SONOZONE TREATMENT ON WASTEWATER TO BE REUSED Via del Cotonificio 108, Udine Friuli Venezia Giulia Italy Tel: Fax: UNIVERSITY OF UDINE Department of Chemistry, Physics and Environment Prof. Goi Daniele, Dott.ssa Rossi Giada

ENVIRONMENTAL ENGINEERING TEAM Prof. Eng. Daniele Goi Expert in environmental sanitary engineering. PhD Giada Rossi Expert in advanced oxidation processes for wastewater treatment. Eng. Valentina Cabbai Expert in wastewater treatment modeling.

GOAL WASTEWATER TREATMENT ON PRIMARY EFFLUENT Disinfection (coliforms, E.coli, Salmonella spp., Enterococcus spp.) Pollutants treatment (aromatic compounds, surfactants, formaldeyde) Nutrient preservation (phosphate, nitrogen) REUSE

OZONATION APPLIED TECHNOLOGIES SONICATION

PARAMETERS CONSIDERED MICROBIOLOGICAL PARAMETERS Salmonella spp. Total coliforms E.coli Enterococcus spp. CHEMICAL PARAMETERS MBAS anionic surfactants Formaldeyde Phosphate Total nitrogen COD UV 254

COD46% UV – 52 % MBAS97 % MAX ABATMENT FORMALDEYDE48 % COLIFORMS99,9992 % Enterococcus spp.99,92 % E.coli99,98 % Salmonella spp.99,98 %

CONCLUSIONS Low frequence ultrasounds used as a pre-treatment don't induce pollutants and microorganisms abatement, but they have only a mechanical activity. Organic matter inside the system is easier to oxidize by ozone thanks to particulate substance disaggregation due to sonication. Sonolitic pretreatment at low frequencies can increase ozone oxidative efficiency. Phosphate and nitrogen concentrations don't vary during sonozone treatment: wastewater characteristics, useful for carbon, nitrogen and phosphorus reintegration in the water-ground system, are preserved.

CONCLUSIONS Sonozone technology optimizes surfactants and bacteria abatement better than the application of the single techniques. Anionic surfanctants (MBAS) are degraded by sonozone in the same way if we use a longer ozone treatment and an higher dose of chemical oxidant. Sonozone disinfection efficiency is more evident on E.coli and coliforms otherwise is less efficient on enterococci.

FURTHER RESEARCH Design and use of pilot plant have to be pursued in order to test bigger volumes of wastewater and simulate real plants function. In addition, it may be interesting to evaluate the treatment from an economic point of view, calculating costs and energy efficiency in order to identify whether the application can compete with the solutions already existing. Preliminary data indicate that the combined used of ultrasonic and ozone treatment could reduce the costs due to the chemical disinfectant. Several types of wastewater, from civil and industrial wastewater plants, have to be tested for sonozone treatment, in order to prove process effectiveness on samples with different characteristics in terms of organic load, suspended solids and pollutants.

FURTHER APPLICATIONS This process treatment could be even applied in wastewater treatment, to refine secondary treatment, in order to implement disinfection and abatement of refractory pollutants. The process should be applied on small plants treating wastewater from little communities or productive realities. A possible application could be the treatment of wastewater on boards, from mobile kitchens and hospitals, in camping, small settlements or mountain retreat placed in areas of particular environmental interest. The R&D results suggested that sonozone technique is suitable for the use in agro-industrial sector, in particular to treat wastewater, rich in surfactant and bacterial load, to be reuse.