APCBEE Procedia最新文献

During the manufacture of recycled paper, paper sludge is discharged as an industrial waste. The amount of sludge discharged from manufacturing plants increases annually. In this study, the organic constituents, such as cellulose, in the sludge were converted into carbonaceous heavy metal absorbents using sulfur treatment, and its removal ability of lead from aqueous solution was examined. The sludge was treated with 5 M HCl to remove inorganic content, and then immersed in 1 M K₂S solution to prepare sulfur-immersed sludge. The immersed-sludge was heated at 100-1000 °C for 1 hour in nitrogen gas to produce the sulfur-impregnated adsorbent by pyrolysis. The product obtained at 400 °C (Product-400) has a high removal ability for lead ion, which has high specific surface areas and high sulfur content. The product-400 shows the highest adsorption of lead from aqueous solution, and high selective removal for lead ions in low pH solution.

This research is aimed to study fundamental dynamic properties of an esteemed brick masonry inverted bell-shaped chedi at Phrathat Doi Suthep temple, Chiangmai, Thailand, by using full-scale ambient vibration tests associated with the finite element analysis. The study results showed that the finite element analysis indicated 3.817 Hz, 3.836 Hz and 9.294 Hz for the natural frequencies of the first modes on the x, y and torsion directions. From the ambient vibration measurements, the frequencies were 4.086 Hz, 4.025 Hz and 10.819 Hz. In comparison, the finite element gives the similar frequency values with the measured ones. The discrepancies are respectively 6.59, 4.70 and 14.09 percent. Hence, the validation of the finite element model has been made and used for vibration analysis presented in the accompanied paper (Seismic Performances of Brick Masonry Inverted Bell-Shaped Chedi)

This paper evaluated four waste limestones mined in the Minas Gerais State, Brazil, and its potential as soil acidity amendments and its effects upon soil fertility attributes. Laboratory and greenhouse experiments were performed at the University Centre of Formiga (UNIFOR), with Oxisols collected under native conditions. A randomly experimental design was set with four replications, five liming materials (four waste limestones products + a mix pure product, to comparison) applied in two liming rates (50% and 70% of base saturation), and a control plot (no lime applied). Each liming material was characterized with respect to CaO(%), MgO(%), and micronutrients Ca, Mg, Fe, Cu, Mn, Zn contents by atomic absorption spectrophotometer and the mineralogy by X-ray diffractometry. Results indicated that all liming materials tested could be classified as supplemental source of calcium and magnesium and caused an increase in soil pH, soil Ca and Mg, and base saturation levels, whereas aluminum saturation decreased. Dolomite, calcite and quartz are major minerals. Cu, Fe, Mn, and Zn were found in trace-amounts in all waste limestones, which was considered typical for such products. Considering the improvement of chemical characteristics and increase soil fertility, the use of waste limestone is an alternative that allows the use of commercial discarded material in small properties.

The experiment was carried out to study the dissolved air flotation (DAF) process in a tank involving mainly velocity distribution and turbidity removal. Chitosan and Bentonite were known as coagulant agents thus were used in the study. Measurements were carried out on four cases with different inlet velocities of 0.3m/s, 0.6m/s, 0.9m/s and 1.2m/s. Laboratory tests were conducted to test the water quality based on turbidity values and basic drinking water parameters. From the test results, it was found that the inlet velocity gave impacts on the distribution of flow in the tank and thus affected the efficiency of the flotation process. Chitosan and Bentonite can be applied to the flotation tank resulting in an average of 97% turbidity removal. This study successfully proved the effectiveness of the combination of Chitosan and Bentonite as a coagulating agent in the DAF tank for raw water treatment process.

Recovery of tantalum resource from used tantalum capacitor in electric equipment is important because the production of tantalum have not been stable for the price and the quantity. However, recovery of tantalum sintered compact from tantalum capacitor is difficult since the compact strongly covered with the flame retardant resin made of halogenated compounds (mold resin). In this study, steam gasification with sodium hydroxide was applied for recovery of tantalum sintered compact by destroying mold resin and stabilization of halogenated compounds in sodium hydroxide to prevent exhausting halogenated gas. Mold resin can be decomposed by steam gasification with NaOH to recover the sintered compact of tantalum. Furthermore, most halogen gas generated from decomposition of mold resin can be trapped in sodium hydroxide not to exhaust halogen gas. These results suggested that recovery process of tantalum sintered compact from the used condenser using steam gasification with sodium hydroxide is expected as a feasible way to recycle the rare metal in electric equipment.

Recently, it has been argued that, contrary to earlier energy ladder thinking, households in developing countries do not switch to modern energy sources but instead tend to consume a combination of fuels. This article aimed to gather a better understanding of the relative importance of fuel substitution and fuel complementation, especially among charcoal, fuel briquettes and kerosene, and the factors associated with these choices. In this paper we present results of a household survey conducted during October 2010 in Kibera slums in Nairobi, Kenya. The results revealed that widely various household characteristics influence demand for charcoal and briquettes for cooking. In addition to these factors, the household income level affects the use of kerosene for cooking. At the same time, we found the fact households tend to switch to multiple fuels strategy as their increasing in income instead of completely switching from the consumption of traditional fuels to modern energy sources.

Toxic organic substances are considered among the pollutants that have direct effect on humans and animals. Industrial wastewaters containing dissolved phenol can contaminate groundwater resources and thus lead to a serious groundwater pollution problem. In the present research, the adsorption technique for the efficient removal of phenol pollutants at trace level in water was employed. Four type of micro and nanocarbon materials including carbon nanotubes (CNTs) and carbon nanofibers (CNFs) as nano carbon adsorbents, activated carbon (AC) and industrial carbon fly ash (CFA) as micro carbon adsorbents were used to remove phenol from water. Characterization of these adsorbents was performed by Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy(TEM), Thermogravimetric Analysis (TGA), BET specific surface area while the concentration of phenol in water before and after treatment was analyzed using UV-Spectroscopy. The pH (3-9) of the solution, was varied in order to determine their effect on the removal of phenol from water and hence on the adsorption rate.

The diversity of adult Trichoptera was surveyed at Mae Tao and Mae Ku watersheds, northern Thailand during July 2011 to May 2012. The aim of the study was to determine the relationship between physicochemical parameters of water quality and adult Trichoptera for monitoring of water quality. A total of 9,475 adult Trichoptera representing 14 families and 126 species were collected. The correlation between the biodiversity of adult Trichoptera and water quality showed that the Ecnomus jojachin, Cheumatopsyche carmentis, C. chryseis, C. lucida, C. chrysothemis, C. dhanikari, Potamyia dryope, Leptocerus dirghachuka, L. trophonios, L. ganymedes, Oecetis scutulata, O. armadillo, O. raghava, O. asmada, O. tripunctata, Setodes flivialis, S. neptunus, S. endymion, S. okypete, Chimarra chiangmaiensis, Paduniella semarangensis, Lepidostoma doligung, Polyplectropus ahas, Psychomyia lak, Marilia sumatrana, Hydroptila thuna and Orthrotrichia typhoeus depended on some physicochemical factors including air temperature, pH, electrical conductivity, turbidity, sulfate, nitrate-nitrogen, orthrophosphate, ammonia-nitrogen and alkalinity in water.

pH sensitive hydrogel particles were characterized for their rheological and swelling behaviour at various pH values specific to the gastrointestinal tract simulated conditions. Scanning electron microscopy was used to view the surface morphology of the hydrogels at different pHs. Swelling at pH 7.4 and shrinkage at pH 1.2 confirmed the pH sensitive behaviour of the hydrogel particles. The Linear Viscoelastic (LVE) range was determined by considering G’, one of the strain amplitude. Furthermore frequency sweep tests were performed in the LVE range where the storage modulus and loss modulus were determined at constant strain. It was observed that the loss modulus was higher at basic pH while the storage modulus was higher at lower pH. This rheological method can be used to explain the pH sensitive behaviour of hydrogels.

Gas transmission rate through fruit peel is needed to understand gas exchange between fruit and the environment. It can be used to design packaging material and formulate edible coatings to be used by the fruit. It can also be used to predict oxygen consumption and possible carbon dioxide injury which could affect ripening and could predict the internal gas level inside the fruit. Oxygen and carbon dioxide transmission rates (O2TR and CO2TR) of mango (Mangifera indica, L.) peel at different stages of maturity and ripeness which were stored under two temperature regimes were measured using gas diffusion chamber. Nitrogen gas was flushed inside the chamber to decrease the oxygen level. Then a gas mixture of known concentration was flushed in the chamber and the concentration inside the chamber was measured through time. The Exponential Decay Method of Gas Transmission Rate of Films as described by Moyls (1992) was used to relate partial pressure of the gas concentration inside the chamber and the outside condition. Results showed that overmature fruit peel-PCI3 under 27 °C had the highest O₂TR and CO₂TR (1.636 mLO₂/cm²-hr - 4.744 mLCO2/cm²-hr) while immature fruit peel-PCI1 under 14 °C had the lowest O₂TR and CO₂TR (1.104 mLO₂/cm²-hr - 3.321 mLO₂/cm²-hr). At constant temperature, gas transmission rates increase with maturity and as the fruit peel turns yellow.