Ispitivanje uticaja odabranih amida na adsorpciju nitro derivata fenola iz vodene sredine na aktivnom uglju

Abstract

U radu je ispitan uticaj amida kao modela AOM-a (Algalne organske materije) na adsorpciju nitrofenola iz vodene sredine na aktivnom uglju. Istraţivanje se sastojalo iz tri faze: ispitivanje uticaja karateristika amida na adsorpciju nitrofenola, ispitivanje uticaja granulacije na adsorpciju nitrofenola u prisustvu amida i ispitvanje karakterisitka samih nitrofenola na adsorpciju u prisustvu amida. Pre ispitivanja adsorpcije u dvokomponentnim sistemima ispitana je adsorpcija jednokomponentnih sistema 4-nitrofenola, 2,4-dinitrofenola i 2,4,6-trinitrofenola, kao i amida Nmetilbenzamid, nikotinamida i N-benzilbenzamida na komercijalnim aktivnim ugljevima NORIT SA2 i dve granulacije aktivnog uglja DARCO. Aktivni ugljevi su ispitani metodom FTIR spektroskopije, SEM analizom, analizom površine adsorpcijom azota na niskoj temperaturi i određivanjem taĉke nultog naelektrisanja. Urađena je geometrijska optimizacija modela molekula ispitivanih nitrofenola i amida i izraĉunati su molekulski parametri. Uticaj amida kao modela AOM-a je ispitan korišćenjem razliĉitih ravnotežnih i difuzionih adsorpcionih modela. Kao kriterijum za određivanje najsporije adsorpcione faze korišćen je Biotov broj. Adsorpcioni parametri dobijeni u eksperimentima sa dvokomponentnim sistemima su upoređivani sa parametrima dobijenim za adsorpciju samih nitrofenola.

In this research influence of selected amides, as a model of AOM (Algal organic matter), on adsorption of nitrophenols from water on activated carbon has been investigated. Research is divided in three phases: investigation of influence of amide molecule characteristics on the adsorption of nitrophenols, investigation of granulation influence on nitrophenol adsorption in the presence of amide and investigation of nitrophenol characteristics that can influence adsorption in the presence of amides. Adsorption of nitrophenols and amides in single- component systems has also been carried out. Adsorption kinetics of 4-nitrophenol, 2,4-dinitrophenol, 2,4,6-trinitrophenol, N-methylbenzamide, nicotinamide and N-benzylbenzamide has also been investigated. Commercial activated carbons NORIT SA2 and two granulations of DARCO were used. Activated carbons were characterized using FTIR spectroscopy, SEM analysis, internal surface analysis using nitrogen adsorption on low temperature and determination of point of zero charge. Geometry optimization of nitrophenol and amide molecules has been carried out and different molecular parameters have been calculated. Influence of amides as AOM model has been investigated by using diffusion and equilibrium models. Biot number has been obtained in order to establish the limiting step in adsorption process. Adsorption parameters obtained in two-component adsorption systems were compared to parameters obtained for adsorption of nitrophenols alone.