Study On Grain Size Distribution Characteristics Of Suspended Particulate Matter On Apparent Pollution Of Urban Water

By the rapid development of economy in our country, pollution of city surface water aggravated and water quality declined. Most of city surface water lost the function of drinking water source area, and main function transfer into landscape function. Due to urban landscape water has its own ecological vulnerability, and impact of human activity, landscape function was severely weakened and pollution of urban landscape water was increasing serious.Water suspended particles are the main reason to lead to urban landscape water pollution of apparent. Grain fineness distribution of suspended particulate matter decided water particles to the function of attenuation, absorption and scattering to decide color, transparency and true light layer depth of water and other relevant water apparent characteristics. Distribution characteristic of particle size of solid suspended can reflect apparent water pollution condition of urban landscape. Based on the study to make urban landscape water in Suzhou as research object to systematically analyze the relationship between grain fineness distribution of water suspended particulate matter and level of apparent water pollution to resolve pollution effects of urban landscape water apparent from the side of suspended particle size to get the following conclusion.(1)Different types of urban landscape water possess a similar characteristics on grain size distribution. The suspended particle size of yellow urban landscape water body presented unimodal distribution with the distribution characteristic of good sorting features, normal peak and nearly symmetric. The suspended particle size of green urban landscape water body presented abnormal distribution with the distribution characteristic of poor sorting and multimodal(2)Fraction of 8-35?m of green urban landscape water is the sensitive graded of water apparent, and SPI value and Chl-a concentration have significant positive correlation with graded component volume fraction. The graded component volume fraction increased is particle size results representation of population level of green water body apparent increased, which component volume fraction increased mainly because of algae content increased.(3)Fraction of 3.8-16?m and 32-64?m of yellow urban landscape water are all apparent water sensitive grade, and SPI value has segmentation with sensitivecomponents graded volume fraction, and segmented node is turbidity 45 NTU. When turbidity is less than 45 NTU, SPI value has positive correlation with component volume fraction of 3.8-16?m and negative correlation with volume fraction. When turbidity is greater than or equal to 45 NTU, the relationship is opposite. When the content of the suspended particulate matter reached a certain degree, something mainly contribute to SPI is relatively large grained particles.(4)Changes of impact factor of source factor, environmental factor, external factor and hydrodynamic conditions present consistent response of suspension particle size distribution and water apparent, and changes of suspension particle size distribution is the most basic reason to produce apparent water pollution.