Controlling micropollutants in tertiary municipal wastewater by O3/H2O2, granular biofiltration and UV254/H2O2 for potable reuse applications.

A comprehensive pilot study was carried out to experimentally assess the potential of newly developed treatment trains integrating two-stage AOPs and biofiltration to reach potable reuse water quality standards from municipal wastewater. The processes consisted of a two-stage AOPs with (carbon or limestone) biofiltration, the first AOP (O3/H2O2) serving as pre-treatment to biofiltration and the second AOP (UV254/H2O2) serving as post-biofiltration finishing step to ensure advanced disinfection. A comprehensive monitoring campaign was put in place resulting from the combination of targeted, non-targeted and suspect screening measurements. It was found that 13 organic micropollutants were detected from a list of 219 suspects although at ng/L level only. For the treatment conditions piloted in this study (O3 = 13 ±â€¯0.5 mg/L, H2O2 = 11 ±â€¯0.4 mg/L for the O3/H2O2 process, and UV = 410 ±â€¯63.5 mJ/cm2, H2O2 = 5 mg/l for the UV254/H2O2 process), it was possible to estimate the overall removal efficacy for each unit process, which was found to follow this order: RO (99%)  > BAC (87%) > O3-H2O2 (78%)  > BAL (67%)  > UV/H2O2 (43%)  > AOP contact chamber (19%)  > UF(0%), with the treatment train integrating two AOPs and granular biofiltration with activated carbon (O3/H2O2 + BAC + UV254/H2O2) showing superior performance with a 99% abatement in total micropollutants. No ecotoxicologically-positive response was generally observed for any of the effluent samples from the tested trains, even when pre-concentration factors up to 100-1000 times were employed to increase the sensitivity of the bioassay methods.

Carbonic anhydrase integrated into a multimarker approach for the detection of the stress status induced by pollution exposure in Mytilus galloprovincialis: A field case study.

The work was addressed to study the sensitivity of the enzyme carbonic anhydrase (CA) to chemical pollution in the hepatopancreas of the bioindicator organism Mytilus galloprovincialis in the context of a multimarker approach in view of ecotoxicological biomonitoring and assessment application. The study was carried out by means of a transplanting experiment in the field, using caged organisms from an initial population exposed in the field in two areas of interest: Augusta-Melilli-Priolo, an heavy polluted industrial site (eastern Sicily, Italy), and Brucoli (eastern Sicily, Italy) an area not affected by any contamination and selected as a reference site. Mussels in Augusta presented a significant increase in the digestive gland CA activity and gene expression compared to the animals caged in the control site of Brucoli. The CA response in animals from the polluted site was paralleled by proliferation/increase in the size of lysosomes, as assessed by Lysosensor green charged cells, induction of metallothionein, up-regulation of hif-α (hypoxia-inducible factor), metabolic changes associated with protein metabolism, and changes in the condition factor. Biological responses data were integrated with information about sediment chemical analysis and metal residue concentration in animal soft tissues. In conclusion, obtained results highlighted the induction of CAs in the hepatopancreas of Mytilus galloprovincialis following to pollution exposure, and demonstrated its suitability to be integrated into a multimarker approach for the detection and characterization of the stress status induced by pollution exposure in this bioindicator organism.

Integrated use of biomarkers (acetylcholinesterase and antioxidant enzymes activities) in Mytilus galloprovincialis and Mullus barbatus in an Italian coastal marine area.

The use of biomarkers to evaluate the biological effects of chemical pollutants in marine organisms represents a recent tool in the monitoring field responding to the need to detect and assess the effects of chemical contaminants on the biota. The aim of the present work was the field application of the integrated use of acetylcholinesterase (AChE) and antioxidant enzymes (catalase--CAT, glutathione peroxidase--GSH-Px), for detecting the possible exposure/effect induced by chemical pollutants in native marine organisms from a coastal marine area, represented by Salento Peninsula (Italy), that shows a coastline of high environmental value, but under constant urban pressure, including agriculture activities, widely diffused in the whole hinterland. Eight sampling stations were chosen: four not urbanized areas considered "uncontaminated" controls and four clearly exposed to anthropogenic impact. The bioindicator species studied were a sessile invertebrate, Mytilus galloprovincialis, and a benthic teleost fish, Mullus barbatus.AChE activity in M. galloprovincialis revealed significant differences among places; the minimum values observed (3.9+/-1.8 nmolmin(-1)mg(-1)) was about 50% reduced with respect to the maximum found (11.4+/-0.9 nmolmin(-1)mg(-1)). The reduction in AChE activity observed in two control stations could be explained by the leaching of pesticides into the sea from the agricultural lands. Moreover, the inhibition of AChE activity by heavy metals besides pesticides, can also explain the reduction of the enzymatic activity observed in an industrialized and harbour area. In M. galloprovincialis AChE activity showed a significant inverse correlation with catalase activity but not with glutathione peroxidase that did not significantly change in animals sampled from the eight stations. Also in M. barbatus AChE activity showed significant differences among places; it was inversely correlated with liver GSH-Px activity, but not with catalase activity, that did not show any significantly variation in animals sampled in the different stations. In conclusion, the integrated use of AChE and antioxidant enzymes (catalase or glutathione peroxidase) in M. galloprovincialis and M. barbatus, two species living in different compartment of marine coastal ecosystem, can find a useful application within the framework of marine coastal environment monitoring programs for detecting the possible exposure/effect induced by chemical pollutants, including pesticides, on living marine organisms.