Wastewater remediation via controlled hydrocavitation

Abstract

Controlled hydrodynamic cavitation is an energy- and chemicals-saving technology increasingly applied to water sanitation and wastewater remediation via mechanical, oxidative, and thermal degradation of chemical and biological pollutants, including recalcitrant contaminants. Reviewing the advances that have allowed hydrocavitation to emerge as an economically and technically viable environmental technology, we identify the key design parameters that decide its efficacy in degrading biological and chemical contaminants. The ongoing renewable energy boom, lowering the cost of electricity across the world, will only accelerate the adoption of hydrodynamic cavitation as an eminent technology of our common path to sustainability, with energy and clean water access for all.

Hydrogen Peroxide: A Key Chemical for Today's Sustainable Development

“…[41] The addition of H 2 O 2 largely also improves UV disinfection processes.I nt he UV disinfection of surfacew ater and wastewater from am unicipal treatment plant, for instance, the inactivation of Escherichia coli bacteria, Bacilluss ubtilis spores, and MS2 bacteriophage viruses proceeded best when UV irradiation was coupled with optimized doses of H 2 O 2 and peroxydisulfate (PDS,S 2 O 8 2À ). [41] The addition of H 2 O 2 largely also improves UV disinfection processes.I nt he UV disinfection of surfacew ater and wastewater from am unicipal treatment plant, for instance, the inactivation of Escherichia coli bacteria, Bacilluss ubtilis spores, and MS2 bacteriophage viruses proceeded best when UV irradiation was coupled with optimized doses of H 2 O 2 and peroxydisulfate (PDS,S 2 O 8 2À ).…”

“…Althoughc ertain metal catalysts, such as Fenton reagents, can sometimes contributet ot he overall efficacy,e nergyefficient CHC-based processes can successfully achievet heir remediation targets, even withouta ssistance from any other chemicals apart from H 2 O 2 in low concentration. [41] The addition of H 2 O 2 largely also improves UV disinfection processes.I nt he UV disinfection of surfacew ater and wastewater from am unicipal treatment plant, for instance, the inactivation of Escherichia coli bacteria, Bacilluss ubtilis spores, and MS2 bacteriophage viruses proceeded best when UV irradiation was coupled with optimized doses of H 2 O 2 and peroxydisulfate (PDS,S 2 O 8 2À ). [42] Although UV-only treatment performed well with regardt oEscherichia coli,a ny improvement for H 2 O 2 or PDS was marginal, whereas UV/H 2 O 2 far outperformed UV/ PDS with regard to UV-resistant MS2, and only UV/H 2 O 2 succeeded in deactivating Bacillussubtilis.…”

Hydrodynamic cavitation as an energy efficient process to increase biochar surface area and porosity: a case study

“…Such jump could be related to the increasing aggressiveness of the cavitation process with increasing temperature, at least up to a certain temperature: in pure water, the peak aggressiveness was observed around 60°C (Dular, 2016), but it could occur at lower temperatures in the study case. In turn, more aggressive cavitation is likely to enhance the generation of molecular oxygen, according to well-known water splitting reactions (Ciriminna et al, 2017), which could be absorbed by the biochar, as well as to enhance carbon solubilization, i.e. the release of carbon from the biochar to the aqueous medium (Maeng et al, 2010;Topac Sagban et al, 2017).…”

Que faire? A Bioeconomy and Solar Energy Institute at Italy's Research Council in the Context of the Global Transition to the Solar Economy

“…Another technology with major sustainabilityi mplications is wastewater remediation based on controlled hydrodynamic cavitation.T he dramatic valueso ft emperature and pressure createdb yt he collapsing bubbles formed in the process of cavitation allow for degradation processes that are more effective and less costly than conventional chemical and biological treatments. Along with significant energy savings,c lean oxidants, such as aqueous H 2 O 2 ,a re used to remediate urban, agriculturea nd industrial wastewater, [41] affording cleanerw ater and producing as ludge as by-product that can be used to fertilise soil, closing therebyt he materialcycle.…”