URBAN STORMWATER QUANTITY/QUALITY MODELING USING THE SCS METHOD AND EMPIRICAL EQUATIONS1

ABSTRACT: Runoff depth and pollutant loading (Biological Oxygen Demand [BOD₅], Total Suspended Solids [TSS], Total Kjeldahl Nitrogen [TKN] and lead [Pb]) computations of urban stormwater runoff from four small sites (i.e., 14.7–58.3 ac) in South Florida were performed using the Soil Conservation Service (SCS) hydrology method and empirical equations developed by the U.S. Environmental Protection Agency (EPA). Each site had different predominant land uses (i.e., low density residential, high density residential, highway and commercial). Quantity and quality data from 95 storm events at these sites were measured by the U.S. Geological Survey (USGS), and used for calibration of the methodology to derive appropriate input parameters. Calibrated input parameters were developed for each land use to test the applicability of the methodology in small sub-tropical urban watersheds, and to provide hydrologists with a way to select appropriate parameter values for planning studies. A total of 16 independent rainfall events were used for verification of the methodology. Comparisons of predicted versus measured data for both hydrographs and pollutant loadings were performed.     

Carbon storage potential in natural fiber composites

The environmental performance of hemp based natural fiber mat thermoplastic (NMT) has been evaluated in this study by quantifying carbon storage potential and CO₂ emissions and comparing the results with commercially available glass fiber composites. Non-woven mats of hemp fiber and polypropylene matrix were used to make NMT samples by film-stacking method without using any binder aid. The results showed that hemp based NMT have compatible or even better strength properties as compared to conventional flax based thermoplastics. A value of 63 MPa for flexural strength is achieved at 64% fiber content by weight. Similarly, impact energy values (84–154 J/m) are also promising. The carbon sequestration and storage by hemp crop through photosynthesis is estimated by quantifying dry biomass of fibers based on one metric ton of NMT. A value of 325 kg carbon per metric ton of hemp based composite is estimated which can be stored by the product during its useful life. An extra 22% carbon storage can be achieved by increasing the compression ratio by 13% while maintaining same flexural strength. Further, net carbon sequestration by industrial hemp crop is estimated as 0.67 ton/h/year, which is compatible to all USA urban trees and very close to naturally, regenerated forests. A comparative life cycle analysis focused on non-renewable energy consumption of natural and glass fiber composites shows that a net saving of 50 000 MJ (3 ton CO₂ emissions) per ton of thermoplastic can be achieved by replacing 30% glass fiber reinforcement with 65% hemp fiber. It is further estimated that 3.07 million ton CO₂ emissions (4.3% of total USA industrial emissions) and 1.19 million m³ crude oil (1.0% of total Canadian oil consumption) can be saved by substituting 50% fiber glass plastics with natural fiber composites in North American auto applications. However, to compete with glass fiber effectively, further research is needed to improve natural fiber processing, interfacial bonding and control moisture sensitivity in longer run.     

Au nanoring arrays as surface enhanced Raman spectroscopy substrate for chemical component study of individual atmospheric aerosol particle

Monolayer-ordered gold nanoring arrays were prepared by ion-sputtering method and used as surface enhanced Raman spectroscopy (SERS) substrates to test the individual atmospheric aerosols particle. Compared to other methods used for testing atmospheric aerosols particles, the collection and subsequent detection in our work is performed directly on the gold nanoring SERS substrate without any treatment of the analyte. The SERS performance can be tuned by changing the depth of the gold nanoring cavity as originating from coupling of dipolar modes at the inner and outer surfaces of the nanorings. The electric field exhibits uniform enhancement and polarization in the ordered Au nanoring substrate, which can improve the accuracy for detecting atmospheric aerosol particles. Combined with Raman mapping, the information about chemical composition of individual atmospheric aerosols particle and distribution of specific components can be presented visually. The results show the potential of SERS in enabling improved analysis of aerosol particle chemical composition, mixing state, and other related physicochemical properties.     

Effect of compaction on soil CO2 and CH4 fluxes from tropical peatland in Sarawak,Malaysia

Environment, Development and Sustainability - Tropical peatland stores a large amount of carbon (C) and is an important C sink. In Malaysia, about 25% of the peatland area has been converted to oil...     

Adoption of green banking practices and environmental performance in Pakistan: a demonstration of structural equation modelling

Environment, Development and Sustainability - Banking industries are blamed to be among the major factors that affect global climate change both directly and indirectly. The green banking concept...     

Tumor necrosis factor-alpha,prostaglandin-E2 and interleukin-1β targeted anti-arthritic potential of fluvoxamine: drug repurposing

Environmental Science and Pollution Research - Fluvoxamine, a selective serotonin re uptake inhibitor, is used to treat depression. The aim of present study was to evaluate fluvoxamine in acute...     

Economic feasibility of solar-powered reverse osmosis water desalination: a comparative systemic review

Environmental Science and Pollution Research - Due to disparities in the allocation of rainwater and drought, extreme exploitation of groundwater reservoirs has depleted water supplies in many...     

Biomass energy consumption and sustainable development: empirical evidence from Asian economies

Environmental Science and Pollution Research - Biomass energy is an important source of energy consumption. It is a renewable, abundant, and easily produced energy source. Its usage supports...     

Microplastics in water,sediments, and fish at Alpine River,originating from the Hindu Kush Mountain,Pakistan: implications for conservation

Environmental Science and Pollution Research - Microplastics (MP) pollution is an emerging threat to life and the environment. These particles are not restricted to human-inhabited lands but also...     

Endocrine disrupting pesticides in soil and their health risk through ingestion of vegetables grown in Pakistan

Environmental Science and Pollution Research - A comprehensive study was conducted to appraise the concentrations of 30 endocrine disrupting pesticides (EDPs) in soil and vegetable samples...