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1.
Beer bran was found to effectively adsorb several organic compounds, such as dichloromethane, chloroform, trichloroethylene, benzene, pretilachlor, and esprocarb. Equilibrium adsorption isotherms conformed to the Freundlich isotherm (log-log linear). Adsorption of these organic compounds by beer bran was observed in the pH range of 1-11. At equilibrium, the adsorption efficiency of beer bran for benzene, chloroform, and dichiloromethane was higher than that of activated carbon. The removal of these organic compounds by beer bran was attributed to the uptake by intracellular particles called spherosomes. The object of this work was to investigate several adsorbents for the effective removal of organic compounds from wastewater.  相似文献   

2.
To evaluate the effectiveness in adsorbing organochlorine compounds such as chloroform, dichloromethane, or benzene by lees materials, the determination of spherosomes from different lees materials was established by using a hemacytometer under an optical microscope. Rice bran, wheat bran, rapeseed, linseed, okara, and sakekasu were used for this investigation, and activated carbon was also used as a standard adsorbent material. The number of spherosomes varied from 1.82 x 10(10) particles/g for sakekasu to 4.95 x 10(10) particles/g for wheat bran. There was a high correlation between the removal efficiency in adsorbing organochlorine compounds such as chloroform, dichloromethane, or benzene by lees materials and the number of spherosomes from different lees materials.  相似文献   

3.
Spherosomes were elucidated to be a key for removal of chloroform by rice bran (Adachi, A.; Okano, T. Chemosphere 2002, 46, 87-92). On the basis of the above findings, a large amount of spherosomes was separated from rice bran using an industrial scale machine in order to investigate direct removal of chloroform by spherosome from tap water. The efficiency of removal of chloroform from water by rice bran spherosome was evaluated. Equilibrium adsorption isotherms conformed to the Freundlich isotherm (log-log linear). Adsorption of this compound by spherosome was observed in the pH range of 1-12. At equilibrium, the adsorption efficiency of spherosome for chloroform was higher than that of rice bran or activated carbon in the high chloroform concentration range (concentration>0.1 g/L). In the low chloroform concentration range (concentration<0.08 g/L), activated carbon adsorbs more chloroform than spherosome, but the adsorbed amount by spherosome is of the same order as that by activated carbon, which is several orders higher than that by rice bran. Chloroform was removed from tap water with an average removal efficiency of 90% after 90 min when spherosome (2 g/L) was added to tap water containing 0.105 mg/L of chloroform.  相似文献   

4.
Defatted seeds were evaluated for effective adsorption of organochlorine compounds such as chloroform, dichloromethane, and trichloroethylene. The amounts of these compounds adsorbed were plotted against the equilibrium concentration of substances in solution on a logarithmic scale. A linear relationship was obtained, indicating that the adsorption reactions were of the Freundlich type. The removal of these organochlorine compounds by defatted seed was attributed to the uptake by intracellular particles called spherosomes.  相似文献   

5.
The sorption efficiency of indigenous rice (Oryza sativa) bran for the removal of organics, that is, benzene, toluene, ethylbenzene, and cumene (BTEC), from aqueous solutions has been studied. The sorption of BTEC by rice bran is observed over a wide pH range of 1-10, indicating its high applicability to remove these organics from various industrial effluents. Rice bran effectively adsorbs BTEC of 10 microg mL(-1) sorbate concentration from water at temperatures of 283-323 +/- 2 K. The effect of pH, agitation time between solid and liquid phases, sorbent dose, its particle size, and temperature on the sorption of BTEC onto rice bran has been studied. The pore area and average pore diameter of rice bran by BET method are found to be 19 +/- 0.7 m(2) g(-1) and 52.8 +/- 1.3 nm. The rice bran exhibits appreciable sorption of the order of 85 +/- 3.5, 91 +/- 1.8, 94 +/- 1.4, and 96 +/- 1.2% for 10 microg mL(-1) concentration of benzene, toluene, ethylbenzene, and cumene, respectively, in 60 min of agitation time using 0.1 g of rice bran at pH 6 and 303 K. The sorption data follow Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) models. Sorption capacities have been computed for BTEC by Freundlich (32 +/- 3, 61 +/- 14, 123 +/- 28, and 142 +/- 37 m mol g(-1)), Langmuir (6.6 +/- 0.1, 7.5 +/- 0.13, 9.5 +/- 0.22, and 9.4 +/- 0.18 m mol g(-1)), and D-R isotherms (11 +/- 0.5, 16 +/- 1.3, 30 +/- 2.2, and 33 +/- 2.5 m mol g(-1)), respectively. The Lagergren equation is employed for the kinetics of the sorption of BTEC onto rice bran and first-order rate constants (0.03 +/- 0.002, 0.04 +/- 0.003, 0.04 +/- 0.003, and 0.05 +/- 0.004 min(-1)) have been computed for BTEC at their concentration of 100 mug mL(-1) at 303 K. Studies on the variation of sorption with temperatures (283-323 K) at 100 mug mL(-1) sorbate concentration gave thermodynamic constants DeltaH (kJ mol(-1)), DeltaG (kJ mol(-1)), and DeltaS (J mol(-1) K(-1)). The results indicate that the sorption of organics onto rice bran is exothermic and spontaneous in nature under the optimized experimental conditions selected. This sorbent has been used successfully to accumulate and then to determine benzene, toluene, and ethylbenzene in wastewater sample.  相似文献   

6.
The concentrations of 9 chlorinated pesticides in the water sources and tap waters of Istanbul, Turkey, were determined by gas chromatographic methods following the enrichment through adsorption and elution techniques. The observed organochlorine pesticides were α- and γ-HCH and aldrin which had been banned from use. The contents of α- and γ-HCH in raw waters were in the range of 0.34–1.7 ppb and not detected-0.077 ppb, respectively. Aldrin was observed at the concentration of 0.03 ppb in some samples. The residue levels of organochlorine pesticides in drinking water supplies of Istanbul were found significantly under the maximum permissible levels of standards. The effectiveness of potable water treatment processes and the importance of maintenance and back- washing of sand filters in pesticide removal were observed. Improper and delayed back-washings of filters caused an increase in the pesticide residues in the distributed water. In older water distribution lines, higher concentrations of some organochlorines were also observed.  相似文献   

7.
Rice bran is a rich natural source of vitamin E and gamma-oryzanol, which have been extensively studied and reported to possess important health-promoting properties. However, commercial rice bran is a mixture of rice bran and germ, and profiles of vitamin E and gamma-oryzanol components in these two different materials are less well-studied. In the current study, vitamin E and gamma-oryzanol components in rice bran and germ were analyzed by liquid chromatography/mass spectrometry/mass spectrometry. The components were identified by electrospray ionization mass spectrometry (ESI-MS) with both positive- and negative-ion modes. Both deprotonated molecular ion [M - H](-) and protonated molecular ion [M + H](+) found as the base peaks in spectra of vitamin E components made ESI-MS a valuable analytic method in detecting vitamin E compounds, especially when they were at very low levels in samples. Ultraviolet absorption was used for quantification of vitamin E and gamma-oryzanol components. While the level of vitamin E in rice germ was 5 times greater than in rice bran, the level of gamma-oryzanol in rice germ was 5 times lower than in rice bran. Also, the major vitamin E component was alpha-tocopherol in rice germ and gamma-tocotrienol in rice bran. These data suggest that rice bran and germ have significantly different profiles of vitamin E and gamma-oryzanol components. The method enables rapid and direct on-line identification and quantification of the vitamin E and gamma-oryzanol components in rice bran and germ.  相似文献   

8.
9.
Sulphuric acid-modified bagasse has been used as low-cost adsorbent for the removal of methylene blue (MB) dye from aqueous solution. In order to remove organic compounds that contribute to chemical oxygen demand (COD), pretreatment with thorough washing of adsorbent using boiling distilled water was performed instead of conventional washing using distilled water at room temperature only. This has resulted in the highest efficiency of color removal of 99.45% and COD reduction of 99.36% for MB dye solution at pH 9. Effects of initial pH, dye concentration, adsorbent dosage, temperature, and contact time have been studied. The adsorption of MB dye was pH dependent. Langmuir and Freundlich isotherm models were tested on the adsorption data. The kinetic experimental data were analyzed using pseudo-first order, pseudo-second order, and the intraparticle diffusion model in order to examine the adsorption mechanisms. The adsorption process followed the Langmuir isotherm as well as the Freundlich isotherm and pseudo-second-order kinetic model. The process was found to be endothermic in nature.  相似文献   

10.
《Cereal Chemistry》2017,94(4):654-658
The bile acid binding capacity of wheat bran with different particle sizes was determined. Unmilled wheat bran with an average particle size of 900 μm (WB‐900), milled wheat bran at two particle sizes, 500 and 200 μm (WB‐500 and WB‐200), and all three bran samples washed with water (WWB‐900, WWB‐500, and WWB‐200) were mixed with bile acids at pH 6.3 to determine their in vitro adsorption capacity. On a dry matter basis, the order of relative bile acid binding values was WB‐900 ∼ WB‐500 > WWB‐900 > WB‐200 > WWB‐500 > WWB‐200. Data suggests that the surface area as measured by the Brunauer–Emmett–Teller (BET) method and water holding capacity may significantly affect the bile acid binding capacity of wheat bran. As the BET surface area increased with decreasing particle size, the water holding capacity and bile acid binding decreased. Bile acid binding capacity of wheat bran appears to be linked to the ability of the samples to physically adsorb the bile acids. Bile acid binding capacity significantly decreased with reduction in particle size of wheat bran after water washing.  相似文献   

11.
ABSTRACT

Growth of the weed Monochoria vaginalis (Burm. f.) Kunth under the conditions of organic rice production is a serious problem. The reason for the growth of M. vaginalis being dominant, especially in organic rice production, is not fully understood. In this study, laboratory experiments were conducted to analyze soil and seed factors in relation to the promotion of germination. (1) After incubation of flooded soil with or without the addition of rice bran (0.3%, 0.6%, and 0.9% in an air-dried soil basis), soil solutions were recovered and seeds of M. vaginalis were incubated in the soil solutions. Germination in the soils solutions without and with 0.3% rice bran was greater than that in distilled water. However, germination was suppressed in the presence of 0.6% and 0.9% of rice bran. These findings indicate that the solution from the soils with rice bran has different effects that may either increase or decrease germination. (2) A mixture of air-dried soil and distilled water was filtered to obtain a soil solution. Seeds were incubated in the soil solution (same as above). Environmental and physiological factors affected germination: exposure of seeds to light was an environmental factor and high germination activity and shallow dormancy of seed were physiological. The recovered soil solution promoted germination when these factors were not optimized. (3) There was a negative and significant correlation between dissolved oxygen (DO) in the soil solution and germination, indicating that a low content of DO was a promotive factor for germination. (4) Based on an experiment using pH buffers, germination increased with decrease in pH of soil solution, as long as the pH ranged from 4.0 to 7.0. This finding indicates that pH is also a factor that promotes germination.  相似文献   

12.
The protective effects of whole grain cereals against heart disease and certain cancers may be due, at least partly, to the antioxidant effects of phenolics concentrated in the bran. However, it is unclear to what extent these phenolics are absorbed, and whether these phenolics exert significant physiological antioxidant effects. Thus, this study aimed to compare total phenolics (TP) and antioxidant potential (AOP) in the plasma and urine of humans following consumption of a single meal of unprocessed wheat bran or a refined cereal (ground white rice). Using a randomized cross‐over design, 17 adults consumed ≈93 g of wheat bran or ground rice after an overnight fast. Baseline and postmeal plasma and urine samples were analyzed for TP (Folin‐Ciocalteu method) and AOP (FRAP method). Compared with ground rice, wheat bran gave significantly (P < 0.05) higher plasma TP at 1 hr, and significantly (P < 0.001) higher plasma AOP from 0.5 to 3 hr. Furthermore, compared with ground rice, wheat bran led to consistently higher TP and AOP in urine, and these differences were significant (P < 0.05) at 2 hr. Comparisons with data from a range of other phenolic‐rich foods indicated that wheat bran phenolics are relatively well absorbed and may enhance antioxidant status.  相似文献   

13.
14.
The Adsorption of Fluoride Ion from Aqueous Solution by Activated Alumina   总被引:1,自引:0,他引:1  
The adsorption of fluoride ion in aqueous solution by using alumina was studied in this research. The experimental resultsindicated that the removal efficiency was influenced significantly by solution pH and the optimum operating pH wasfound to be in the range of 5 to 7. For neutral and acidic solutions, the adsorption capacities of fluoride by alumina wasinterfered by the presence of sulfate. The Langmuir and Freundlich isotherms can well describe the equilibrium behaviorsof the adsorption processes. The experimentally determined lowvalues of activation energy indicate nonspecific adsorption isthe predominant mechanism. The surface reaction-limiting batchkinetic model can adequately describe the removal behaviors offluoride ion by alumina adsorption in the batch system.  相似文献   

15.
The adsorption of As(III), As(V), Se(IV) and Se(VI) by seawater neutralized red mud and alum water treatment sludge was investigated and compared using the batch adsorption technique. For water treatment sludge, adsorption of As(V), Se(IV) and Se(VI), at equimolar concentrations of added metalloid, declined with increasing pH. The decline was rapid above pH?4.0 for Se(VI), above pH?5.0 for Se(IV) and above pH?6.0 for As(V). Adsorption of As(III) increased with increasing pH up to pH?9.0 and then declined. For red mud, adsorption of As(V), Se(IV) and Se(VI) showed a maximum at about pH?5.0 and for As(III) adsorption remained relatively constant over the pH range 2.0?C10.0 after which it declined. Water treatment sludge removed 50?% or more of solution As(V) between pH?2.0 and 10.8, Se(IV) between 2.0 and 8.9, Se(VI) between 2.0 and 5.8 and As(III) between 8.4 and 10.9. By contrast, red mud showed less than 25?% adsorption of added Se(VI) and As(III) over the entire pH range tested (2.0?C12.0) and reached 50?% or more for As(V) only over the pH range 4.0?C6.9 and for Se(IV) between pH?4.3 and 5.6. At pH?5.0, adsorption of As(III) and Se(IV) was better described by the Langmuir than Freundlich equation but the reverse was the case for As(V) and Se(VI). Kinetic data for adsorption of all four oxyanions onto both adsorbents correlated well with a pseudo-second-order kinetic model suggesting the process involved was chemisorption. NaOH was more effective at removing adsorbed metals from both adsorbents than HNO3. Water treatment sludge maintained its As(III) and Se(IV) adsorption capability at greater than 70?% of that added over eight successive cycles of adsorption/regeneration using 0.5?M NaOH as a regenerating agent. By contrast, for red mud, As(V) adsorption capacity declined very rapidly after three adsorption/desorption cycles and that for Se(IV) it decreased progressively with increasing numbers of cycles. It was concluded that water treatment sludge is a suitable material to develop as a low-cost adsorbent for removal of heavy metal oxyanions from wastewater streams.  相似文献   

16.
Prevention of hydrolytic rancidity in rice bran during storage.   总被引:5,自引:0,他引:5  
The effect of microwave heating, packaging, and storage temperature on the production of free fatty acids (FFA) in rice bran was examined. Freshly milled raw rice bran was adjusted to 21% moisture content and heated in a microwave oven at 850 W for 3 min. Raw and microwave-heated rice bran were packed in zipper-top bags or vacuum-sealed bags and stored at 4-5 or 25 degrees C for 16 weeks. FFA content of bran was measured at 4-week intervals. Total FFA increased rapidly over the 16-week period from the initial value of 2.5% in raw bran stored at 25 degrees C to 54.9% in vacuum bags and 48.1% in zipper-top bags. However, total FFA of raw bran stored at 4-5 degrees C increased at a slower rate from an initial value of 2. 5 to 25.4% in vacuum bags and 19.5% in zipper-top bags. After 16 weeks of storage, total FFA of microwave-heated bran stored at 25 degrees C increased from 2.8 to 6.9 and 5.2%, respectively, for samples stored in vacuum bags and zipper-top bags. Total FFA of microwave-heated samples stored at 4-5 degrees C did not change significantly with storage time. Results showed that hydrolytic rancidity of rice bran can be prevented by microwave heating and that the recommended storage condition for microwaved rice bran is 4-5 degrees C in zipper-top bags.  相似文献   

17.
Emerging evidence supporting chronic disease fighting properties of rice bran has advanced the development of stabilized rice bran for human use as a functional food and dietary supplement. A global and targeted metabolomic investigation of stabilized rice bran fermented with Saccharomyces boulardii was performed in three rice varieties. Metabolites from S. boulardii-fermented rice bran were detected by gas chromatography-mass spectrometry (GC-MS) and assessed for bioactivity compared to nonfermented rice bran in normal and malignant lymphocytes. Global metabolite profiling revealed significant differences in the metabolome that led to discovery of candidate compounds modulated by S. boulardii fermentation. Fermented rice bran extracts from three rice varieties reduced growth of human B lymphomas compared to each variety's nonfermented control and revealed that fermentation differentially altered bioactive compounds. These data support that integration of global and targeted metabolite analysis can be utilized for assessing health properties of rice bran phytochemicals that are enhanced by yeast fermentation and that differ across rice varieties.  相似文献   

18.
基质是生态沟渠的重要组成部分,但在我国北方寒旱地区,由于高寒、降雨少、蒸发强等原因,导致土壤和水体中盐度较高,可供选择的基质种类较少,从而限制了生态沟渠技术在该地区的应用。选取天然沸石、麦饭石、无烟煤、炉渣、废砖块5种北方地区常见基质作为试验材料,通过静态吸附试验对选用材料进行氨氮和磷的吸附,并将吸附效果较好的3种基质组合成不同比例的生态沟渠基质试样,再次通过筛选试验确定出去除效果最好的基质比例组合,同时研究了温度、pH和盐度对最优基质组合去除氨氮和磷效果的影响。结果表明:废砖块、天然沸石、炉渣在质量比例为1∶1∶3时对氨氮和磷的去除率最优,均达到90%以上。随着温度的升高,氨氮的吸附量降低,磷的吸附量升高。pH对氨氮和磷的吸附效果有显著的影响,对磷的去除率随着pH升高而降低,对氨氮的去除率随着pH升高呈现先增后减的趋势,在pH=7时,氨氮去除效果最好,去除率为91.78%。氨氮和磷的去除效果均随着溶液盐度的增加而降低,对磷的吸附效果影响不明显,但对氨氮影响较大,表现为盐度低于1%时,溶液中氨氮的去除效果下降幅度并不明显,均在3%左右,而当盐度达到2%时,氨氮的去除率仅有68%,比盐度为0时的去除率(92%)降低了24%。  相似文献   

19.
The present study was performed to investigate calcium-binding characteristics of different brans under simulated gastrointestinal pH conditions and to explore the significance of dietary fiber, oxalate, and phytate for calcium binding. Different brans (rice, rye, soy, fine wheat, coarse wheat, and oat) and CaCl(2) solution containing (45)Ca were incubated at 37 degrees C at gastric pH (2.2) followed by buffering steps of 1 degree from pH 3.0 to pH 8.0. Total calcium binding and calcium-binding capacity of the pH 2.2 soluble bran fraction were determined. Additionally, oxalate and phytate contents of brans and solubility profiles of phytic acid were investigated. Calcium-binding capacities of brans showed a clear pH dependence. At gastric pH calcium binding was low in all brans, ranging from 0.022 to 0.040 mmol of calcium/g of bran. Soy bran, nearly phytate-free, showed higher binding values up to pH 4.0 and lower values between pH 5.0 and 8.0. In all other brans, binding values increased strongly with increasing pH in the quantitative order rice bran > coarse wheat bran > fine wheat bran > rye bran > oat bran. The solubility profiles indicate that in the cases of rye, wheat, and rice bran phytate accounts for 70-82% of their total calcium-binding capacities. The results suggest that dietary fiber makes no important contribution to calcium binding, except for soy and oat brans. Oxalate plays only a minor role in calcium binding by brans.  相似文献   

20.
Residual bran on milled rice is directly related to its quality. This study proposes a method to measure the residual bran patterns on a single rice grain by using hyperspectral imaging (HSI). HSI is a sensing technique that combines both spatial and spectral information and may be used for chemical compound identification and quantification. In this study, HSI was applied to assess rice bran residue nondestructively. In the experiment, rice samples were milled and scanned with an HSI system. Afterward, the rice samples were dyed to enable the residual bran to be identified with optical microscopy and image processing algorithms. Classifiers were then developed to predict the rice bran residue by using the HSI measurements as inputs. The predicted images were compared with the micrograph images for classifier performance evaluation. The proposed approach can estimate the residual bran distribution on milled rice surface with an accuracy of 93.5%.  相似文献   

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