Nanofiltration as post-treatment of MBR treating landfill leachate

Abstract

Landfill leachate management has been a major environmental, economic, and social concern, and its treatment brings forth a challenge, especially regarding the high concentration of refractory organic matter, ammonia, and toxic compounds, which may vary considerably depending on the maturity, age, and biochemical reactions occurring in the landfill, besides the high variation on the volume generated. This study was aimed to investigate NF use as a post-treatment of landfill leachate that has been treated by membrane bioreactor (MBR). The experimental setup consisted of pilot plant comprised by an air stripping reactor, plus MBR and NF membranes. The pilot plant has a treatment capacity of 3 m 3 /d. The system has shown excellent leachate treatment performance, especially regarding the removal of chemical oxigen demand (80-96%), ammonia (85-95%), color (98-99.9%), and phosphorus (78-99.8%). The results have also shown the importance of NF to improve the effluent condition, and to produce treated effluents free of chemical substances and sludge. The membrane fouling was imputed to the adsorption of a humic substance on the membrane surface and the pore-blocking phenomena. By this route, treated landfill leachate may be reused at the landfill as water for dust arrestment, and also as earth work on construction sites.

Novel and Conventional Technologies for Landfill Leachates Treatment: A Review

“…Liu et al [160] performed an innovative combined treatment process of air stripping, Fenton, SBR and coagulation, finding high COD and NH 4 -N removal rates of 92.8% and 98%, respectively. Amaral et al [161] suggested a landfill treatment configuration consisting of an association of air stripping, MBR, and a NF (nano-filtration) membrane which has shown excellent performance, especially regarding the removal of COD (80%-96%), ammonia (85%-95%), color (98%-99.9%), and phosphorus (78%-99.8%). Gao et al [162] introduced an integrated approach with the continuous recirculation of ozonated autotrophic nitrogen removal (ANR) effluent, showing the possibility to reach a COD removal as high as 40% in the ANR with a slight decrease in nitrogen removal of around 70%-80% when compared with no leachate ozonated recirculation.…”

An Overview of Treatments for Ultraviolet Quenching Substances (UVQS) and Per- and Polyfluoroalkyl Substances (PFAS) Removal from Landfill Leachate

“…For example, a study on ultrafiltration of biologically treated leachates showed an increase of UV absorbance removal close to 43% when pore size decreased from 700 nm to 7 nm; in this pore size range, HA and FA were mainly retained; for pore size of 4 nm, additional UV absorbance removal was obtained due to retention of HPI [60,61]; in consequence, the smaller the pore size, the greater the removal of UVQS. The main handicap of using membranes to remove UVQS is the increase of membrane fouling in the presence of these compounds [62,63].…”

Detoxification of Leachate by Coagulation Treatment Prior to Fermentation and Possible Reuse in Irrigation

“…The obtained results presented high COD (92.8%) and NH 4 + ‐N (98%) removal rates. Amaral and his co‐workers [ 25 ] performed an LFL treatment method consisting in air stripping associated with a membrane bioreactor using a nanofiltration membrane. This system has shown good performances for the removal of COD, ammonia, color, and phosphorus, where the recorded values exceeded 80%.…”