Study On The Organic Pollutants Distribution In Nansha River And The Adsorption/Desorption Mechanism Of Demethyl Phthalate

The persistant organic pollutants (POPs) have been thought as the global pollutants for its special toxicity and contamination. The distribution of POPs in the water environment and the treatment of POPs become the keystone in recent research. In this paper, the distribution of POPs and the adsorption/desorption characteristic of demethyl phthalate were studied.Using the GC-MS apparatus detect the POPs in the surface samples and column samples in Nansha River. The results show that:①A lot kinds of POPs have been detected in the sediment samples of Nansha River, mainly include the polycyclic aromatic hydrocarbons(PAHs), aromatic compounds, phthalic acid esters(PAEs), alkanes, amines, alcohols alkenes, hydroxybenzenes, ketones and some other kinds of POPs.②In the surface samples, the alkanes is the most part of total POPs have been detected. It includes 11 kinds of pri-control pollutant listed in US EPA and Environmental Monitoring of China. There are 14 kinds of POPs have been chosed for quantitative analysis, include 7 kinds of PAHs. In the surface samples, the mean contant of Fluoranthene reach 0.1581mg/kg, the mean contant of 9H-Fluorene is only 0.0358mg/kg. The mean contant of Toluene reach 0.1794mg/kg。Along the river, the contant of POPs increase gradually.③Because of the different geological features, the contant of POPs in each segment of column samples is different. The mean contant of PAHs is under O.lmg/kg。The different adsorption results are shown between Nansha River sediment and two kinds of carbon adsorbents, the qe of Nansha River sediment is far low congtrast with the other two adsorbents. Therefore, we do the farther research use the two carbon adsorbents.The physical and chemical properties of two adsorbents were studied, the microshape and elements constitute are greatly different, this can affect the adsorption/desorption process.Using the HPLC apparatus sthdy the DMP adsorption/desorption characteristic on two carbon adsorbents, then fitting the isotherm and kinetics curves. The results show that:the qe of Donghai ash is lower than Shishou ash in different temperature; in the isotherm fitting curves, the Freundlich fitting coefficient n is less than 1, therefore both of the two adsorotion process of different adsorbent behave as non-linear adsorption; the△H of two adsorption processes are negative, this indicate the processes are exothermic reaction; the fast adsorption stage of Shishou ash use less time than the other; the desorption processes are behave as non-linear adsorption.