Is anaerobic digestion a reliable barrier for deactivation of pathogens in biosludge?

Abstract

Editor: Huu Hao NgoAs World Health Organization advocates, the global burden of sanitation related disease and access to safely managed sanitation and safely treated wastewater should be monitored strictly. However, the spread of pathogens through various agricultural applications or direct discharge of sewage sludge generated in municipal wastewater treatment plants poses a serious challenge on the environment and public health. Anaerobic digestion (AD), the principal method of stabilizing biosolids, can efficiently and largely deactivate viable pathogens, including parasite, virus, and the pathogens harboring antibiotic resistance genes. This review aims to provide a critical overview regarding the deactivation of sludge-associated pathogens by AD, through which a serious concern on the effectiveness and rationality of AD towards sludge pathogens control was raised. Meanwhile, the underlying deactivation mechanisms and affecting factors were all discussed, with the focus on pathogen-associated modeling, engineering design and technological aspects of AD. Lastly, a matric method incorporating the operating strategy of AD with the risk assessment was proposed for evaluating the reliability of AD-based pathogen deactivation, while the research agenda forward was also outlined.

Plant Bioestimulants: Compost Tea and Bioslurry Characterization

“…in the compost used in teas brewing, suggesting that the sanitation was produced in composting process [45.46]. Besides the fresh manure utilized in bioslurry preparation, no pathogen were detected, which indicates the sanitization in the anaerobic process, in agree with Zhao and Liu [47].…”

What do we know about the SARS-CoV-2 coronavirus in the environment?

“…If this virus is not eradicated, we should think on further screening focusing on wastewater (Martínez-Puchol et al, 2020 -have recently published a paper dealing with related aspects), but also on sewage sludge (as shown by Nag et al, 2020 -evaluating survival of bacteria and viruses causing different diseases, as well as in previous papers, such as that by Zhao and Liu, 2019), soils and sediments (Katz et al, 2018;Nag et al, 2020;Zhao and Liu, 2019), crops (Ahmed et al, 2019;Nag et al, 2020;Zhao and Liu, 2019), animals (Pruvot et al, 2019), surface and ground-waters (Corsi et al, 2014;Givens et al, 2016). Further research should also focus on eventual technical treatments, including biosorbents and other materials to retain and/or inactive this and other pathogens circulating in these environmental compartments, before and after going out from wastewater treatment plants (in case of these treatment systems existing, as it could be worse, with spreading of untreated wastes).…”

Phase Separation in Anaerobic Digestion: A Potential for Easier Process Combination?

“…This is of particular importance for the treatment of residues with high solid-contents like organic fractions of municipal solid waste (OFMSW) (Fernández-Rodríguez et al, 2016). Thermophilic operation, on the other side, promotes the deactivation of infectious pathogens as present in biogenic residues (Zhao and Liu, 2019). According to Pandey and Soupir (2011), the inactivation rate of Escherichia coli, as a representative for pathogenic organisms is 15-fold higher at 52°C than at 37°C.…”