Microwave ultrasonic pre-treatment for enhanced aeration and anaerobic degradation of pharmaceutical waste

Abstract

Pharmaceutical plants produce a huge amount of sludge and effluent; around 15% of this waste can be considered toxic to the environment and humans. The development of the pharmaceutical industry includes a different amount of production and a complex process known as high concentration and poor biodegradability. There are several physical chemical and biological treatment methods for the degradation of pharmaceutical waste. Yet, most of these technologies are expensive and suffer from technical limitations. An alternative to address this problem is Anaerobic Digestion process (AD) which is a biodegradation process that removes organic matter and total and suspended solids in oxygen free reactors. However, anaerobic digestion has a very slow rate-limiting hydrolysis stage. To address this problem and make the process faster and improve the efficiency, pretreatment methods as microwave, ultrasonic, chemical, mechanical or thermal pretreatment techniques can be applied. This research focuses on investigating the use of microwave, ultrasonic and oxidation pretreatment techniques at microwave frequency of 2450 MHz and a maximum power supply of 640 W. Ultrasonication, creates high shear forces which result in cavitation and sludge disruption due to the ultrasonic waves. These forces damage the membranes at lower sonic intensities, making the bacteria more vulnerable to the effects of biocides. Additionally, cavitation's hydroxyl radical can help with disinfection, the experiment is sampled in three stages to note the affected of different pretreatment on anaerobic and note digestion settings.