14 research outputs found
Riverbank Filtration Impacts on Post Disinfection Water Quality in Small Systems—A Case Study from Auburn and Nebraska City, Nebraska
Small water systems can experience a fluctuating quality of water in the distribution system after disinfection. As chlorine is the most common disinfectant for small systems, the occurrence of disinfection byproducts (DBPs) represents a common problem for these systems. Riverbank filtration (RBF) can be a valuable solution for small communities located on riverbanks. The objectives of this study were to evaluate (i) the improvements in water quality at two selected RBF systems, and (ii) the potential lower concentrations of DBPs, in particular, trihalomethanes (THMs), in small systems that use RBF. Two small communities in Nebraska, Auburn and Nebraska City, using RBF were selected. Results from this study highlight the ability of RBF systems to consistently improve the quality of the source water and reduce the occurrence of THMs in the distribution water. However, the relative removal of THMs was directly impacted by the dissolved organic carbon (DOC) removal. Different THM concentrations and different DOC removals were observed at the two RBF sites due to the different travel distances between the river and the extractions wells
Flow Analysis through CollectorWell Laterals: A Case Study from Sonoma County Water Agency, California
The Sonoma County Water Agency (SWCA) uses six radial collector wells along the Russian River west of Santa Rosa, to provide water for several municipalities and water districts in north-western California. Three collector wells (1, 2, and 6) are located in the Wohler area, and three collector wells (3, 4, and 5) are located in the Mirabel area. The objective of this paper is to highlight the performance of the three collector wells located in the Mirabel area since their construction. The 2015 investigation showed a lower performance of Collectors 3 and 4 compared to their original performances after construction in 1975, while the performance of Collector 5 was relatively stable since 1982. The potential change in capacity could be due to the increase in encrustation observed during the visual inspection of laterals in all three collector wells. Overall, the three collectors are still within the optimal design parameters (screen entrance velocity \u3c 0.305 m min1 and axial flow velocity of lateral screens \u3c 1.524 m s1)
Development and performance assessment of an integrated vermifiltration based treatment system for the treatment of feedlot runoff
The objective of this study was to treat feedlot runoff by developing an ecologically sustainable, affordable, and resilient treatment system having a relatively long life span. Three horizontal flow soil biofilters were utilized in this study: 1) without earthworms and plants (Biofilter (BF)), 2) with earthworms only (Vermifilter (VF)), and 3) with earthworms and plants (Macrophyte Assisted Vermifilter (MAVF)). The experiments were conducted with a hydraulic retention time of four days using Lumbricus terestrris earthworms and Carex frankii wetland plants. The average COD removal from the BF, VF, and MAVF were 23.2–30.4%, 61.4–69.1%, and 68.3–78.1%, respectively. Average TN removal efficiencies for BF, VF, and MAVF were 15.5–21.4%, 34.4–38.8%, and 39.1–44.0%, respectively. Additionally, average TP removals for BF, VF, and MAVF were 31.9–40.8%, 48.0–54.0%, and 51.1–58.3%, respectively. Comparison of results with literature indicate that the developed system can facilitate more nitrogen removal. Plant roots, along with earthworms, create an aerobic ecosystem within the treatment filter, leading to high organics oxidation and nitrification efficiency among BF, VF, and MAVF. Observational analysis indicates the system with earthworms is prone to clogging while the system with earthworms and plants was less prone to clogging. Thus, it can be concluded that if modularized, the application of MAVF systems can treat feedlot runoffs with higher removal efficiency and expanded life span
Flow Analysis through Collector Well Laterals: A Case Study from Sonoma County Water Agency, California
The Sonoma County Water Agency (SWCA) uses six radial collector wells along the Russian River west of Santa Rosa, to provide water for several municipalities and water districts in north-western California. Three collector wells (1, 2, and 6) are located in the Wohler area, and three collector wells (3, 4, and 5) are located in the Mirabel area. The objective of this paper is to highlight the performance of the three collector wells located in the Mirabel area since their construction. The 2015 investigation showed a lower performance of Collectors 3 and 4 compared to their original performances after construction in 1975, while the performance of Collector 5 was relatively stable since 1982. The potential change in capacity could be due to the increase in encrustation observed during the visual inspection of laterals in all three collector wells. Overall, the three collectors are still within the optimal design parameters (screen entrance velocity \u3c 0.305 m min-1 and axial flow velocity of lateral screens \u3c 1.524 m s-1)
Flow Analysis through Collector Well Laterals: A Case Study from Sonoma County Water Agency, California
The Sonoma County Water Agency (SWCA) uses six radial collector wells along the Russian River west of Santa Rosa, to provide water for several municipalities and water districts in north-western California. Three collector wells (1, 2, and 6) are located in the Wohler area, and three collector wells (3, 4, and 5) are located in the Mirabel area. The objective of this paper is to highlight the performance of the three collector wells located in the Mirabel area since their construction. The 2015 investigation showed a lower performance of Collectors 3 and 4 compared to their original performances after construction in 1975, while the performance of Collector 5 was relatively stable since 1982. The potential change in capacity could be due to the increase in encrustation observed during the visual inspection of laterals in all three collector wells. Overall, the three collectors are still within the optimal design parameters (screen entrance velocity \u3c 0.305 m min-1 and axial flow velocity of lateral screens \u3c 1.524 m s-1)
Detection, Occurrence and Fate of Emerging Contaminants in Agricultural Environments
A total of 43 papers published in 2014 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to measuring and predicting biological effects for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, natural and synthetics steroids, and antibiotic resistance genes in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Occurrence and Fate, Antibiotic Resistance Genes, and Risk Assessment
Rapporto 2007. Quadro degli interventi di prevenzione, cura e riabilitazione sul consumo di droghe nella provincia di Rimini.
Report on the state of legal and illegal substances use in the territory of Rimini province.La relazione ? articolata in 3 parti. Nella prima - diffusione delle sostanze - vengono riportati gli ultimi dati relativi alla stima dei consumatori di sostanze psicotrope nella provincia di Rimini attraverso la sintesi di due indagini sulla popolazione generale (indagine Ipsad?) e sulla popolazione studentesca di et? 15-19 anni (indagine Espad-Italia?). Una seconda parte - attivit? dei servizi - in cui vengo descritte non solo le caratteristiche delle persone che accedono ai servizi per le dipendenze pubblici e privati, compresa il Carcere di Rimini, ma anche le risposte fornite in termini di cura e riabilitazione. Una terza parte - interventi sul territorio - in cui vengono descritte le attivit? sia di prevenzione sia di contrasto all\u27uso. Risulta particolarmente interessante una prima valutazione delle attivit? realizzata all\u27interno dei piani di zona dei comuni di Rimini e Riccione
Stock de carbono en el componenetes vegetal en diferentes estratos del Bosque Reservado de la Universidad Nacional Agraria de la Selva.
TesisEl Bosque Reservado de la Universidad Nacional Agraria de la Selva (BRUNAS) representa una pequeña cantidad de superficie terrestre a nivel local (217.22 ha), pero su deterioro implicaría la emisión de cantidades importantes de dióxido de carbono a la atmósfera, es por esto que se debe cuantificar los almacenes de carbono terrestre en estos sistemas de la manera más precisa y completa posible. El estudio de investigación tuvo la finalidad de estimar el stock de carbono en el componente aéreo vegetal del BRUNAS, teniendo en cuenta cómo influye el gradiente altitudinal (estratos fisiográficos) en el stock de carbono; en la fase de pre-campo se realizó la recopilación respectiva de distinta información que presenta el BRUNAS, se realizó la digitalización de las unidades fisiográficas y por coberturas que presenta, para posteriormente seleccionar sistemáticamente las parcelas a instalar; en la fase de campo se realizó la instalación de unidades de evaluación, inventario y el registro de variables para la estimación de biomasa. Se determinó el Índice de Valor de Importancia simplificado (I.V.I.), se calculó el stock de carbono en la biomasa del componente arbóreo, del componente sotobosque, del componente herbáceo dentro del dosel, del componente hojarasca, del componente herbáceo sin bosque y en la biomasa aérea total dentro del dosel; para el análisis estadístico se realizó el análisis de varianza multifactorial con interacción A X B (estrato fisiográfico vs componentes del bosque), un análisis de varianza simple para el stock de carbono aéreo total (suma de los componentes dentro del dosel) y para el stock de carbono en cobertura herbácea (parcelas representativas). Al realizar el análisis estadístico se estimó el stock de carbono para cada componente en los diferentes estratos del BRUNAS, determinándose que el componente arbóreo es estadísticamente diferente a los demás componentes y que hay diferencias estadísticas significativas en el stock de carbono entre los factores componentes del bosque por estratos fisiográficos; para el stock de carbono total (suma de componentes por estrato) Colina Alta Clase 1 presenta diferencia significativa con Montaña en 30.76 t ha-1. El stock de carbono almacenado en la biomasa del componente aéreo en el BRUNAS, oscila entre 11576.36 t y 14025.81t
Flow Analysis through CollectorWell Laterals: A Case Study from Sonoma County Water Agency, California
The Sonoma County Water Agency (SWCA) uses six radial collector wells along the Russian River west of Santa Rosa, to provide water for several municipalities and water districts in north-western California. Three collector wells (1, 2, and 6) are located in the Wohler area, and three collector wells (3, 4, and 5) are located in the Mirabel area. The objective of this paper is to highlight the performance of the three collector wells located in the Mirabel area since their construction. The 2015 investigation showed a lower performance of Collectors 3 and 4 compared to their original performances after construction in 1975, while the performance of Collector 5 was relatively stable since 1982. The potential change in capacity could be due to the increase in encrustation observed during the visual inspection of laterals in all three collector wells. Overall, the three collectors are still within the optimal design parameters (screen entrance velocity \u3c 0.305 m min1 and axial flow velocity of lateral screens \u3c 1.524 m s1)
Environmental fate and microbial effects of monensin, lincomycin, and sulfamethazine residues in soil
The impact of commonly-used livestock antibiotics on soil nitrogen transformations under varying redox conditions is largely unknown. Soil column incubations were conducted using three livestock antibiotics (monensin, lincomycin and sulfamethazine) to better understand the fate of the antibiotics, their effect on nitrogen transformation, and their impact on soil microbial communities under aerobic, anoxic, and denitrifying conditions. While monensin was not recovered in the effluent, lincomycin and sulfamethazine concentrations decreased slightly during transport through the columns. Sorption, and to a limited extent degradation, are likely to be the primary processes leading to antibiotic attenuation during leaching. Antibiotics also affected microbial respiration and clearly impacted nitrogen transformation. The occurrence of the three antibiotics as a mixture, as well as the occurrence of lincomycin alone affected, by inhibiting any nitrite reduction, the denitrification process. Discontinuing antibiotics additions restored microbial denitrification. Metagenomic analysis indicated that Proteobacteria, Bacteroidetes, Actinobacteria, and Chloroflexi were the predominant phyla observed throughout the study. Results suggested that episodic occurrence of antibiotics led to a temporal change in microbial community composition in the upper portion of the columns while only transient changes occurred in the lower portion. Thus, the occurrence of high concentrations of veterinary antibiotic residues could impact nitrogen cycling in soils receiving wastewater runoff or manure applications with potential longer-term microbial community changes possible at higher antibiotic concentrations