Organic matter and concentrated nitrogen removal by shortcut nitrification and denitrification from mature municipal landfill leachate

An UASB＋Anoxic/Oxic （A/O） system was introduced to treat a mature landfill leachate with low carbon-to-nitrogen ratio and high ammonia concentration. To make the best use of the biodegradable COD in the leaehate, the denitrifieation of NOx^--N in the reeireulation effluent from the elarifier was carried out in the UASB. The results showed that most biodegradable organic matters were removed by the denitrifieation in the UASB. The NH4^＋-N loading rate （ALR） of A/O reactor and operational temperature was 0.28- 0.60 kg NH4^＋-N/（m^3-d） and 17-29℃ during experimental period, respectively. The short-cut nitrification with nitrite accumulation efficiency of 90%-99% was stabilized during the whole experiment. The NH4^＋-N removal efficiency varied between 90% and 100%. When ALR was less than 0.45 kg NH4^＋-N/（m^3.d）, the NH4^＋-N removal efficiency was more than 98%. With the influent NH4^＋-N of 1200-1800 mg/L, the effluent NH4^＋-N was less than 15 mg/L. The shortcut nitrification and denitrifieation can save 40% carbon source, with a highly efficient denitrifieation taking place in the UASB. When the ratio of the feed COD to feed NH4^＋-N was only 2-3, the total inorganic nitrogen （TIN） removal efficiency attained 67%-80%. Besides, the sludge samples from A/O reactor were analyzed using FISH. The FISH analysis revealed that ammonia oxidation bacteria （AOB） accounted for 4% of the total eubaeterial population, whereas nitrite oxidation bacteria （NOB） accounted only for 0.2% of the total eubaeterial population.     

Connotation and principles of ecological compensation in water source reserve areas based on the theory of externality

Understanding the connotation and principles of ecological compensation in water source reserve areas is the basis and guarantee for establishing and improving the ecological compensation mechanism of water source reserve areas. First, this paper reviews the three stages of ecological compensation research progress. Based on the review, using the theory of externality, the ecological environment system of water source reserve areas is then analyzed. This paper argues that the connotation of ecological compensation in water source reserve areas is a kind of institutional arrangement, which is designed to internalize externalities. Finally, based on the understanding of the connotation of ecological compensation in water source reserve areas, five principles for establishing and improving the ecological compensation mechanism are proposed, including the principle of fairness and justice, the principle of equivalence of equality and responsibility, the principle of flexibility and effectiveness, the principle of “earmark funds, and implementation by law,” and the principle of government compensation supplemented with market compensation.     

建设项目竣工环境保护验收监测在环境管理中的任务与对策

建设项目竣工环境保护验收监测对于落实“三同时”制度、实现总量控制目标、为环境监督管理提供重要技术支持具有重要意义与作用。目前,验收监测在管理体制、收费标准、成果应用等方面存在的突出问题,可通过创新管理机制、健全管理制度、提高管理水平等具体措施解决。     

江河水源地突发性水污染事故风险评价

近年来,我国江河饮用水水源地突发性水质污染事故频发,成为我国面临的最严重的环境问题之一.江河水源地突发性水质污染事件的风险评价是确保饮用水源地水质安全的重要手段,对突发性水质污染事故,采取适当的应急处理措施.     

中国21世纪城市供水新概念--分质供水

结合我国城市一直使用的统一给水方式已与当前水资源紧缺,用水多样化,人们饮用水质质化的状况极不适应的情况,提出对传统的给水方式进行改革的最适宜方式是分质供水。     

原子吸收光谱分析技术在环境,医学卫生和食品分析方面的应用

回顾了原子吸收光谱分析在我国环境、医学卫生和食品分析方面的应用概况。     

城市垃圾预处理改善焚烧特性的探讨

针对目前我国城市垃圾的高水分、低热值的特性,提出了2种改善城市垃圾焚烧特性的有效措施:生物质垃圾源分类和生物干燥.在我国建立生物质垃圾源分类体系,将生物质垃圾源头分类后,剩余垃圾的热值可以提高约50%～120%,已适合直接入炉焚烧,同时分离出来的生物质垃圾也更易于好氧堆肥或厌氧消化.另外一项技术措施是在焚烧前利用生物干燥技术,降低城市垃圾的水分含量,提高入炉垃圾的热值,这种方法主要是利用生物反应热来干燥城市生活垃圾,只需要在垃圾投入焚烧炉前增加一个预处理步骤,不必改变目前的垃圾收运体系,而且进行生物干燥后的垃圾更易于分选其中的可回收物质.     

A new approach to spatial source apportionment of haze pollution in large scale and its application in China

Long-lasting expansion of haze pollution in China has already presented a stern challenge to regional joint prevention and control. There is an urgent need to enlarge and reconstruct the coverage of joint prevention and control of air pollution in key area. Air quality models can identify and quantify the regional contribution of haze pollution and its key components with the help of numerical simulation, but it is difficult to be applied to larger spatial scale due to the complexity of model parameters. The time series analysis can recognize the existence of spatial interaction of haze pollution between cities, but it has not yet been used to further identify the spatial sources of haze pollution in large scale. Using econometric framework of time series analysis, this paper developed a new approach to perform spatial source apportionment. We applied this approach to calculate the contribution from spatial sources of haze pollution in China, using the monitoring data of particulate matter (PM_2.5) across 161 Chinese cities. This approach overcame the limitation of numerical simulation that the model complexity increases at excess with the expansion of sample range, and could effectively deal with severe large-scale haze episodes.     

Optimization-Based Atmospheric Plume Source Identification

This work applies optimization and an Eulerian inversion approach presented by Bagtzoglou and Baun in 2005 in order to reconstruct contaminant plume time histories and to identify the likely source of atmospheric contamination using data from a real test site for the first time. Present-day distribution of an atmospheric contaminant plume as well as data points reflecting the plume history allow the reconstruction and provide the plume velocity, distribution, and probable source. The method was tested to a hypothetical case and with data from the Forest Atmosphere Transfer and Storage (FACTS) experiment in the Duke experimental forest site. In the scenarios presented herein, as well as in numerous cases tested for verification purposes, the model conserved mass, successfully located the peak of the plume, and managed to capture the motion of the plume well but underestimated the contaminant peak.     

Evaluating anthropogenic N inputs to diverse lake basins: A case study of three Chinese lakes

The environmental degradation of lakes in China has become increasingly serious over the last 30 years and eutrophication resulting from enhanced nutrient inputs is considered a top threat. In this study, a quasi-mass balance method, net anthropogenic N inputs (NANI), was introduced to assess the human influence on N input into three typical Chinese lake basins. The resultant NANI exceeded 10 000 kg N km⁻² year⁻¹ for all three basins, and mineral fertilizers were generally the largest sources. However, rapid urbanization and shrinking agricultural production capability may significantly increase N inputs from food and feed imports. Higher percentages of NANI were observed to be exported at urban river outlets, suggesting the acceleration of NANI transfer to rivers by urbanization. Over the last decade, the N inputs have declined in the basins dominated by the fertilizer use but have increased in the basins dominated by the food and feed import. In the foreseeable future, urban areas may arise as new hotspots for nitrogen in China while fertilizer use may decline in importance in areas of high population density.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0638-8) contains supplementary material, which is available to authorized users.