The degradation of iprodione (IPR), a once frequently used but recently banned dicarboximide fungicide, by UV-C light-, zero-valent iron- (ZVI), and zero-valent aluminium (ZVA)-activated persulfate (PS) oxidation processes was comparatively studied in distilled (pure) water (DW) and simulated, tertiary treated urban wastewater (SWW). The performance of PS-activated oxidation processes was examined by following IPR (2–10 mg/L) removal, PS (0.01–1.00 mM) consumption, metal ion release (for the two heterogeneous catalytic oxidation processes), dissolved organic carbon (DOC) removal as well as hydroxylated aromatic and low molecular weight aliphatic degradation products. The effect of pH and PS concentrations on IPR removal was examined in DW. While the experiments in DW highlighted the superior performance of UV-C/PS treatment (with 78% DOC removal after 120 min at pH = 6.2), the performance of UV-C/PS treatment decreased sharply (to 24% DOC removal after 120 min at pH = 6.8) in the complex wastewater matrix (in SWW). Complete IPR (in 20 min) and 40% DOC (in 120 min) removals were obtained with ZVI/PS treatment (1 g/L ZVI, 1.5 mM PS, pH = 3.0), which was the most effective oxidation process in SWW. The treatment performance was strongly influenced by the SWW constituents, and UV-C/PS treatment appeared to be the most sensitive to it.

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This Methyl tert-butyl ether (MTBE) is one of the main additives in gasoline to increase octane rating and consequently reduce air pollution. The physico-chemical properties of this substance (high water solubility, low sorption in soil) result in high mobility and considerable concentrations in aquifers. In this survey, Isfehan Refinery that was encountered with MTBE contamination problem was selected as a case study and the MTBE degradation ability of this contaminated area by its indigenous microorganisms was investigated. In the first step of this survey, the influence of various factors on the aerobic degradation of MTBE such as mixed culture type, incubation time, microbial culture and optimal concentration of MTBE were investigated in shaking flasks and the most important factors were specified by means of fractional factorial design ½. In the second stage by using optimal values which obtained from the first stage, the effects of co-substare parameter and inoculum parameter were assayed by means of response surface method. The results of the experiments showed that the mixed culture type and initial concentration of MTBE were the most significant factors. The results of the experiments showed that the mixed indigenous culture acted better than activated sludge. The initial concentration of MTBE was also one of the most significant factors. At the best condition about 31 percent of MTBE was treated by co-substrating with n-hexane in a ratio of 0.2.

Zero-valent iron (ZVI)- and zero-valent aluminium (ZVA)-activated persulfate (PS) oxidation procedure was applied to remove the industrial pollutants 3,5-dichlorophenol (3,5-DCP; 12.27 µM) and 2,4-dichloroaniline (2,4-DCA; 12.34 µM) from aqueous solutions. The effects of PS concentration and pH were investigated to optimize heterogeneous treatment systems. Negligible removals were obtained for both pollutants by individual applications of nanoparticles (1 g/L) and PS (1.00 mM). PS activation with ZVI resulted in 59% (1.00 mM PS; 1 g/L ZVI; pH 5.0; 120 min) and 100% (0.75 mM PS; 1 g/L ZVI; pH 5.0; 80 min) 3,5-DCP and 2,4-DCA removals, respectively. The ZVA/PS treatment system gave rise to only 31% 3,5-DCP (1.00 mM PS; 1 g/L ZVA; pH 3.0; 120 min) and 47% 2,4-DCA (0.25 mM PS; 1 g/L ZVA; pH 3.0; 120 min) removals. The pH decreases from 5.0 to 3.0 and from 3.0 to 1.5 enhanced contaminant removals for ZVI/PS and ZVA/PS treatments, respectively. Pollutant removal rates were in correlation with the consumption rates of the oxidants. Metal ion (Al, Fe) release increased in the presence of PS and with decreasing pH.