In this experimental study both biological treatability of pharmaceuticals and their potential toxic effect in biological processes were evaluated. The pharmaceuticals were selected among those that are present at higher concentration in the Italian wastewater treatment plant effluents and widely used as antiulcer (ranitidine), β-blocker (atenolol) and antibiotic (lincomycin). The present paper is the continuation of a work already presented,[ 1 Cappai, G. , Carucci, A , Onnis, A and Piredda, M. 2004. Study on the Fate of Drugs in Wastewater Treatment Plants (WWTP) and their Inhibition Effects on Nitrification. In Proceedings of IWA 2004 World Water Congress and Exhibition. September 19–24 2004 , Marrakeçh. [Google Scholar] ] which used a synthetic wastewater fed to laboratory scale SBR (Sequencing Batch Reactor) operated with different sludge ages (8 and 14 days), different biochemical conditions (aerobic or anoxic-aerobic mode) and several influent drug concentrations (2, 3 and 5 mg/L). In this case a real municipal wastewater was used as influent to the SBR. In parallel, batch tests were conducted to determine the removal kinetics of drugs and nitrogen. Toxicity tests using a titrimetric biosensor to verify possible inhibition on microorganisms were also performed. Finally, the possible adsorption of the pharmaceuticals on activated sludge was evaluated. The drugs under investigation showed different behaviours in terms of both biodegradability and toxicity effect on nitrifiers. Ranitidine showed generally low removal efficiencies (17–26%) and a chronic inhibition on nitrification. Atenolol showed generally higher removal efficiencies than ranitidine, even if the fairly good efficiency obtained in the previous experimentation with synthetic wastewater (up to 90%) was not attained with real wastewater (36%). No inhibition on nitrification was observed on both acclimated and non acclimated microorganisms with a high nitrification activity, whilst it was present with activated sludge characterised by a lower nitrification activity. Consistently with his pharmaceutical properties, lincomycin showed significant inhibition on nitrification activity.
Ports and marinas are central nodes in transport network and play a strategic role in coastal development. They receive pollution from land-based sources, marine traffic and port infrastructures on one side and constitute a potential pollution source for the adjacent coastal areas on the other. The aim of the present study was to evaluate the effects of organic and inorganic co-contamination on the prokaryotic communities in sediments from three Mediterranean ports. The structure and composition of the bacterial and archaeal communities were assessed by targeted metagenomic analysis of the 16S rRNA gene, and the links of prokaryotic communities with environmental and pollution variables were investigated. The harbors presented pronounced site-specificity in the environmental properties and pollution status. Consistently, the structure of archaeal and bacterial communities in surface sediments exhibited a strong spatial variation among the three investigated ports. On the contrary, a wide overlap in composition of prokaryotic assemblages among sites was found, but local variation in the community composition and loss of prokaryotic diversity was highlighted in a heavily impacted port sector near a shipyard. We provided evidences that organic matter, metals and PAHs as well as temperature and salinity play a strong role in structuring benthic bacterial communities significantly contributing to the understanding of their responses to anthropogenic perturbations in marine coastal areas. Among metals, copper was recognized as strongly associated with the observed changes in bacterial assemblages. Overall, this study provides the first assessment of the effects exerted by multiple organic and inorganic contaminations on benthic prokaryotes in ports over a large spatial scale and designates bacterial community as a candidate tool for the monitoring of the sediment quality status in harbors.
6 February 2008 in Environmental Geochemistry and Health
Wastewater discharges containing high nitrogen levels can be toxic to aquatic life and cause eutrophication. In this study, the application of the SHARON (Single reactor for High activity Ammonium Removal Over Nitrite) process for the treatment of refinery wastewater (sour water) was evaluated, in view of its coupling with the ANAMMOX (ANaerobic AMMonium OXidation) process. A Continuous Flow Stirred Tank Reactor was initially fed with a synthetic medium, and the applied NH4-N concentration and wastewater/synthetic medium ratio were progressively increased up to 2000 mgN/L and 100%, respectively. Despite the high potential toxic effect of the real wastewater, overall SHARON performance did not decrease with the increasing real wastewater/synthetic medium ratio, and biomass showed progressive acclimation to the toxic compounds in the real wastewater, as demonstrated by toxicity assessments. NH4-N and dissolved organic carbon removal efficiency were around 50% and 65%, respectively. Moreover, the effluent was characterized by a NO2− N/NH4-N ratio of 0.9±0.01 and low nitrate concentration (<30 mgN/L), in line with the requirements for the subsequent treatment by the ANAMMOX process.