Investigation And Screening Of Water Quality Control Pollutants In Pcb Industry In China

The pace of economic globalization is accelerating,the relationship between countries is becoming increasingly close,industrial,layout,industrial pattern is also constantly changing.China has overtaken Japan as the country with the highest output value in the printed circuit board industry.Printed circuit board production process is long and complex,involving hundreds of process sections,and the use of raw and auxiliary materials and additives,intermediate by-products and other complex toxic and harmful organic substances,if these toxic and harmful organic substances are not timely and effective control and enter the environment,will bring huge safety risks to the environment and human health and safety.And the current research on priority control of pollutants is mainly aimed at rivers,lakes,reservoirs and other watershed water bodies,and less research for the industry,and are carried out after the watershed water bodies have been polluted by toxic and harmful pollutants,the lack of methods and technologies to control from the source.In response to the issues raised above,the study was conducted and concluded as follows:（1）This study takes clean production as the basic concept and starts the research by means of whole-process control.Through data collection,process flow production and discharge analysis and wastewater sample testing and analysis,the emission characteristics of pollutants from the whole process of the industry are studied.Then form a list of key industries to investigate the characteristics of pollutants and screening techniques.Four typical enterprises in the printed circuit board industry in Changzhou City were studied,and after a comprehensive analysis of theproduction and discharge analysis of the industry’s production process,the collected wastewater samples were tested by gas chromatography-massspectrometry instrument,and the substances with a matching degree of more than 90%with the database were collated as the test results of the water samples,and the list of 172 characteristic pollutants of the printed circuit board industry in Changzhou City was finally obtained,including11 acids,10 long-chain alkanes,and 10 alkanes.The final listof172characteristic pollutants in Changzhou printed circuit board industry includes 3 olefins,11 acids,10 long-chain alkanes,4 halogenated hydrocarbons,30 benzenes,13 ketones,36 esters,9 metal ions,7 amides,23 alcohols,1aldehyde,11 others,4 ethers,10 salts.（2）On the basis of comparing the list of industry characteristic pollutants with the existing list of superior controlled pollutants at home and abroad,the comprehensive evaluation method,Hasse’s diagramming method and hierarchical analysis method are combined for comprehensive analysis to carry out further screening of superior controlled pollutants,summarize and combine the top 50%of substances ranked by each screening method to obtain the list of superior controlled pollutants in the industry,and finally form a survey of the list of superior controlled pollutants in the industry and screening techniques.The comprehensive evaluation method is used to assign and rank the exposure,toxicity and persistence of organic substances,while the Hasse diagramming method is used to conduct orthogonal comparison among all substances based on the numerical magnitude of COD_cr contribution value,biodegradability and bioaccumulation indexes,and then combined with the hierarchical analysis method to calculate and determine the contribution value of COD_cr,solubility in water,volatility,bioaccumulation,biodegradability,general Toxicity,carcinogenicity of the index weights for the final calculation of the score,and finally get Changzhou City printing The list of 30 kinds of pollutants in the PCB industry,including 9 kinds of benzenes,5kindsof alcohols,3 kinds of halogenated hydrocarbons,3 kinds of esters,1 kind of aldehydes,1 kind of salts,5 kinds of metal ions,2 kinds of ketones and 1 kind of others.From the perspective of the industry,this study proposes a set of investigation and screening techniques for the list of characteristic pollutants and the list of priority control pollutants in key industries based on the concept of whole process control and source control.To provide effective scientific and technological ideas and reference methods for source control of organic pollutant risks in regional watersheds,and also to provide scientific and feasible screening techniques for industry enterprises to determine the list of characteristic pollutants and the list of priority control pollutants,as well as to provide data reference for the traceability of organic pollutants in the direction of industry in water bodies and the development of water pollutant discharge standards in the printedcircuit board industry.