Advancement and Challenges in Municipal Landfill Leachate Treatment–The Path Forward!

Abstract

Although landfill leachate is a small volumetric fraction compared to municipal wastewater, its complexity raises concerns for researchers and practitioners. Emerging and novel treatment technologies are being investigated to address landfill leachate treatment challenges. In the past decade, leachate research shifted from the removal of contaminants to the simultaneous recovery of resources and removal of contaminants. While resource recovery is appealing, it is also questionable due to the economic feasibility and post-environmental impact of applied resources. Various emerging contaminants may remain in recovered resources, making recovery a less preferred option. Because of the ineffectiveness of biological treatment of emerging contaminants, such as per- and polyfluoroalkyl substances, leachate cotreatment has been restricted in some wastewater treatment plants. Thus, in the wake of emerging contaminants and stringent regulations, it seems wiser to develop effective, integrated leachate treatments in lieu of widely practiced biological cotreatment. The solid waste industry needs viable, cost-efficient, and readily executable technologies to effectively handle the upcoming need. Thus, in this paper, academic and industry experts discuss the progress, challenges, and future of leachate treatment. This paper provides a forward-thinking evaluation of the past decade’s advancements and challenges in the field of landfill leachate treatment.

Industrial Water Demand and Wastewater Generation: Challenges for Bangladesh’s Water Industry

“…In general, leachate consists of dissolved organic matter, xenobiotic organic compounds, heavy metals, and different anions and cations. − The chemical characteristics of leachate in Bangladesh are comparable to those in other parts of the world (Figure ). − The median concentrations of Fe (17.20 mg L –1 ), Cu (0.93 mg L –1 ), TSS (1395.50 mg L –1 ), BOD (216 mg L –1 ), COD (1571 mg L –1 ), and TDS (6970 mg L –1 ) in leachate are greater than the Bangladesh inland water discharge limits (Figure and Tables S3 and S4). The highest concentrations of these parameters are significantly higher than the median values and the discharge limits.…”

“…from landfill leachate using advanced technologies. 43 Therefore, Bangladesh should consider the shortcomings of the conventional wastewater treatment plants in treating leachate 41 and address such shortcomings to improve the existing treatments. At the same time, the Bangladesh DOE should extend the list of leachate contaminants to include the emerging contaminants and start implementing regulatory discharge limits for such contaminants.…”

“…The existing landfill leachate treatment technologies in Bangladesh are struggling with conventional pollutants (e.g., BOD, COD, NH 3 , and metals), while the worldwide solid waste industry is focusing on removing different emerging contaminants (e.g., per- and polyfluoroalkyl substances, antibiotic resistance genes, plasticizers, etc.) from landfill leachate using advanced technologies . Therefore, Bangladesh should consider the shortcomings of the conventional wastewater treatment plants in treating leachate and address such shortcomings to improve the existing treatments.…”

Chlorine Reuse in UV/Electrochemical Oxidation to Advance Sewage Cotreatment of Landfill Leachate

“…In terms of energy consumption, the chlorine-reuse process coupled with UV dechlorination consumed half the energy required to operate a conventional UV/EO process at 27.3 kWh•m −3 (7.5 and 19.8 kWh•m −3 for R 1 and R 2 , respectively) or 5.1 USD•m −3 . Although studies have suggested that Fenton's oxidation is cost-effective at 0.59−2.70 USD•m −3 in hybrid treatment lines, 4 such processes rely on coagulants, which return to the landfill, and introduce contaminants like iron and sulfate into the treated effluent. 50 Thus, the chlorinereuse process offers better prospects for cost reductions and scalability.…”

“…Plants that prefer on-site methods often implement membrane-based processes such as reverse osmosis (RO). 4 However, these methods are often cost-prohibitive, with operational costs between 6 and 7 USD•m −3 , which dissuade their implementation in many regions. 5 In addition, the RO modules generate brine that can be up to 20 times more concentrated than the original leachate feed, requiring costly treatment that can increase aquatic ecotoxicity according to life cycle assessments.…”