高炉共处置固体废物低温段Pb Cd的吸附/冷凝动力学特征

利用管式回转炉和控温立式炉联用装置模拟炼铁高炉,对Pb、Cd在共处置过程中低温段的吸附/冷凝特性进行了研究,通过建立吸附/冷凝动力学模型,分析共处置过程中Pb、Cd在非热力学平衡状态下的迁移转化规律.结果表明:高炉共处置固体废物低温段对Pb、Cd的吸附/冷凝作用以冷凝为主.进入控温立式炉的重金属去向分三部分:①冷凝在管壁上,这部分的Pb、Cd分别占Pb、Cd入炉总量的42%～49%、45%～50%;②吸附在炉料上,其中Pb、Cd分别占各自入炉总量的23%～26%、23%～25%;③随烟气释放到空气中,这部分Pb、Cd分别占各自入炉总量的25%～35%、25%～32%.Pb、Cd在炼铁炉料上的吸附/冷凝量均随时间的增加而升高,随温度的升高而降低.炼铁炉料对Pb、Cd的吸附/冷凝动力学可采用双常数速率方程拟合,研究得到Pb、Cd的吸附/冷凝表观活化能分别为6.813、5.839 kJ/mol.      

Case Study Comparing Multiple Irrigated Land Datasets in Arizona and Colorado,USA

While there are currently a number of irrigated land datasets available for the western United States (U.S.), there is uncertainty regarding in how they relate to each other. To help understand the characteristics of available irrigated datasets, we compared (1) the Cropland Data Layer (CDL), (2) Moderate Resolution Imaging Spectroradiometer Irrigated Agriculture Dataset (IAD), (3) Digitized Irrigated Land (DIL), and (4) Consumptive Use for Irrigation (CUI) data in Arizona and Colorado, U.S. These datasets were derived from multiple sources at various spatial resolutions and temporal scales. We found spatial and temporal trends among all of them. The datasets showed decreases in irrigated land area in Arizona during the 2000–2010 time period. The change ranges and ratios were similar in all Arizona datasets. Irrigated land in Colorado decreased in DIL and CUI but increased in IAD and CDL. The agreement within the same type of dataset during different time periods was from 60% to 80% (R² from 0.35 to 0.72) in Arizona and from 50% to 80% (R² from 0.23 to 0.68) in Colorado. DIL had the highest agreement (80%) in both states. The agreement among different datasets acquired at approximately the same time frame ranged from 51% to 63% (R² from 0.14 to 0.31) in Arizona and from 47% to 69% (R² from 0.32 to 0.40) in Colorado. The results from this study support a greater understanding of the multiresolution and multitemporal nature of these datasets for various applications.     

How China’s current energy pricing mechanisms will impact its marginal carbon abatement costs?

Economic and social costs and benefits are critical factors affecting greenhouse gas abatement activities. Recognizing that energy prices are one of the most important factors influencing abatement costs, this study improved the basic China Energy and Environmental Policy Analysis (CEEPA) model by introducing a current energy pricing mechanism for China. The improved model was applied to generate marginal abatement cost (MAC) curves for China including the current energy pricing mechanism and to analyze MACs for the whole country and main abatement sectors in China under different energy pricing mechanisms. The results show that China MACs are sensitive to pricing mechanisms for electricity and refined oil. Ignoring the current regulation of these prices will lead to MAC underestimation, and price liberalization of these two energy sources could lead to a decrease in China MACs. Under a 50 % emission reduction target, if the electricity price regulation is ignored, the China MAC is underestimated by almost 16 %. Energy pricing reforms will lead to variations in sectoral abatement costs and overall abatement potential, and these impacts are projected to be large in the electricity sector. Under a 50 % reduction target, if the electricity price regulation is liberalized, MAC for the electricity sector nearly will decrease 50 %.     

含硫废水受控氧化及单质硫团聚过程研究

采用过氧化氢在常温常压下对模拟含硫废水进行受控氧化,探讨了受控氧化过程对单质硫收率的影响,并对氧化过程中固相产物的形态特性进行了研究.结果表明,在过氧化氢投加量为9 m L·L-1、初始p H为6、反应时间为10min条件下,将反应体系氧化还原电位(ORP)控制在(30±5)m V时能较好实现含硫废水的受控氧化,此时单质硫收率达76.35%,当体系ORP由(-50±5)m V升高至(50±5)m V时,副产物S2O2-3收率显著下降,由26.54%下降至5.32%.X射线衍射分析表明,氧化过程中的固相产物主要为正交晶系斜方硫;扫描电子显微镜分析表明,液相中的单质硫由多个极小的颗粒聚集而成,其粒径由纳米级逐渐增大至微米级.同时,通过向反应体系中加入分散剂证明了单质硫颗粒增大的主要原因是颗粒间发生了团聚.     

Distribution and mode of occurrence of uranium in bottom ash derived from high-germanium coals

The radioactivity of uranium in radioactive coal bottom ash(CBA) may be a potential danger to the ambient environment and human health. Concerning the limited research on the distribution and mode of occurrence of uranium in CBA, we herein report our investigations into this topic using a number of techniques including a five-step Tessier sequential extraction, hydrogen fluoride(HF) leaching, Siroquant(Rietveld) quantification, magnetic separation, and electron probe microanalysis(EPMA). The Tessier sequential extraction showed that the uranium in the residual and Fe–Mn oxide fractions was dominant(59.1%and 34.9%, respectively). The former was mainly incorporated into aluminosilicates,retained with glass and cristobalite, whereas the latter was especially enriched in the magnetic fraction, of which about 50% was present with magnetite(Fe_3O_4) and the rest in other iron oxides. In addition, the uranium in the magnetic fraction was 2.6 times that in the non-magnetic fraction. The experimental findings in this work may be important for establishing an effective strategy to reduce radioactivity from CBA for the protection of our local environment.     

海洋底栖硅藻胞外多聚物化学成分的定量研究

海洋底栖硅藻通过分泌胞外多聚物（Extracellular polymeric substance,EPS）实现滑行运动和附着。为探查不同生长期硅藻EPS的变化,以及同一生长期不同硅藻EPS的异同,本文以单个细胞分泌的EPS为考量依据,进行了定量分析。采用热溶剂浸提法对海洋底栖硅藻EPS的水溶性和水不溶性组分进行提取;利用苯酚-硫酸法定量提取液中的多糖,利用考马斯亮蓝G-250法定量蛋白质。结果表明,不同生长期的羽状舟形藻（Navicula pinna）,随着细胞密度增大,EPS中多糖和蛋白质的分泌量减少,且多糖和蛋白质含量存在差异,表明EPS分泌行为因硅藻生长期不同而发生变化;同为生长指数期,三种海洋底栖硅藻:平滑舟形藻（Navicula leavissima）、小形舟形藻（Navicula parva）、羽状舟形藻（Navicula pinna）的EPS分泌量不同,但EPS中的多糖和蛋白质百分含量无明显差别。     

Microwave enhanced stabilization of copper in artificially contaminated soil

Microwave processing was used to stabilize copper ions in soil samples. Its effects on the stabilization efficiency were studied as a function of additive, microwave power, process time, and reaction atmosphere. The stabilization efficiency of the microwave process was evaluated based on the results of the toxicity characteristic leaching procedure (TCLP) test. The results showed that the optimal experimental condition contained a 700W microwave power, 20 min process time and 3 iron wires as the additive, and that the highest stabilization efficiency level was more than 70%. In addition, the different reaction atmospheres showed no apparent effect on the stabilization efficiency of copper in the artificially contaminated soil. According to the result of the Tessier sequential extraction, the partial species of copper in the contaminated soil was deduced to transform from unstable species to stable states after the microwave process.     

工业-环境系统的非线性描述

利用自组织的理论与方法建立了一个描述工业－环境系统时间演化的非线性动力学模型。该模型刻画了产值,环保投资,改进生产技术以及环境容量的数量关系,模型简单易于应用。本文还应用所建立的模型研究了白银地区工业发展和环境问题。     

慢速渗滤土地处理法去除污水中污染物的效率研究

本文就不同水质、不同水量、不同作物对慢速渗滤系统中污染物去除效率进行了探讨.通过该法与其它土地处理法和人工常规二级、三级污水处理技术对污染物去除率的比较,表明慢速渗滤土地处理法效果更好.