A Review of Landfill Leachate Treatment by Microalgae: Current Status and Future Directions

Abstract

Solid waste generation has been projected to increase worldwide. Presently, the most applied methodology to dispose of solid waste is landfilling. However, these landfill sites, over time release a significant quantity of leachate, which can pose serious environmental issues, including contamination of water resources. There exist many physicochemical and biological landfill leachate treatment schemes with varying degrees of success. With an increasing focus on sustainability, there has been a demand for developing eco-friendly, green treatment schemes for landfill leachates with viable resource recovery and minimum environmental footprints. Microalgae-based techniques can be a potential candidate for such a treatment scenario. In this article, research on microalgae-based landfill leachate treatments reported in the last 15 years have been summarized and critically reviewed. The scale-up aspect of microalgae technology has been discussed, and the related critical factors have been elucidated. The article also analyzes the resource recovery potential for microalgal techniques with respect to leachate treatment and explores possible methodologies to minimize the environmental footprints of the microalgae-based treatment process. The future research potential in the area has been identified and discussed.

Performance of integrated sequencing batch reactor (SBR) and reverse osmosis (RO) process for leachate treatment: effect of pH

“…The sample also contained a high content of TDS with value of 10,800 mg/L. The concentrations of raw leachate were found within reported range and suggested that analyzed leachate are at intermediate stage, between acidogenic and matured (methanogenic) phase of biodegradation [ 3 , 39 – 42 ].…”

Potential of Native Microalgae from the Peruvian Amazon on the Removal of Pollutants

“…In these open-air garbage dumps, the solid wastes can be dispersed and degraded by abiotic and biotic factors, producing a gamma of solid, gaseous, and liquid products; the latter is known as leachate. This wastewater flows out from a landfill or an open-air garbage dump sites due to precipitation, ground-water intrusion, moisture content of waste, and rate of evaporation [18]. The volume and pollutant composition of this leachate wastewater fluctuate over time; therefore, in the early acid phase, there exists a high concentration of the four groups of pollutants (dissolved organic matter, heavy metals, inorganic macrocomponents, and xenobiotic organic compounds); finally, in the long methanogenic phase, the leachate liquid has a lower concentration of the four groups of pollutants and is characterized by its very low concentration of heavy metals and biochemical oxygen demand/chemical oxygen demand (BOD/COD) ratio [19][20][21].…”

Phycoremediation of Landfill Leachate with Desmodesmus subspicatus: A Pre-Treatment for Reverse Osmosis

“…However, in some cases, the amount of water required would make the process unsustainable and barely possible. According to the review by Nawaz et al [56], freshwater consumption is one of the major drawbacks of the LL phycoremediation process as it increases material costs and water footprint. To address this issue, several studies have investigated the basic idea of utilizing an LL-wastewater mixture as the medium for microalgal growth.…”

“…was observed to accumulate high lipid (20%) and carbohydrate (41%) content. Nawaz et al [56] also suggested that phosphorus deficiency typical to LL may be remedied by diluting the LL with agricultural effluent rich in phosphorus.…”