A review on heterogeneous sonocatalyst for treatment of organic pollutants in aqueous phase based on catalytic mechanism.

Heterogeneous sonocatalysis, as an emerging advanced oxidation process (AOP), has shown immense potential in water treatment and been widely demonstrated to remove persistent organic compounds in the past decade. The present article aims to provide a comprehensive review on the development of a heterogeneous catalyst for enhancing the ultrasonic degradation rate of organic pollutants from a viewpoint of sonocatalytic mechanism. The rational design and fundamentals for preparing sonocatalysts are presented in the context of facilitating the heterogeneous nucleation and photo-thermal-catalytic effects as well as considering the mechanical stability and separation capacity of the heterogeneous catalyst.

Peat moss-derived biochar for sonocatalytic applications.

Peat-moss derived biochar was used as a sonocatalyst for the degradation of rhodamine B (RhB) at different ultrasonic frequencies (40 kHz and 300 kHz). The biochar was prepared by pyrolysis of peat-moss at 300 °C under N-saturated conditions. High removal efficiency was achieved when biochar (1000 mg L) was used as a sonocatalyst in the 40 kHz system, and high removal could be achieved by pre-adsorption and radical oxidation reactions on the surface of the biochar.

Magnetic Pd@FeO composite nanostructure as recoverable catalyst for sonoelectrohybrid degradation of Ibuprofen.

In the present research, the degradation of an emerging pharmaceutical micro-pollutant, Ibuprofen (IBP) by using Pd@FeO and a hybrid sono-electrolytical (US/EC) treatment system has been demonstrated for the first time. The magnetically separable nanocomposite, Pd@FeO catalyst was synthesized following co-precipitation method to enhance the efficiency of US/EC system. The synthesized catalyst showed a strong reusable property even after applying for five times and in all the five cases, 100% degradation of IBP was maintained.

Ultrasonic and mechanical soil washing processes for the removal of heavy metals from soils.

In order to determine the optimal operating conditions of full-scale soil washing processes for the removal of heavy metals, the effect of high-power ultrasound on the conventional mechanical soil washing process was investigated in a large lab-scale 28kHz sonoreactor. The soil samples were obtained from an abandoned railway station site in Seoul, Korea, which was contaminated with Cu (242.7±40.

A review on sonoelectrochemical technology as an upcoming alternative for pollutant degradation.

Sonoelectrochemical process has emerged as a novel integrated technology for various applications starting from sonoelectroplating till the remediation of a wide range of contaminants. Although a promising new technology, the application of sonoelectrochemical technology for pollutant degradation are mostly on a laboratory scale, utilizing the conventional reactor configuration of the electrolytic vessel and ultrasonic horns dipped in it. This type of configuration has been believed to be responsible for its sluggish evolution with lower reproducibility, scale-up and design aspects.

Distribution of electrical energy consumption for the efficient degradation control of THMs mixture in sonophotolytic process.

Sonophotolytic degradation of THMs mixture with different electrical energy ratio was carried out for efficient design of process. The total consumed electrical energy was fixed around 50W, and five different energy conditions were applied. The maximum degradation rate showed in conditions of US:UV=1:3 and US:UV=0:4.

Investigation of sonochemical activities at a frequency of 334 kHz: the effect of geometric parameters of sonoreactor.

In this study, the effect of the dimensions of the bottom plate and liquid height was investigated for high-frequency sonoreactors under a vertically irradiated system. The dimensions of the bottom plate did not significantly influence sonochemical activity considering power density. However, as the bottom plate was increased in size, the hydroxyl radical generation rate decreased because of a decrease in power density.

Arsenite removal using a pilot system of ultrasound and ultraviolet followed by microfiltration.

Batch and continuous-flow pilot tests using ultrasound (US), ultraviolet (UV) and a combination of US and UV were conducted to determine the oxidation rates of arsenite [As(III)]. Compared to the single processes of US or UV, the combined US/UV system was more effective for As(III) oxidation with a synergy index of more than 1.5.