Eco-sanitation and its benefits: an experimental demonstration program to raise awareness in central Nepal

This study focuses on awareness and an experimental demonstration about the use of human urine and wood ash as a fertilizer. This study was conducted in Chanauta, central Nepal, from November 2009 to February 2010. The villagers (N = 27) were asked about their awareness of eco-sanitation and fertilizer value of urine and ash. All the participants agreed that the use of urine and ash was a good idea. In the experimental study, the fertilizer value of urine+ash was compared with animal manure and no-fertilizer in the cultivation of radish, potato, broadleaf mustard, cauliflower, and cabbage. Different plants cultivated plots received 54–81 kgN/ha with urine+ash or manure fertilizer. The urine+ash fertilizer produced significantly (p < 0.05) higher broadleaf mustard biomass than obtained from animal manure and without fertilization. Urine+ash-fertilized plots growing radish, potato, cauliflower, and cabbage produced similar or slightly higher yields biomass compared to those achieved with manure fertilization. This might be because of high P, K as well as greater availability of N in applied urine compared to manure. It is concluded that urine+ash fertilizer can be used instead of animal manure; in this study, a dose of 4 L of urine was equal to 1 kg of dry cattle manure and produced a similar or greater yield of vegetable biomass than manure fertilization. To be able to generalize this conclusion, it is important to conduct these kinds of experiments with different seasonal crops and in other parts of the world.     

The Role of Catalyst Properties on Methanol Oxidation over V2O5–TiO2 Using Ozone

Oxidation of methanol over V₂O₅ catalysts supported on anatase TiO₂ that were prepared using sol-gel formation and impregnation procedures were investigated. The effects of incorporating Mg in sol-gel to influence the properties of the catalyst were also studied. The process provides an alternative low temperature reaction pathway for reducing emissions of hazardous air pollutant (HAPs) such as methanol and total reduced sulfur compounds (TRS) from pulp and paper mills. The bulk and surface composition of the catalysts were determined by XRD and SEM-EDAX, respectively. The X-ray diffraction patterns of the vanadia–titania catalysts showed mainly the anatase phase of TiO₂. Temperature programmed desorption of methanol from the different catalyst showed that the α and β peaks differ significantly with V content and addition of Mg. The combination of gas phase and surface reactions on the V/TiO₂ catalysts reduced the amount of ozone required for high degradation of methanol to mainly CO _x with small quantities of methyl formate. In the absence of ozone the catalysts showed very low activity. It is hypothesized that the ozone is directly influencing the V⁴⁺ and V⁵⁺ redox cycle of the catalyst. Oxidation of methanol is influenced by the operation variables and catalyst properties. The results of this study revealed that the V content has significant influence on the catalyst activity, and the optimum vanadia loading of about 6 wt%. Higher turnover frequencies were observed over sol-gel catalysts than with catalysts prepared by the impregnation method.     

Environmental impact of leaching of trace elements from fly ash dumps on aquatic ecosystems

Ten sampling points were selected in Kanhan River, situated near the ash dump sites of Koradi Thermal Power Plant, Nagpur. The leaching of trace elements from fly ash dumps was experimentally determined by acid digestion, batch leaching and toxicity characteristic leaching procedure tests. Elemental concentrations in river water, sediment, plankton and five commonly prevailing fish species (Catla catla, Labeo bata, Cyprinus carpio, Cirrhinus reba, Puntius ticto) were determined using a Flame Atomic Absorption Spectrophotometer during the pre-monsoon and post-monsoon seasons. Metal concentrations (Cr, Mn, Zn, Cu, Fe, Ni, Cu and Pb) in river water were higher during the pre-monsoon season compared to the post-monsoon season. Zn (30.65?mg/kg) was observed to be the most predominant metal in plankton during the pre-monsoon season while, during the post-monsoon season, Fe (21.19?mg/kg) showed the maximum concentration. Muscles of C. catla had metal concentrations (Cr, Mn, Zn, Fe, Cu and Pb) above the permissible limits of Food and Agricultural Organization (FAO 1983) during the pre-monsoon season. Bioaccumulation factor (BAF) was found highest for Cr (37.5) in muscles of C. catla during the pre-monsoon season, while BAF was observed to be maximum in L. bata for Cu (28.09), which may be detrimental for human consumption.     

GIS-based statistical model for the prediction of flood hazard susceptibility

At present, flood is the most significant environmental problem in the entire world. In this work, flood susceptibility (FS) analysis has been done in the Dwarkeswar River basin of Bengal basin, India. Fourteen flood causative factors extracted from different datasets like DEM, satellite images, geology, soil and rainfall data have been considered to predict FS. Three heuristic models and one statistical model fuzzy Logic (FL), frequency ratio (FR), multi-criteria decision analysis (MCDA) and logistic regression (LR) have been used. The validating datasets are used to validate these models. The result shows that 68.71%, 68.7%, 60.56% and 48.51% area of the basin is under the moderate to very high FS by the MCDA, FR, FL and LR, respectively. The ROC curve with AUC analysis has shown that the accuracy level of the LR model (AUC?=?0.916) is very much successful to predict the flood. The rest of the models like FL, MCDA and FR (AUC?=?0.893, 0.857 and 0.835, respectively) have lesser accuracy than the LR model. The elevation was the most dominating factor with coefficient value of 19.078 in preparation of the FS according to the LR model. The outcome of this study can be implemented by local and state authority to minimize the flood hazard.

     

Chemical characteristics and source apportionment of PM<Subscript>2.5</Subscript> using PCA/APCS,UNMIX, and PMF at an urban site of Delhi,India

The present study investigated the comprehensive chemical composition [organic carbon (OC), elemental carbon (EC), water-soluble inorganic ionic components (WSICs), and major & trace elements] of particulate matter (PM_2.5) and scrutinized their emission sources for urban region of Delhi. The 135 PM_2.5 samples were collected from January 2013 to December 2014 and analyzed for chemical constituents for source apportionment study. The average concentration of PM_2.5 was recorded as 121.9 ± 93.2 μg m^?3 (range 25.1–429.8 μg m^?3), whereas the total concentration of trace elements (Na, Ca, Mg, Al, S, Cl, K, Cr, Si, Ti, As, Br, Pb, Fe, Zn, and Mn) was accounted for ～17% of PM_2.5. Strong seasonal variation was observed in PM_2.5 mass concentration and its chemical composition with maxima during winter and minima during monsoon seasons. The chemical composition of the PM_2.5 was reconstructed using IMPROVE equation, which was observed to be in good agreement with the gravimetric mass. Source apportionment of PM_2.5 was carried out using the following three different receptor models: principal component analysis with absolute principal component scores (PCA/APCS), which identified five major sources; UNMIX which identified four major sources; and positive matrix factorization (PMF), which explored seven major sources. The applied models were able to identify the major sources contributing to the PM_2.5 and re-confirmed that secondary aerosols (SAs), soil/road dust (SD), vehicular emissions (VEs), biomass burning (BB), fossil fuel combustion (FFC), and industrial emission (IE) were dominant contributors to PM_2.5 in Delhi. The influences of local and regional sources were also explored using 5-day backward air mass trajectory analysis, cluster analysis, and potential source contribution function (PSCF). Cluster and PSCF results indicated that local as well as long-transported PM_2.5 from the north-west India and Pakistan were mostly pertinent.     

Experimental investigation of performance and emissions of a VCR diesel engine fuelled with <Emphasis Type="Italic">n</Emphasis>-butanol diesel blends under varying engine parameters

The continuous rise in the cost of fossil fuels as well as in environmental pollution has attracted research in the area of clean alternative fuels for improving the performance and emissions of internal combustion (IC) engines. In the present work, n-butanol is treated as a bio-fuel and investigations have been made to evaluate the feasibility of replacing diesel with a suitable n-butanol-diesel blend. In the current research, an experimental investigation was carried out on a variable compression ratio CI engine with n-butanol-diesel blends (10–25% by volume) to determine the optimum blending ratio and optimum operating parameters of the engine for reduced emissions. The best results of performance and emissions were observed for 20% n-butanol-diesel blend (B20) at a higher compression ratio as compared to diesel while keeping the other parameters unchanged. The observed deterioration in engine performance was within tolerable limits. The reductions in smoke, nitrogen oxides (NO _x ), and carbon monoxide (CO) were observed up to 56.52, 17.19, and 30.43%, respectively, for B20 in comparison to diesel at rated power. However, carbon dioxide (CO₂) and hydrocarbons (HC) were found to be higher by 17.58 and 15.78%, respectively, for B20. It is concluded that n-butanol-diesel blend would be a potential fuel to control emissions from diesel engines.

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Identification of sources affecting fog formation using receptor modeling approaches and inventory estimates of sectoral emissions

Positive matrix factorization (PMF) was used to identify factors affecting fog formation in Kanpur during the ISRO-GBP land campaign-II (LC-II) in December 2004. PMF predicted factors were validated by contrasting the emission strength of sources in the foggy and clear periods, using a combination of potential source contribution function (PSCF) analysis and quantitative emission inventory information. A time series aerosol chemical data set of 29 days and 12 species was decomposed to identify 4-factors: Secondary species, Biomass burning, Dust and Sea salt. PMF predicted particle mass with a satisfactory goodness-of-fit (slope of 0.83 ± 0.17 and R² of 0.8), and strong species within 11–12% relative standard deviation. Mean contributions of anthropogenic factors were significantly higher during the foggy period for secondary species (2.9 ± 0.3) and biomass burning (1.2 ± 0.09) compared to the clear period. Local sources contributing to aerosols that mediated fog events at Kanpur, based on emissions in a 200 km × 200 km area around Kanpur city were thermal power plants and transportation (SO₂) and biofuel combustion (BC and OM). Regional scale sources influencing emissions during the foggy period, in probable source regions identified by PSCF included thermal power plants, transportation, brick kilns and biofuel combustion. While biofuel combustion and transportation are distributed area sources, individual point sources include coal-fired thermal power plants located in Aligarh, Delhi, Ghaziabad, Jhansi, Kanpur, Rae Bareli and Rupnagar and brick kilns located in Allahabad, Agra, Farrukhabad, Ghaziabad, Kanpur, Ludhiana, Lucknow and Rae Bareli. Additionally, in the foggy period, large areas of probable source regions lay outside India, implying the significance of aerosol incursion from outside India.     

Assessment of the potential hazards of nitrate contamination in surface and groundwater in a heavily fertilized and intensively cultivated district of India

We made an inventory of nitrate (NO3-N) enrichment in surface and groundwater systems in the Hooghly district of India owing to intensive farming with high fertilizer doses as a function of quantity of fertilizers use, soil characteristics, types of crop grown, depth of groundwater sampling and also N-load in soil profiles. Water samples were collected from different sources at 412 odd sites spread over in 17 blocks of the district along with representative soil profiles. On average, the study area had high clay and NO3-N in soil profiles with an increasing and decreasing trends along depth, respectively. The NO3-N content both in surface and groundwater varied from 0.01 microg mL(-1) to 4.56 microg mL(-1), being well below the threshold limit of 10 microg mL(-1) fixed by WHO for drinking purpose. The content decreased with increasing depth of wells (r = -0.39**) and clay content of soil profiles (r = -0.31**). It, however, increased with increasing rate of fertilizer application (r = 0.72**), NO3-N load in soil profiles (r = 0.85**) and was higher in areas where shallow--rather than deep-rooted crops are grown. Results indicated even under fairly high quantity of fertilizer use, groundwater of the study area is safe for drinking purpose.     

Assessment of potential hazards of fluoride contamination in drinking groundwater of an intensively cultivated district in West Bengal, India

We assessed the potential of fluoride (F) contamination in drinking groundwater of an intensively cultivated district in India as a function of its lithology and agricultural activities. Three hundred and eight groundwater samples were collected at different depths from various types of wells and analyzed for pH, EC, NO(3)-N load and F content. A typical litholog was constructed and database on fertilizer and pesticide uses were also recorded for the district. The water samples were almost neutral in reaction and non-saline in nature with low NO(3)-N content (0.02 to 4.56 microg mL(-1)). Fluoride content in water was also low (0.01 to 1.18 microg mL(-1)) with only 2.27% of them exceeding 1.0 microg mL(-1) posing a potential threat of fluorosis. On average, its content varied little spatially and along depth of sampling aquifers because of homogeneity in lithology of the district. The F content in these samples showed a significant positive correlation (r = 0.12, P < or = 0.05) with the amount of phosphatic fertilizer (single super phosphate) used for agriculture but no such relation either with the anthropogenic activities of pesticide use or NO(3)-N content, pH and EC values of the samples was found. The results suggest that the use of phosphatic fertilizer may have some role to play in F enrichment of groundwater.     

Effect of light on DIMBOA synthesis in maize leaves as revealed by modified cost-effective extraction method

2,4-Dihydroxy-7-methoxy-1,4-benzoxazine-3-one (DIMBOA) known for its antibiotic properties against many pests and diseases in maize plant was extracted from different varieties. In one of the extraction methods of DIMBOA from maize leaves, Amberlite XAD7, an adsorbent, was used for extracting this and it gave a pure fraction containing DIMBOA. The adsorbent Amberlite XAD, being an expensive material, was uneconomical for processing a large number of samples. Therefore, one of the reported solvent extraction method was modified to make the extraction procedure cost effective without losing the target compounds. Using the modified method, DIMBOA was extracted for different varieties under dark and light condition. Results showed that high concentrations of DIMBOA were extracted from plants grown in dark condition as compared to plants grown in light indicating that light played significant role in inhibition of DIMBOA.