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Application of Hydrous Bismuth Oxide for Arsenic Removal from Aqueous Solutions 全文
2021
Manish Ranjan, Prabhat Kumar Singh and Arun Lal Srivastav
The present study is devoted to arsenic sorption on hydrous bismuth oxide (HBO) through batch and column studies. Advantage of the adsorbent includes arsenic removal in addition to the simultaneous removal of nitrate and fluoride from aqueous solution. Both the forms of arsenic tested by adsorbent in which affinity for arsenic (V) was found better than arsenic (III). Langmuir isotherm and pseudo-second-order kinetic models were found a fit with the experimental data. Calculation of adsorption energy and increased level of chloride in treated water indicated the possible role of physical adsorption and ion exchange phenomenon in arsenic(V) sorption. A fixed bed column study gave 615 mL of treated water [As (V) < 0.01mg/L] from 0.085 mg/L arsenic (V) spiked influent with a sorption potential of 13.1-19.6 μg/g. XRD and EDS analyses confirmed the adsorption of arsenic (V) and the presence of chloride in the exhausted bed of adsorbent. The thermodynamic parameter has shown the endothermic and spontaneous process of adsorption.
显示更多 [+] 显示较少 [-]Plastic and Petroleum Hydrocarbon Degrading Potentials of Single and Mixed Bacterial Cultures Isolated from Garbage Areas of Darrang, Assam 全文
2021
R. S. Ahmed and M. D. Swargiary
The ability of bacterial isolates viz., Enterococcus cloacae and mixed bacterial isolates, to degrade plastic was studied. The bacteria were isolated from waste effluent sites viz., industrial waste sites of Nilon’s pickle factory, Dalgaon and market waste sites of Balugaon vegetable market, Kharupetia, Assam. Plastic degradation was carried out at different time intervals within 15 and 30 days. It was observed that degradation increased with an increase in the time interval and hence effective observation was recovered after 30 days interval. Polythene bags showed maximum degradation by Enterococcus cloacae (85.25%). Plastic degradation was observed by Scanning Electron Microscope (SEM). In biodegradation of petroleum hydrocarbon, Enterococcus cloacae, Pseudomonas putidia and Ralstonia pickettii were found to degrade oil as well as they were able to grow in presence of petroleum hydrocarbons.
显示更多 [+] 显示较少 [-]Numerical Simulation of Effect of Sand Thickness on Soil Evaporation 全文
2021
Wenju Zhao, Junhong Hu, Zongli Li, Ping Yu and Changquan Zhou
Evaporation from the soil is an important component of evapotranspiration, and mulching greatly affects soil evaporation. We conducted numerical simulations to study the effect of the thickness of sand mulch on soil evaporation. We tested nine treatments: mulching with sand thicknesses of 1, 3, 5, 6, 8, 10, 15 and 20 cm plus an unmulched control (CK). Accumulated evaporation was significantly lower, and the resistance to evaporation was significantly higher, for the mulched treatments than CK. The volumetric soil water content (SWC) was significantly higher for the mulched treatments than CK, but SWC varied little for thicknesses >5 cm. Heating was slower and more uniform for the mulched treatments than for CK. With the increase of the thickness of sand, the temperature transmission was slowed down. The change of soil temperature was not obvious at thicknesses >15 cm. A thickness of 5 cm was the most effective for storing water and preserving heat. Our results provide a theoretical basis and technical guidance for the effective use and management of soil water in farmland in arid regions.
显示更多 [+] 显示较少 [-]Relationship Between NDVI and the Microbial Content of Soil in Detecting Fertility Level at Semarang Regency, Jawa Tengah, Indonesia 全文
2021
Ananto Aji, Sigit Bayhu Iryanthony, Wahid Akhsin Budi Nur Sidiq and Edy Trihatmoko
Global warming is the most significant environmental issue that causes the utmost concern for researchers and scientists. Furthermore, impacts recorded include the potential for drought and the reduction of soil ability to support biomass production, subsequently posing a significant threat to agriculture. Moreover, vegetation density is known to support microorganism activities actively, and its analysis requires remote sensing techniques, involving normalized differential vegetation index (NDVI) and soil adjustment vegetation index (SAVI), associated with microbial content in the soil. Besides, the level recorded is assumed to have a strong correlation with soil fertility, which is a prerequisite for the development of vegetation cover. Hence, most of the research was conducted in fertile lands situated in the Ungaran, Merbabu, and Telomoyo volcanic areas. The results show the absence of a positive correlation between soil fertility and the number of microorganism’s present, although the association with vegetation cover is relatively low.
显示更多 [+] 显示较少 [-]Carbon Emission Efficiency Measurement of Construction Industry and Its Treatment Measures-A Case Study of Henan Province, China 全文
2021
Zhang Hui, Du Liu Jie, Wang Bai Tian and Qi Ping
Energy demand and carbon emission in building construction and utilization have presented an increasing trend with urbanization development and improvement of living standard. Improving the carbon emission efficiency of the construction industry is a precondition for allocating carbon emission reduction objectives and interregional experience exchange over carbon emission reduction. An input-output index system was first constructed in this study to obtain the carbon emission efficiency of the construction industry. Carbon dioxide emission of the construction industry was taken as unexpected output, and the super efficiency slack-based measure-data envelopment analysis (SBM–DEA) model was used to estimate the carbon emission efficiency of the construction industry in Henan Province, China during 2008-2019. Finally, treatment measures were proposed to retard the rising trend of carbon emission in the construction industry. Results showed that the mean carbon emission efficiency of the construction industry in Henan Province during 2008-2019 is 1.007 and the carbon emission efficiency of the construction industry reaches the minimum value of only 0.807 in 2012. The carbon emission efficiency of the construction industry in Henan Province demonstrated an overall rising trend with a small amplitude during the investigation period. The results of this study can provide a reference for exploring the efficiency of the construction industry in Henan Province under carbon emission constraint, analyzing and identifying efficiency improvement objectives and methods for the construction industry, and facilitating its sustainable development.
显示更多 [+] 显示较少 [-]Tropical Fruit Wastes as an Organic Nutrient Sources for the Cultivation of Chlorella vulgaris and Haematococcus pluvialis 全文
2021
Y.H. Tan, Y.J. Khoo, M.K. Chai and L.S. Wong
The possibility of replacing the inorganic medium with tropical organic fruit waste medium as a nutrient supplement was evaluated for the cultivation of Chlorella vulgaris and Haematococcus pluvialis in this study. Various concentrations of tropical fruit waste medium such as papaya, pineapple and mango were prepared to cultivate microalgae of C. vulgaris and H. pluvialis. The biomass concentration, productivity and specific growth rate were determined and compared with those grown in a fully inorganic medium. For C. vulgaris, the use of a 20% tropical fruit waste medium was found to yield higher biomass concentration (4.133-4.533 g/L) compared with cultivation in a fully inorganic medium (3.400 g/L). For H. pluvialis, the use of a 10% mango waste medium was found to yield a similar biomass concentration compared with cultivation in a fully inorganic medium (3.400 g/L). These results unveiled the potential of utilizing with tropical organic fruit waste medium as an effective strategy to reduce the cultivation cost of microalgae and treat the tropical fruit waste prior to discharge to the environment.
显示更多 [+] 显示较少 [-]A Statistical Methodology for Impact Study on Irrigation Tank Rehabilitation 全文
2021
B. Anuradha, L. Iyappan, P. Partheeban, C. Hariharasudan and Y.J. Breetha
Tank systems are essential for the agricultural growth and the livelihood of rural populations in India. Comprehending the multiple benefits from these traditional systems, tank rehabilitation has been one of the policy significances at the state level. The study was undertaken with the objective of assessing the impact of tank rehabilitation on cropped area, cropping pattern change, cost returns and income of farmers in a selected study village of south Tamil Nadu. The study was conducted on the basis of primary data obtained from 102 sample farmers belonging to “Pelasur” village of Thiruvannamalai district in south Tamil Nadu using a stratified sampling method. There was a significant difference in the cropped area, cropping intensity and irrigation intensity among the farmers before and after tank rehabilitation. It is found that there is an increase of 41.02 ha cultivated area and an increase in the net amount of Rs. 7,99,945. Many farmers shifted from paddy to sugarcane (cash crops) cultivation due to the availability of excess surface water in the tank and improved water table in their wells. Cropping intensity has been increased to 26% in the post-rehabilitation period. Thus, investment in tank rehabilitation shows a positive implication on marginal farmers and landless labours. Using SPSS, a paired-sample t-test is applied for analysing data collected from respondents.
显示更多 [+] 显示较少 [-]Effect of Water Chemistry on the Uptake of Co(II) on Graphene Oxide Investigated by Batch Technique 全文
2021
X. Tang, J. Luo, L. Wang and X. Li
The uptake of Co(II) on graphene oxide (GO) by an adsorption process as a function of pH and ionic strength in the absence and presence of humic acid (HA) or fulvic acid (FA) was studied using batch technique. The results indicated that the uptake is strongly dependent on pH but independent of ionic strength. A stimulative effect of HA/FA on Co(II) uptake was found at pH < 7.0, whereas an inhibitory effect was observed at pH > 7.0. Kinetic studies suggest that Co(II) uptake on GO could be described more favorably by the pseudo-second-order kinetic model. The uptake isotherms can be described better by the Langmuir, Freundlich, and D-R models than by the linear model. The thermodynamic data calculated from the temperature-dependent uptake isotherms suggests that the uptake of Co(II) on GO is spontaneous and endothermic. Results of this work are of great importance for the environmental application of GO in the treatment of Co(II) from wastewater and indicated that GO is promising for the natural attenuation of Co(II) and related metal ions from aqueous solution.
显示更多 [+] 显示较少 [-]Contamination of Cadmium, Lead, Mercury and Manganese in Leachate from Open Dump, Controlled Dump and Sanitary Landfill Sites in Rural Thailand: A Case Study in Sakon Nakhon Province 全文
2021
K. Ruengruehan, R. Junggoth, S. Suttibak, C. Sirikoon and N. Sanphoti
The contamination of heavy metal in leachate was investigated at various sites with different solid waste management, namely an open dump, controlled dump, and sanitary landfill. The results indicated that all four heavy metals investigated (cadmium, lead, mercury, and manganese) were present in the leachate at all solid waste management sites. The highest cadmium and lead concentrations were each observed in open dump leachate samples, while the highest manganese and mercury concentrations were each observed in controlled dump leachate samples.
显示更多 [+] 显示较少 [-]Assessment of LULC Changes for Hesaraghatta Watershed Using GIS Tools and Remote Sensed Data 全文
2021
Bharath A., Manjunatha M., Ranjitha B. Tangadagi, Preethi S. and Mukund Dangeti
Hesaraghatta watershed is one of the most vital and environmentally substantial watersheds in the Arkavathi basin. It has a freshwater lake created in the year 1894 across the Arkavathi River to quench the drinking water requirements of Bengaluru city. The watershed is facing significant stresses due to rapid urbanization and other developmental activities. For this study, an attempt is made to assess the distribution of various land use land cover classes and their temporal changes over 18 years using remote sensed data and GIS tools. The watershed is categorized into four land use land cover classifications: settlement, waterbody, vegetation, and bare soil. The maximum likelihood technique is utilized for the image classification and accuracy assessment is carried out to evaluate the accuracy of image classification. The outcome of the study revealed that there is a substantial change in land use land cover classes in the Hesaraghatta watershed.
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