Recovering metal(loids) and rare earth elements from closed landfill sites without excavation: Leachate recirculation opportunities and challenges

Lee, H.; Coulon, Frédéric; Beriro, Darren J.; Wagland, Stuart T.

doi:10.1016/j.chemosphere.2021.133418

Cited by 14 publications

(4 citation statements)

References 154 publications

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“…Minimizing settlement is essential to maintain the landfill’s structural integrity and prevent damage to the waste containment system. Moreover, increased biological activity leads to an improved compression index of waste, enabling the accommodation of more waste in the same area 41 . In landfills with larger waste particles and more significant void spaces, heat might be confined and concentrated, potentially leading to the formation of heat pockets.…”

Section: Discussionmentioning

confidence: 99%

Experimental investigation and multi-performance optimization of the leachate recirculation based sustainable landfills using Taguchi approach and an integrated MCDM method

Khan,

Mufazzal,

Sherwani

et al. 2023

Sci Rep

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Landfill leachates contain harmful substances viz. chemicals, heavy metals, and pathogens, that pose a threat to human health and the environment. Unattended leachate can also cause ground water contamination, soil pollution and air pollution. This study focuses on management of leachate, by recirculating the rich, nutrient-filled fluid back into the landfills, turning it to a bioreactor, thereby maximising the performance parameters of landfills favourable for electricity production by the waste to energy plants. This study demonstrates a sustainable alternative method for utilising the fluid, rather than treating it using an extremely expensive treatment process. Further, it also experimentally investigates the effect of varying levels of five input parameters of the landfill including waste particle size, waste addition, inorganic content in waste, leachate recirculation rate, and landfill age, each at five levels, on the multiple performance of the landfill using Taguchi’s L25 standard orthogonal array. Experimental results are analysed using an integrated MCDM approach i.e. MEREC-PIV method and statistical techniques such as analysis of mean (ANOM) and analysis of variance (ANOVA). The results indicate that the optimal setting of the input parameters is waste particle size at 9 ppm, waste addition at 80 Ktoe, inorganic content in waste at 2%, leachate recirculation rate at 250 l/day and landfill age at 3 years. Further, inorganic content waste is found to be the most significant parameter for the multiple performance of the landfill. This study presents a novel approach to produce input parameters for power plants which may enhance their profitability and sustainability.

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Section: Discussionmentioning

confidence: 99%

Experimental investigation and multi-performance optimization of the leachate recirculation based sustainable landfills using Taguchi approach and an integrated MCDM method

Khan,

Mufazzal,

Sherwani

et al. 2023

Sci Rep

View full text Add to dashboard Cite

show abstract

“…It also accelerates landfill stabilization, which leads to reducing land use, reducing the required time from several decades to 2-3 years, and reducing environmental pollution [130]. Leachate recycling can decrease the COD and BOD 5 concentrations of leachate over time, but it may also result in a low BOD 5 /COD ratio and an increase in nitrogen concentration [131,132]. Leachate recirculation enhances waste decomposition, landfill gas production, settlement, and leachate treatment.…”

Section: Recyclingmentioning

confidence: 99%

An Extensive Analysis of Combined Processes for Landfill Leachate Treatment

Jamrah,

AL-Zghoul,

Al-Qodah

2024

Water

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Sanitary landfilling is the predominant process for solid urban waste disposal, but it generates leachate that poses environmental, economic, and social concerns. Landfill leachate (LL) contains complex and refractory pollutants and toxic compounds that can vary depending on landfill maturity, age, and biochemical reactions, making its treatment challenging. Due to its unique characteristics and occurrence in remote locations, LL requires separate treatment from wastewater. Various conventional treatment processes involving biological, chemical, and physical processes have been used for LL treatment, but a single treatment process is insufficient to meet environmental standards. This review demonstrates that combined treatment processes are more effective and efficient for LL treatment compared to single processes. Among the various combinations, chemical–chemical and chemical–biological treatments are the most commonly used. Specifically, the integration of Fenton with adsorption and a membrane bioreactor (MBR) with nanofiltration (NF) processes shows promising results. The combined processes of MBR with NF, Fenton with adsorption, and PF with biological treatment show maximum removal efficiencies for COD, reaching 99 ± 1%, 99%, 98%, and 97%, respectively. Additionally, the combined Fenton with adsorption process and EC with SPF process enhance biodegradability as indicated by increased BOD5/COD ratios, from 0.084 to 0.82 and 0.35 to 0.75, respectively. The findings emphasize the importance of developing and implementing enhanced combined treatment processes for LL, with the aim of achieving efficient and comprehensive pollutant mineralization. Such processes have the potential to address the environmental concerns associated with LL and contribute to sustainable waste management practices.

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“…In the past decade, materials containing metals at the end of their useful life, often referred to as metal-bearing wastes, have gained widespread recognition as secondary resources for critical raw materials. This acknowledgement stems from the fact that the metal content in such wastes is comparable to that found in natural ores [9,14,15]. For instance, e-waste can contain Cu levels up to 26.0 times higher and Au content up to 50.0 times higher compared to ores and concentrates [16].…”

Section: Introductionmentioning

confidence: 99%

“…Metals, encompassing varying metal elements and alloys, metalloids and rare earth elements, collectively referred to as 'metals,' are in exceptionally high demand, playing an indispensable role in the development of modern cities and technological products [9]. Meeting the continuously growing demand for metals has become a challenging task due to the declining quality of ore sources [10,11].…”

Section: Introductionmentioning

confidence: 99%

Discarded e-waste/printed circuit boards: a review of their recent methods of disassembly, sorting and environmental implications

Oke,

Potgieter

2024

J Mater Cycles Waste Manag

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The improper disposal of discarded electronic and electrical equipment raises environmental and health concerns, spanning air pollution to water and soil contamination, underscoring the imperative for responsible management practises. This review explores the complex composition of discarded printed circuit boards (DPCBs), crucial components in electronic devices. Comprising substrates, electronic elements and solder, DPCBs showcase a heterogeneous structure with metal (30.0–50.0%) and non-metal (50.0–70.0%) fractions. Notably abundant in precious metals such as Au, Ag, and Pd, DPCBs offer a compelling avenue for recycling initiatives. The inclusion of heavy metals and flame retardants adds complexity, necessitating environmentally sound disposal methods. Ongoing research on smart disassembly, utilising 3D image recognition technology, underscores the importance of accurate identification and positioning of electronic components (ECs). The targeted approach of smart disassembly, centred on valuable components, highlights its significance, albeit with challenges in equipment costs and capacity limitations. In mechanical disassembly, techniques such as grinding and heat application are employed to extract ECs, with innovations addressing gas emissions and damage induced by overheating. Chemical disassembly methods, encompassing epoxy resin delamination and tin removal, present promising recovery options, whilst the integration of chemical and electrochemical processes shows potential. Efficient sorting, encompassing both manual and automated methods, is imperative post-disassembly, with smart sorting technologies augmenting accuracy in the identification and categorisation of ECs. In addition, explorations into NH3/NH4+ solutions for selective metal recovery underscore challenges and stress the necessity for meticulous process optimisation in environmentally sustainable PCB recycling. Challenges and future perspectives have also been expounded.

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Recovering metal(loids) and rare earth elements from closed landfill sites without excavation: Leachate recirculation opportunities and challenges

Cited by 14 publications

References 154 publications

Experimental investigation and multi-performance optimization of the leachate recirculation based sustainable landfills using Taguchi approach and an integrated MCDM method

Experimental investigation and multi-performance optimization of the leachate recirculation based sustainable landfills using Taguchi approach and an integrated MCDM method

An Extensive Analysis of Combined Processes for Landfill Leachate Treatment

Discarded e-waste/printed circuit boards: a review of their recent methods of disassembly, sorting and environmental implications

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