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

Abstract

Reverse osmosis is widely used as one of the most effective and advanced technologies for the treatment of leachate from landfill sites. Unfortunately, high leachate contamination—above all, ammonia nitrogen—affects membrane selectivity and is reflected in permeate quality. Furthermore, iron contained in leachate can facilitate chelates forming, which reduces the membrane anti-fouling capacity. The addition of a pre-treatment step could alleviate the adverse impact of the pollutants. As such, we investigated pollutant removal by phycoremediation. Initial ecotoxicity tests of three algal strains (Scenedesmus obliquus (S. obliquus), Desmodesmus subspicatus (D. subspicatus), and Chlorella vulgaris (C. vulgaris)) identified D. subspicatus as the strain most tolerant to leachate toxicity. Subsequently, D. subspicatus was cultivated in six landfill leachates of different origin and, after the cultivation, removal rates were determined for ammonia nitrogen and iron. Furthermore, the impact of input leachate parameters on remediation efficiency was also investigated. By phycoremediation, the reduction of up to 100% in iron and 83% in ammonia nitrogen load was achieved, which demonstrates the high potential of microalgae to mitigate environmental risks and reduce membrane foulant content.

Organic matter and nutrients removal from landfill leachate by airlift aerobic three‐phase fluidized bed reactor

“…[ 11 ] LL is one of the most difficult wastewaters to treat because of its varied composition, particularly its high organic and total ammonia nitrogen (TAN) load. [ 12 ]…”

“…[11] LL is one of the most difficult wastewaters to treat because of its varied composition, particularly its high organic and total ammonia nitrogen (TAN) load. [12] In biological treatment processes, microorganisms play an essential role in the biodegradation of organic contaminants, which are simple, economical, attractive, and ecofriendly in nature. [13] Due to its low cost and applicability, biological treatment is widely employed to remove the bulk of the COD in the leachate, thus, minimizing future liquid and gaseous emissions.…”

Application of Chlorella sp. and Scenedesmus sp. in the Bioconversion of Urban Leachates into Industrially Relevant Metabolites

“…[21,22], Chlorella sp. [1,[22][23][24][25][26][27][28][29][30][31][32][33], Desmodesmus sp. [23,34], Picochlorum sp.…”

“…[23,28]; and even a consortium of microalgae [20] have been studied. Table 1 shows that the most reported concentration of leachate is 10% v/v [20,22,23,[28][29][30]33]; however, some authors claim that higher concentrations of leachate (from 20%, up to undiluted leachate) can also be used by algae and cyanobacteria [24,26,32,36]. In a different approach, Kumari et al [37] demonstrated that a microalgae-bacteria consortium (Scenedesmus sp.…”