A modular electrocoagulation unit, supported by Ca(OH)2 addition to treated water, was operated in the vicinity of a Natura 2000 site for the removal of Cr6+ or Ni2+ from contaminated groundwater. The process was performed at a constant flow rate of 350 L/h. Day 0 concentrations of Cr6+ and Ni2+ started at 91.6 mg/L for Ni2+ and 43 mg/L for Cr and during testing, were decreased by 15%–25%. Residual concentrations of Crtot. and Ni2+ below the required limits of 0.5 mg/L for Crtot. and 0.8 mg/L for Ni2+ can be achieved with the electrocoagulation unit and total removal efficiencies often exceeded 98%. The overall economic assessment showed its feasible application for removal of Cr6+ and Ni2+ on sites with requirements of high environmental protection standards. The polluted area was about 150 × 150 m (22,500 m2), and it contained approximately 78,750 m3 of water contaminated with Cr6+ and Ni2+ (over 41 and 91 mg/L, respectively). The modular arrangement might allow a scaling up. The process’ output could be thus increased according to the number of EC modules in operation.
Electrocoagulation (EC) is a practical alternative to chemical coagulation for the treatment of drinking water that contains various pollutants, including humic substances. Nevertheless, the performance of EC for removal of algal organic matter (AOM) is still largely unexplored. In this review, the properties of AOM, the principles of chemical coagulation and EC, and the current state of knowledge on the coagulation of AOM have been outlined. The limited available literature on the EC of AOM is critically reviewed and let conclude that this is a promising technology for AOM removal. However, the studies on EC are inconsistent in their approaches, and they lack thorough optimization of operating conditions (resultant pH, coagulant dosing) and reports of residual metal concentrations. Some of the identified needs for future research include the complete optimization of EC for AOM removal, its direct comparison with chemical coagulation, and EC testing for the elimination of mixtures of AOM, humic substances, and inorganic particles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.