Double Metal Modified Bentonite As PRB Reaction Medium Test Research

Landfill leachate is one kind of organic wastewater which is difficult to be treated, with complex components and high concentration of organic compounds and NH+4-N. C ompared with the traditional remediation technologies, the permeable reactive barriers tech nology has the characteristics of less cost and long aging etc,it is is a new developed te chnique among the techniques of the remediation of polluted groundwater in the world.Bentonite adsorption capacity due to its large, abundant, inexpensive, non-toxic harmle ss to the environment, etc., On the aspect remove of groundwater pollutant has broad a pplication prospects.The natural Ca-bentonite of Heishan in Liaoning and Landfill Leachate of laohucho ng in Shenyang as the experiment raw material,This paper has talked using three kinds o f Al-Fe, Al-Cu and Fe-Cu modifies the bentonite, carries on a series of influence fact ors of the research and taking the application of modified bentonite as PRB reaction me dium from the actual processing waste leachate water research, and designing the laohuch ong refuse landfill PRB structure.Researches shows, Through the three groups of orthogonal test, The best modified conditions for:Fe-Cu bimetal modified bentonite, column transition temperature is80℃, suspension mass concentration is4g/L, aging temperature of80℃, aging time is12h, the resule of removal rate of the groundwater CODCr, ammonia nitrogen were66.97%and62.57%, the biggest influence alcohols is mass concentration.Through the singl e factor test, in the best modification conditions, the reaction temperature is higher, the b etter to reaction, and with the increasing of adding amount of soil, the organic pollutant adsorption capacity change bigger, the resule of removal rate of the groundwater COD Cr, ammonia nitrogen were d93%, and82%. Through the X-ray diffraction and scann ing electron microscopy (sem) analysis, modified bentonite layer spacing increases, adsorp tion capacity, and enhance the removal ability of CODCr, ammonia nitrogen the bentonit e of groundwater.Based on the double metal modified bentonite as PRB single reaction medium and double metal modified bentonite and zero-valent iron mixed as PRB mixed medium indo or column simulation test results show that these two kinds of PRB reaction medium pro cessing by rubbish leachate pollution of groundwater are feasible.And the modified bento nite to pH have buffer role in simulation test, the pH value and water pH value is quite. The absorption of modified bentonite and the Oxidation-reduction of zerovalent and biodegradat ion actions work together reduce waste leachate CODCr and ammonia nitrogen in water qu ality concentration. Two reactors in indoor simulation test in continuous use65days wer e penetrated.Through The previous study of the economic and technical analysis, PRB technology used in groundwater management especially by rubbish leachate pollution of groundwate r have a very good development prospects. Double metal column brace bentonite as PRB reaction medium preparation cost is1089.7yuan per cubic meter, double metal modifie d bentonite as PRB reaction medium no matter from the pollutants removal efficiency or economic aspects are better reaction medium material.Reference to the survey data and assumptions, the tiger rushed landfill site PRB stru cture design for:continuous reaction wall, reaction medium for double metal modified be ntonite, reaction wall height10m thick1.7m, reaction wall permeability coefficient is0.45～0.85m. d-1, stay time setting for2d, in the reaction wall before and after each set monitoring well.In the actual installation, should be ready to deal with the regional environmental characteristics and underground hydrogeological environment investigation, PRB reaction wall processing capacity and reaction stay time determination.