Control of environmental impact with modern chemical technology

Here are assembled representative excerpts from a new text in applied chemistry. They illustrate the well-referenced treatment of industrial processes that are here considered with their related emission control problems and solutions. A brief account of general aspects of the industry is followed by surveys of the significance and technical aspects of air and water pollution chemistry. Consideration is given to emission avoidance or containment, waste treatment, and waste disposal options as they relate to both of these environmental areas. Details of salt recovery and the products of brine electrolysis plus environmental aspects of these operations are treated as examples of some of the processes discussed. Also covered are fertilizer constituent preparation, formulation, and use with consideration of the large-scale effects of each of these activities. Detailed reference is made to the chemical technology and emission control aspects of the pulp and paper industry and refinery operations. Throughout, integral process changes and waste recycling practices are directly related to emission control aspects of each process in a way to be useful to the student and professional alike. These excerpts are extracted from one of the first, single volume accounts to take this unified approach to the subject.Extract from the bookModern Chemical Technology and Emission Control by M. B. Hocking, published by Springer-Verlag, Berlin, Heidelberg, New York, Tokyo (1985).     

Source resolution and risk apportionment to augment the Bubble Policy: Application to a steel plant “bubble”

Source resolution and risk apportionment of emission source categories for risk reduction purposes can be used to enhance the Bubble Policy of the Clean Air Act. This is performed by incorporating receptor modeling techniques of factor analysis and chemical mass balances to assess noncarcinogenic and carcinogenic inhalation risks to a target population for certain pollutants coming from major emission source categories in a steel plant air shed. Source resolution, using factor analysis, statistically interprets a “source” from ambient data. By subsequently quantifying risks from identified metal emission sources using chemical mass balances and risk apportionment, a total additive risk from main source contributors in the steel plant is estimated. From this methodology, the Bubble Policy can be enhanced by targeting only main risk sources or by “risk-trading” with minor impact sources to reduce the total risk (if deemed significant) without arbitrarily reducing risk for all sources in an industrial source complex’s “bubble.”     

WATER LOSS EQUATIONS AND COEFFICIENTS TO ESTIMATE RUNOFF FROM RAINFALL1

Infiltration models are based on physical characteristics of the soil and initial soil moisture. For a given soil it is based on the initial soil moisture distribution. A computer simulation model for flood runoff systems (FH-Model) was used to analyze 39 sets of rainfall-runoff data on four small watersheds ranging in size from 17 to 342 square kilometers located in the Yamaska River basin in Quebec. From these analyses, parameters and coefficients have been determined for a water loss (infiltration) equation. A method for determining the loss parameters, using a nonlinear least square curve fitting technique, is presented. Expressions were made to relate the loss parameters to antecedent precipitation. The equations were tested on 11 storm rainfall and runoff events on a watershed located in the same region and close agreements were found.     

基于地理探测器的流域土壤磷流失影响因素分析

基于修正的通用土壤流失方程(RUSLE)和地理探测器,定量分析了甘肃白龙江流域土壤磷流失的空间分异及其影响因素.结果表明:①2014年流域平均土壤磷流失量为0.214 t·km~(-2)·a~(-1),流失总量为3945.38 t·a~(-1);②磷流失空间分布较为破碎,热点区集中于迭部北部和舟曲东北部等高山区及舟曲、文县和武都三区县交界的低山河谷区,冷点区集聚于宕昌北部耕作区和文县南部森林保护区;③流域磷流失的空间分异主要受土地利用和地形的影响,农牧业生产也发挥了一定作用,磷流失整体表现为随海拔和坡度的抬升而增加,草地林地耕地;④流域及其内部冷热区影响因素差异较大,这是由各区地理环境协同差异所致,最大交互因子分别为土壤类型∩景观破碎度、土壤类型∩植被覆盖度、降水∩第一产业从业人口比重.在流域磷流失治理中,应合理安排农牧业生产,在提高植被覆盖度的同时降低景观破碎度.     

损失瓦斯量与煤的破坏类型关系研究

损失瓦斯量是准确获取煤层瓦斯含量的基础数据。通过实验室测定和不同损失量计算模型的对比分析,表明采用 传统的t法和幂函数法获取损失瓦斯量时,Ⅱ类、Ⅲ类和Ⅳ类煤符合性较好,误差小于20%,I类煤和Ⅴ类煤的损失瓦斯 量误差为25%~31%;煤中孔隙结构的差异是误差产生的原因,I类煤中原生孔隙占多数,Ⅴ类煤的孔隙受构造影响最大, 其它类型煤的孔隙结构介于I类煤和Ⅴ类煤之间;对于I类煤和Ⅴ类煤,采用表征原生孔隙和构造孔隙双孔隙特征的模型 获得的损失瓦斯量误差低于10%。研究结论对煤层瓦斯含量测定具有重要意义。     

Thermal runaway criterion for chemical reaction systems: A modified divergence method

The chemical reaction in certain range of operating conditions may exhibit parametric sensitivity where small changes in one or more of the input parameters lead to changes in the output variables (eg. reaction temperature). The sharp rise of the reaction temperature is a critical behavior that may lead to runaway conditions. Thus, it is of vital importance to determine the critical operating parameters consisting of the parametric sensitivity region under the consideration of intrinsic safety. In this paper, a modified divergence criterion is proposed based on the trace of Jacobian matrix at the maximum temperature. The nonlinear differential equations describing the dynamic behavior of the chemical reaction is linearized locally in the vicinity of the equilibrium point by the small perturbation analysis. The relationship between the perturbation equation and parametric sensitivity of the reaction system is investigated. The critical values computed by the modified divergence criterion are compared with Morbidelli and Varma criterion (MV criterion), Adler and Enig criterion (AE criterion) and divergence criterion (Div criterion). The comparison demonstrates the validity of the new criterion. In addition, the critical explosion pressures of two kinds of hazardous chemicals are computed by the various critical criteria and compared with published experimental data. The results show that the modified divergence criterion could give smaller computational error compared with the previous criteria.     

四川德昌县虎皮弯沟泥石流及灾害损失评估

论述了四川德昌县虎皮弯沟泥石流形成环境、触发条件和泥石流特征.分析了泥石流危险度,着重评估了"8.24"泥石流灾害损失并提出了相应的防治建议.     

The Environmental Limits to Globalization

Abstract:  Criticisms of globalization have been largely based on its socioeconomic effects, but the environmental impacts of globalization are equally important. These include acceleration of climate change; drawdown of global stocks of cheap energy; substantial increases in air, water, and soil pollution; decreases in biodiversity, including a massive loss of crop and livestock varieties; depletion of ocean fisheries; and a significant increase in invasions of exotic species, including plant, animal, and human pathogens. Because of negative feedback from these changes, the future of globalization itself is bleak. The environmental and social problems inherent in globalization are completely interrelated—any attempt to treat them as separate entities is unlikely to succeed in easing the transition to a postglobalized world.     

Degradation of the herbicide imazapyr by Fenton reactions

The degradation of the herbicide imazapyr has been carried out by three advanced oxidation processes involving iron ions as catalysts: Fentons reagent, photo-Fenton and electro-Fenton. We show that all processes are rapid and efficient. The kinetic rate constant was found to be k=5.4×10⁹ M^–1 s^–1. The mineralization of imazapyr is almost complete using the photo-Fenton and electro-Fenton processes.     

环境噪声达标区建设的宏观经济效益分析方法

从环境经济学观点出发，运用系统论，数理统计等方法，分析环境噪声污染的直接损失与间接损失，达标区建设的硬件与软件投资、达标区建成后的直接与间接效益，建立了环境噪声达标区建设中损失－投资－效益三者的分析法，以价格机制和价值规律，促进环境噪声污染防治。