Analysis of the recycling system for aluminum cans,focusing on collection,transportation, and the intermediate processing methods

In this article, the systems for the collection and intermediate processing of used beverage cans (UBCs) are compared and analyzed, focusing on the time taken and the cost of processing, the energy consumption, and the emissions of CO₂, SO _x , and NO _x , during the process. We found that cases where the UBCs were crushed in the discharging process gave better results, and how the UBCs were collected was the most important factor. It was more desirable to treat UBCs in one place than in two places. When the transportation distance was longer, the pressed form of UBCs was more convenient. When the transportation distance was short, the original form, the crushed form, and the shredded form of UBCs were all suitable. That is, the contribution of the transportation process to the evaluation was large when the transport distance was long, and the contribution of the treatment process was large when the transport distance was short.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans from food salt samples processed by heat treatment in Korea

Eight samples of processed food salt collected from five plants in Korea were analyzed for 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) using liquid-liquid extraction, clean-up procedures, and high resolution gas chromatography-high resolution mass spectrometry. The study included the analyses of two kinds of salt product sample: bamboo-salt and parched salt. The levels of toxic PCDD/Fs found in the salt product samples were extremely low: the results revealed TEQ levels ranging between the sub pg TEQ/g and sub fg TEQ/g. The differences in the TEQ values of toxic PCDD/F were observed between the salt product samples, which were treated with different frequency of baking using four different fuels (firewood, pine wood, pine resin, and indirect heating by gas) at temperatures from 300 to 2000 degrees C. In bamboo-salt samples, the concentrations and TEQ values of toxic PCDD/Fs ranged between 0.57-66 pg/g and 5.7x10(-5)-0.64 pg TEQ/g, respectively. PCDD/Fs levels in bamboo-salts baked by firewood were found to be higher than those baked by pinewood or pine resin. In parched salt samples, the concentrations and TEQ values of toxic PCDD/Fs ranged between 0.97-3.7 pg/g and 0.0097-0.017 pg TEQ/g, respectively. The data was discussed regarding the concentration and the distribution pattern of congeners.     

对我国水资源可持续利用的一点思考

按照“认识——规划——建设”的思路,分析了我国水资源开发利用中所面临的主要问题和挑战,提出水资源可持续开发利用的策略和对策,特别提出分质供水和中水回用相结合的供水方式,作出了各地区重点建设项目的构想。     

景观生态学在建设项目生态环境影响评价中的应用

景观生态学目前是国家环境保护总局《非污染生态影响评价技术导则》引入的概念框架和理论方法。本文通过景观生态学在不同性质建设项目中的运用分析,进行了一定的尝试,更加希望在今后建设项目生态环境影响评价工作中得到修正和完善。     

Lead phytoextraction from contaminated soil with high-biomass plant species

In this study, cabbage [Brassica rapa L. subsp. chinensis (L.) Hanelt cv. Xinza No 1], mung bean [Vigna radiata (L.) R. Wilczek var. radiata cv. VC-3762], and wheat (Triticum aestivum L. cv. Altas 66) were grown in Pb-contaminated soils. Application of ethylenediaminetetraacetic acid (EDTA) (3.0 mmol of EDTA/kg soil) to the soil significantly increased the concentrations of Pb in the shoots and roots of all the plants. Lead concentrations in the cabbage shoots reached 5010 and 4620 mg/kg dry matter on Days 7 and 14 after EDTA application, respectively. EDTA was the best in solubilizing soil-bound Pb and enhancing Pb accumulation in the cabbage shoots among various chelates (EDTA, diethylenetriaminepentaacetic acid [DTPA], hydroxyethylenediaminetriacetic acid [HEDTA], nitrilotriacetic acid [NTA], and citric acid). Results of the sequential chemical extraction of soil samples showed that the Pb concentrations in the carbonate-specifically adsorbed and Fe-Mn oxide phases were significantly decreased after EDTA treatment. The results indicated that EDTA solubilized Pb mainly from these two phases in the soil. The relative efficiency of EDTA enhancing Pb accumulation in shoots (defined as the ratio of shoot Pb concentration to EDTA concentration applied) was highest when 1.5 or 3.0 mmol EDTA/kg soil was used. Application of EDTA in three separate doses was most effective in enhancing the accumulation of Pb in cabbage shoots and decreased mobility of Pb in soil compared with one- and two-dose application methods. This approach could help to minimize the amount of chelate applied in the field and to reduce the potential risk of soluble Pb movement into ground water.     

合肥"10·28"特大爆炸事故分析

本文对合肥"10·28"特大爆炸事故进行了分析,确定了本次爆炸事故的爆炸位置和类型,分析了爆炸混合气体来源及本次爆炸的特点.提出了今后为防止类似爆炸事故的发生,在设计规范标准、设计布置、施工和日常管理中应注意的问题.     

人工神经网络方法在资源与环境预测方面的应用

用人工神经网络方法对不同水域、不同环境因子之间非线性和不确定性的复杂关系进行学习训练并预测检验。结果表明：人工神经网络方法在模拟和预测方面 优于传统的统计回归模型,在资源与环境方面的应用是可行的。具有较强的模拟预测能力。与传统的回归模型相比,人工神经网络方法不要求监测数据具有很强的规律性,就可用后的网络模型对其进行预报,燕且预测相对误差均比回归模型预测相对误差要小,具有一定的实用性。两个实例的应用     

用配合饲料饲喂乌梢蛇的试验研究

试验选用的乌梢蛇均为亚成蛇，平均体重291．79g。试验分2组进行，试验期45d。对照组用活饵投喂，处理组全程均用配合饲料人工填喂。活饵为泽蛙，人工饵料用鱼肉、明胶、添加剂等配成（粒度规格1—1．5cm^3）。各组饲养条件相同，试验结束时逐组逐个测量体重、体长、尾长，并计算存活率。试验结果表明，人工饵料组的增重、体长、尾长好于对照组，但人工饵料组的存活率低于对照组。     

表面过滤技术在焚烧厂烟气脱酸净化中的作用

随着城市垃圾焚烧工程的发展，国家对焚烧后尾气的处理技术提出了越来越高的要求。基于“表面过滤”理论的Gore过滤技术，不但为粉尘排放达到欧洲标准提供了技术保障，而且为脱酸／硫的后续反应提供了反应界面，在实际应用中可以有效节约反应剂。     

Exposure Programme on Atmospheric Corrosion Effects of Acidifying Pollutants in Tropical and Subtropical Climates

Many national exposure programmes have been performed in tropical and subtropical climates during the last 50 years. However, ambitious programmes involving more than a few countries are scarce. In this paper a recently formed network of test sites is described involving 12 test sites in Asia (India, Vietnam, Thailand, Malaysia and China including Hong Kong) and four test sites in Africa (South Africa, Zambia and Zimbabwe). This effort is part of the 2001–2004 Swedish International Development Agency (SIDA) funded Programme on Regional Air Pollution in Developing Countries (RAPIDC). Corrosion attack after one (2002–2003) year of exposure (carbon steel, zinc, copper, limestone and paint coated steel) are presented together with environmental data (SO₂, NO₂, HNO₃, O₃, particles, amount and pH of precipitation, temperature and relative humidity) for all the test sites. The obtained corrosion values are substantially higher than expected for limestone, higher than expected for carbon steel and lower than expected for zinc compared to values calculated using the best available dose–response functions.