Treatability of U.S. Environmental Protection Agency Contaminant Candidate List Viruses: Removal of Coxsackievirus and Echovirus using Enhanced Coagulation

Enhanced coagulation was evaluated for removal efficacy of coxsackievirus and echovirus (Contaminant Candidate List [CCL] enteroviruses), poliovirus, four potential surrogate bacteriophages, and dissolved organic carbon (DOC). Viruses and DOC were effectively removed using enhanced coagulation, with removals generally improving as dose increased and pH decreased. Optimal enhanced coagulation conditions of 40 mg/L FeCl3 and pH between 5 and 6.5 resulted in a maximum removal of 3.0 logs of coxsackievirus B6, 1.75 logs of echovirus 12, 2.5 logs of poliovirus 1, 1.8 logs of fr, 1.3 logs of phi-X174, 0.36 logs of MS2, 0.29 logs of PRD1, and 41% DOC. Bacteriophages fr and phi-X174 appear to be the most representative surrogates for the physical removal of coxsackievirus, while MS2 and PRD1 are more conservative. For echovirus, MS2 and PRD1 appear to be the most appropriate surrogates. The relative removal profiles of the enteroviruses (greatest removal of coxsackievirus followed by poliovirus and then echovirus) suggest that studies of the physical removal of poliovirus may be extended to the CCL enteroviruses. These results contribute to evaluations of the CCL and regulatory status of coxsackievirus and echovirus and aid in building a database of the treatment efficiencies of enteroviruses and their surrogates

Efficacy of Removal of CCL Viruses under Enhanced Coagulation Conditions

The focus of coagulation as a water treatment process is shifting to accommodate recent regulatory additions that strive to balance the risks between microbial and chemical contamination of drinking water. In this work, enhanced coagulation using increased ferric chloride dose and/or pH adjustment was evaluated for removal efficacy of viruses on the United States Environmental Protection Agency (USEPA) Contaminant Candidate List (CCL), their surrogates, and dissolved organic carbon (DOC). Jar tests demonstrated that optimal DOC removal was achieved using 40 mg/L FeCl3 at a pH between 5 and 6. Under these conditions, bench-scale testing resulted in a maximum removal of 2.58 log units of adenovirus type 4, 2.50 log units of feline calicivirus, 2.32 log units of MS2, 1.75 log units of PRD1, 1.52 log units of phi-X174, 2.49 log units of fr, and 56% of DOC. The trend in virus removals (MS2 and fr \u3e PRD1 and phi-X174) was consistent between bench- and pilot-scale testing; however, pilot-plant removals exceeded bench-scale removals. Feline calicivirus was more efficiently removed than the bacteriophages, thereby suggesting potential for the bacteriophages as suitable surrogates, with MS2 and fr being more representative and PRD1 and phi-X174 (which were removed to a lesser extent) more conservative. The bacteriophages do not appear to be appropriate surrogates for adenovirus

Molecular Detection of \u3ci\u3eCampylobacter\u3c/i\u3e spp. and Fecal Indicator Bacteria during the Northern Migration of Sandhill Cranes (\u3ci\u3eGrus canadensis\u3c/i\u3e) at the Central Platte River

The risk to human health of the annual sandhill crane (Grus canadensis) migration through Nebraska, which is thought to be a major source of fecal pollution of the central Platte River, is unknown. To better understand potential risks, the presence of Campylobacter species and three fecal indicator bacterial groups (Enterococcus spp., Escherichia coli, and Bacteroidetes) was assayed by PCR from crane excreta and water samples collected during their stopover at the Platte River, Nebraska, in 2010. Genus-specific PCR assays and sequence analyses identified Campylobacter jejuni as the predominant Campylobacter species in sandhill crane excreta. Campylobacter spp. were detected in 48% of crane excreta, 24% of water samples, and 11% of sediment samples. The estimated densities of Enterococcus spp. were highest in excreta samples (mean, 4.6 x108 cell equivalents [CE]/g), while water samples contained higher levels of Bacteroidetes (mean, 5.1 x 105 CE/100 ml). Enterococcus spp., E. coli, and Campylobacter spp. were significantly increased in river water and sediments during the crane migration period, with Enterococcus sp. densities (~3.3 x 105 CE/g) 2 to 4 orders of magnitude higher than those of Bacteroidetes (4.9 x 103 CE/g), E. coli (2.2 x 103 CE/ g), and Campylobacter spp. (37 CE/g). Sequencing data for the 16S rRNA gene and Campylobacter species-specific PCR assays indicated that C. jejuni was the major Campylobacter species present in water, sediments, and crane excreta. Overall, migration appeared to result in a significant, but temporary, change in water quality in spring, when there may be a C. jejuni health hazard associated with water and crops visited by the migrating birds

Bacterial diversity and predicted enzymatic function in a multipurpose surface water system – from wastewater effluent discharges to drinking water production

Funding Information: The authors would like to express special acknowledgment to the CONPAT research team at the Finnish Institute for Health and Welfare, Finnish Environment Institute, and VATT Institute for Economic Research. Special thanks go to Tiina Heiskanen and Laura Wessels for extracting the nucleic acids. The Water Protection Association of the River Kokem?enjoki (KVVY) is acknowledged for surface water and wastewater sampling. Funding Information: Academy of Finland (grant number 263451) and Kaute Foundation (grant number 20190366) are acknowledged for providing funds for the project establishment and manuscript writing, respectively. Funding Information: The authors declare that they have no competing interests. This work was in part supported by the U.S. Environmental Protection Agency (EPA), and any opinions expressed do not reflect the views of the agency; therefore, no official endorsement should be inferred. Any mention of trade names or commercial products does not constitute endorsement or recommendation for use. Publisher Copyright: © 2021, The Author(s).Background Rivers and lakes are used for multiple purposes such as for drinking water (DW) production, recreation, and as recipients of wastewater from various sources. The deterioration of surface water quality with wastewater is well-known, but less is known about the bacterial community dynamics in the affected surface waters. Understanding the bacterial community characteristics -from the source of contamination, through the watershed to the DW production process-may help safeguard human health and the environment. Results The spatial and seasonal dynamics of bacterial communities, their predicted functions, and potential health-related bacterial (PHRB) reads within the Kokemaenjoki River watershed in southwest Finland were analyzed with the 16S rRNA-gene amplicon sequencing method. Water samples were collected from various sampling points of the watershed, from its major pollution sources (sewage influent and effluent, industrial effluent, mine runoff) and different stages of the DW treatment process (pre-treatment, groundwater observation well, DW production well) by using the river water as raw water with an artificial groundwater recharge (AGR). The beta-diversity analysis revealed that bacterial communities were highly varied among sample groups (R = 0.92, p = 13%) than in other groups (= 13%) than in others (Peer reviewe

Development of Quantitative PCR Assays Targeting the 16S rRNA Genes of Enterococcus spp. and Their Application to the Identification of Enterococcus Species in Environmental Samples

ABSTRACT The detection of environmental enterococci has been determined primarily by using culture-based techniques that might exclude some enterococcal species as well as those that are nonculturable. To address this, the relative abundances of enterococci were examined by challenging fecal and water samples against a currently available genus-specific assay (Entero1). To determine the diversity of enterococcal species, 16S rRNA gene-based group-specific quantitative PCR (qPCR) assays were developed and evaluated against eight of the most common environmental enterococcal species. Partial 16S rRNA gene sequences of 439 presumptive environmental enterococcal strains were analyzed to study further the diversity of enterococci and to confirm the specificities of group-specific assays. The group-specific qPCR assays showed relatively high amplification rates with targeted species (>98%), although some assays cross-amplified with nontargeted species (1.3 to 6.5%). The results with the group-specific assays also showed that different enterococcal species co-occurred in most fecal samples. The most abundant enterococci in water and fecal samples were Enterococcus faecalis and Enterococcus faecium , although we identified more water isolates as Enterococcus casseliflavus than as any of the other species. The prevalence of the Entero1 marker was in agreement with the combined number of positive signals determined by the group-specific assays in most fecal samples, except in gull feces. On the other hand, the number of group-specific assay signals was lower in all water samples tested, suggesting that other enterococcal species are present in these samples. While the results highlight the value of genus- and group-specific assays for detecting the major enterococcal groups in environmental water samples, additional studies are needed to determine further the diversity, distributions, and relative abundances of all enterococcal species found in water

Effects of urban stream burial on organic matter dynamics and reach scale nitrate retention

Nitrogen (N) retention in streams is an important ecosystem service that may be affected by the widespread burial of streams in stormwater pipes in urban watersheds. We predicted that stream burial suppresses the capacity of streams to retain nitrate (NO3 −) by eliminating primary production, reducing respiration rates and organic matter availability, and increasing specific discharge. We tested these predictions by measuring whole-stream NO3 − removal rates using 15NO3 − isotope tracer releases in paired buried and open reaches in three streams in Cincinnati, Ohio (USA) during four seasons. Nitrate uptake lengths were 29 times greater in buried than open reaches, indicating that buried reaches were less effective at retaining NO3 − than open reaches. Burial suppressed NO3 − retention through a combination of hydrological and biological processes. The channel shape of two of the buried reaches increased specific discharge which enhanced NO3 − transport from the channel, highlighting the relationship between urban infrastructure and ecosystem function. Uptake lengths in the buried reaches were further lengthened by low stream biological NO3 − demand, as indicated by NO3 − uptake velocities 17-fold lower than that of the open reaches. We also observed differences in the periphyton enzyme activity between reaches, indicating that the effects of burial cascade from the microbial to the ecosystem scale. Our results suggest that stream restoration practices involving “daylighting” buried streams have the potential to increase N retention. Further work is needed to elucidate the impacts of stream burial on ecosystem functions at the larger stream network scale

Efficacy of Inactivation of Human Enteroviruses by Dual-Wavelength Germicidal Ultraviolet (UV-C) Light Emitting Diodes (LEDs)

The efficacy of germicidal ultraviolet (UV-C) light emitting diodes (LEDs) was evaluated for inactivating human enteroviruses included on the United States Environmental Protection Agency (EPA)&rsquo;s Contaminant Candidate List (CCL). A UV-C LED device, emitting at peaks of 260 nm and 280 nm and the combination of 260/280 nm together, was used to measure and compare potential synergistic effects of dual wavelengths for disinfecting viral organisms. The 260 nm LED proved to be the most effective at inactivating the CCL enteroviruses tested. To obtain 2-log10 inactivation credit for the 260 nm LED, the fluences (UV doses) required are approximately 8 mJ/cm2 for coxsackievirus A10 and poliovirus 1, 10 mJ/cm2 for enterovirus 70, and 13 mJ/cm2 for echovirus 30. No synergistic effect was detected when evaluating the log inactivation of enteroviruses irradiated by the dual-wavelength UV-C LEDs.</p

Molecular detection of Campylobacter spp. and fecal indicator bacteria during the northern migration of sandhill cranes (Grus canadensis) at the central Platte River

The risk to human health of the annual sandhill crane (Grus canadensis) migration through Nebraska, which is thought to be a major source of fecal pollution of the central Platte River, is unknown. To better understand potential risks, the presence of Campylobacter species and three fecal indicator bacterial groups (Enterococcus spp., Escherichia coli, and Bacteroidetes) was assayed by PCR from crane excreta and water samples collected during their stopover at the Platte River, Nebraska, in 2010. Genus-specific PCR assays and sequence analyses identified Campylobacter jejuni as the predominant Campylobacter species in sandhill crane excreta. Campylobacter spp. were detected in 48% of crane excreta, 24% of water samples, and 11% of sediment samples. The estimated densities of Enterococcus spp. were highest in excreta samples (mean, 4.6 x 10^8 cell equivalents [CE]/g), while water samples contained higher levels of Bacteroidetes (mean, 5.1 x 10^5 CE/100 ml). Enterococcus spp., E. coli, and Campylobacter spp. were significantly increased in river water and sediments during the crane migration period, with Enterococcus sp. densities (~3.3 x 10^5 CE/g) 2 to 4 orders of magnitude higher than those of Bacteroidetes (4.9 x 10^3 CE/g), E. coli (2.2 x 10^3 CE/g), and Campylobacter spp. (37 CE/g). Sequencing data for the 16S rRNA gene and Campylobacter species-specific PCR assays indicated that C. jejuni was the major Campylobacter species present in water, sediments, and crane excreta. Overall, migration appeared to result in a significant, but temporary, change in water quality in spring, when there may be a C. jejuni health hazard associated with water and crops visited by the migrating birds.Peer reviewedBiosystems and Agricultural Engineerin