Evaluation of Fenton and ozone-based advanced oxidation processes as mature landfill leachate pre-treatments

Abstract

Fenton treatment (Fe(2+)/H(2)O(2)) and different ozone-based Advanced Oxidation Processes (AOPs) (O(3), O(3)/OH(-) and O(3)/H(2)O(2)) were evaluated as pre-treatment of a mature landfill leachate, in order to improve the biodegradability of its recalcitrant organic matter for subsequent biological treatment. With a two-fold diluted leachate, at optimised experimental conditions (initial pH 3, H(2)O(2) to Fe(2+) molar ratio of 3, Fe(2+) dosage of 4 mmol L(-1), and reaction time of 40 min) Fenton treatment removed about 46% of chemical oxygen demand (COD) and increased the five-day biochemical oxygen demand (BOD(5)) to COD ratio (BOD(5)/COD) from 0.01 to 0.15. The highest removal efficiency and biodegradability was achieved by ozone at higher pH values, solely or combined with H(2)O(2). These results confirm the enhanced production of hydroxyl radical under such conditions. After the application for 60 min of ozone at 5.6 g O(3)h(-1), initial pH 7, and 400 mg L(-1) of hydrogen peroxide, COD removal efficiency was 72% and BOD(5)/COD increased from 0.01 to 0.24. An estimation of the operating costs of the AOPs processes investigated revealed that Fe(2+)/H(2)O(2) was the most economical system (8.2 € m(-3)g(-1) of COD removed) to treat the landfill leachate. This economic study, however, should be treated with caution since it does not consider the initial investment, prices at plant scale, maintenance and labour costs.

Molecular mechanisms of phosphatidylcholine monolayer solidification due to hydroxyl radicals

“…500 µm with a glass block. If the electron density on the surface is laterally periodical, the evanescent wave is difDeleted: [10] Deleted: [11] Page 7 of 32 Soft Matter …”

Semi-aerobic stabilized landfill leachate treatment by ion exchange resin: isotherm and kinetic study

“…Despite rapid changes of landfill technology from uncontrolled dump site to a highly engineered landfill for ultimate solid waste disposal method, generation of heavily polluted leachate remains inevitable (Cortez et al 2011). Poorly managed inefficient landfilling has been seen as the major factor contributing to hydro geological contamination that originates from leachate that infiltrates into soil and groundwater.…”

The removal of organic compounds from landfill leachate using ozone-based advanced oxidation processes

“…The final product is usually acetic and oxalic acid. With the use of lower doses of ozone, the disruption of bonds in macromolecular compounds can lead to the formation of alcohols, aldehydes and ketones [6,7,8]. In addition to removing the organic compounds, ozonation also reduces the color of landfill leachates and eliminates odor nuisance [2].…”