Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/21/2001
Publication Date: N/A
Technical Abstract: Useful life of landfills can be shortened or their operation become costly if concentration of ammonia in the leachate exceeds discharge limits. Ammonia nitrogen in the leachate of a six-county landfill in central Pennsylvania with 10 yr of additional capacity increased from about 250 mg/L for the first 20 yr of operation to >1000 mg/L in the last 2 yr. An aerated lagoon was not effective and removed only 33% of ammonia. We investigated whether the use of nitrifiers immobilized in polymer pellets, a technology that has been proven effective to treat animal wastewater, has the potential for enhancing ammonia removal from landfill leachate. The leachate was treated in batch and continuous mode using aerated, suspended bioreactors with 10-15% pellets made of polyethylene glycol (PEG) or polyvinyl alcohol (PVA) polymer gels. Nitrification rate increased two-fold with water temperatures from 20 to 30 degrees C and was optimized at 30 to 35 degrees C. Natural alkalinity was supplemented to obtain complete nitrification. Ammonia removal rate of 430 mg N/L-reactor/day and nitrification efficiency of 99% were consistently obtained with short hydraulic retention time of 24 hours. Performance of polymers was similar except that PEG was more effective at lower water temperature. Our results indicate that the use of immobilized polymer technology is useful for treatment of high-ammonia landfill leachate.