The Detection Of Surface Drinking Water Sources For Emergency Treatment Of Sudden Pollution Accidents And Biological Toxicity

In recent years, the sudden water pollution accidents have occurred wordwide accasionally, and the water ecological environment security and city water supply system have been threatened. The rapid alert and effective treatment for these accidents are important. Shijiazhuang Gangnan Reservoir, as an area of drinking water source, is charging of the supply water tasks with the provincial capital of Hebei province, the downstream of railway, highway of North China Oil field, Jizhong plain area agriculture,industry and city. It’s significant to rapid alert and deal with its sudden water pollution accidents.In this study, the Gangnan Reservoir water was used to simulate the sudden water pollution accident of nitrobenzene. The influence of nitrobenzene pollution on water quality was investigated. When the activated carbon adsorption was used to treat nitrobenzene pollution, the particle size of activated carbon, activated carbon dosage,adsorption time and pH were optimized for economical and rapid treatment.The results showed that when the initial concentration of nitrobenzene was 1.7mg/L, the efficient treatment performance could be achieved when particle size ranges of activated carbon were 0.710mm-0.850 mm, 0.850mm-2.36 mm and 2.36mm-4.75 mm, the dosage of activated carbon were 20g/L, 30g/L and 50g/L, and the adsorption time were 15 min,60min and 75 min, respectively. In addition, when the pH value was lower than 10, the adsorption of nitrobenzene by activated carbon would not be affected.According to the standard of 《The acute toxicity of water quality determination of luminescent bacteria method》(GB/T15441-1995),the luminescent bacteria was used to detect the toxicity and HgCl2 was used as the reference toxicant to set up the work curve.The luminous intensity of luminescent bacteria reached the maximum after culturing 12 h and it was duluted 65 times to get the job strain liquid. The toxicity levels of the samples were determined based on the relative luminescence intensity of the luminescent bacteria and the reference toxicity line was established for rapid alert and monitoring of sudden water pollution accidents. The results showed that when the particle size of activated carbon decreased, the nitrobenzene concentration of water samples decreased slowly and,the relative luminescence intensity increased, indicating the toxicity decreased to high toxic level. When the dosage activated carbon increased, the nitrobenzene concentration of water samples decreased greatly and the relative luminescence intensity increased,indicating the toxicity decreased to low toxic level. When the adsorption time increaseed,the nitrobenzene concentration of water samples decreased slowly and the luminescence intensity increased, indicating the toxicity decreased to heavy toxic level. When ClO2 was used to treat contaminated water after adsorption, the toxicity decreased to low toxic level and met the standards.The sediment of the nitrobenzene polluted water treatment system was analyzed to identify the dominant microbial population and the variation of dominant dominant microbial population could indicate water ecological environment as an important index.The results showed that algae were sensitive to nitrobenzene pollution and it could not restor after a short time if poisoned.The adsorption treatment of nitrobenzene cantaminanted water by activated carbon showed different influence on water ecological environment, and algae and bacteria were affected little by activated carbon adsorption.The staining method was applied to monitor the bacteria amount. The amounts of algae and bacteria increased when nitrobenzene concentration decreased. Then water quality could be indicated by the amounts of algae and bacteria.