Do Application Rates of Wastewater Sewage Sludge Affect the Removal of PAHs from Alkaline Saline Soil?
Fabián Fernández-Luqueño1, Reyna Mendoza-Cristino1, Luc Dendooven2
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1Sustainability of Natural Resources and Energy Program, Cinvestav-Saltillo, Coahuila. C.P. 25900, Mexico
2Laboratory of Soil Ecology, GIP, Cinvestav, México D.F, C.P. 07360 Mexico
Submission date: 2016-05-13
Final revision date: 2016-06-23
Acceptance date: 2016-06-23
Publication date: 2016-11-24
Pol. J. Environ. Stud. 2016;25(6):2367–2372
The application of wastewater sludge to an alkaline saline soil of Texcoco accelerated removal of polycyclic aromatic hydrocarbons (PAHs), but not always. As part of a study into factors that might affect dissipation of PAHs from soil, the effect of different application rates (0, 3, 9, 18, and 36 tons dry sludge ha-1) of wastewater sludge on removal of phenanthrene and anthracene was studied in an alkaline saline soil with pH 9.7 and electrolytic conductivity (EC) of 7.6 dS m-1. The dynamics of phenanthrene, anthracene, ammonium, nitrite, nitrate, and CO2 were monitored for 56 days. Application of wastewater increased the removal rate of the PAHs independent of the concentration applied, and between 70 and 79% of the phenanthrene and 69 and 79% of the anthracene was removed after 56 days. Spiking soil with PAHs increased emissions of CO2 while applying sludge further increased it. It was found that the removal of PAHs was initially low as the amount of phenanthrene and anthracene decreased after only 14 days. The addition of wastewater sludge increased the removal of phenanthrene and anthracene, but the effect was independent of the application rate or the PAHs studied. Spiking soil with PAHs increased emissions of CO2 and reduced the amount of NH4+ and NO3- in soil.