The Analysis of Water Quality of Xi’an from2000to2010
|School||Northwest University of Science and Technology|
|Keywords||water quality assessment pollution sources measures|
Xi’an is a world famous ancient capital of one of the world’s greatest civilizations,ranking first in the ancient capital of China, the cradle of the Chinese nation, the birthplace ofChinese civilization, the representative of Chinese culture. Therefore, surface water pollutioncontrol security Xi’an stake. In order to control water pollution in Xi’an, Xi’an to ensure publicsafety of drinking water to ease the grim situation of water resources in Xi’an, Xi’an, surfacewater pollution on the degree of their pollution monitoring and evaluation and analysis ofspecific causes. To this end, eight rivers in Xi’an, sections14and20cross-section distributionsampling and laboratory analysis through field measurement of surface water environmentalfactors to get the data, and using single-factor evaluation methods and comprehensivepollution index of Xi’an status of surface water quality analysis and evaluation, and finallyproposed pollution control strategy. This research got the following conclusions:(1) BOD and COD values of Xi’an in surface water emerged gradually decreased, thewater tends to reduce organic pollution, water tends to clean. In general, Xi’an organicpollutants to a lesser extent.(2) Ammonia content fluctuated on the whole, after2003the amount of ammonia waterdownward trend, while the ammonia pollution from2008on wards showing a worseningtrend.(3) The oil in surface water pollution is more serious, the annual change showed adownward trend after the first rise in2004and2005after the maximum, then decreases,appeared in2008after a slight recovery.(4) The volatile phenol in surface water in Xi’an tend to a downward trend. Only in2000year class beyond the surface water Ⅴstandard phenol the standard value, in the2001dryseason period of peace over Ⅲwater quality standard, other times are low, even lower thanthe detection limit.(5) Changes in the total cyanide law is not too obvious, volatile. Open to the general, lowlevels of total cyanide, water quality standards are not exceeded Ⅰ, several years or even lessthan the detection limit, is clean water.(6) Mercury in the statistics of11years there has been increasing at first and then decreased in2000and2001are relatively small, but the content of the dramatic increase inthe next three years, the dry season in three years, Hg levels were Ⅱwater quality standardsbeyond the2005and later restored clean.(7) By calculating the integrated pollution we found index in2006, before the water ispoor, in the dry season from2000to2005(except2001), are heavily polluted;2004and2005the water level period of relatively poor water quality; in the wet period In2004alone, thewater is heavily polluted; annual average in2000,2003,2004and2005, four years more than2.0, is heavily polluted. Among these, the oil pollution in the composite index of themaximum rate of the total share, accounting for70%of other pollutants in accordance withthe contribution rate in order of descending order of BOD, phenol type, COD, ammonianitrogen, Hg, and total cyanide compounds. Thus available in the11years2000to2010, theXi’an main pollutants to surface water-based organic pollutants, especially oil. Accordancewith the above results, the causes of surface water pollution has made analysis of Xi’an. Xi’an,presented the main pollutants in surface water sources, and finally made a deal with therational use of water resources, surface water pollution in Xi’an appropriate countermeasures.