Modeling sediment and nitrogen export from a rural watershed in eastern Canada using the soil and water assessment tool

Watershed simulation models can be used to assess agricultural nonpoint-source pollution and for environmental planning and improvement projects. However, before application of any process-based watershed model, the model performance and reliability must be tested with measured data. The Soil and Water Assessment Tool version 2005 (SWAT2005) was used to model sediment and nitrogen loads from the Thomas Brook Watershed, which drains a 7.84 km rural landscape in the Annapolis Valley of Nova Scotia, Canada. The Thomas Brook SWAT model was comprised of 28 subbasins and 265 hydrologic response units, most of them containing agricultural land use, which is the main nonpoint nitrogen source in the watershed. Crop rotation schedules were incorporated into the model using field data collected within Agriculture and Agri-Food Canada's Watershed Evaluation of Beneficial Management Practices program. Model calibration (2004-2006) and validation (2007-2008) were performed on a monthly basis using continuous stream flow, sediment, and nitrogen export measurements. Model performance was evaluated using the coefficient of determination, Nash-Sutcliff efficiency (NSE), and percent bias (PBIAS) statistics. Study results show that the model performance was satisfactory (NSE > 0.4; > 0.5) for stream flow, sediment, nitrate-nitrogen, and total nitrogen simulations. Annual corn, barley, and wheat yields were also simulated well, with PBIAS values ranging from 0.3 to 7.2%. This evaluation of SWAT demonstrated that the model has the potential to be used as a decision support tool for agricultural watershed management in Nova Scotia.     

Electrocoagulation of palm oil mill effluent as wastewater treatment and hydrogen production using electrode aluminum

Palm oil mill effluent (POME) is highly polluting wastewater generated from the palm oil milling process. Palm oil mill effluent was used as an electrolyte without any additive or pretreatment to perform electrocoagulation (EC) using electricity (direct current) ranging from 2 to 4 volts in the presence of aluminum electrodes with a reactor volume of 20 L. The production of hydrogen gas, removal of chemical oxygen demand (COD), and turbidity as a result of electrocoagulation of POME were determined. The results show that EC can reduce the COD and turbidity of POME by 57 and 62%, respectively, in addition to the 42% hydrogen production. Hydrogen production was also helpful to remove the lighter suspended solids toward the surface. The production of Al(OH)XHO at the aluminum electrode (anode) was responsible for the flocculation-coagulation process of suspended solids followed by sedimentation under gravity. The production of hydrogen gas from POME during EC was also compared with hydrogen gas production by electrolysis of tap water at pH 4 and tap water without pH adjustment under the same conditions. The main advantage of this study is to produce hydrogen gas while treating POME with EC to reduce COD and turbidity effectively.     

Performance improvement potential of sensor embedded products in environmental supply chains

Environmental supply chain is a desirable alternative to traditional supply chain due to new and stricter environmental regulations by local governments and increasing consumer awareness towards environmental issues. The two most common types of environmental supply chains are reverse supply chains and closed-loop supply chains. In reverse or closed-loop supply chains, collected used products are subjected to one of four recovery options, viz., reuse, recycling, remanufacturing or disposal. Regardless of the chosen recovery option, all products are disassembled up to some level. However, there is a high level of uncertainty associated with the disassembly yield due to non-functional and/or missing components. Sensor embedded products (SEPs) is a viable approach to cope with this uncertainty since they involve sensors which can detect non-functional and/or missing components prior to disassembly. This study presents a quantitative assessment of the impact of SEPs on the various performance measures of a kanban-controlled disassembly line. First, separate design of experiments studies based on Orthogonal Arrays are carried out for conventional products and SEPs. Then, the results of paired t-tests comparing the two cases based on different performance measures are presented.     

Sustainable options of post treatment of UASB effluent treating sewage: A review

The upflow anaerobic sludge blanket (UASB) process is reported to be a sustainable technology for domestic wastewaters treatment in developing countries and for small communities. However, the inability of UASB process to meet the desired disposal standards has given enough impetus for subsequent post treatment. In order to upgrade the UASB based sewage treatment plants (STPs) to achieve desired effluent quality for disposal or for reuse, various technological options are available and broadly differentiated as primary post-treatment for the removal of organic and inorganic compounds and suspended matter; secondary post-treatment for the removal of hardly degradable soluble matter, colloidal and nutrients; and polishing systems for removals of pathogens. Hence, this paper discusses the different systems for the treatment of UASB reactor effluent treating sewage. Additionally, a comparative review, an economic evaluation of some of the emerging options was conducted and based on the extensive review of different integrated combination, i.e. UASB-different aerobic systems, a treatment concept based on natural biological mineralization route recognized as an advanced technology to meet all practical aspects to make it a sustainable for environmental protection, resource preservation and recovering maximum resources.     

Designing a mixed performance measurement system for environmental supply chain management using evolutionary game theory and balanced scorecard: A case study of an auto industry supply chain

This paper proposes a mixed performance measurement system using a combination of evolutionary game theory and the balanced scorecard (BSC) in environmental supply chain management (ESCM) that measures and evaluates business operations using the four different perspectives of finance, customer, internal business process, and learning and growth. ESCM plays an important role in the supply chain which leads to the reduction, reuse and recycling of resources involved in both upstream and downstream activities. This paper presents guidance for practical managers in evaluating and measuring ESCM by developing a knowledge-based BSC and evolutionary game theory. The primary purpose of this paper is to apply the proposed method in a case study to one of Iran's biggest auto industry supply chain SAIPA Company. The results of this study indicate that the adoption of ESCM, in the absence of regulatory pressures and cost-saving measures is triggered by public pressures and its implementation is limited by organizational factors and strategic myopia.     

Relative salinity tolerance of warm season turfgrass species

Fresh water, coupled with soil salinization in many areas has resulted in an increased need forscreening of salt tolerant turf grasses. Relative salinity tolerance of eightwarm season turfgrass species were examined in this study in sand culture. Grasses were grown in a glasshouse, irrigated with either distilled water or saline sea water adjusted to 24, 48 or 72 dSm-1. Salt tolerances of the grasses were assessed on the basis of their shoot and root growth, leaf firing and turf quality. Regression analysis indicated that Zoysiajaponica (Japanese lawn grass) (JG), Stenotaphrum secundatum (St. Augustine) (SA), Cynodon dactylon (satiri) (BS), Zoysia teneuifolia (Korean grass) (KG), Digitaria didactyla (Serangoon grass) (SG), Cynodon dactylon (Tifdwarf) (TD), Paspalum notatum (Bahia grass) (BG) and Axonopus compressus(Pearl blue) (PB) suffered a 50% shoot growth reduction at 36.0, 31.8, 30.9, 28.4, 26.4, 25.7, 20.0 and 18.6 dSm1 of salinity, respectively and a root growth reduction at44.9, 43.7, 33.4, 31.0, 29.5 27.5, 21.5 and 21.4 dSm- of salinity, respectively. Leaf firing and turf quality of the selected species, as a whole, were also found to be affected harmoniously with the change in root and shoot growth. On the basis of the experimental results the selected species were ranked for salinity tolerance as JG>SA>BS>KG>SG >TD>BG>PB.     

Screening and detection of biomarkers in chickpea plants exposed to chromium and cadmium

A broad screening protocol, covering the most general phytochemical groups of compounds, was developed on the basis of high performance thin layer chromatography (HPTLC). A total of six TLC systems, comprising three derivatization reagents, two stationary phases and two mobile phases, were included. The screening method was applied for the identification of biomarkers in the chickpea plant exposed to cadmium and chromium. The biomarkers were selected on the basis of significant changes (0.26-4.6 fold) in concentration levels of phytochemicals. Totally, five different amino acids, three organic acids, one sulphur containing compound and one sugar were identified as biomarkers in chickpea exposed heavy metal.     

Studies on oxidative stress induced nerve conduction deficits in cigarette smokers

An important role of oxidative stress for the development of vascular and neurological complications has encouraged us to undertake a study to assess the oxidative stress induced nerve conduction deficits among cigarette smokers. Eighteen regular male cigarette smokers and twenty nine male non-smokers were diagnosed for clinical neuro-physiological tests viz., motor and sensory nerve conduction velocity (MNCV and SNCV) and redox status. Significant depletion of reduced glutathione (GSH) level (p < 0.05) and significant increase in malondialdehyde (MDA) level (p < 0.01) was found in smokers compared to non-smokers. Motor and sensory nerve conduction velocity showed no significant difference among smokers compared to non-smokers. The present study shows that smoking can induce oxidative stress among smokers but could not exacerbate to nerve conduction deficits.     

Food Insecurity in Pakistan: Causes and Policy Response

There is evidence of continued food insecurity and malnutrition in Pakistan despite significant progress made in terms of food production in recent years. According to “Vision 2030” of the Planning Commission of Pakistan, about half of the population in the country suffers from absolute to moderate malnutrition, with the most vulnerable being children, women, and elderly among the lowest income group. The Government of Pakistan has been taking a series of policy initiatives and strategic measures to combat food insecurity issues. These range from increasing production to food imports, implementation of poverty reduction strategies, nutritional improvement programs, as well as provision of social safety nets. The article aims to instill some fresh thinking into the debate regarding the challenges of food security. It underscores the limitations of hitherto policy response, and suggests crucial measures to improve the present grim scenario. Policy makers, planners, practitioners, and academicians in countries with comparable socio-political and economic setup can view this discussion as a case study and may apply the findings in their domain accordingly.     

Land degradation assessment by geo-spatially modeling different soil erodibility equations in a semi-arid catchment

Land degradation by soil erosion is one of the most serious problems and environmental issues in many ecosystems of arid and semi-arid regions. Especially, the disturbed areas have greater soil detachability and transportability capacity. Evaluation of land degradation in terms of soil erodibility, by using geostatistical modeling, is vital to protect and reclaim susceptible areas. Soil erodibility, described as the ability of soils to resist erosion, can be measured either directly under natural or simulated rainfall conditions, or indirectly estimated by empirical regression models. This study compares three empirical equations used to determine the soil erodibility factor of revised universal soil loss equation prediction technology based on their geospatial performances in the semi-arid catchment of the Saraykoy II Irrigation Dam located in Cankiri, Turkey. A total of 311 geo-referenced soil samples were collected with irregular intervals from the top soil layer (0-10?cm). Geostatistical analysis was performed with the point values of each equation to determine its spatial pattern. Results showed that equations that used soil organic matter in combination with the soil particle size better agreed with the variations in land use and topography of the catchment than the one using only the particle size distribution. It is recommended that the equations which dynamically integrate soil intrinsic properties with land use, topography, and its influences on the local microclimates, could be successfully used to geospatially determine sites highly susceptible to water erosion, and therefore, to select the agricultural and bio-engineering control measures needed.