Article

Pretreatment of stabilized leachate using ozone/persulfate oxidation process

The Chemical Engineering Journal (Impact Factor: 4.32). 01/2013; 221. DOI: 10.1016/j.cej.2013.02.038

ABSTRACT

A combination of ozonation and persulfate ðO3=S2O2� 8 Þ was used to treat stabilized landfill leachate. COD,
color, and NH3–N, ozone and persulfate doses, pH and reaction time were evaluated to define the optimum
operational conditions. The results indicated that under optimum operation conditions (i.e.
210 min of ozonation, a COD=S2O2� 8 ratio (1 g/7 g), and pH 10), the best removal values of COD, color,
and NH3–N were 72%, 93%, and 55%, respectively. The biodegradability (BOD5/COD ratio) has improved
from 0.05 to 0.29. The ozone consumption for COD removal was 0.76 kg O3/kg COD. The results obtained
by employing the combined use of persulfate and ozone were compared with those by employing ozone
only and persulfate only. The results achieved with the combined use of persulfate and ozone were compared
with those obtained with ozone only and persulfate only. The combined method (i.e., O3=S2O2� 8 )
achieved higher removal efficiencies for COD, color, and NH3–N compared with other studied applications.
Additionally, the combined of ozone/persulfate method proved to be more efficient than the combined
use of ozone/Fenton in advanced oxidation processes in the treatment of the same studied leachate.

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Available from: Salem Abu Amr
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    • "Persulfate can act as a direct oxidant; however, its effectivenessto treat high recalcitrant contaminants is limited (Watts, 2011; Liu et al., 2012). The effectiveness of persulfate alone in stabilized leachate treatment is relatively low (Abu Amr et al., 2013a, b, c); however, its effectiveness can be improved using advanced oxidation materials and techniques. Shabiimam and Dikshit (2012) used low pH (2e4.5) to improve persulfate oxidation in removing Total organic carbon (TOC) and color from stabilized leachate. "
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    ABSTRACT: A combination of persulfate and hydrogen peroxide (S 2 O 2À 8 /H 2 O 2) was used to oxidizelandfill leachate. The reaction was performed under varying S 2 O 2À 8 /H 2 O 2 ratio (g/g), S 2 O 2À 8 /H 2 O 2 dosages (g/g), pH, and reaction time (minutes), so as to determine the optimum operational conditions. Results indicated that under optimum operational conditions (i.e. 120 min of oxidation using a S 2 O 2À 8 /H 2 O 2 ratio of 1 g/1.47 g at a persulfate and hydrogen peroxide dosage of 5.88 g/50 ml and8.63 g/50 ml respectively, at pH 11) removal of 81% COD and 83% NH 3 eN was achieved. In addition, the biodegradability (BOD 5 /COD ratio) of the leachate was improved from 0.09 to 0.17. The results obtained from the combined use of (S 2 O 2À 8 /H 2 O 2) were compared with those obtained with sodium persulfate only, hydrogen peroxide only and sodium persulfate followed by hydrogen peroxide. The combined method (S 2 O 2À 8 /H 2 O 2) achieved higher removal efficiencies for COD and NH 3 eN compared with the other methods using a single oxidizing agent. Additionally, the study has proved that the combination of S 2 O 2À 8 /H 2 O 2 is more efficient than the sequential use of sodium persulfate followed by hydrogen peroxide in advanced oxidation processes aiming at treatingstabilizedlandfill leachate.
    Full-text · Article · Nov 2015 · Journal of Environmental Management
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    • "Abu Amr et al. (2013a) used ozone gas to initiate sulfate radical from persulfate during ozonation of stabilized leachate . Ozone cannot react directly with persulfate; however, at high pH (11), significant amount of ozone applied will dissociate and produce hydroxyl radicals which will be involved in the activation of persulfate during ozonation (Abu Amr et al., 2013a,b). "
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    ABSTRACT: The current study investigated the effects of S2O8(2-) and S2O8(2-)/H2O2 oxidation processes on the biodegradable characteristics of an anaerobic stabilized leachate. Total COD removal efficiency was found to be 46% after S2O8(2-) oxidation (using 4.2g S2O8(2-)/1g COD0, at pH 7, for 60min reaction time and at 350rpm shaking speed), and improved to 81% following S2O8(2-)/H2O2 oxidation process (using 5.88g S2O8(2-) dosage, 8.63g H2O2 dosage, at pH 11 and for 120min reaction time at 350rpm). Biodegradability in terms of BOD5/COD ratio of the leachate enhanced from 0.09 to 0.1 and to 0.17 following S2O8(2-) and S2O8(2-)/H2O2 oxidation processes, respectively. The fractions of COD were determined before and after each oxidation processes (S2O8(2-) and S2O8(2-)/H2O2). The fraction of biodegradable COD(bi) increased from 36% in raw leachate to 57% and 68% after applying S2O8(2-) and S2O8(2-)/H2O2 oxidation, respectively. As for soluble COD(s), its removal efficiency was 39% and 78% following S2O8(2-) and S2O8(2-)/H2O2 oxidation, respectively. The maximum removal for particulate COD was 94% and was obtained after 120min of S2O8(2-)/H2O2 oxidation. As a conclusion, S2O8(2-)/H2O2 oxidation could be an efficient method for improving the biodegradability of anaerobic stabilized leachate. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Aug 2015 · Waste Management
    • "As a consequence, biological treatment methods, such as activated sludge, anaerobic filtration, and anaerobic lagoons, which normally effect reducing concentrations of organic matter in young landfill leachate [5] are ineffective for treating stabilized leachate. Thus, physico-chemical techniques are demanded for stabilized landfill leachate treatment [6] [7] [8] [9]. Several physicochemical treatments have been studied for stabilized landfill leachate treatments including electro-oxidation [10] [11], ion-exchange [11] [12], coagulation–flocculation [13] [14], and adsorption [15]. "
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    ABSTRACT: Adsorption via activated carbon (AC) is one of the best methods to treat stabilized landfill leachate. However, this technique has been justified due to expensive and limited resource of AC precursor. Thus, in this study, sugarcane bagasse, a cheap and abundant biomass from agricultural waste, was used to prepare AC. The prepared sugarcane bagasse activated carbon (SCAC) was tested for color, chemical oxygen demand (COD), and ammoniacal nitrogen (NH3-N) removals from anaerobic stabilized landfill leachate. SCAC was prepared using physical and chemical activation. SCAC was characterized for its surface area, surface morphology, and functional groups. The performance of the adsorbent was examined in a batch mode study by varying the shaking speed, contact time, adsorbent dosage, and pH. The experimental results indicated that SCAC could adsorb and remove the pollutants from anaerobic municipal stabilized landfill. Removal of color, COD, and NH3-N were favorably described by Langmuir isotherm model, with a maximum monolayer adsorption capacity of 555.56 Pt/Co, 126.58 and 14.62 mg/g, respectively. Pseudo-second-order model fits well with the experimental results and indicates that the adsorption was controlled by chemisorptions. The experimental results revealed that the optimum experimental conditions (e.g. 200 rpm shaking speed, 180 min contact time, 7 g AC dosage, and pH 7) resulted in 94.74, 83.61, and 46.65% removal of color, COD, and NH3-N, respectively.
    No preview · Article · Dec 2014 · Desalination and water treatment
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