Treatment of waste thermal waters by ozonation and nanofiltraton

Abstract

After their use for heating, e.g. in greenhouses, waste thermal waters may cause environmental problems due to their high contents of ions, and in some cases organic matter (associated with an oxygen demand) or toxic compounds. The aims of this work were to decrease the high organic content of waste thermal water by a combination of ozone treatment and membrane separation, and to investigate the accompanying membrane fouling. The results demonstrated that the chemical oxygen demand and the total organic content can be effectively decreased by a combination of ozone pretreatment and membrane filtration. Ozone treatment is more effective for phenol elimination than nanofiltration alone: with a combination of the two processes, 100% elimination efficiency can be achieved. The fouling index b proved to correlate well with the fouling and polarization layer resistances.

Thermal baths as sources of pharmaceutical and illicit drug contamination

“…Although, in general, used thermal water is known to have a potentially harmful environmental impact (e.g. heat and salt load; Benz et al 2017;Farsang et al 2015;Kiss et al 2013), little remains to be known about the level of their pharmaceutical contamination, as there are few reports on PhAC contamination of used thermal watersourced surface water. A related test was carried out by Avar et al (2016a, b); it revealed the existence of EE2 (0.52 ng L −1 ) and other hormones (drospirenone, levonorgestrel, progesterone; 1.26-2.28 ng L −1 ) in the Hévíz-Páhoki Canal, which is fed by Lake Hévíz, one of the largest thermal lakes in the world.…”

The formation of aldehydes and ketones ozonation by-products and their variation through general water treatment plant in Hamadan, Iran

“…Ozone is a strong oxidant and microbicide (Derrouiche et al, 2013;Asgari et al, 2013), which can eliminate or decompose many undesirable color, taste, odor, forming compounds, toxic substances and micro-pollutants from water. Since ozone treatment produces a lower level of halogenated disinfection by-products, it has been widely accepted as an alternative technology to chlorination in water treatment (Kiss et al, 2013;Rivera-Utrilla and Sánchez-Polo, 2002). Moreover, ozone oxidation can be used to remove disinfection by-products and microorganisms in water (Kasprzyk-Horden et al, 2003;Chiang et al, 2009).…”