面的先进做法,对比分析了我国石油化工行业在这些方面存在的差距,提出了针对性的建议措施。     

九龙江拟多甲藻水华预警和应急处置的初步研究

介绍了九龙江北溪及甲藻水华暴发的情况,根据国内外研究报道和九龙江北溪拟多甲藻水华暴发期间相关监测结果,拟定甲藻密度达到5×10^5个／L、叶绿素a含量〉15mg／m^3、pH〉7、D0〉8mg／L、高锰酸盐指数〉2．0mg／L为临界状态;甲藻密度达到1×10^6个／L、叶绿素a含量〉40mg／m^3、pH值接近8、D0〉9mg／L、高锰酸盐指数〉3．5mg／L为初步暴发状态;甲藻密度达到〉1×10^7个／L、叶绿素a含量〉85mg／m^3、pH〉8、D0〉10mg／L、高锰酸盐指数〉6．0mg／L为严重暴发状态。并结合当地的实际情况,对不同预警条件下应急响应和处置拟多甲藻水华的物理、化学和生物等具体措施进行初步研究。提出九龙江水系中封闭型水域可采取化学方法,支流水域可采用植物及化感技术和超声波方法,干流自来水厂采取围隔过滤和生态调水等方法应急处置拟多甲藻水华。     

城市突发事件的危机管理：挑战与对策

20多年的改革开放使我国国民经济得到了迅速发展，加入世界贸易组织、融入经济全球化的大潮又为我们带来了新的发展机遇，但是在发展的同时，在获得新机遇的时候，遭遇经济风险甚至经济危机的可能性也在不断加大。在城市突发事件管理上，只要政府建立起应急反应机制和完善的危机预警系统，完善处置危机的权威体制，动员社会参与危机救治，加强信息流通，增进社会认同，促进危机管理的法制化建设，就一定能确保我们在各种危机和突发事件面前处变不惊，控制局面，转危为安，最大限度地减少城市突发事件的伤害，最大可能地保护公众的安全，维护社会的安定。