Photoactivation and photoregeneration of TiO2/PAC mixture applied in suspension in water treatments: approach to a real application.

The process TiO/PAC/UV-vis has been under study and compared with the isolated treatments of adsorption and photocatalysis determining possible synergies between adsorption and photocatalysis of target antibiotics: amoxicillin, enrofloxacin, sulfadiazine, and trimethoprim. The characterization of the TiO2/PAC mixture was carried out via FESEM and FTIR. Moreover, a kinetic study has been performed.

Antibiotics removal from aquatic environments: adsorption of enrofloxacin, trimethoprim, sulfadiazine, and amoxicillin on vegetal powdered activated carbon.

This study addresses the growing concern about the high levels of antibiotics in water, outlining an alternative for their removal. The adsorption of four representative antibiotics from commonly used families (fluoroquinolones, β-lactams, trimethoprim, and sulfonamides) was performed over vegetal powdered activated carbon. The evolution of the adsorption was studied during 60 min for different initial antibiotic concentrations, not only individually but also simultaneously to determine competitive adsorption.

Study of Evolution of Microbiological Properties in Sewage Sludge-Amended Soils: A Pilot Experience.

Large amounts of sewage sludge are generated in urban wastewater treatment plants and used as fertilizer in agriculture due to its characteristics. They can contain contaminants such as heavy metals and pathogenic microorganisms. The objective of this research work is to study, in real conditions, the evolution of microbial concentration in agricultural soils fertilized by biologically treated sewage sludge.

Comparative adsorption of ciprofloxacin on sugarcane bagasse from Ecuador and on commercial powdered activated carbon.

This work examined the adsorption capacity of sugarcane bagasse (SB) for the removal of ciprofloxacin (CPX) from water using batch experiments and a fixed bed column and compared its adsorption performance with a powdered activated commercial carbon (PAC). Both adsorbents achieved a similar percentage removal of about 78% with doses of 3 g L of SB and 0.3 g L of PAC (20 mg L initial CPX concentration at 30 °C).

Identification of free-living amoebas and amoeba-resistant bacteria accumulated in Dreissena polymorpha.

To identify the free-living amoeba (FLA) and amoeba-resistant bacteria (ARB) accumulated in zebra mussels and in the water in which they are found, mussels were collected at two locations in the Ebro river basin (North East Spain). FLAs and bacteria were isolated from mussel extracts and from natural water. PCR techniques were used to identify the FLAs and endosymbiont bacteria (Legionella, Mycobacterium, Pseudomonas and cyanobacteria), and to detect Giardia and Cryptosporidium.

Visible light plays a significant role during bacterial inactivation by the photo-fenton process, even at sub-critical light intensities.

The aim of this research is to clarify the contribution of sunlight wavelengths, irradiance and Fe/HO during bacterial disinfection by the photo-Fenton process in clear surface waters. We considered different solar spectrum distributions (visible, UVA-Visible), sub-critical irradiances (0-400 W/m), focusing on the action modes of E. coli inactivation by the constituents involved in the composite process, at low μM reactants concentration (Fe/HO) in in ultrapure (MQ) water.

Performance comparison of commercial TiO: separation and reuse for bacterial photo-inactivation and emerging pollutants photo-degradation.

This research aims to compare the disinfection and degradation effectiveness in water of a commercial suspension of nano-TiO (TiOLevenger) with the standard TiODegussa P25. Photo-inactivation and photo-degradation experiments were conducted with UVA-vis light. Concerning the disinfection, the effects of TiO dose (0-2 g/l), water matrix, bacterium type (Gram-positive or Gram-negative), and bacterial regrowth after the photo-treatments were studied for each catalyst.

Electrochemical advanced oxidation processes for Staphylococcus aureus disinfection in municipal WWTP effluents.

This paper presents the Staphylococcus aureus inactivation in a simulated wastewater treatment plant effluent by different electrochemical techniques, including the photo-electro-Fenton process. S. aureus, dissolved organic carbon (DOC), total oxidants and HO concentrations, as well as pH, were monitored during the assays.

Synergistic effect of the presence of suspended and dissolved matter on the removal of cyanide from coking wastewater by TiO photocatalysis.

This study assesses the influence of the presence of suspended and dissolved matter on the efficiency of TiO photocatalysis for the removal of cyanide from coking wastewater. Photocatalytic processes were carried out at basic pH (pH 9) with titanium dioxide (1 g/L), artificial radiation (290-800 nm) and during different time periods (20-100 min). The first assays applied in aqueous solutions achieved promising results in terms of removing cyanide.

Combined photo-fenton-SBR processes for the treatment of wastewater from the citrus processing industry.

In this study, the photo-Fenton process was combined with a sequencing batch reactor (SBR) for the treatment of synthetic samples of citrus wastewater (CWW). An experimental design based on the surface response methodology was applied to assess the individual and combined effects of several operating parameters (CODinitial, Fe3(+) concentration and H2O2 concentration) on the photo-Fenton treatment efficiency (DOC removal) with the aim of optimizing the process. The experimental results obtained under optimal conditions for CWW with high CODinitial (10000 mgO2/L) showed a partial degradation of organic matter of around of 61% (measured as DOC).

Sediment quality evolution (2001-2011) in the Ebro River basin (Spain).

Spatio-temporal variations in sediment quality (20 sample sites) of the Ebro River basin between 2001 and 2011 have been assessed. The self-organizing map classified the sediment samples according to similarities in their chemical compositions. Its powerful visualization tools helped establish the main pollution contribution on each sample.

Potential risk assessment of trace elements and PAHs in sediment samples of the Ebro River basin (Spain).

This study was carried out in order to assess potential toxicity of hazardous pollutants (8 trace elements and 8 polycyclic aromatic hydrocarbons) in 20 sediment samples of the Ebro River basin (Spain) sampled in 2009. Mean-probable effect concentration quotient (m-PECQ) was found to range from 0.03 to 0.

Potential toxicity of polycyclic aromatic hydrocarbons and organochlorine pesticides in sediments from the Ebro River basin in Spain.

This study was carried out to estimate the potential toxicity of 8 Polycyclic Aromatic Hydrocarbons (PAHs) and 5 organochlorine pesticides (OCPs) in sediments in the Ebro River Basin (20 sampling points) according to different methodologies. Detection limit (DL) concentrations were used for compounds reported below the DL (worst-case scenario). The majority of PAH concentrations were found to be below their method detection limit.

Experimental design approach applied to the elimination of crystal violet in water by electrocoagulation with Fe or Al electrodes.

An experimental design methodology was applied to evaluate the decolourization of crystal violet (CV) dye by electrocoagulation using iron or aluminium electrodes. The effects and interactions of four parameters, initial pH (3-9), current density (6-28 A m(-2)), substrate concentration (50-200 mg L(-1)) and supporting electrolyte concentration (284-1420 mg L(-1) of Na(2)SO(4)), were optimized and evaluated. Although the results using iron anodes were better than for aluminium, the effects and interactions of the studied parameters were quite similar.

Solar photochemical treatment of winery wastewater in a CPC reactor.

Degradation of simulated winery wastewater was studied in a pilot-scale compound parabolic collector (CPC) solar reactor. Total organic carbon (TOC) reduction by heterogeneous photocatalysis (TiO(2)) and homogeneous photocatalysis with photo-Fenton was observed. The influence of TiO(2) concentration (200 or 500 mg/L) and also of combining TiO(2) with H(2)O(2) or Na(2)S(2)O(8) on heterogeneous photocatalysis was evaluated.

Coupled photo-Fenton-biological system: effect of the Fenton parameters such as residual H2O2, Fe2+ and pH on the efficiency of biological process.

The aim of this research work is to evaluate the performance of packed-bed bioreactors under typical conditions of photo-Fenton treatment (residual iron, residual hydrogen peroxide, acidic pH). The target pollutant selected was 4-Chlorophenol which is included in the list of Priority Substances (Decision No 2455/2001/EC) in the field of water policy and amending Directive 2000/60/EC. It was found that the biological process operated correctly during eight days when the pH was in the range of 3.

Experimental design approach to the optimization of ultrasonic degradation of alachlor and enhancement of treated water biodegradability.

This work presents the application of experimental design for the ultrasonic degradation of alachlor which is pesticide classified as priority substance by the European Commission within the scope of the Water Framework Directive. The effect of electrical power (20-80W), pH (3-10) and substrate concentration (10-50mgL(-1)) was evaluated. For a confidential level of 90%, pH showed a low effect on the initial degradation rate of alachlor; whereas electrical power, pollutant concentration and the interaction of these two parameters were significant.

Factorial experimental design of winery wastewaters treatment by heterogeneous photo-Fenton process.

Winery wastewaters are difficult to treat by conventional biological processes because they are seasonal and experience a substantial flow variations. Photocatalytic advanced oxidation is a promising technology for wastewaters containing high amounts of organic matter. In this work, the photo-Fenton process in heterogeneous phase is presented as an alternative methodology for the treatment of winery wastewaters.

Characterization and photo-Fenton treatment of used tires leachate.

In this study the leachates derived from used tires were firstly characterized by means of the evaluation of their organic matter content. The leachate from tire powder presented a COD value of 508 mg O(2) l(-1) and a TOC of 214 mg Cl (-1). The main identified organic substances were constituents of the rubber structure: benzothiazole derivatives, phthalates, phenolic derivatives, hydrocarbons and fatty acids.