Abstract

Given the high ammonia nitrogen (NH3-N) concentration and low biological oxygen demand/chemical oxygen demand (BOD/COD) ratio (<0.1) in mature landfill leachate, it is hard to treat it with the membrane bioreactor (MBR) system to meet the discharge standard for Pollution Control of the Municipal Solid Waste Landfills” (GB16889-2008) without additional carbon source. This pilot-scale study evaluated the use of negative pressure steam-stripping technology for the pretreatment of mature landfill leachate. Our study results have shown that NH3-N concentrations of raw leachate and treated effluent from steam-stripping tower were respectively 2941–3648 mg/L and 401–710 mg/L, yielding an average NH3-N removal efficiency of 82.03%. Nitrogen (N) was recovered via the formation of NH4HCO3 in the ammonia recovery tower, and the effluent of steam-stripping tower was further treated by MBR system. Economic evaluation results showed that initial investment in pretreatment could be offset by respectively reducing energy consumption and operational costs of the MBR system by 60% and 80%. Furthermore, most of Ca2+ and Mg2+ in mature leachate was removed through the formation of CaCO3 and MgCO3 after pretreatment, which avoided membrane fouling and increased the membrane filtration efficiency of MBR system. To conclude, this pilot-study has indicated that negative pressure steam-stripping pretreatment is an efficient and cost-effective technology for the removal of NH3-N, making MBR technology viable without the need for additional carbon source.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.