Estimation methods and monitoring network issues in the quantitative estimation of land-based COD and TN loads entering the sea: a case study in Qingdao City,China

At present, the monitoring network of China cannot provide sufficient data to estimate land-based pollutant loads that enter the sea, and estimation methods are imprecisely used. In this study, the selection of monitoring stations, monitoring frequency, and pollutant load estimation methods was studied in Qingdao City, a typical coastal city in China, taken as an example. Land-based pollutant loads from Qingdao were estimated, and load distribution, density, and composition were analyzed to identify the key pollution source regions (SRs) that need to be monitored and controlled. Results show that the administrative land area of Qingdao can be divided into 25 sea-sink source regions (SSRs). A total of 14 more rivers and 62 industrial enterprises should be monitored to determine the comprehensive pollutant loads of the city. Furthermore, the monitoring frequency of rivers should not be less than three times/year; a monitoring frequency of five or more times is preferable. The findings on pollutant load estimation with the use of different estimation methods substantially vary; estimation results with the use of ratio-based methods were 10 and 22 % higher than those with the use of monitoring-based methods in terms of chemical oxygen demand (COD) and total nitrogen (TN), respectively. None-point sources contributed the majority of the pollutant loads at about 70 % of the total COD and 60 % of the total TN.     

Emissions of reduced sulphur compounds from the surface of primary and secondary wastewater clarifiers at a Kraft Mill

Emissions of reduced sulphur compounds (RSCs) from the primary and secondary clarifiers at a Kraft mill were measured for respectively 8 and 22 days using a floating flux chamber. In the primary clarifier, dimethyl disulphide (DMDS) had the highest mean flux (0.83 microg s(-1) m(-2)) among all RSCs, and the mean flux of total reduced sulphur (TRS) was 1.53 microg s(-1) m(-2). At the secondary clarifier, dimethyl sulphide (DMS) had the highest mean flux (0.024 microg s(-1) m(-2)), and the mean flux of total reduced sulphur (TRS) was 0.025 microg s(-1) m(-2). Large variations in fluxes as a function of sampling date were observed in both clarifiers. Emission fluxes of DMS from the secondary clarifier were correlated with temperature in the flux chamber and with the biological and chemical oxygen demands (BOD and COD) of the wastewater. Emission rates of RSCs from the clarifiers were found to be insignificant by comparison with other mill sources.     

社区防灾减灾资源评价体系探讨

社区是社会的细胞,是城市的基础组成部分,完善城市公共防灾减灾系统,必须从社区着手。通过对城市社区的分类介绍,对社区内常见公共防灾减灾资源进行了归纳分析,总结出社区防灾减灾资源与社区常见灾害事故的应对关系,构建了社区防灾减灾资源评价体系,并且利用层次分析法和专家打分,确立了各个评价指标的分值及权重系数,还对单项灾害防治资源进行评价打分,在此基础上提出了防灾减灾资源总体评价算法。     

Removal of nitric oxide in a biotrickling filter under thermophilic condition using Chelatococcus daeguensis

The development of a thermophilic biotrickling filter (BTF) system to inoculate a newly isolated strain of Chelatococcus daeguensis TAD1 for the effective treatment of nitric oxide (NO) is described. A bench-scale BTF was run under high concentrations of NO and 8% O2 in thermophilic aerobic environment. A novel aerobic denitrifier Chelatococcus daeguensis TAD1 was isolated from the biofilm of an on-site biotrickling filter and it showed a denitrifying capability of 96.1% nitrate removal rate in a 24 h period in aerobic environment at 50 degrees C, with no nitrite accumulation. The inlet NO concentration fluctuated between approximately 133.9 and 669.6 mg m-3 and kept on a steady NOx removal rate above 80% in an oxygen stream of 8%. The BTF system was able to consistently remove 80-93.7% NO when the inlet NO was 535.7 mg m-3 in an oxygen stream of 2-20%. The biological removal efficiency of NO at 50 degrees C is higher than that at 25 degrees C, suggesting that the aerobic denitrifier TAD1 display well denitrification performance under thermophilic condition. Starvation for 2, 4 and 8 days resulted in the re-acclimation times of Chelatococcus daeguensis TAD1 ranging between 4 and 16 hours. A longer recovery time than that for weekend shutdown will be required when a longer starvation occurs. The results presented here demonstrate the feasibility of biotrickling filter for the thermophilic removal of NOx from gas streams. Implications: A novel denitrifier Chelatococcus daeguensis TAD1 was isolated from an on-site biotrickling filter in aerobic environment at 50 degrees C. To date, C. daeguensis has not been previously reported to be an aerobic denitrifier. In this study, a thermophilic biotrickling filter system inoculated with Chelatococcus daeguensis TADI for treatment of nitric oxide is developed. In coal-fired power plants, influent flue gas stream for nitrogen oxides (NOx) removal typically exhibit temperatures between 50 and 60 degrees C. Traditionally, cooling gases to below 40 degrees C prior to biological treatment is inevitable, which is costly. Therefore, the application ofthermophilic microorganisms for the removal of nitric oxide (NO) at this temperature range would offer great savings and would greatly extend the applicability ofbiofilters and biotrickling filters. Until now there has not been any study published about thermophilic biological treatment of NO under aerobic condition.     

The scale-free network behavior of ambient volatile organic compounds

A scale-free network model with surface and vertical field measurements was used to identify the connectivity distribution of the scale-free network behavior of ambient volatile organic compounds (VOCs). The results show that the carbon number (C _n ) with the total amount of C _n compounds (P(C _n )) possesses an explicit relationship with the scale-free network behavior. The proportionate coefficient (α) and exponent ( γ) of the scale-free network model with spatial and temporal variations are estimated and discussed. The analytical results demonstrate that although photochemical reactions cause the VOCs fraction variation, they do not alter the fraction of C _n compounds observably. Therefore, the values of α and of γ did not vary with time, but with local regional characteristics. The results indicate that the influence of local VOCs emissions occurs at a height of 100 m, but becomes insufficient at a height of 300 m. Air mass mixing increases with greater height; thus, the influence of regional characteristics at a height of 700 m is low. Finally, a successful empirical model was established to evaluate the distribution of surface VOCs in various regions.     

Bioaccumulation, depuration and biotransformation of 4,4'-dibromodiphenyl ether in crucian carp (Carassius auratus)

Polybrominated diphenyl ethers (PBDEs) are extensively used as a class of flame retardants and have become ubiquitous environmental pollutants. Significant biotransformation of some PBDEs via reductive debromination has been observed. However, little is known about the fate of lower brominated BDEs in fish. In this study, the tissue distribution, excretion, depuration and biotransformation of 4,4′-dibromodiphenyl ether (BDE 15) were investigated in crucian carp (Carassius auratus) which were exposed to spiked water solution at different concentrations for 50 d, followed by a 14-d depuration period. Bioaccumulation parameters were calculated and the results showed that BDE 15 was mainly concentrated in the gill and liver. In particular, five biotransformation products of BDE 15 in carp were identified using GC-MS/MS. Besides two debrominated metabolites, three of the metabolites were mono-OH-BDE 15, diOH-BDE 15 and bromophenol. Our results unequivocally suggested that BDE 15 oxidation did occur via the formation of hydroxylated (OH-) metabolites in crucian carp exposed in vivo. These findings will be useful for determination of the metabolic pathways of PBDEs in freshwater fish, especially about their oxidation metabolism.     

基于演化博弈的流域生态补偿利益冲突分析

资源合理利用与环境保护是维护当今经济平稳、健康、较快发展的重要前提。生态补偿是缓解经济快速发展与环境污染、生态环境破坏之间利益矛盾冲突的重要手段。它是为了制止生态破坏而征收或补偿的费用,所以不同于一般排污费和资源补偿费。本文根据补偿的类型不同,将生态补偿分为资源型生态补偿和环境型生态补偿。本文以流域生态补偿为例,将流域上游政府的策略简化为保护或不保护河流,下游政府针对上游的情况,选择"自主型"或"接受型",运用演化博弈的方法,分析流域生态补偿的特点和结果。结果表明:流域生态补偿需要中央政府的适度干预,而且关键点是保证上游地方政府收益始终最大化;中央政府干预的程度是使上游政府群的收益在保护的情况下比不保护的收益要大,而干预的结果则是使流域上下游的(保护,补偿)策略成为演化博弈的长期稳定均衡。最后本文针对我国现行流域管理体制,为我国流域生态补偿提供了政策建议,以推广我国生态补偿政策。     

Effects of basin topography and monsoon conditions on transport and occurrence of atmospheric PCDD/Fs in the Taichung Basin

Background, aim, and scope  

Topographical and meteorological factors, such as monsoons, can drastically affect ambient dioxin levels. In order to better understand these phenomena, four sampling lines (comprising 16 sampling sites) were selected in accordance with the topographical characteristics and the transport paths of the Taichung Basin.     

造纸废水灌溉对黄河三角洲退化湿地可培养土壤微生物的影响

利用造纸废水恢复重度退化湿地,分析了土壤微生物数量、土壤呼吸强度及微生物量碳的变化情况。结果表明,灌溉后,8月份,细菌和真菌数量最多,放线菌5月份数量最多;细菌、真菌、放线菌各灌水深度上层大于中层,各灌水深度、细菌、真菌、放线菌上层数量均大于对照;土壤呼吸主要发生在表层（0~20 cm）;8月份,微生物量碳达到最大值690.3 mg/kg,且上中下层依次递减。相关分析表明,15 cm灌水量,土壤呼吸强度与有机碳呈极显著正相关（r=0.996,P=0.0036）,灌水量为0、5、10和20 cm,土壤微生物量碳与有机碳呈极显著正相关(r=0.999,0.999,0.999;P<0.001),15 cm灌水量,微生物量碳与速效磷呈极显著正相关（r=0.972,P=0.028）;5 cm灌水量,微生物总数与有机碳呈显著线性正相关（r=0.953,P=0.047）,对照和15 cm灌水量,微生物总数与速效磷呈显著正相关（r=0.976,P=0.024;r=0.968;P=0.032）。灌溉处理后的造纸废水,可增加重度退化湿地土壤微生物的活性,改善土壤质量。     

中国自然资源政策演进历程与发展方向

自然资源政策是国家政策体系的重要组成部分,其社会关注度、复杂性、地区差异性等特征较为突出.1980年代以来,中国自然资源政策大致经历了上世纪80年代、1991-1997、1998-2003、2004 - 2010等四个阶段的演进,期间,社会经济发展形势不断发展变化,自然资源政策的需求和目标也不断变化,并为社会经济快速发展提供了政策基础;但同时也在政策一致性、政策权威性、政策公正性、政策认知性等方面,暴露出一些不足和缺憾.自2011年开始,资源政策的演进进入了第五个阶段.展望未来,为全面落实科学发展观和加快转变经济发展方式,中国自然资源政策应不断创新,重点在政府规制、全面负责、促进转型、系统协调和差异设计等方面不断优化和发展.