Treatment of pharmaceutical effluent by ultrasound coupled with dual oxidant system

Abstract

In this study, sonolysis (US), a dual oxidant system (DOX), and ultrasound coupled with a dual oxidant system (US/DOX) were employed to degrade real pharmaceutical effluent. In a DOX system, two effective oxidizing agents such as hydrogen peroxide and activated persulphate were used simultaneously. In this work, for the first time, an easily available waste material, iron swarf, was used as an activator for persulphate oxidation. Iron swarf coupled with an ultrasound system showed better activation. High iron dosage, acidic pH and high temperature favoured degradation with both DOX and US/DOX. Sequential addition of iron swarf produced better results compared to single-step addition. The activation energy was found to be 47.25 and 23.47 kJ/mol for DOX and US/DOX, respectively. The biodegradability index of the effluent was enhanced from 0.13 to 0.81 after treatment with US/DOX.

Synergistic Effect and Mechanisms of Combining Ultrasound and Pectinase on Pectin Hydrolysis

“…Currently, researchers start to utilize the synergistic effect of ultrasound and other methods to improve the degradation of macromolecular substances. The methods studied include microwave (Cravotto et al 2010), ultra violet (Joseph et al 2011), enzyme (Prajapat et al 2016;Sabarez et al 2014), ozone (Nachiappan and Muthukumar 2013) and high hydrostatic pressure (Bashari et al 2014;Geng and Thagard 2013). The combination of ultrasound and enzyme has recently become a research focus because of its strong selectivity, high efficiency and less pollution.…”

Thermal and Radiation Based Catalytic Activation of Persulfate Systems in the Removal of Micropollutants: A Review

“…Many studies show that sonochemical degradation of pollutants is strongly temperature dependent . Temperature changes will affect the gas solubility, surface tension, and vapor pressure, influencing the degradation process . In most cases, an increase in temperature favors persulfate activation of the ultrasonic process .…”

Treatment of high-strength wastewater by Fe2+-activated persulphate and hydrogen peroxide

“…The strength of AOTs relies on the generation of highly reactive hydroxyl radicals (HO • ) that are believed to react fast and non-selectively with a majority of the organic contaminants. The oxidation of organic pollutants by persulfate (S 2 O 8 2-) has been studied as an alternative to conventional HO • -based AOTs [7][8][9][10][11]. The sodium persulfate is characterized by high solubility at ambient temperature, and the sulfate ions, which are the major product of persulfate reduction, are relatively harmless and considered to be environmentally friendly [12].…”