降低污水处理能耗的对策

本文以仙女河污水处理厂近年来为节能降耗所做的几项改造项目为例,阐述了污水处理厂将设备改造与节能降耗的有机结合,证明可以在确保出水水质达标的前提下做到合理低成本运行.     

Regional efforts to mitigate climate change in China: a multi-criteria assessment approach

The task of mitigating climate change is usually allocated through administrative regions in China. In order to put pressure on regions that perform poorly in mitigating climate changes and highlight regions with best-practice climate policies, this study explored a method to assess regional efforts on climate change mitigation at the sub-national level. A climate change mitigation index (CCMI) was developed with 15 objective indicators, which were divided into four categories, namely, emissions, efficiency, non-fossil energy, and climate policy. The indicators’ current level and recent development were measured for the first three categories. The index was applied to assess China’s provincial performance in climate protection based on the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method. Empirical results show that the middle Yangtze River area and southern coastal area perform better than other areas in mitigating climate change. The average performance of the northwest area in China is the worst. In addition, climate change mitigation performance has a negative linear correlation with energy self-sufficiency ratio but does not have a significant linear correlation with social development level. Therefore, regional resource endowments had better be paid much more attention in terms of mitigating climate change because regions with good resource endowments in China tend to perform poorly.     

Effect of scale on flame speeds of methane-air

Explosions are the main types of accidents causing casualties in underground coal mines. Research on the mechanisms of gas explosions is needed as a basis for the development of techniques and strategies for explosion prevention, suppression, and mitigation. The prevention of loss in explosion accidents and inquiries into their causes require understanding of the explosion process of methane in air. Because of the high cost and safety issues in full scale experiments, the experiments with small scale ducts have become a key alternative approach. Whether the experimental results at small scales agree with those at full scales needs to be investigated to validate the significance of the experimental results at small scale. Numerical simulation was used to obtain the explosion characteristics of a methane-air mixture in a gallery or duct. If the grid size is too fine in the numerical simulation for a methane-air explosion it is difficult to calculate using the present computer resource. If the grid size is too coarse, the considerable error may result. The effect of grid size on results of calculation depends on the scenario being investigated. The effect of grid sizes on simulation accuracy was analyzed in this work. The overpressure and temperature distributions and the flame propagation for the deflagration of methane-air mixtures in a gallery or duct were obtained by the AutoReaGas code at three different scales. The geometry of investigated objects and the grids in the calculation domain were similar in the three cases. The calculated overpressures vary with the scale. The calculated temperatures do not vary with the scale for the three cases.     

Confronting two-sex demographic models with data

Most population dynamics models explicitly track the density of a single sex. When the operational sex ratio can vary, two-sex models may be needed to understand and predict population trajectories. Various functions have been proposed to describe the relative contributions of females and males to recruitment, and these functions can differ qualitatively in the patterns that they generate. Which mating function best describes the dynamics of real populations is not known, since alternative two-sex models have not been confronted with experimental data. We conducted the first such comparison, using laboratory populations of the bean beetle Callosobruchus maculatus. Manipulations of the operational sex ratio and total density provided strong support for a demographic model in which the birth rate was proportional to the harmonic mean of female and male densities, and females, males, and their offspring made unique contributions to density dependence. We offer guidelines for transferring this approach to other, less tractable systems in which possibilities for sex ratio manipulations are more limited. We show that informative experimental designs require strong perturbations of the operational sex ratio. The functional form of density dependence (saturating vs. over-compensatory) and the relative contributions of each sex to density dependence can both determine in which direction and at which population densities such perturbations would be most informative. Our experimental results and guidelines for design strategies promote synthesis of two-sex population dynamics theory with empirical data.     

Preparation of amphiphilic composite and removal of oil and hexavalent chromium from wastewater

A new composite for water treatment was prepared by melt blend for oil and hexavalent chromium absorption. Ethylene Propylene Diene Monomer (EPDM) was the matrix, calcinatory Fe₂O₃ and anion-exchange resin 201×7 were the fillers. This composite can suspend in water–oil contact (WOC) and absorb oils and hexavalent chromium in wastewater simultaneously. The absorbencies of composites changed greatly with various ratios of calcinatory Fe₂O₃ and anion-exchange resin 201×7. The results showed that the oil absorbencies increased continuously and hexavalent chromium absorbencies were step-down as calcinatory Fe₂O₃ loadings from 13 to 19%. The composite can adsorb oils and hexavalent chromium simultaneously. The optimized proportion of calcinatory Fe₂O₃ and anion-exchange resin 201×7 in composite was found when the absorbencies of oils and hexavalent chromium reaching the maximum simultaneously. This composite is an inexpensive, convenient and high efficiency material for removing oils and hexavalent chromium from wastewater.     

烟草凋萎叶早期腐解液对莴苣的化感作用

为了研究烟草凋萎叶早期腐解液及其不同组分的化感作用,以对化感物质具有高敏感性的莴苣(Lactuca sativa)为指示材料,对烟草品种K326凋萎叶早期腐解液及其分离后的各组分分别进行了化感潜力的生物测定.结果表明:1)早期腐解液及其组分随处理浓度的增大对莴苣种子萌发的抑制效应逐渐增强,且显著降低了种子萌发速率,并延...     

A preliminary study on the occurrence and behavior of carbamazepine (CBZ) in aquatic environment of Yangtze River Delta, China

The occurrence and behavior of carbamazepine (CBZ) was investigated in aquatic environment of Yangtze River Delta, East China. The water samples were enriched by solid-phase extraction and analyzed by high-performance liquid chromatography with diode array detector. The validation of the analytical method included linearity (0.1?C1 mg/L), recovery studies, and determination of limits of quantification. Limits of quantification of CBZ in various aquatic samples were in the range of 0.1?C0.2 ??g/L. CBZ was detected in the Tongji University Intramural River, the Huangpu River, and the Suzhou River with the highest concentration of 1,090 ng/L, but not detected in the Nanhengyin River and the Caojia River. In sewage water samples, CBZ was not detected in one of the sewage treatment plants (STPs) but was detected in the raw influents and effluents at the other three selected STPs in Shanghai, with the concentrations ranging from 230 to 1,110 ng/L. CBZ was not completely eliminated after secondary treatment (with the active sludge process).     

广西全州县广坑漕山体滑坡成因分析

通过对广西全州县广坑漕滑坡现场勘查,结合气象观测资料综合分析,表明广坑漕山体滑坡的主要原因是:①地质环境受人为工程破坏,山体两侧有新旧采石场存在;②滑坡点是迎风坡地形,有利强降水发生;③滑坡前当地长时间降水少,干旱导致土质疏松,后期天气转折,出现持续降水,土壤经浸泡迅速软化;④南亚季风急流突发性增大,在桂北喇叭口地形迎风坡产生剧烈上升运动,并与高空槽过境相遇造成对流性暴雨,水压力及山体自重量同时增大,导致坡体突然失稳,引发滑坡。     

High-efficient removal of U(VI) from aqueous solution by self-assembly pomelo peel/palygorskite composite

Environmental Science and Pollution Research - The efficient separation of low-concentration radionuclides by the eco-friendly adsorbent is a compelling requirement in the development of nuclear...     

Sensorized waste collection container for content estimation and collection optimization

The concurrent effects of a fast national growth rate, of a large and dense residential area and a pressing demand for urban environmental protection create a challenging framework for waste management in Pudong New Area, Shanghai. The complexity of context and procedures is indeed a primary concern of local municipal authorities due to problems related to the collection, transportation and processing of residential solid waste. In order to design and implement a suitable urban solid waste system, the first task is to forecast the quantity and variance of solid waste as it relates to residential population, consumer index, season, etc. The system here discussed addresses exactly these issues, by means of an intelligent, sensorized container. The container has been prepared and tested in the Pudong New Area, Shanghai.