Bath-type sonicators effectively treat pollutants in wastewater such as chemical oxygen demand (COD), turbidity, pharmaceuticals, azo dyes, and heavy metals. They are particularly advantageous for larger-scale applications compared to probe-type sonicators.
Sonicators of the bath type and sonicators of the probe type represent two different methods for treating contaminated water, each with its own specific advantages depending on the type of pollutants.
Bath-type sonicators typically use ultrasound waves transmitted through water with high amplitudes. This can be effective for:
Organic contaminants - ultrasound can help break down organic molecules such as oils, fats, proteins, and other organic pollutants.
Heavy metals - certain heavy metals (e.g., mercury, lead) can be removed from water using bath-type sonicators.
Particle activation and agglomeration - this technology can help in agglomerating particles like colloidal materials or microorganisms, making the filtration and removal processes easier.
Microorganisms - ultrasound waves can damage the membranes of microorganisms, leading to their destruction or inactivation.
Probe-type sonicators, on the other hand, often have a more direct impact on specific pollutants, but with limitations in treating large volumes of water:
Heavy metals and compounds - probes can be useful in isolating or reducing concentrations of heavy metals such as cadmium or chromium.
Microorganisms and viruses - similar to bath-type sonicators, ultrasound waves can have a strong antiseptic effect on microorganisms.
Pesticides and organic compounds - ultrasound can help in degrading and removing pesticides or other toxic organic compounds.
The main difference is that bath-type sonicators allow for better distribution of waves in larger volumes of water, while probes are focused on more localized effects, which may be more effective in specific applications.
Regarding overall efficiency, choosing between these two types of sonicators depends on the type of pollutants and the requirements of the treatment system.
Soluble organics such as most textile dyes can't be removed by sonication alone. However sonication may increase the mass transfer in chemical and biological degradation of soluble organics. We remove most textile dyes by advanced biotreatment and residual color can be removed by advanced oxidation.