Front Public Health
December 2022
The aim of the study was to determine the exposure of workers within biodegradable waste processing facilities to bacteria and fungi to identify any exposures of potential concern to health. Occupational measurements were performed in six composting and three bioenergy (bioethanol or methane/biogas) producing facilities. Bioaerosols were measured from breathing zones with Button aerosol or open face cassette filter samplers, and swab specimens were taken from the nasal mucous membranes of the workers.
View Article and Find Full Text PDFBiogas production from sewage sludge volatile solids (VS) by anaerobic digestion slows down towards the end of the process, among inhibitory factors being pH increase upon ammonia accumulation, poorly digestible biomaterials, and high fixed solid (FS) content. The possibility of concentrating the digested sludge VS (41.7-56.
View Article and Find Full Text PDFPesticides leaching from soil to surface and groundwater are a global threat for drinking water safety, as no cleaning methods occur for groundwater environment. We examined whether peat, compost-peat-sand (CPS) mixture, NHNO, NHNO with sodium citrate (Na-citrate), and the surfactant methyl-β-cyclodextrin additions enhance atrazine, simazine, hexazinone, dichlobenil, and the degradate 2,6-dichlorobenzamide (BAM) dissipations in sediment slurries under aerobic and anaerobic conditions, with sterilized controls. The vadose zone sediment cores were drilled from a depth of 11.
View Article and Find Full Text PDFThe pesticide atrazine, its degradation products, and 2,6-dichlorobenzamide (BAM) are persistent in groundwater environment. We studied whether their dissipation can be enhanced with a mixture of a complex carbon source and zero-valent iron (ZVI) called EHC®. The application rates were 1.
View Article and Find Full Text PDFMicrobial community compositions in pesticide-contaminated aquifers have not been studied, although such information is important for remediation and maintaining freshwater sources clean under changing climate. Therefore, phospholipid (PLFAs), glycolipid (GLFAs), and neutral lipid (NLFAs) fatty acids were determined from sand and clay sediments at depths of 0.3-24.
View Article and Find Full Text PDFBAM (2,6-dichlorobenzamide) is a metabolite of pesticide dichlobenil and a common groundwater contaminant. Dichlobenil and BAM half-lives were determined in five Finnish subsurface deposits and in topsoil. Aerobic and anaerobic conditions with sterilized controls were included in this 1.
View Article and Find Full Text PDFThe evolution of sporulating bacteria in full-scale composting facilities with online temperature monitoring has been poorly studied, although organic matter recycling increases. We analysed Clostridium perfringens and sulphite-reducing clostridia (SRC) by cultivation, and streptomycetes by real-time PCR in five full-scale, temperature-monitored and aerated composting processes, and two pilot-scale drum composters. Facilities composted woodchips, sawdust, peat, or bark amended sludge or source-separated biowaste.
View Article and Find Full Text PDFThis study aimed to clarify the impacts of pH control by wood ash amendment on biowaste composting processes. To achieve this, fresh source separated municipal biowaste was mixed with low doses (2-8% wt/vol) of wood ash and processed in a pilot and large-scale composting systems. The results indicated a correlation between a low initial pH and delay in the early rise of the process temperature.
View Article and Find Full Text PDFIn the present study, we investigated the effects of two bulking materials, Sphagnum peat and pine wood chips, on the early stages of biowaste composting in two pilot-scale processes. Emphasis was placed on studying the formation conditions of malodorous compost gases in the initial phases of the processes. The results showed that gas emission leaving an open windrow and a closed drum composting system contained elevated concentrations of fermentative microbial metabolites when acid Sphagnum peat (pH 3.
View Article and Find Full Text PDFIn groundwater subsurface deposits and a topsoil from five aquifers having 2,6-dichlorobenzamide (BAM) in water, we determined the most-probable-number (MPN) of 2,6-dichlorobenzonitrile (dichlobenil) and metabolite BAM degrading microorganisms. Dichlobenil and BAM were combined nitrogen sources in the MPN tubes, which were scored positive at concentrations <75% after 1 month incubation. Aerobic and anaerobic microbes degrading dichlobenil and BAM were common in samples in low numbers of 3.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
March 2009
The degradation of pesticides atrazine and terbutryn was investigated under aerobic and anaerobic conditions in the northern boreal region subsurface deposits and sterilized controls from the depths of 6.3-21.0 m below the surface and 1.
View Article and Find Full Text PDFWe studied the population dynamics of nitrifying bacteria during the development of biofilms up to 233 or 280 days on polyvinylchloride pipes connected to two full-scale drinking water distribution networks supplying processed and chloraminated surface water. The numbers of nitrifiers in biofilms were enumerated at intervals of 10-64 days by the most probable number (MPN) method at waterworks and at several study sites in distribution network areas. The numbers of nitrifiers increased towards the distal sites.
View Article and Find Full Text PDFTraditional techniques to study microbes, such as culturable counts, microbial biomass, or microbial activity, do not give information on the microbial ecology of drinking water systems. The aim of this study was to analyze whether the microbial community structure and biomass differed in biofilms collected from two Finnish drinking water distribution systems (A and B) receiving conventionally treated (coagulation, filtration, disinfection) surface water. Phospholipid fatty acid methyl esters (PLFAs) and lipopolysaccharide 3-hydroxy fatty acid methyl esters (LPS 3-OH-FAs) were analyzed from biofilms as a function of water residence time and development time.
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