A comparison between biostimulation and bioaugmentation in a solid treatment of anaerobic sludge: Drug content and microbial evaluation.

Emerging pollutants can reach the environment through the sludge of Wastewater Treatment Plants. In this work, the use of Trametes versicolor in biopiles at lab-scale was studied, evaluating its capacity to remove the most hydrophobic Pharmaceuticals and assessing the evolution of the biopiles microbial communities. The total removal of drugs at real concentrations from sewage sludge was assessed for non-inoculated and fungal inoculated biopiles, testing if the re-inoculation of the biopiles after 22 days of treatment would improve the removal yields. It was found that 2 out of the 15 initially detected pharmaceuticals were totally degraded after 22 days, and re-inoculated fungal biopiles achieved higher removal rates than non-re-inoculated fungal biopiles for single compounds and for all the drugs simultaneously: 66.45% and 49.18% re-inoculated and non-re-inoculated biopiles, respectively. Finally, the study of the bacterial and fungal communities revealed that fungal inoculated and non-inoculated biopiles evolved to similar communities adapted to the presence of those drugs.

Pharmaceuticals removal and microbial community assessment in a continuous fungal treatment of non-sterile real hospital wastewater after a coagulation-flocculation pretreatment.

Hospital wastewaters are a main source of pharmaceutical active compounds, which are usually highly recalcitrant and can accumulate in surface and groundwater bodies. Fungal treatments can remove these contaminants prior to discharge, but real wastewater poses a problem to fungal survival due to bacterial competition. This study successfully treated real non-spiked, non-sterile wastewater in a continuous fungal fluidized bed bioreactor coupled to a coagulation-flocculation pretreatment for 56 days. A control bioreactor without the fungus was also operated and the results were compared. A denaturing gradient gel electrophoresis (DGGE) and sequencing approach was used to study the microbial community arisen in both reactors and as a result some bacterial degraders are proposed. The fungal operation successfully removed analgesics and anti-inflammatories, and even the most recalcitrant pharmaceutical families such as antibiotics and psychiatric drugs.

Stable Carbon Isotope Fractionation During 1,2-Dichloropropane-to-Propene Transformation by an Enrichment Culture Containing Dehalogenimonas Strains and a dcpA Gene.

A stable enrichment culture derived from Besòs river estuary sediments stoichiometrically dechlorinated 1,2-dichloropropane (1,2-DCP) to propene. Sequential transfers in defined anaerobic medium with the inhibitor bromoethanesulfonate produced a sediment-free culture dechlorinating 1,2-DCP in the absence of methanogenesis. Application of previously published genus-specific primers targeting 16S rRNA gene sequences revealed the presence of a Dehalogenimonas strain, and no amplification was obtained with Dehalococcoides-specific primers. The partial sequence of the 16S rRNA amplicon was 100% identical with Dehalogenimonas alkenigignens strain IP3-3. Also, dcpA, a gene described to encode a corrinoid-containing 1,2-DCP reductive dehalogenase was detected. Resistance of the dehalogenating activity to vancomycin, exclusive conversion of vicinally chlorinated alkanes, and tolerance to short-term oxygen exposure is consistent with the hypothesis that a Dehalogenimonas strain is responsible for 1,2-DCP conversion in the culture. Quantitative PCR showed a positive correlation between the number of Dehalogenimonas 16S rRNA genes copies in the culture and consumption of 1,2-DCP. Compound specific isotope analysis revealed that the Dehalogenimonas-catalyzed carbon isotopic fractionation (εC(bulk)) of the 1,2-DCP-to-propene reaction was -15.0 ± 0.7‰ under both methanogenic and nonmethanogenic conditions. This study demonstrates that carbon isotope fractionation is a valuable approach for monitoring in situ 1,2-DCP reductive dechlorination by Dehalogenimonas strains.