Article

Electrochemical advanced oxidation and biological processes for wastewater treatment: A review of the combined approaches

Environmental Science and Pollution Research (Impact Factor: 2.76). 07/2014; 21:8493-8524. DOI: 10.1007/s11356-014-2770-6

ABSTRACT As pollution becomes one of the biggest environmental challenges of the XXI century, pollution of water threatens the very existence of humanity, making immediate action a priority. The most persistent and hazardous pollutants come from industrial and agricultural activities, therefore effective treatment of this wastewater prior to discharge into the natural environment is the solution. Advanced oxidation processes (AOPs) have caused increased interest due to their ability to degrade hazardous substances in contrast to other methods, which mainly only transfer pollution from wastewater to sludge, a membrane filter or an adsorbent. Among a great variety of different AOPs, a group of electrochemical advanced oxidation processes (EAOPs); including electro-Fenton, is emerging as environmentally friendly and effective treatment process for the destruction of persistent hazardous contaminants. The only concern which slows down a large-scale implementation is energy consumption and related investment and operational costs. A combination of EAOPs with biological treatment is an interesting solution. In such a synergetic way, removal efficiency is maximized, while minimizing operational costs. The goal of this review is to present cutting-edge research for treatment of three common and problematic pollutants and effluents: dyes and textile wastewater; olive processing wastewater; pharmaceuticals and hospital wastewater. Each of these types is regarded in terms of recent scientific research on individual electrochemical, individual biological and a combined synergetic treatment.

1 Bookmark
 · 
154 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Occurrence of pharmaceuticals in natural water is considered as an emerging environmental problem owing to their potential toxicological risk on living organisms even at low concentration. Low removal efficiency of pharmaceuticals by conventional wastewater treatment plants requests for a more efficient technology. Nowadays research on advanced oxidation processes (AOPs) have become a hot topic, because these technologies have been shown to be able to oxidize efficiently most organic pollutants until mineralization to inorganic carbon (CO2). Among AOPs, the electrochemical advanced oxidation processes (EAOPs), and in particular, “anodic oxidation” and “electro-Fenton”, have demonstrated good prospective at lab-scale level for the abatement of pollution caused by the presence of residual pharmaceuticals in waters. This paper reviews and discusses the effectiveness of EAOPs for the removal of anti-inflammatory and analgesic pharmaceuticals from aqueous systems.
    Chemical Engineering Journal. 228:944–964.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this study, winery wastewaters are considered for degradation using heterogeneous photo-Fenton as a preliminary step before biotreatment. The heterogeneous photo-Fenton process assisted by solar light is able to partially degrade the organic matter present in winery wastewaters. When an initial hydrogen peroxide concentration of 0.1 M is used over 24 h of treatment, a degradation yield of organic matter (measured as TOC) of around 50% is reached. The later treatment (activated sludge process) allows the elimination of 90% of the initial TOC present in pretreated winery wastewaters without producing nondesired side-effects, such as the bulking phenomenon, which is usually detected when this treatment is used alone. The final effluent contains a concentration of organic matter (measured as COD) of 128 mg O2/L. The coupled system comprising the heterogeneous photo-Fenton process and biological treatment based on activated sludge in simple stage is a real alternative for the treatment of winery wastewater.
    Journal of Agricultural and Food Chemistry 08/2008; 56(16):7333-8. · 3.11 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In hospitals a large variety of substances are in use for medical purposes such as diagnostics and research. After application, diagnostic agents, disinfectants and excreted non-metabolized pharmaceuticals by patients, reach the wastewater. This form of elimination may generate risks for aquatic organisms. The aim of this study was to present: (i) the steps of an ecological risk assessment and management framework related to hospital effluents evacuating into wastewater treatment plant (WWTP) without preliminary treatment; and (ii) the results of its application on wastewater from an infectious and tropical diseases department of a hospital of a large city in southeastern France. The characterization of effects has been made under two assumptions, which were related to: (a) the effects of hospital wastewater on biological treatment process of WWTP, particularly on the community of organisms in charge of the biological decomposition of the organic matter; (b) the effects on aquatic organisms. COD and BOD5 have been measured for studying global organic pollution. Assessment of halogenated organic compounds was made using halogenated organic compounds absorbable on activated carbon (AOX) concentrations. Heavy metals (arsenic, cadmium, chrome, copper, mercury, nickel, lead and zinc) were measured. Lowmost probable number (MPP) for faecal coliforms has been considered as an indirect detection of antibiotics and disinfectants presence. For toxicity assessment, bioluminescence assay using Vibrio fischeri photobacteria, 72-h EC50 algae growth Pseudokirchneriella subcapitata and 24-h EC50 on Daphnia magna were used. The scenario allows to a semi-quantitative risk characterization. It needs to be improved on some aspects, particularly those linked to: long term toxicity assessment on target organisms (bioaccumulation of pollutants, genotoxicity, etc.); ecotoxicological interactions between pharmaceuticals, disinfectants used both in diagnostics and in cleaning of surfaces, and detergents used in cleaning of surfaces; the interactions into the sewage network, between the hospital effluents and the aquatic ecosystem.
    Journal of Hazardous Materials 01/2005; A117:1-11. · 4.33 Impact Factor

Full-text

Download
87 Downloads
Available from
Jul 29, 2014
Available from