Comparative Study on Advanced Nitrogen Removal of Landfill Leachate Treated by SBR and SBBR

Jinfeng Jiang,Liang Ma,Kai Wang,Daoji Wu,Lianjie Hao

doi:10.3390/w13223240

Abstract

In order to achieve advanced nitrogen removal from landfill leachate without the addition of external carbon sources, a Sequencing Batch Reactor (SBR) and a Sequencing Biofilm Batch Reactor (SBBR) were proposed for the treatment of actual landfill leachate with ammonia nitrogen (NH4+-N) and chemical oxygen demand (COD) concentrations of 1000 ± 100 mg/L and 4000 ± 100 mg/L, respectively. The operating modes of both systems are anaerobic–aerobic–anoxic. After 110 days of start-up and biomass acclimation, the effluent COD and the total nitrogen (TN) of the two systems were 650 ± 50 mg/L and 20 ± 10 mg/L, respectively. The removal rates of COD and total nitrogen could reach around 85% and above 95%, respectively. Therefore, advanced nitrogen removal was implemented in landfill leachate without adding any carbon sources. After the two systems were acclimated, nitrogen removing cycles of SBR and SBBR were 24 h and 20 h, respectively. The nitrogen removing efficiency of SBBR was improved by 16.7% in comparison to SBR. In the typical cycle of the two groups of reactors, the nitrification time of the system was the same, which was 5.5 h, indicating that although the fiber filler occupied part of the reactor space, it had no significant impact on the nitrification performance of the system. At the end of aeration, the internal carbon source content of sludge of SBBR was equivalent to that of the SBR system. However, the total nitrogen concentration of SBBR was only 129 mg/L, which is 33.8% lower than that of SBR at 195 mg/L. The main reason was that biofilm enhanced the simultaneous nitrification and denitrification (SND) effect of the system.

Highlights

With the development of the world economy, increasing generation of solid waste can be witnessed
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Summary

Introduction

With the development of the world economy, increasing generation of solid waste can be witnessed. Rainwater percolating through the landfill, together with the production of liquids during the stabilization of the solid wastes, generates landfill leachate. This is a particular type of wastewater with complex composition, high organic matter, high ammonia nitrogen, and high salt content, which has always been a difficult point and highlight in the water treatment industry [1,2]. One of the difficulties in landfill leachate treatment is advanced nitrogen removal. An anaerobic-oxic (AO) process has been frequently adopted to achieve partial nitrification–denitrification in most of the research on landfill leachate treatment [14]. The changing process has a good effect on the ammonia-nitrogen removal of leachates. The removal rate of the total nitrogen is unlikely to exceed

Methods

Results

Discussion

Conclusion