物理法COD减排理论极限能耗的热力学分析

Thermodynamic analysis on theoretical energy consumption for organic contaminants removal by physical methods

首先针对系统的可持续性发展提出了三点本质要求,在此基础上提出了基于减排过程节能机制的热力学框架,并根据热力学第一、第二定律建立了计算物理法脱除有机污染物理论极限能耗的热力学分析方法.此外,以典型有机污染物的脱除为例,分别计算了封闭体系中298.15K和1.01325×105Pa下不同初始浓度、不同种类以及不同COD减排量的有机污染物脱除的理论极限能耗.本文的计算结果表明,废水中有机污染物的减排需要很高的能耗,脱除相同量有机污染物所需的理论极限能耗随着初始浓度的减小而显著增加,且不同种类污染物处理的难易程度和能耗高低相差很大,这充分说明减排与节能有着密不可分的联系,充分考虑污染物的种类、物理化学性质、毒性和浓度将有助于减排政策的科学制定.

Energy-saving and environmental protections are two important and hot issues worldwide in recent years. The scholars all over the world are paying more and more attention on sustainable development and the relationships of energy consumption efficiency with green chemistry. However,no quantitative investigations on the theoretical energy consumptions of the waste removal process have been reported. In this work,the essential requirements for evaluating the sustainable development of a system and the thermodynamic framework of energy conservation mechanism for waste-removal process are proposed. A thermodynamic analysis method based on the First and Second Law of Thermodynamics is proposed to analyze the theoretical approach of energy consumption for the organic contaminant removal process by physical methods. Moreover,the theoretical approach of energy consumption for the removal of representative organic contaminants with different initial concentrations,different kinds and different amounts at 298.15 K and 1.01325×10^5 Pa by physical methods is investigated. The results show that the waste treatment process is with high energy consumption. And the theoretical approach of energy consumption for the removal of organic contaminant increases with the decrease of initial concentrations in aqueous solutions. The theoretical approach of energy consumption for the removal of different organic contaminants is quite different. Furthermore,the theoretical approach of energy consumption increases greatly with the increase of the COD removal amount. The quantitative investigations on the theoretical approach of energy consumptions for the organic contaminant removal process will provide important information for the study of the energy conservation mechanism for waste-removal process and the relationships of energy consumption efficiency with the waste removal efficiency and greenness.