Chitosan composites reinforced with nanostructured waste fly ash

Journal of Material Cycles and Waste Management - This paper outlines the preparation and characterization of chitosan (CS) composites reinforced with mechano-chemically activated fly ash (MCA-FA)....     

Geographical analysis of tourism sites in Andaman Archipelago (India) and ecotourism development for Smith Island of North Andaman

This paper applies the nearest-neighbour analysis to analyse the clustering of tourist attractions in Andaman region and suggests ecotourism development for Smith Island of North Andaman using remote sensing techniques. The results indicated that present tourism sites are distributed in clusters in three regions (Port Blair, Mayabunder and Diglipur). To avoid concentration of tourism sites and population pressure in one particular area, there is a need to promote tourism to other locations as well. The study provided suggestions for ecotourism development in Smith Island after analysing its various ecological features to support the Andaman Administration’s vision to promote ecotourism.     

Microalgae Scenedesmus obliquus as renewable biomass feedstock for electricity generation in microbial fuel cells （MFCs）

Renewable algae biomass, Scenedesmus obliquus, was used as substrate for generating electricity in two chamber microbial fuel cells （MFCs）. From polarization test, maximum power density with pretreated algal biomass was 102mW·m^2 （951mW·m^3） at current generation of 276mA·m^-2. The individual electrode potential as a function of current generation suggested that anodic oxidation process of algae substrate had limitation for high current generation in MFC. Total chemical oxygen demand （TCOD） reduction of 74% was obtained when initial TCOD concentration was 534mg · L^-1 for 150 h of operation. The main organic compounds of algae oriented biomass were lactate and acetate, which were mainly used for electricity generation. Other byproducts such as propionate and butyrate were formed at a negligible amount. Electrochemical Impedance Spectroscopy （EIS） analysis pinpointed the charge transfer resistance （112Ω ） of anode electrode, and the exchange current density of anode electrode was 1214 nA·cm^-2.     

SPATIAL CLUSTERS OF SUBSURFACE DRAINAGE WATER NO3‐N LEACHING LOSSES1

ABSTRACT: Grouping of nitrate‐nitrogen (NO₃‐N) leaching losses from agricultural fields into spatial clusters can help determine the cause/effect relationships for their occurrence. This study was designed to investigate the spatial relationships of low, medium, and high NO₃‐N leaching losses clusters with soil and landscape attributes using cluster and discriminant analysis and the map overlay capability of a geographical information system (GIS). Field measured data of a six‐year (1993 through 1998) study on NO₃‐N leaching losses from 36 experimental fields at the Iowa State University's northeastern research center near Nashua, Iowa, were normalized on an annual basis to compare over the years. The cluster analysis resulted in the formation of three clusters based on the satisfactory evaluation criteria of pseudo‐F statistic, cubic clustering criterion, and R² values. The discriminant analysis, carried out on the basis of clusters, identified elevation and subsurface drainage as the factors that contributed significantly (p > 0.01) in discriminating among these clusters. The verification of discriminant functions developed on these factors predicted the cluster membership for all the groups with an overall accuracy of 86 percent. The map overlay analyses of GIS showed that spatial occurrence of the clusters transporting high NO₃‐N leaching losses was affected by the interaction of soil type and elevation levels.     

Study on ground water characteristics and the effects of discharged effluents from textile units at Karur District

A study was made on the physico-chemical characteristics of water samples mixed with effluent discharged from textile industries at Chellandipalayam (Site--I), Senaparatti (Site--II) and Pasupathipalayam (Sites--III and IV) revealed the elevated levels of Ca, Mg, Na, Cr, K, Ni, Cu, Zn, CO3, SO4, NO3 and Cl- . The concentrations of these ions exceeded the limit prescribed by ISI. The increase in the concentrations of ions was revealed by higher values of electrical conductivity (EC). Water at these sites was found to be hard, brackish and unsuitable for drinking purpose. In all these sites, the seed germination of rice alone was significantly affected among the other crops tested. Irrigation of crops with ground water notably lowered the quantity of reserve food in rice, wheat (starch), and sugarcane (sugar), indicating the interference of their metabolic pathway by polluted ground water.     

Near-real-time determination of hydrogen peroxide generated from cigarette smoke

The ability to monitor hydrogen peroxide (H2O2) in aqueous smoke extracts will advance our understanding of the relationship between cigarette smoke-induced oxidative stress, inflammation, and disease and help elucidate the pathways by which the various smoke constituents exert their pathogenic effects. We have demonstrated, for the first time, the measurement of H2O2 production from cigarette smoke without prior separation of the sample. Cigarettes were tested on a commercial smoking machine, such that the whole smoke or gas vapor phase was bubbled through phosphate buffered saline solution at pH 7.4. Aliquots of these solutions were analyzed using an Amplex Red/horseradish peroxidase fluorimetric assay that required only a 2 minute incubation time, facilitating the rapid, facile collection of data. Catalase was used to demonstrate the selectivity and specificity of the assay for H2O2 in the complex smoke matrix. We measured approximately 7-8 microM H2O2 from two reference cigarettes (i.e., 1R4F and 2R4F). We also observed 9x more H2O2 from whole smoke bubbled samples compared to the gas vapor phase, indicating that the major constituent(s) responsible for H2O2 formation reside in the particulate phase of cigarette smoke. Aqueous solutions of hydroquinone and catechol, both of which are particulate phase constituents of cigarette smoke, generated no H2O2 even though they are free radical precursors involved in the production of reactive oxygen species in the smoke matrix.     

Curbside collection of recyclables. II. Simulation and economic analysis

Curbside collection of recyclable material can be expensive because the inherent costs of curbside collection are high, but also because amounts collected per residence are small compared to the total waste stream, and extra activity may be required, such as sorting. In this paper a simulation model is used to investigate the effect of collection method and route characteristics on route time. The simulation models presented calculate set-out amount based on route characteristics, set-out rate (SOR), and participation rate (PR). Route times are estimated for various conditions: constant SOR, constant PR, and constant set-out amount. Furthermore, a method for using route time to estimate vehicle and labor needs is presented, and used to estimate economic costs for one and two-person crew collection methods for the three simulation conditions mentioned above. The two-person crew is found to cost less than the one-person crew, for most simulated conditions.     

Development of food-grade antimicrobials of fenugreek oil nanoemulsion—bioactivity and toxicity analysis

Environmental Science and Pollution Research - Antimicrobials of natural origin are proving to be an effective solution to emerging antimicrobial resistance and its physiological side effects....     

Analyzing composition and generation rates of biomedical waste in selected hospitals of Uttarakhand,India

In India, a few studies have been conducted for analyzing the generation rates and composition of medical waste (MW). Inadequate information about the amount and composition of MW results in ineffective management practices. The present study seeks to evaluate healthcare waste (HCW) generation rates by healthcare facilities (HCFs) available in Uttarakhand, a northern state of India. Study also focuses on modeling the quantity of different types of MW generated at various HCFs and determining significant factors contributing towards MW generation. Seasonal variation in amount of MW generated from various HCFs has also been considered. To achieve these objectives, cross-sectional as well as longitudinal data have been collected from various HCFs in Uttarakhand, India. The survey revealed that around 36% of the total HCFs did not segregate their MW as per policy guidelines. Cross-sectional data for May 2015 were collected from 75 HCFs to analyze and model the composition and quantity of HCW generated. Multiple Linear Regression and Artificial Neural Network techniques were applied to model cross-sectional data. In the composition of the overall MW, ‘yellow waste’ carries the maximum share, followed by ‘red waste’ and then the ‘blue waste’. In addition, the ‘type of HCF’ and ‘bed occupancy’ have been modeled as the important factors, contributing towards the MW generations rates. Longitudinal data for 2 years (2013 and 2014) were collected to examine seasonal variation in HCW generation rates using polynomial regression analysis. Result shows that MW quantity also varies with the change in the season. Findings of the study will help hospitals and waste treatment facilities to predict amount of waste that may be generated, and plan resources towards efficient handling and disposal of MW.     

Status of ecotourism in Nepal: a case of Bhadaure-Tamagi village of Panchase area

Environment, Development and Sustainability - This study was conducted with an aim to assess the status of ecotourism in terms of tourism demand, tourist characteristics, and strength,...