Determining Pathogen and Indicator Levels in Class B Municipal Organic Residuals Used for Land Application

Abstract

Biosolids are nutrient-rich organic residuals that are currently used to amend soils for food production. Treatment requirements to inactivate pathogens for production of Class A biosolids are energy intensive. One less energy intensive alternative is to treat biosolids to Class B standards, but it could result in higher pathogen loads. Quantitative microbial risk assessments models have been developed on land application of Class B biosolids but contain many uncertainties because of limited data on specific pathogen densities and the use of fecal indicator organisms as accurate surrogates of pathogen loads. To address this gap, a 12-mo study of the levels and relationships between , , and human adenovirus (HAdV) with fecal coliform, somatic, and F-RNA coliphage levels in Class B biosolids from nine wastewater treatment plants throughout the United States was conducted. Results revealed that fecal coliform, somatic, and F-RNA coliphage densities were consistent throughout the year. More important, results revealed that HAdV ( = 2.5 × 10 genome copies dry g) and ( = 4.14 × 10 cysts dry g) were in all biosolids samples regardless of treatment processes, location, or season. oocysts were also detected (38% positive; range: 0-1.9 × 10 oocysts dry g), albeit sporadically. Positive correlations among three fecal indicator organisms and HAdV, but not protozoa, were also observed. Overall, this study reveals that high concentrations of enteric pathogens (e.g., , , and HAdV) are present in biosolids throughout the United States. Microbial densities found can further assist management and policymakers in establishing more accurate risk assessment models associated with land application of Class B biosolids.

Achilles heel of environmental risk from recycling of sludge to soil as amendment: A summary in recent ten years (2007–2016)

“…Pathogen microorganism in sludge and the change in vitality when sludge is harmless treated followed by being recycled to soil Sludge contains broad-spectrum profile of pathogenic microorganisms due to originating from domestic sewage, which is abundant in all kinds of bacteria (Arora et al, 2014;Li et al, 2015;Scheinemann et al, 2015), such as fecal coliform (Cabanas-Vargas et al, 2013;Ozdemir et al, 2013;Rhodes et al, 2015), Salmonella coli (Bonetta et al, 2014;Cabanas-Vargas et al, 2013;Levantesi et al, 2015), Escherichia coli (Levantesi et al, 2015;Verbyla et al, 2016;Pascual-Benito et al, 2015). In addition, there are a plenty of ascaris egg in sludge because most of its solid constitute is mainly from human faeces (Darimani et al, 2016;Verbyla et al, 2016;Fidjeland et al, 2015Fidjeland et al, , 2013.…”

Propagation of Giardia duodenalis cysts in immunosuppressed CF-1 mice

“…Giardia duodenalis is a protozoan parasite that commonly causes waterborne gastrointestinal illness in humans, with outbreaks across the world (Efstratiou et al, 2017). Giardia cysts are often found in wastewater and biosolid samples at high concentrations, and remains an important waterborne pathogen (King et al, 2016;Ramo et al, 2017a;Ramo et al, 2017b;Rhodes et al, 2015). Since the cyst is the only stable life stage in the environment, viable G. duodenalis cysts are required to study this pathogen in environmental matrices.…”

Comparative Assessment of BGM and PLC/PRF/5 Cell Lines for Enteric Virus Detection in Biosolids

“…To our knowledge, this is the first report of the utilization of PLC/PRF/5 cells for the detection of adenoviruses in raw sludge and Class B biosolids and one of only a few studies on the occurrence of human adenoviruses in biosolids (Lyndholm and Nielsen 1983; Williams and Hurst 1988;Bofill-Mas et al 2006;Pepper et al 2010;Rhodes et al 2015). This study further confirms the survival of infectious adenoviruses after mesophilic and aerobic sludge digestion (Lyndholm and Nielsen 1983).…”