Study On The Removal Of Minim Mercury In Reservoir Water

Mercury is one kind of harmful heavy metal to people's health. Nowadays the lack of water resource is a global problem.. Especially, as one of the countries which is short of water severely in the world, we couldn't come to the conclusion that changing the water resource casually when we are up against the problem of mercury pollution. Therefore, to find some water treatment medicament or material and then to research their mercury removal eflficiency, principles and the feasibility in practical applications has been an urgent task.At present, the researches about mercury removal in water are emphasized particularly on removing mercury from industrial wastewater. The researches about removing minim mercury in water resources are reported scarcely. There are many common principles to remove mercury in industrial wastewater, such as absorption, sedimentation, flocculation, ion exchange and filtration etc., all these are effective methods to remove mercury in industrial wastewater. The means for removing minim mercury in water resources are based on above-mentioned principles too. The paper study on the mercury removal efficiency in water resources of using powder activated carbon, bentonite, KMnO₄, flocculants (PAC, FeCl₃,Al₂(SO₄)₃ included), KFeO4 and iron-coated sand by captive test. To research the mercury removal performance of these medicaments or materials, then to find out their optimal use condition, such as the best use combination of medicaments, the feasible action time and quantity of medicaments, the optimal pH of water. At last, the principles of mercury removal are researched and analyzed.The mercury contained water samples are compoumded by HgCl₂, the concentration of Hg2+ is about 0.5μg/L .The efficiency of mercury removal is about 35% when using poweder active carbon. The removal effiency increased to about 65% when active carbon and PAC are used together. The removal effiency rise to 75% when the combination techinics of acitvated carbon+KMnO₄+PAC applied, meawhile the effect is steady. The bentonite have a certain effect on mercury removal, but the effeciency is about 10%lower than powder active carbon. All kinds of flocculants are effective on removing minim mercury in water resource, but the efficiencies of mercury removal changed by the different kinds of flocculants. The efficiency of mercury removal reach upwords of 70% when combination technics of KMnO +PAC applied, but this technics is severly influenced by the pH of water. The iron coated sand showes obvious improvement in mercury removal efficiency than the primary sand. The iron coated sand is 15% higher than primary sand on mercury removal efficiency. The mercury concentration in water has positive correlation with the mercury removal efficiency by iron coated sand.