Environmental Investigation And Assessment Of Black Smelly Water And Catalytic Degradation Of Pollutants In Water

This paper took a polluted site with black and smelly water as the research object,carried out site environmental investigation and risk assessment.Using Surfer software,we calculated the amount of water and mud in the site,and tested the feasibility of the treatment scheme.Furthermore,a new type of sponge composite nanomaterial loaded with palladium nanoparticles was prepared and its application on the treatment of different types of pollutants in water was investigated.(1)Environmental investigation,risk assessment of a black and smelly water fieldBy referring to the relevant technical specifications and guidelines for environmental investigation and risk assessment of construction land and combining with the characteristics of black and smelly water polluted sites,the environmental investigation,pollution risk and degree assessment,relevant accounting and exploration experiments are carried out on the research objects.The results showed that the conventional indexes of total nitrogen and ammonia nitrogen in the sediment of the black and odorous water site exceeded the standard at 0.3 m and 0.6 m in the middle,and the heavy metals had mixed pollution of different degrees.The maximum mercury exceeded the standard by 61.1 times and arsenic exceeded the standard by 1.4 times.The carcinogenic risk of arsenic and the non-carcinogenic hazard index of mercury in sediment are 1.9×10^-5,1.7 respectively,which have exceeded the acceptable level of human health.According to the preliminary calculation,the water volume of the site is 320,000 cubic meters,and the mud volume is 246,200 cubic meters.The process of"geodesic bag dehydration activated carbon adsorption decolorization"not only reduced the moisture content of sediment by about 40%,but also reduced the conventional indexes of the remaining water.(2)Preparation of natural sponge-supported palladium nanoparticles and their application on catalytic degradation of pollutants in waterA new kind of palladium nanoparticle supported composite material was prepared by using natural sponge with porous structure.The results showed that the concentration of pollutant could be basically reduced to 0 within 5 min,and the catalytic performance was still high after 6 experiments were repeated.Using the new injection-extrusion reaction form,the conversion rate of 20 times of repetition is above 98%.The reaction rate constant was 2.372 min^-1,which was consistent with the pseudo-first-order reaction kinetics.The catalytic effect of sponge composites can be enhanced by constant stirring and increasing temperature.In addition,the new composite material can also achieve efficient catalytic degradation of pollutants such as 4-nitrophenol and organic dyes in water.