Screening And Assessment Of The Disposal Technology In Urban Drinking Water Source Emergent Response

Pollution events caused by environmental measures’ lagging behind economicdevelopment have attracted great attention, especially the emergent ones whichseriously threat urban water supply. Relevant departments had often been verypassive dealing with such events due to lack of technologies and experience.Therefore, it’s very important for the national emergency management to researchon screening and assessment of disposal technologies in urban water sourceemergency. This paper researched on surface water source, based on the researchand analysis of typical emergent events and disposal technologies, it establishedindex systems and screening and assessment methods through hierarchy analysis,and applied them into real cases. Research results would be good for emergencymanagement of similar events.This paper statistically analysed118emergent pollution events in water sourcein recent25years, the river type water source is main source type which accountedfor85.0%; chemicals, oil, heavy metals were main pollutant types which accountedfor70.0%; safety production, traffic accidents and enterprise pollution dischargewere main pollution cause types which accounted for70.0%; events that affected apopulation under200thousand accounted for75.0%; events that caused waterfailure within one week accounted for83.3%.An assessment index system of event severity which contained12indexesabout pollution situation, pollution position, water source scale, emergencymanagement and alternative water source was established, index weights wereobtained through ROC method, linear weighted average method was adopted ascomprehensive evaluation method. A technology screening and assessment indexsystem which contained20indexes about engineering difficulty, time and effect,disposal cost, emergent coordination, emergent supply, social impact andenvironmental impact was established; two sets of index weights were obtainedthrough ROC method according to event severity, RSR method was adopted ascomprehensive evaluating method.A screening and ranking index system which contained9indexes aboutpollutants’ nature of risk, toxicology, physics, chemistry, environmental migrationbehavior and public interest was established, index weights were obtained throughROC method, linear weighted average method was used to evaluate and rank36pollutants. Compared with the “Chinese priority water pollutants blacklist”, resultsshowed that16of the top18pollutants were in the blacklist and the number ofpollutants which had caused water pollution incidents and serious pollution events were14and12, respectively.Research results were applied to arsenic pollution in Duliujiang River ofGuizhou province and alage bloom in Xinlicheng reservoir of Changchun city,results showed that adding composite adsorbent is preferred alternative for theformer event, while air flotation or filtering for the latter event.