Wastewater deodorization: problems and solutions

The problem of specific malodours odorants, emitted from the territory of wastewater and sludge treatment facilities is set in the article. This article presents a critical review concerning the reasons of odorants formation during wastewater treatment, their influence on human health and ways of wastewater and sludge deodorization. Review is presented by 52 resources of Russian, Chinese, Italian, Greek, Indian, American and other researches from 2000 to 2021 years. According to the review the main sources of odours emission are units of mechanical treatment, sludge thickening and sludge digestion. The main odorants are volatile organic compounds (VOCs), hydrogen sulphide, ammonia, particulate matters and greenhouse gases (carbon dioxide, methane, nitrogen oxide). Based on the article, there are two ways of emission controlling: controlling the technological parameters of wastewater treatment process or gases treatment at specific facilities (adsorbers, biofilters, bioscrubbers, chemical scrubbers).

Impact of the anaerobic digestion process configuration on the sludge dewaterability

Anaerobic sludge digestion is an important tool for converting sludge into a renewable fuel - biogas. However, digested sludge can also be used as a fuel, and a fundamental parameter determining the energy value of digested sludge is as effective as possible dewatering. The main aim of the presented study was to evaluate how the anaerobic digestion (AD) technology and post-treatment technology can affect sludge dewaterability. Two technological alternatives of AD were evaluated: mesophilic (MAD) and thermophilic (TAD). In addition, also the effect of postaeration of digested was evaluated. The dewaterability was assessed using two methods based on centrifugation and filter pressing. Finally, the sludge cake concentration of total suspended solids (TSS) was compared. The results showed the difference in sludge dewaterability for the tested sludges: The sludge cake concentration was similar or slightly higher for MAD compared to TAD sludge. Post-aeration of digested sludge increased sludge cake concentration.