Sequencing treatment of landfill leachate using ammonia stripping, Fenton oxidation and biological treatment

Abstract

Landfill leachates contain a wide variety of pollutants such as organic matter, refractory compounds, ammonia, particulate and dissolved solids and hazardous metals requiring application of advanced and well designed treatment processes before release to the environment. The main purpose of this research was to evaluate the efficiency of combined air stripping, Fenton oxidation and biological treatment in treating landfill leachate, especially the elimination of ammonia and refractory organics. The laboratory scale set-up consisted of three sequential but separate steps. The optimum conditions for air stripping and the Fenton oxidation were determined for landfill leachate from Karaj city, Iran. The final step was a moving bed bioreactor with HRTs of 18, 12 and 6 h. The highest NH(3)-N removal was 79% in the air stripping process at pH 10.5. At the optimum conditions for the Fenton reaction at a reaction time of 90 min, pH 3 and a H(2)O(2)/Fe(2+) mass ratio of 20, the COD removal was 61% and improved the BOD/COD ratio from 0.42 to 0.78. The overall COD removal including the final biological reactor with a HRT of 6 h resulted in an effluent COD concentration of less than 100 mg L(-1).

Ammonia removal from landfill leachate by air stripping and absorption

“…Several studies have reported that air stripping is successful in removing ammonia from landfill leachate [6][7][8][9][10][11][12][13][14][15] and many other wastewaters, such as those from the fertilizer industry [16], pig slurry [17,18], anaerobic digestion effluent [19,20] or source-segregated food waste [21]. The effectiveness of ammonia removal obtained in these studies was in the range of 90-99%.…”

“…The results of treating landfill leachate by air stripping in this work were compared with those reported by several authors and are summarized in Table 4. The TAN removal rate of Batch 1 was the greatest among the previously reported values [6][7][8][9][10][11][12][13][14][15]. Based on the cited literature data, the times required to reach the Brazilian environmental law discharge limit for TAN were estimated.…”

“…In addition, the majority of studies on air stripping relied on small stripping units in which air was bubbled at low rates (from 1.2-300 L h −1 ) and only a small volume of leachate (0.8-4 L) was treated [6][7][8][9][10]13,15,17,18,20]. …”

Investigating Activated Sludge Microbial Population Efficiency in Heavy Metals Removal from Compost Leachate

“…The mixing ratio of the leachate and activated sludge was 1/1 (3-l leachate/3-l sludge). A spherical poly propylene media with 55 mm diameter and specific surface of 300 m 2 COD removal of leachate in suspended and attached growth reactors are shown in Fig. 2.…”

A comparative examination of MBR and SBR performance for the treatment of high-strength landfill leachate

“…Leachate quality can exhibit considerable spatial and temporal variations depending on site operations, refuse characteristics (composition and age), and internal landfill processes requiring varied management options. For this purpose, several options can be adopted, including discharge into sewer systems for subsequent treatment with municipal wastewater (Çeçen and Çakiroğlu, 2001;Trabelsi et al, 2011;Puszczało et al, 2010), recirculation (Rodríguez et al, 2004;Sethi et al, 2013), evaporation followed by sludge disposal (Afsharnia et al, 2012), and on-site treatment and disposal (Bodzek et al, 2006;Nurisepehr et al, 2012).…”