Removal of carbendazim fungicide from aqueous solution by adsorption on different zeolites : bachelor thesis

U ovom radu ispitana je mogućnost primjene različitih vrsta zeolita - prirodnog zeolita klinoptilolita (PZ), njegova homoionskog Na - oblika (NaZ3) te sintetskog Zeolite Socony Mobil-5 zeolita (ZSM-5) za uklanjanje fungicida karbendazima iz vodene otopine početne koncentracije γ o ≈ 5 mg/L. Uklanjanje je provedeno procesom adsorpcije šaržnim postupkom pri sobnoj temperaturi miješanjem zeolita i vodene otopine karbendazima u inkubatorskoj tresilici brzinom od 140 okr/min. Proces je praćen mjerenjem pH vrijednosti u određenim vremenskim intervalima te je određivana ravnotežna koncentracija karbendazima na HPLC uređaju. Najbolju učinkovitost uklanjanja od ≈ 95% pokazao je ZSM-5 zeolit, dok je učinkovitost PZ-a i NaZ3 bila u rasponu od 19,5 do 23,3%, odnosno od 22,5 do 29,0%. Ostatna koncentracija karbendazima nakon obrade na ZSM-5 zeolitu iznosila je 0,31 mg/L, dok je za PZ bila u rasponu od 4,46 do 4,83 mg/L te za NaZ3 u rasponu od 3,98 do 4,88 mg/L. Sve ostatne koncentracije bile su iznad propisanih maksimalno dopuštenih koncentracija (MDK) u vodi, koje za svaki pojedini pesticid iznose 0,10 µg/L, odnosno 0,50 µg/L za ukupne pesticide. Da bi se povećala učinkovitost PZ nužno je poboljšati njegova adsorpcijska svojstva za organskim komponentama iz vode modifikacijom s organskim surfaktantima. Nadalje, u svrhu smanjenja ostatne koncentracije karbendazima ispod MDK daljnja istraživanja trebalo bi usmjeriti na višestupanjsku adsorpciju na sintetskom ili modificiranom PZ šaržnim postupkom ili postupkom u koloni. This paper investigated the possibility of using different types of zeolite - natural zeolite (NZ) clinoptilolite, its homoionic Na - form (NaZ3) and synthetic Zeolite Socony Mobil-5 (ZSM-5), for the removal of carbendazim fungicides from aqueous solution of initial concentration γ o ≈ 5 mg/L. The adsorption was performed by batch process at room temperature, by mixing zeolites and carbendazim solution in an incubator shaker at a speed of 140 rpm. The process was monitored by measuring pH at specific time intervals and equilibrium concentration of carbendazim by HPLC. The best removal efficiency of ≈ 95% was achieved by ZSM-5 zeolite, while the efficiency of NZ and NaZ3 was in the range 19.5 - 23.3% and 22.5 - 29.0%, respectively. The residual concentration of carbendazim after treatment on ZSM-5 zeolite was 0.31 mg/L, while for NZ and NaZ3 was in the range of 4.46 - 4.83 mg/L, and of 3.98 - 4.88 mg/L, respectively. All residual concentrations were above the maximum permissible levels (MPL) in water, which for each pesticide equals to 0.10 µg/L, and 0.50 µg/L for total pesticides. In order to increase the efficiency of NZ, it is necessary to improve its adsorption properties for organic components from water by modification with organic surfactants. Furthermore, for the purpose of reducing the residual concentration of carbendazim below the MPL, further studies should be focused on multistage adsorption on a synthetic ZSM-5 zeolite or modified NZ by batch or column method.