Analysis of Contemporary Methods and Technologies for the Removal of Pollutants from Natural Waters

This review deals with contemporary methods and technologies for the removal of pollutants from natural waters with emphasis on the integration of physicochemical and biological methods with advanced oxidation processes (AOPs). In the introduction, the urgency of this problem is substantiated with consideration for the significant accumulation of organic and inorganic contaminants (ammonium nitrogen, phosphorus, phenols, surfactants, chlorinated organic compounds) as a result of anthropogenic burden on natural waters and insufficient efficiency of traditional treatment technologies. The method implies the comprehensive analysis of conventional approaches (biological and aerated filters, floatation, adsorption) and the empirical evaluation of AOP schemes with UV, O3, and H2O2 with consideration for efficiency, power consumption, and economic viability. Results indicate that optimal combinations, in particular, O3 + H2O2 + UV provide essential disinfection and degradation of persistent pollutants at a lower power consumption as compared to simpler schemes, (e.g., UV + H2O2), though require high-power UV sources. Biological methods (based on natural conditions or bioplateau systems) are more environmentally promising and less power consumptive, but slower and depend on pH, temperature, and availability of biogenic chemical elements. The discussion highlights the necessity of using AOPs and biotechnologies for maximum synergetic clean-up effect. Contemporary wastewater treatment technologies are described. In the conclusions, it is pointed out that the future development of treatment systems must be based on the rational combination of physicochemical and biological methods with AOP technologies with consideration for water characteristics, energy efficiency, and economic viability.