煤化工中焦化废水的污染、控制原理与技术应用

Pollution control principles and technology applications in the treatment of coking wastewater from coal chemical industry

煤化工废水成分复杂,毒性大,以焦化废水最具代表性,研究废水中典型污染物的控制原理很有必要.从煤制气、煤制焦、煤制油及煤制甲醇4个方面介绍了煤化工过程在能源与经济方面上的地位与特点,分析了煤化工过程水污染特征与水污染控制的共性问题,对水质结构的描述及其变化过程的理解是水处理工艺选择的科学基础.固相微萃取(SPME)与GC-MS结合的分析手段能够快速、准确地获得废水水质的化学结构特征及浓度水平的信息,基于元素分析可以获知典型污染物的转化与归趋;结合废水组成、反应、降解与转移的定量考察,可以深入了解废水的生成机制及其处理过程的变化;根据污染物特征选择有效的化学原理如吸附与催化氧化的结合,根据惰性污染物的存在选择生物电化学催化分解,基于协同降解或共基质降解,培养功能微生物,构建基因工程菌,开发功能微生物的应用技术.上述可归纳为根据不同污染物的性质提出相适应的去除原理,系统考虑废水的成分特征、化学转化、生物转化以及相互协调优化,追求更高水平上实现污染物转化与降解的技术目标.最后,根据煤化工焦化废水处理目前暴露的缺陷,提出了未来需要加强研究的若干关键问题.

The coking wastewater is the most representative one of coal chemical wastewaters which are typically characterized by complex composition and high toxicity.Investigation on pollution control principles of typical contaminants in this wastewater is in great need.The coal chemical processes including coal-to-gas,coal-to-coke,coal-to-oil and coal-to-methanol conversions were introduced in terms of their status and characteristics during the development of energy and economics.The analysis on the common problems of water pollution and its control in the coal chemical industry was conducted.It was considered that understanding wastewater composition and its change behavior has scientific meanings for choosing the relevant treatment technologies.Combination of solid phase micro extraction（SPME） and gas chromatography-mass spectrometry（GC-MS） techniques can allow the quick and accurate determination of chemicals and their concentration in the wastewater.Based on the elemental analysis,transformation and fate of typical contaminants can be obtained.Insights into the formation mechanism of wastewater and change in the treatment process can be gained by quantitative investigating the composition,reaction,degradation and transfer of contaminants.Efficient chemical treatment technology like the combination of adsorption and catalytic oxidation should be selected by evaluating pollutant characteristics,and bio-electrochemical catalytic technology should be selected due to the presence of inert pollutants.Based on the synergetic and co-substrate degradation,functional microorganisms should be cultivated,genetically engineered bacteria should be constructed,and ultimately the application technology of function microorganisms should be developed.The above suggestions can be summarized as the proposal of appropriate control principles according to the inherent nature of different pollutants.To achieve the technical objectives of pollutant conversion and degradation at a high level,the composition of wastewater characteristics,and the chemical-transformation and bio-transformation of pollutants should be systematically taken into account.Finally,a number of key issues that need to be strengthened in the future research were proposed in light of the current challenges of coking wastewater treatment.