title: Comparative assessment of compost and zeolite utilisation for the simultaneous removal of BTEX, Cd and Zn from the aqueous phase: Batch and continuous flow study.
abstract: The present study focuses on the comparison of two materials, compost from municipal solid waste and natural zeolite for the simultaneous removal of petroleum hydrocarbons (benzene, toluene, ethylbenzene, xylenes - BTEX) and toxic metals from groundwater. First, batch experiments were conducted to identify the optimal removal conditions. All of the kinetic experiments were fitted to the pseudo-second-order kinetic model; equilibrium was reached within approximately 8 h for the zeolite and 12 h for the compost. An increase in the adsorbent dose and the pH value as well as a decrease in the initial concentration enhanced the pollutants' removal. The removal selectivity of both materials with slight differences follows the order Cd > Zn & toluene > ethylbenzene > m- & p-xylene > o-xylene > benzene. According, to the results derived from the continuous flow experiments the maximum adsorption capacity of the compost (90%) referred to Cd (0.88 mmol/g) whereas the minimum refers to benzene (65%) with a capacity up to 0.065 mmol/g. Zeolite had lower efficiencies for the studied pollutants with a higher performance corresponding to Cd (0.26 mmol/g), whereas the minimum zeolite capacity (63%) corresponds to toluene (0.045 mmol/g). Thus, this paper provides evidence that compost, a low cost material produced from waste, is capable for the simultaneous removal of both organic and inorganic pollutants from wastewater, and its performance is superior to zeolite.
authors.affiliation: School of Environmental Engineering, Laboratory of Toxic and Hazardous Waste Management Technical University of Crete, GR-73100, Chania, Crete, Greece.
authors.forename: Fotini
authors.initials: F
authors.lastname: Simantiraki
authors.affiliation: School of Environmental Engineering, Laboratory of Toxic and Hazardous Waste Management Technical University of Crete, GR-73100, Chania, Crete, Greece. Electronic address: gidarako@mred.tuc.gr.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Gidarakos
mesh_terms: D000327:Adsorption; D001554:Benzene / Q000302:isolation & purification; D001555:Benzene Derivatives / Q000737:chemistry / Q000302:isolation & purification; D002104:Cadmium / Q000737:chemistry / Q000302:isolation & purification; D060587:Groundwater / Q000737:chemistry; D006838:Hydrocarbons / Q000737:chemistry / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010578:Petroleum; D012987:Soil; D062611:Solid Waste; D014050:Toluene / Q000737:chemistry / Q000302:isolation & purification; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D014992:Xylenes / Q000737:chemistry / Q000302:isolation & purification; D017641:Zeolites; D015032:Zinc / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D001555:Benzene Derivatives; D006838:Hydrocarbons; D010578:Petroleum; D012987:Soil; D062611:Solid Waste; D014874:Water Pollutants, Chemical; D014992:Xylenes; D002104:Cadmium; D017641:Zeolites; D014050:Toluene; C031286:4-xylene; D015032:Zinc; D001554:Benzene; C004912:ethylbenzene; C026114:2-xylene
keywords: Compost; Continuous flow; Hydrocarbons; Metals; Zeolite