Influence of seasonality on the quality of oysters from the Sado and Mira rivers.

There is a lack of knowledge about the influence of seasonality on the microbial and physicochemical quality of oysters in Sado and Mira rivers. Water, sediment, and oysters (Crassostrea angulata and Crassostrea gigas) were collected for microbiological, nutritional, and sensory analyses. The microbiological water quality and the oyster shell contamination were better during the warmer months. No seasonal effect was observed on sediments and on oyster meat. A good physicochemical and nutritional quality was also observed, with high content of polyunsaturated fatty acids, including omega-3 fatty acids, resulting in good lipid quality indices. From the sensory evaluation, both oysters' species were well scored and presented the highest scores (4) in parameters such as cream-ivory colour, sea smell, firmness and juiciness. These attributes denote the freshness degree at the time of the tasting, reflecting the quality of the bivalve.

Overview of bioremediation with technology assessment and emphasis on fungal bioremediation of oil contaminated soils.

Environmental contamination is a problem that requires sustainable solutions. Bioremediation technologies have been developed in the last decades and are increasingly used to mitigate environmental accidents and systematic contaminations. A review of bioremediation technologies, based on published article and patent documents, is presented for different types of contaminated matrices, bioremediation agents and contaminants. The worldwide database of the European Patent Office was searched using radicals of keyword as well as the International Patent Classification (IPC) to identify patents in our areas of concern. Technological domains, annual filing volume, legal status, assignee countries and development collaborations are presented and examples are discussed. The total number of patents is compared with the total number of articles. A SWOT analysis for bioremediation technologies is presented. The technologies for water (53%), soils (36%), and sludges (11%) are growing yearly at nearly constant rates. The bioremediation agents are predominantly bacteria (57%), enzymes (19%), fungi (13%), algae (6%), plants (4%) and protozoa. The major contaminants are oils (38%), followed by metals (21%), organic waste (21%), polymers (10%), food (5%), cellulose (5%) and biodiesel. Most of the patents are generally originated from China and United States of America. The soils bioremediation technology of oil is centered on bacteria usage (about two thirds of the articles and patents), being fungi a technology with critical mass and high growth potential. A recent trend in oil bioremediation of soils is the combination of bioremediation agents (fungi and bacteria) in the same process, thus making the process more robust to environment changes.

Effect of an azo dye on the performance of an aerobic granular sludge sequencing batch reactor treating a simulated textile wastewater.

This study analyzed the effect of an azo dye (Acid Red 14) on the performance of an aerobic granular sludge (AGS) sequencing batch reactor (SBR) system operated with 6-h anaerobic-aerobic cycles for the treatment of a synthetic textile wastewater. In this sense, two SBRs inoculated with AGS from a domestic wastewater treatment plant were run in parallel, being one supplied with the dye and the other used as a dye-free control. The AGS successfully adapted to the new hydrodynamic conditions forming smaller, denser granules in both reactors, with optimal sludge volume index values of 19 and 17 mL g(-1) after 5-min and 30-min settling, respectively. As a result, high biomass concentration levels and sludge age values were registered, up to 13 gTSS L(-1) and 40 days, respectively, when deliberate biomass wastage was limited to the sampling needs. Stable dye removal yields above 90% were attained during the anaerobic reaction phase, confirmed by the formation of one of the aromatic amines arising from azo bond reduction. The control of the sludge retention time (SRT) to 15 days triggered a 30% reduction in the biodecolorization yield. However, the increase of the SRT values back to levels above 25 days reverted this effect and also promoted the complete bioconversion of the identified aromatic amine during the aerobic reaction phase. The dye and its breakdown products did not negatively affect the treatment performance, as organic load removal yields higher than 80% were attained in both reactors, up to 77% occurring in the anaerobic phase. These high anaerobic organic removal levels were correlated to an increase of Defluviicoccus-related glycogen accumulating organisms in the biomass. Also, the capacity of the system to deal with shocks of high dye concentration and organic load was successfully demonstrated. Granule breakup after long-term operation only occurred in the dye-free control SBR, suggesting that the azo dye plays an important role in improving granule stability. Fluorescence in situ hybridization (FISH) analysis confirmed the compact structure of the dye-fed granules, microbial activity being apparently maintained in the granule core, as opposed to the dye-free control. These findings support the potential application of the AGS technology for textile wastewater treatment.