A Risk Assessment Model for Water Resources: releases of dangerous and hazardous substances.

Many dangerous and hazardous substances are used, transported and handled daily in diverse situations, from domestic use to industrial processing, and during those operations, spills or other anomalous situations may occur that can lead to contaminant releases followed by contamination of surface water or groundwater through direct or indirect pathways. When dealing with this problem, rapid, technically sound decisions are desirable, and the use of complex methods may not be able to deliver information quickly. This work describes a simple conceptual model established on multi-criteria based analysis involving a strategic appraisal for contamination risk assessment to support local authorities on rapid technical decisions.

Behaviour of different anaerobic populations on the biodegradation of textile chemicals.

The anaerobic biodegradation of textile chemicals was evaluated with inocula grown under mesophilic (37+/-2 degrees C) or thermophilic (55+/-2 degrees C) conditions, on glucose (glucose-grown) or acetate (acetate-grown) as sole carbon sources. Wool dyebath chemicals (acetic acid, a liposomal surfactant, a synthetic amphoteric surfactant), single or as binary acetate-surfactant mixtures, were used as test carbon sources, in the presence or absence of Acid Orange 7 as model dye. First, the two mesophilic inocula (glucose- or acetate-grown) were compared relatively to lag-phase durations, specific biogas production rates, biogas yields and overall COD removal yields.

Integrated nanofiltration and upflow anaerobic sludge blanket treatment of textile wastewater for in-plant reuse.

The filtration characteristics of simulated dyeing effluents containing Acid Orange 7, sodium sulfate, and a pH buffer made of acetic acid and sodium acetate is described using a commercially available nanofiltration membrane. The original membrane filtration properties were characterized with deionized water to provide a baseline of membrane performance. At high volumetric concentration of the test solutions, greater than 98% rejection of dye and sodium sulfate were obtained.

Evaluation of an integrated anaerobic/aerobic SBR system for the treatment of wool dyeing effluents. Purification of wool dyeing effluent in a SBR.

This work examined the performance of a sequencing batch reactor treating dyeing effluents from a factory that processes mainly wool and wool/polyester blends. Different operational conditions were evaluated, namely the influence of the anaerobic and the subsequent aerobic phase on the organic load removal, as well as the effect of the length of the aeration period (from 8 to 12 h) on process efficiency. A comparison between a fill stage in fast and slow modes was carried out.