Effect of Composting Under Semipermeable Film on the Sewage Sludge Virome

Novel multiplexed alkali enzyme lysis coupled with EDTA pretreatment for RNA virus extraction from wastewater sludge: Optimization, recovery, and detection

RNA viruses are readily enriched in wastewater sludge owing to adsorption by extracellular polymeric substances (EPS) during wastewater treatment, causing pathogenicity. However, conventional wastewater extraction methods often fail to fully extract these viruses from sludge. In this study, three methods: enzymatic (ENP), alkaline (ALP), and ethylenediaminetetraacetic acid (EDTA) pretreatments were applied to sludges and promote the RNA virus extraction from sludge. Our results show that the total recovery rate of RNA viruses increased by 87.73% after ENP pretreatment, whereas ALP pretreatment inhibited virus extraction. The highest recovery rate of viruses from sludge, reaching 296.80%, was achieved with EDTA pretreatment (EDP) coupled with ENP. Notably, the most significant increase was observed in the abundance of Astroviruses, which increased from 7.60 × 107 to 7.86 × 108 copies/g TSS after EDP + ENP treatment. Our investigations revealed that virus extraction was affected by a class of short-wavelength protein substances, as opposed to tryptophan or tyrosine, which were eluted by proteins with beef paste buffer by substitution after EDP + ENP treatment. The results of this study provide essential insights for sludge-based epidemiology with the required sensitivity for managing the extraction of RNA epidemic viruses to control viral transmission.

Inactivation and risk control of pathogenic microorganisms in municipal sludge treatment: A review

The rapid global spread of coronavirus disease 2019 (COVID-19) has promoted concern over human pathogens and their significant threats to public health security. The monitoring and control of human pathogens in public sanitation and health facilities are of great importance. Excessive sludge is an inevitable byproduct of sewage that contains human and animal feces in wastewater treatment plants (WWTPs). It is an important sink of different pollutants and pathogens, and the proper treatment and disposal of sludge are important to minimize potential risks to the environment and public health. However, there is a lack of comprehensive analysis of the diversity, exposure risks, assessment methods and inactivation techniques of pathogenic microorganisms in sludge. Based on this consideration, this review summarizes the control performance of pathogenic microorganisms such as enterovirus, Salmonella spp., and Escherichia coli by different sludge treatment technologies, including composting, anaerobic digestion, aerobic digestion, and microwave irradiation, and the mechanisms of pathogenic microorganism inactivation in sludge treatment processes are discussed. Additionally, this study reviews the diversity, detection methods, and exposure risks of pathogenic microorganisms in sludge. This review advances the quantitative assessment of pathogenic microorganism risks involved in sludge reuse and is practically valuable to optimize the treatment and disposal of sludge for pathogenic microorganism control.

Applicability of pepper mild mottle virus and cucumber green mottle mosaic virus as process indicators of enteric virus removal by membrane processes at a potable reuse facility

Treatment of wastewater for potable reuse is increasingly becoming a suitable alternative water source to meet the growing urban water needs worldwide. Potable reuse requires reduction of enteric viruses to levels at which they do not pose a risk to human health. Advanced water treatment trains (e.g., microfiltration (MF), ultrafiltration (UF), reverse osmosis (RO), and ultraviolet light and advanced oxidation process (UV/AOP)) provide significant protection and reduce virus loads in highly treated final product waters. Even though viruses are a principal concern, the performance of virus removal by membrane processes is not easily determined. The objective of this study was to evaluate the applicability of Aichi virus (AiV), pepper mild mottle virus (PMMoV), cucumber green mottle mosaic virus (CGMMV), and cross-assembly phage (crAssphage) removal as possible process indicators for MF, UF, and RO. Virus log reduction values (LRVs) based on gene copies measured using molecular methods were determined for MF and UF. The median LRVs of all viruses obtained after MF and UF were 2.9 and 3.1, respectively. The LRVs of the proposed indicators were lower than those of human enteric viruses. The morphological and physicochemical difference among indicators was not found to affect LRVs. Therefore, all proposed indicator viruses were determined to be suitable candidates as process indicators for MF and UF. Regarding RO, most of the viruses measured in this study were undetectable in permeate. Only PMMoV and CGMMV were detected showing median LRVs of 2.8 and 2.5, respectively. PMMoV and CGMMV are recommended as good process indicators of physical virus removal for the overall water treatment process.

Virome studies of food production systems: time for 'farm to fork' analyses

The food industry is under increasing pressure to produce high quality, traceable and minimally processed foods that are produced using sustainable approaches and ingredients. In line with the latter, there is an increased pressure for plant-based products to replace animal-derived products. Until recently, research efforts have mainly focused on dairy and meat products owing to their economic importance. The shift towards plant-based diets and food production requires a corresponding shift in research efforts to define the microbial requirements for and composition of (novel) plant-based foods, the (micro)organisms that are beneficial to such production systems, and the abundance and role of (bacterio)phages in shaping the microbial landscape of these foods. In this review, we explore current efforts in the area of virome analysis of foods and food production environments and highlight the need for more unified approaches to understand the contribution of phages in food safety and quality, and to develop novel tools to enhance the traceability of foods.

Residuals, sludge, and biosolids: Advancements in the field

Advancements in the field of residuals, sludge, and biosolids have been made in 2019. This review outlines the major contributions of researchers that have been published in peer-reviewed journals and conference proceedings throughout 2019 and includes brief summaries from over 125 articles. The review is organized in sections including life cycle and risk assessments; characteristics, quality, and measurement including micropollutants, nanoparticles, pathogens, and metals; sludge treatment technologies including dewatering, digestion, composting, and wetlands; disposal and reuse including adsorbents, land application and agricultural uses, nutrient recovery, and innovative uses; odor and air emissions; and energy issues.