27 research outputs found
Phosphorus and Metal Sorption in Aged Bioretention Cells with Fly-ash Amended Filter Media
Stormwater runoff from urban areas can transport a significant load of phosphorus (P) and heavy metals. Media samples from seven year old bioretention cells (BRC) were collected, to a depth of 0.6 m, to assess the accumulation of phosphorus and heavy metals. Analysis consisted of total soil digestion (T-P), Mehlich-3 (M3-P) and water soluble (WS-P) extraction for both metals and phosphorus. The mean T-P concentration increased over the seven years of operation, but the results were not statistically significant (p > 0.05). The average M3-P and WS-P concentrations in the media profiles showed higher P accumulation in the top 0.15 m of media. Significant (p 0.9). The batch sorption experiments showed phosphorus adsorption capacity of the fly-ash filter media after seven years of operation was (160 mg/g) around half the amount of the initial material (350 mg/g). Batch testing of the aged fly-ash amended filter media exhibited phosphorus removal of 61%, Zn Cu and Pb removal of 95%, 98%, and 99%. Desorption experiments showed the media released 24% of initially sorbed phosphorus and only 0.6% of initially sorbed Zn and Cu at initial phosphorus and metal concentration of 30 mg/L. Thus, phosphorus and heavy metal adsorption in sand/fly-ash filter media may be considered irreversible, and can provide long-term phosphorus and heavy metal retention.Biosystems & Agricultural Engineerin
THE USE OF STOMP TO EVALUATE THE IMPACT OF HETEROGENEITY ON LNAPL POOL CONFIGURATION
AN ABSTRACT OF THE THESIS OF SAROJ KANDEL, for the Masters of Science degree in CIVIL ENGINEERING, presented on February 6, 2012, at Southern Illinois University Carbondale. TITLE: THE USE OF STOMP TO EVALUATE THE IMPACT OF HETEROGENEITY ON LNAPL POOL CONFIGURATION MAJOR PROFESSOR: Dr. Lizette R. Chevalier Subsurface contamination by light non-aqueous phase liquid (LNAPL) is a widespread problem. A common LNAPL contamination is gasoline from leaking underground storage tanks (LUST). Heterogeneities in the media properties play a crucial role for defining the LNAPL movement and distribution in the subsurface. Hence, enhanced understanding of light non-aqueous phase liquid (LNAPL) movement into heterogeneous porous media is important for the effective design of remediation strategies. Numerical simulations are important tools for the understanding of subsurface multi-phase flow and transport processes. The numerical simulator Subsurface Transport Over Multiple Phases (STOMP) was used to simulate two-phase flow in porous media in an unconfined aquifer. The simulations was conducted with the water-oil (w-o) mode of the of the multi-fluid flow simulator STOMP. Two different patterns of layered heterogeneity were used for the simulation of LNAPL movement in an unconfined aquifer. The first pattern (P1: coarse - fine - coarse) showed the maximum LNAPL distribution occurred in the capillary fringe region just above the water table in the fine sand layer region. The second pattern (P2: fine - coarse -fine) showed the LNAPL spreading just above the capillary fringe region not even reaching the capillary zone. The main controlling factor determining the final LNAPL movement and distribution in the layered heterogeneous pattern (P1: coarse - fine - coarse) and (P2: fine -coarse - fine) was capillary pressure and permeability of the media present
Lessons learned from web- and social media- based educational initiatives by pulmonary, critical care and sleep societies
Notes for genera: basal clades of Fungi (including Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota)
Compared to the higher fungi (Dikarya), taxonomic and evolutionary studies on the basal clades of fungi are fewer in number. Thus, the generic boundaries and higher ranks in the basal clades of fungi are poorly known. Recent DNA based taxonomic studies have provided reliable and accurate information. It is therefore necessary to compile all available information since basal clades genera lack updated checklists or outlines. Recently, Tedersoo et al. (MycoKeys 13:1--20, 2016) accepted Aphelidiomycota and Rozellomycota in Fungal clade. Thus, we regard both these phyla as members in Kingdom Fungi. We accept 16 phyla in basal clades viz. Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. Thus, 611 genera in 153 families, 43 orders and 18 classes are provided with details of classification, synonyms, life modes, distribution, recent literature and genomic data. Moreover, Catenariaceae Couch is proposed to be conserved, Cladochytriales Mozl.-Standr. is emended and the family Nephridiophagaceae is introduced
An assessment of the impact of ecotourism on forest rules and on the livelihood of various ethnic groups : A case study of Chitwan National Park in Nepal
Phosphorus Retention by Fly Ash Amended Filter Media in Aged Bioretention Cells
Bioretention cells (BRCs) have shown potential for storm water quantity and quality control. However, the phosphorus (P) removal in BRC has been variable due to differences of soil properties in filter media. The objectives of this research were to identify and evaluate P accumulation in filter media and to quantify effluent P reduction in BRC. Each cell has a sand and fly ash media designed to remove phosphorous. Filter media were collected in 2014 across the cell surface and to a depth of 0.6 m to quantify the P accumulation. The mean total P (T-P) concentration increased over the seven years of operation, but the changes were not statistically significant. The average Mehlich-3 P (M3-P) and water-soluble P (WS-P) concentrations in the media profiles showed higher P accumulation in the top 0.15 m. The average M3-P and WS-P concentrations between 0.15 m to 0.30 m, and 0.30 m to 0.60 m were variable on all four BRCs media. The media with 5% fly ash significantly retained M3-P and WS-P over the top 0.15 m. Stormwater influent and effluent samples from three of the BRCs monitored over one year showed reductions in both P concentration (68% to 75%) and P mass (76% to 93%)
Earthquake Impacts on the Livelihoods of Community Forest Users in Sindhupalchok District, Nepal, and Their Perceptions towards Forest Conservation
Community forests are a crucial component of farming systems and people’s livelihoods in the rural middle hills of Nepal, where the population depends upon the forest for fuelwood, fodder, and leaf litter for their daily needs. This study aims to assess the perception of community forest user groups towards their postearthquake situations by using the five forms of capital from the sustainable livelihood framework. It further analyzes whether forest user’s attitudes towards forest conservation have changed or not. In addition to household interviews with 68 earthquake-affected households and extensive visits to the study area, key informant interviews and focus group discussions were conducted. This study confirms that the community forest user groups perceived negative effects on the natural, physical, human, and financial capitals, whereas they perceived a positive effect on social capital after the earthquake. Controlled access to forest products, such as timber collection during the recovery phase, restricted their resilience, although nontimber forest products supported it. Low agricultural production because of the scarcity of water for irrigation, as well as the soil infertility because of the landslides, caused local people to shift towards nonagricultural activities for income generation. Further, out-migration for job opportunities resulted in an inflow of remittances and, thus, manpower shortages were observed. Our results show that, despite facing the postdisaster impact on their livelihoods, 92% of the respondents were found to be positive towards forest conservation. This was because of their emotional attachment to the forest and the benefits received from the forest in the past. Local institutional policies and mechanisms must be strengthened to provide communities with the knowledge, skills, and practices for effective postdisaster recovery or for upcoming disasters, as well as the benefits of promoting sustainable forest conservation
Earthquake Impacts on the Livelihoods of Community Forest Users in Sindhupalchok District, Nepal, and Their Perceptions towards Forest Conservation
Community forests are a crucial component of farming systems and people’s livelihoods in the rural middle hills of Nepal, where the population depends upon the forest for fuelwood, fodder, and leaf litter for their daily needs. This study aims to assess the perception of community forest user groups towards their postearthquake situations by using the five forms of capital from the sustainable livelihood framework. It further analyzes whether forest user’s attitudes towards forest conservation have changed or not. In addition to household interviews with 68 earthquake-affected households and extensive visits to the study area, key informant interviews and focus group discussions were conducted. This study confirms that the community forest user groups perceived negative effects on the natural, physical, human, and financial capitals, whereas they perceived a positive effect on social capital after the earthquake. Controlled access to forest products, such as timber collection during the recovery phase, restricted their resilience, although nontimber forest products supported it. Low agricultural production because of the scarcity of water for irrigation, as well as the soil infertility because of the landslides, caused local people to shift towards nonagricultural activities for income generation. Further, out-migration for job opportunities resulted in an inflow of remittances and, thus, manpower shortages were observed. Our results show that, despite facing the postdisaster impact on their livelihoods, 92% of the respondents were found to be positive towards forest conservation. This was because of their emotional attachment to the forest and the benefits received from the forest in the past. Local institutional policies and mechanisms must be strengthened to provide communities with the knowledge, skills, and practices for effective postdisaster recovery or for upcoming disasters, as well as the benefits of promoting sustainable forest conservation
Field Scale Demonstration of Fly Ash Amended Bioretention Cells for Stormwater Phosphorus Removal: A Review of 12 Years of Work
In 2007, ten bioretention cells were constructed in Oklahoma as part of a full-scale technology project to demonstrate stormwater phosphorus reduction. The filter media used was amended with 5%, Class C fly ash by weight to increase phosphorus and heavy metal retention. In 2014, core samples were collected from four of the cells, and three were instrumented for continuous water monitoring for the following year. This paper will review the design, construction, computer modeling of phosphorus retention, and measured phosphorus removal after seven years of operation. Total phosphorus retained in the sampled cells showed reductions in effluent water concentrations of 68 to 75%, while total effluent mass reductions of 51 to 93% were achieved. Total phosphorus accumulation in the cells measured in cores ranged from 0.33 to 0.60 kg/year, which was somewhat greater than the annual calculated effluent reduction of 0.27 to 0.41 kg/year. While good, phosphorus retention was not as high as computer modeling predicted. Other research on the cells, including hydraulics, heavy metal adsorption, and microbial transport, is summarized. Experimental challenges with phosphorus extraction from samples are also discussed. All experience and results suggest that fly ash amendments are an effective option for phosphorus removal in bioretention cells
Susceptibility - weighted imaging: A valuable diagnostic tool for early detection of high-altitude cerebral edema: A case report
High altitude cerebral edema (HACE) is a clinical spectrum of high-altitude illness. The working diagnosis of HACE should be based on the history of rapid ascent with signs of encephalopathy. Magnetic resonance imaging (MRI) can be crucial in the timely diagnosis of the condition. A 38-year-old female was airlifted from Everest base camp due to sudden onset of vertigo and dizziness. She had no significant medical or surgical history, and routine laboratory tests showed normal results. MRI was performed, which showed no abnormalities except for the detection of subcortical white matter and corpus callosum hemorrhages on susceptibility-weighted imaging (SWI). The patient was hospitalized for 2 days and treated with dexamethasone and oxygen, and had a smooth recovery during follow-up. HACE is a serious and potentially life-threatening condition that can occur in individuals who rapidly ascend to high altitudes. MRI is a valuable diagnostic tool in the evaluation of early HACE, and can detect various abnormalities in the brain that may indicate the presence of HACE, including micro-hemorrhages. Micro-hemorrhages are tiny areas of bleeding in the brain that may not be visible on other MRI sequences but can be detected on SWI. Clinicians especially radiologists, should be aware of the importance of SWI in the diagnosis of HACE, and ensure that it is included in the standard MRI protocol for evaluating individuals with high altitude-related illnesses for early diagnosis and appropriate treatment to prevent further neurological damage and improve patient outcomes