Abstract:

Eutrophication of lakes has become one of the environmental health issues of widespread concern， among which endogenous ammonia nitrogen pollution is the key to control eutrophication. Granular natural volcanic rocks are often used for the adsorption treatment of endogenous nitrogen and ammonia wastewater， but the adsorption removal effect is not ideal. Therefore， volcanic rock that is conducive to dehydration and separation treatment is selected as the basic material， and two solutions， HCl and NaOH， are used to chemically modify volcanic rock to improve its adsorption performance and effectively remove ammonia nitrogen from water. Test the ammonia nitrogen adsorption effect of modified volcanic rocks from two aspects： characterization and experimental testing. The characterization observation results show that the modified volcanic rock surface forms more adsorption sites and more complex pore structures， which increases the specific surface area and the number of active sites of volcanic rock， thereby improving its adsorption capacity for ammonia nitrogen in solution. Experimental tests were conducted on the effects of modified volcanic stone adsorption capacity， adsorption isotherms， initial solution pH， and dosage on adsorption performance. The experimental test results show that the process of modified volcanic rock adsorbent adsorbing ammonia nitrogen pollutants in water after fitting belongs to quasi second order adsorption； And the maximum adsorption capacity of modified volcanic rock is 2.29 times that of natural volcanic rock， indicating that modified volcanic rock has a good adsorption capacity for ammonia nitrogen pollutants and can effectively remove ammonia nitrogen pollution from water.

Key words: Volcanic stone modification, Ammonia nitrogen removal, Adsorption sites, Pore structure, Ammonia nitrogen pollution