Remediation of Perfluoroalkyl Substances in Landfill Leachates by Electrocoagulation

Abstract

A process for the determination of anaerobic-oxic biologically treated perfluoroalkyl substances (PFASs) in leachates from a landfill in Beijing, China, is provided. The applicability of electrocoagulation (EC) with aluminum electrodes for the remediation of PFASs in landfill leachates is investigated in detailed. With reaction time of 45 min, plate distance of 1 cm, current density of 35 mA/cm 2 and plate amounts of four pairs, the EC reactor achieved the optimal removal efficiencies for chemical oxygen demand and PFASs. Perfluorooctane sulfonate was not detected in the treated leachates after the EC treatment. The average removal efficiencies of perfluorohexanoic acid, perfluoroheptanoic acid, perfluorooctanoate acid, perfluorononanoic acid and perfluorodecanoic acid were 65.1, 58.5, 75.2, and 33.8%, respectively. However, perfluoroundecanoic acid and perfluorododecanoic acid concentration increased by about 20.2 and 18.6% after the EC treatment process.

PFOA and PFOS Are Generated from Zwitterionic and Cationic Precursor Compounds During Water Disinfection with Chlorine or Ozone

“…5,7−9 The U.S. EPA recently released an updated drinking water advisory on PFOA and PFOS specifying a maximum combined level of 70 ng/L, 10 making removal of PFOA/PFOS from drinking water 11−16 and remediation of PFAS-contaminated sites a priority issue. 17,18 The contamination of drinking water by PFOA or PFOS may result from both direct 3,19 and indirect 20 sources. Indirect sources are precursor compounds that contribute to secondary formation of PFOA/PFOS in natural and engineered systems.…”

“…Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS), members of a group of compounds known as per- and polyfluoroalkyl substances (PFASs), have been detected in drinking water in many locations. − PFOA and PFOS are both resistant to degradation − and difficult to remove during conventional water and wastewater treatment. ,− The U.S. EPA recently released an updated drinking water advisory on PFOA and PFOS specifying a maximum combined level of 70 ng/L, making removal of PFOA/PFOS from drinking water − and remediation of PFAS-contaminated sites a priority issue. , …”

Perfluoroalkyl acids in municipal landfill leachates from China: Occurrence, fate during leachate treatment and potential impact on groundwater

“…Efficient removal of PFAAs during leachate treatment is expected to be a challenging task; additional expensive treatment processes (e.g. black carbon adsorption) are probably required but mostly not implemented (Appleman et al, 2014;Zhang et al, 2014a). However, the effectiveness of commonly-applied leachate treatment processes for removing PFAAs is not well-known due to the limited studies reporting the fate and mass flow of PFAAs during leachate treatment processes.…”

The Current Status of Hazardous Waste Management in China: Identification, Distribution, and Treatment

“…Recycling means the utilization of HW as substitutes or feedstocks in commercial products or industrial processes. HW recycling is not only beneficial for environmental protection but also advantageous in the financial perspective (Zhang et al, 2014;Zhao et al, 2020). Guo et al (2020) used microemulsion extraction method to separate and recover vanadium (V) and chromium (Cr) from ammonium Yu et al (2019) recycled La-and Ce-containing polishing slurry by acid extraction and studied the preparation of ammonia decomposition catalysts through glycine-nitrate combustion process using the recycled products.…”