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991.
Preparation of alinite based cement from incinerator ash 总被引:1,自引:0,他引:1
Alinite based cements have attracted a great deal of attention because these can be produced at considerable energy savings. Alinite has an additional ability to incorporate in its structure various impurity ions and can thus be made using a number of industrial and mining wastes. In this paper, the work done in the preparation of alinite based cements using incinerator ashes is presented. It is shown that alinite cements having strengths comparable to ordinary Portland cement can be successfully prepared by controlling the composition and firing schedule. 相似文献
992.
Surendra N. Singh D. Todd Donavan Sanjay Mishra Todd D. Little 《Journal of environmental psychology》2008,28(4):339-352
Mean and covariance structure (MACS) modeling is used to explore a central question in contemporary environmental psychology: “How should human environments be conceptualized?”. Specifically, an expanded version of the preference model of landscape perception proposed by S. and R. Kaplan is presented. The proposed model not only constitutes a respecification and deepening of the Kaplans’ model but also presents an integrative perspective that simultaneously considers the interrelations among cognitive, motivational, affective, evaluative, and behavioral tendencies in landscape perception. In a series of four studies, we develop and validate multi-item measures of various constructs, test the measure invariances, and the structural model. The findings reveal the crucial role of various constructs that originally were hypothesized by the Kaplans but never included in the model tests. In addition, positive and negative feelings induced by the landscape emerge as antecedents to landscape perception. The implications of these findings are discussed. 相似文献
993.
Dhakate R Singh VS Negi BC Chandra S Rao VA 《Journal of environmental management》2008,88(4):1373-1383
The increasing demand for fresh water has necessitated the exploration for new sources of groundwater, particularly in hard rock terrain, where groundwater is a vital source of fresh water. A fast, cost effective and economical way of exploration is to study and analyze remote sensing data. Interpreted remote sensing data was used to select sites for carrying out surface geophysical investigations. Various geomorphologic units were demarcated and the lineaments were identified by interpretation of remote sensing satellite images. The potential for occurrence of groundwater in the watershed areas was classified as very good, good, moderate and poor by interpreting the images. Sub-surface geophysical investigations, namely vertical electrical soundings, were carried out to delineate potential water-bearing zones. Integrated studies of interpretation of geomorphologic and geophysical data were used to prepare a groundwater potential map. The studies reveal that the groundwater potential of shallow aquifers is due to geomorphologic features and the potential of deeper aquifers is determined by lineaments such as faults and joints. 相似文献
994.
Moti L. Mittal Chhemendra Sharma Richa Singh 《Environmental monitoring and assessment》2014,186(10):6857-6866
This study aims to estimate the emissions of carbon dioxide (CO2), sulfur dioxide (SO2), and nitric oxide (NO) for coal combustion in thermal power plants in India using plant-specific emission factors during the period of 2001/02 to 2009/10. The mass emission factors have been theoretically calculated using the basic principles of combustion under representative prevailing operating conditions in the plants and fuel composition. The results show that from 2001/02 to 2009/10 period, total CO2 emissions have increased from 324 to 499 Mt/year; SO2 emissions have increased from 2,519 to 3,840 kt/year; and NO emissions have increased from 948 to 1,539 kt/year from the Indian coal-fired power plants. National average emissions per unit of electricity from the power plants do not show a noticeable improvement during this period. Emission efficiencies for new plants that use improved technology are found to be better than those of old plants. As per these estimates, the national average of CO2 emissions per unit of electricity varies between 0.91 and 0.95 kg/kWh while SO2 and NO emissions vary in the range of 6.9 to 7.3 and 2.8 to 2.9 g/kWh, respectively. Yamunagar plant in Haryana state showed the highest emission efficiencies with CO2 emissions as 0.58 kg/kWh, SO2 emissions as 3.87 g/kWh, and NO emissions as 1.78 g/kWh, while the Faridabad plant has the lowest emission efficiencies with CO2 emissions as 1.5 kg/kWh, SO2 emissions as 10.56 g/kWh, and NO emissions as 4.85 g/kWh. Emission values at other plants vary between the values of these two plants. 相似文献
995.
Garg SK Tripathi M Kumar S Singh SK Singh SK 《Environmental monitoring and assessment》2012,184(9):5533-5544
The physicochemical analyses of pulp-paper mill effluent revealed that it was dark brown with 1761?±?2.3 color PtCo units having slightly alkaline pH, high biological oxygen demand and chemical oxygen demand values, and contained large quantities of organic and inorganic constituents, well above the prescribed standards. The bacterial growth, color reduction, and dechlorination were evident in all the four sets of experiments with different possible combinations of nutrient supplementation and Pseudomonas putida augmentation. A high degree of decolorization at 29.7% and 27.4% was observed by the effluent native microflora during 48 and 24 h, in unaugmented effluent supplemented with glucose + yeast extract and glucose + peptone, respectively. The extent of decolorization in glucose + yeast extract unaugmented effluent also corresponded with high degree of dechlorination (59.3%) during 60-h incubation (SET III). An appreciable level of growth, decolorization, and dechlorination was evident in nutrient unsupplemented P. putida augmented effluent as well as in the control natural effluent. However, a maximum level of growth response (OD 1.641-1.902) during 36-48 h, removal of color (39.72-48.2%) during 24-36 h, and chloride ions (80.1-83.5%) during 36 h was achieved in P. putida augmented effluent supplemented with glucose + yeast extract or peptone. Therefore, supplementation of effluent with glucose and yeast extract or peptone and concomitant augmentation with P. putida is required for efficient effluent decolorization and detoxification. 相似文献
996.
Keoladeo National Park (KNP) is an important wintering ground for thousands of birds that undertake a perilous journey over the Himalaya to make a seasonal home in a wetland ecosystem. However, this wetland is now getting polluted by various types of contaminants such as pesticides because of the agricultural practices in the catchment area from where the park receives water. Keeping this in mind, the present study has been undertaken to assess the organochlorine pesticide (OCP) residues in the sediments inside and around KNP. Samples were collected from the different blocks of the park. The concentrations of α-HCH, β-HCH, γ-HCH, δ-HCH, S-HCH, aldrin, dieldrin, heptachlor, hept.epoxide, endosulfan-I, endosulfan-II, endo.sulfate, S-endosulfan, endrin, 4,4'-DDE, 4,4'-DDD, and DDT were quantified using gas chromatography with electron capture detection. Analysis showed that the samples were contaminated with the above mentioned pesticides and that the concentration of total OCPs in the sediments varied from 0.1173 (dieldrin) to 5.558 ppm (γ HCH) in the samples collected from inside the park, whereas a range of pesticides varying in concentration from 0.1245 (4,4'-DDD) to 7.54 ppm (γ HCH) was found in samples from outside the park. Residues of S-HCH and S-endosulfan were not detected in any of the sediment samples. The occurrence of pesticides inside the park is a major threat to the park's biodiversity. Eco-friendly agriculture practices with minimal use of inorganic chemicals are suggested to minimize the pesticide residue levels in the park. 相似文献
997.
The oxides of nitrogen—NO
x
(NO and NO2)—are an important constituent of the troposphere. The availability of relatively higher spatial (0.25° grid) and temporal
(daily) resolution data from ozone monitoring instrument (OMI) onboard Aura helps us to better differentiate between the point
sources such as thermal power plants from large cities and rural areas compared to previous sensors. The annual and seasonal
(summer and winter) distributions shows very high mean tropospheric NO2 in specific pockets over India especially over the Indo-Gangetic plains (up to 14.2 × 1015 molecules/cm2). These pockets correspond with the known locations of major thermal power plants. The tropospheric NO2 over India show a large seasonal variability that is also observed in the ground NO2 data. The multiple regression analysis show that the influence of a unit of power plant (in gigawatts) over tropospheric
NO2 (×1015 molecules/cm2) is around ten times compared to a unit of population (in millions) over India. The OMI data show that the NO2 increases by 0.794 ± 0.12 (×1015 molecules/cm2; annual) per GW compared to a previous estimate of 0.014 (×1015 molecules/cm2) over India. The increase of tropospheric NO2 per gigawatt is found to be 1.088 ± 0.18, 0.898 ± 0.14, and 0.395 ± 0.13 (×1015 molecules/cm2) during winter, summer, and monsoon seasons, respectively. The strong seasonal variation is attributed to the enhancement
or suppression of NO2 due to various controlling factors which is discussed here. The recent increasing trend (2005–2007) over rural thermal power
plants pockets like Agori and Korba is due to recent large capacity additions in these regions. 相似文献
998.
Bhatia A Pathak H Jain N Singh PK Tomer R 《Environmental monitoring and assessment》2012,184(5):3095-3107
Conventional blanket application of nitrogen (N) fertilizer results in more loss of N from soil system and emission of nitrous
oxide, a greenhouse gas (GHG). The leaf color chart (LCC) can be used for real-time N management and synchronizing N application
with crop demand to reduce GHG emission. A 1-year study was carried out to evaluate the impact of conventional and LCC-based
urea application on emission of nitrous oxide, methane, and carbon dioxide in a rice–wheat system of the Indo-Gangetic Plains
of India. Treatments consisted of LCC scores of ≤4 and 5 for rice and wheat and were compared with conventional fixed-time
N splitting schedule. The LCC-based urea application reduced nitrous oxide emission in rice and wheat. Application of 120 kg
N per hectare at LCC ≤ 4 decreased nitrous oxide emission by 16% and methane by 11% over the conventional split application
of urea in rice. However, application of N at LCC ≤ 5 increased nitrous oxide emission by 11% over the LCC ≤ 4 treatment in
rice. Wheat reduction of nitrous oxide at LCC ≤ 4 was 18% as compared to the conventional method. Application of LCC-based
N did not affect carbon dioxide emission from soil in rice and wheat. The global warming potential (GWP) were 12,395 and 13,692 kg CO2 ha−1 in LCC ≤ 4 and conventional urea application, respectively. Total carbon fixed in conventional urea application in rice–wheat
system was 4.89 Mg C ha−1 and it increased to 5.54 Mg C ha−1 in LCC-based urea application (LCC ≤ 4). The study showed that LCC-based urea application can reduce GWP of a rice–wheat
system by 10.5%. 相似文献
999.
Singh P Singh S Agrawal SB Agrawal M 《Environmental monitoring and assessment》2012,184(10):5863-5874
Rising O(3) concentrations in agricultural areas have been identified as a significant threat to crop production in Asia including India. The present work reports the results of a field study conducted to assess the usefulness of higher than recommended NPK dose in modifying the physiological, growth, yield, and seed quality responses of two mustard (Brassica campestris L. var. Vardan and Aashirwad) varieties under ambient ozone level at a rural site of India, using open-top chambers. Twelve hourly mean O(3) concentrations ranged between 27.7 and 59.04 ppb during the growth period. Plants in nonfiltered chambers (NFCs) showed reductions in photosynthetic rate, stomatal conductance, and growth parameters compared to the plants in filtered chambers (FCs), but reductions were of lower magnitude at 1.5 times recommended dose of NPK (1.5 RNPK) compared to recommended (RNPK). Yield and seed quality reduced significantly in plants of NFCs compared to FCs at RNPK, but no significant differences were recorded at 1.5 RNPK. There were higher N uptake and N uptake efficiency of plants in FCs compared to NFCs. Nitrogen utilization efficiency increased in Vardan, but decreased in Aashirwad in NFCs compared to FCs suggesting higher capability of N acquisition and utilization under ambient O(3), which led to a less pronounced reduction in the yield of the former than the latter variety. The differential nitrogen utilization efficiency in these varieties may be potentially used as measure of sensitivity characteristics in breeding programs for yield improvement in mustard under the present trend of increase in O(3) concentrations. 相似文献
1000.
Groundwater in a tannery belt in Southern India is being polluted by the discharge of untreated effluents from 80 operating
tanneries. Total dissolved solids and chloride (Cl−) measurements in open wells in the tannery cluster vary from 27,686 to 39,100 and 12,000 to 13,652 mg/l, respectively. A
mass transport model was constructed using Visual MODFLOW Premium 4.4 software to investigate the chloride migration in an
area of 75.56 km2. Input to the chloride migration model was a groundwater flow model that considered steady and transient conditions. This
model was calibrated with field observations; and sensitivity analysis was carried out whereby model parameters, viz., conductivity,
dispersivity, and source concentration were altered slightly, and the effect on calibration statistics was evaluated. Results
indicated that hydraulic conductivity played a more sensitive role than did dispersivity. The Cl− migration was mainly through advection rather than dispersion. It was found that even if the pollutant load reduced to 50%
of the present level, the Cl− concentration in groundwater, even after 6 years, would not be reduced to the permissible limit of drinking water in the
tannery belt. 相似文献