Contemporary Environmental Issues of Landfill Leachate: Assessment and Remedies

Abstract

Landfills are the primary option for waste disposal all over the world. Most of the landfill sites across the world are old and are not engineered to prevent contamination of the underlying soil and groundwater by the toxic leachate. The pollutants from landfill leachate have accumulative and detrimental effect on the ecology and food chains leading to carcinogenic effects, acute toxicity and genotoxicity among human beings. Management of this highly toxic leachate presents a challenging problem to the regulatory authorities who have set specific regulations regarding maximum limits of contaminants in treated leachate prior to disposal into the environment to ensure minimal environmental impact. There are different stages of leachate management such as monitoring of its formation and flow into the environment, identification of hazards associated with it and its treatment prior to disposal into the environment. This review focuses on: (i) leachate composition, (ii) Plume migration, (iii) Contaminant fate, (iv) Leachate plume monitoring techniques, (v) Risk assessment techniques, Hazard rating methods, mathematical modeling, and (vi) Recent innovations in leachate treatment technologies.However, due to seasonal fluctuations in leachate composition, flow rate and leachate volume, the management approaches cannot be stereotyped. Every scenario is unique and the strategy will vary accordingly. This paper lays out the choices for making an educated guess leading to the best management option.

Characterization of Lakhodair Landfill Leachate

“…Monitoring and predicting landfill leachate and the variation in its flows and composition, associated risk assessment and hazard rating, and designing the most accurate treatment system before disposing it into environmental sinks are the phases of leachate management required to protect environment and the human beings from its harmful impacts [3,13].…”

“…Rather, these are globally considered the best option for managing municipal solid waste [2,3] and have maintained their status of the eventual fortune for all types of solid waste [4]. Further, this is the cheapest way for the disposal of large amount of waste [5] and is hence a common practice in most of the countries across the globe [6].…”

“…This leachate varies in its flows and characteristics at different phases of a landfill life cycle [1][2][3]9,10] and along different seasons [1,10].…”

Characterization of the Organic Fraction of Pretreated Leachate from Old Landfill after Sonication Exposure

“…On young landfill leachate production is slightly smaller compared to the old (over 10 years of operation). This is due to the decreasing water retention capacity of the waste and increasing over time stabilization of organic substances [9,12]. Due to inter alia the varied composition of the waste and the variety of storage technologies leachate show a different and difficult to predict the composition In addition, as a result of biochemical processes in the deposited, waste is changing the nature of the leachate and their composition reflects the degree of decomposition of organic matter [8].…”

“…They are characterized by pollutants that make reach high value of the parameters related to the organic pollution BOD 5 and COD which the ratio reaches high values above 0.7 which shows the ready biodegradability pH of the leachate is also slightly acidic due to the presence of significant amounts of volatile fatty acids [8][9][10]12].…”