Ecological risk assessment of domestic sewage sludge: a case study

Authors : Elif YAKAMERCAN, Ahmet AYGÜN
Pages : 422-433
View : 29 | Download : 10
Publication Date : 2021-11-17
Article Type : Research Paper
Abstract :This study aims to evaluate potential ecological risks and heavy metal pollution in sewage sludge. For these purposes, domestic sewage sludge samples were collected for a period of one year from a wastewater treatment plant in Bursa, Turkey and analyzed for heavy metals. The average heavy metal content of the sewage sludge was wherein decreasing order of Zn>Cu>Ni>Cr>Pb>As>Se>Cd. As a whole, the concentration of heavy metals was below the limit values indicated within the agricultural land application legal standards. Correlation analysis showed a very strong correlation observed between Ni and Cr. Determining to pollution degree and potential ecological risks, some indices such as Enrichment factor insert ignore into journalissuearticles values(EF);, Single-factor pollution index insert ignore into journalissuearticles values(PI);, Geoaccumulation index insert ignore into journalissuearticles values(Igeo);, Nemerow synthetic pollution index insert ignore into journalissuearticles values(PN);, Contamination factor insert ignore into journalissuearticles values(Cf);, Integrated pollution degree insert ignore into journalissuearticles values(Cd);, Pollution Load Index insert ignore into journalissuearticles values(PLI);, Monominal potential ecological risk insert ignore into journalissuearticles values(ER);, Potential ecological risk index insert ignore into journalissuearticles values(RI);, and the Probability of toxicity insert ignore into journalissuearticles values(mERM-Q); were used in this study. Based on the pollution index calculations, Zn and Se posed the highest contamination while As and Cd posed the lowest contamination. The mERM-Q values indicated that the probability of toxicity varied from 21 to 49%, while ecological indices indicated that ER insert ignore into journalissuearticles values(2.0–23.7); and RI insert ignore into journalissuearticles values(67.3–106.2); values were lower than a threshold value for all samples.
Keywords : Ecological risk assessment, Heavy metal, Pollution indices, Sewage sludge

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