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DTC型采出水净化剂研究进展概述 总被引:2,自引:0,他引:2
二硫代胺基甲酸盐(DTC)是一种高效、多功能采出水净化剂,它由二硫化碳与伯胺或仲胺反应生成二硫代胺基甲酸,然后再与碱反应而制备。其作用机理是与采出水中的铁或其它溶解金属反应形成絮体,絮体迅速聚结形成网状而包裹油,从而使油去除。DTC具有净化作用快,除油功效高,适用于分离、重力沉降和浮选等水处理过程。目前,国外DTC型冷水剂已发展到第三代。 相似文献
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王云 《中国环境管理干部学院学报》2012,22(2):68-72
研究了短时游离氯后转氯胺的联合消毒方法对大肠杆菌的灭活作用,并对其协同作用以及pH值和温度对协同作用的影响进行了探讨。结果表明:pH值在6.5~8范围内,温度不超过30℃时,短时游离氯后转氯胺的消毒方法对大肠杆菌的灭活具有协同作用,且随pH值的降低而加强,在低温下该方法的协同效果更加明显。 相似文献
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前言根据康尼反应原理制定的比色法广泛地应用于氰化物的微量测定。这个特殊反应先是由氧化剂将氰离子氧化成活泼的卤化氰,卤化氰打开吡啶环,生成共轭的戊烯二醛中间体,这个中间体与含有伯胺或活泼亚甲基的偶联剂偶合成有色物质。人们用不同的偶联剂,先后提出了吡啶—吡唑啉酮法、吡啶—联苯胺法和吡啶—巴比妥酸法等。吡啶—联苯胺法的优点是试剂稳定和易于配制,而试剂的强烈毒性和显色液的不稳定性是该法的致命缺点。由于吡啶有恶臭,石井等提出 相似文献
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A novel cellulose-based anion exchanger (Cell-AE) with tertiary amine functionality was synthesized by graft polymerization reaction of cellulose and glycidyl methacrylate using N,N′-methylene-bis-acrylamide as a crosslinker and benzoyl peroxide as an initiator, followed by dimethylamine (amination) and acid (HCl) treatment. The chemical modification was confirmed by infrared spectroscopy and CHN analysis. The anion exchanger was used in batch processes to study AS(V) adsorption in solutions. The operating variables studied were pH, contact time, initial As(V) concentration, sorbent mass, and ionic strength. The process was affected by solution pH with an optimum adsorption occurring at pH 6.0. Adsorption equilibrium was achieved within 1 h. Increasing ionic strength of solution negatively affected the arsenic uptake. The adsorption process performed more than 99.0% of As(V) removal from an initial concentration of 25.0 mg/L. The process of adsorption followed pseudo-second-order kinetics. The adsorption equilibrium isotherm data were analyzed using the Langmuir, Freundlich, Redlich–Peterson and Langmuir–Freundlich equations. The Langmuir–Freundlich isotherm described the adsorption data over the concentration range 25–400 mg/L. The adsorption mechanism appears to be a ligand-exchange process. A simulated groundwater sample was treated with Cell-AE to demonstrate its efficiency in removing As(V). The adsorbed As(V) ions were desorbed effectively by a 0.1 M NaOH solution. 相似文献
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Flores-Álvarez JM González I García-de la Rosa LA Mancilla-Peña F Reyes-Gómez J 《Journal of environmental management》2011,92(3):448-456
Carbon paste electrodes (CPEs) modified with a biosolid, two types of soils with different amounts of organic matter (OM), and two biocomposites (soils mixed with a biosolid) were used to assess and compare the Cu(II) ion retention properties of the organic matter contained in the samples. The accumulation of Cu(II) on the surface of the modified carbon paste electrodes (MCPEs) was performed under open-circuit conditions. When comparing the response of the MCPEs while assessing parameters such as pH, preconcentration time, and adsorption/desorption capacity, it was found that the reaction mechanism of the two soils is different between the soils and dissimilar from the biosolid; while the biocomposites show reaction mechanisms that are intermediate between those of the soils and the biosolid. This was proven with the use of infrared spectroscopy, since the FTIR spectra show similarities between the two soils and significant differences between the soils and the biosolid. 相似文献
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利用有机酸改性壳聚糖和交联法制备酸化壳聚糖载体,然后用改性壳聚糖载体固定漆酶。结果表明,甲酸、酒石酸改性壳聚糖的最适条件是壳聚糖与酸的量比分别为100/1(g/mol)、100/0.5(g/mol),戊二醛的浓度分别为1%、2%,缓冲溶液的pH分别为4.4、3.6,反应时间分别为3h、4.5h。两种酸改性的壳聚糖用于漆酶的固定,其酶活都有所提高,尤其用酒石酸改性的壳聚糖载体的效果最好,其酶活提高了57%。 相似文献
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In the present study, chemically modified Aleppo pine (Pinus halepensis Miller) sawdust was used for the removal of phosphate from water. Biosorbent preparation process included size fractionation, extraction
for surface activation, acid prehydrolysis, and treatment with urea. Sorption of phosphate ions onto biosorbent was studied
using the batch technique. The effect of different parameters such as contact time, adsorbate concentration, and temperature
was investigated. The adsorption kinetics data were best described by the pseudo-second-order rate equation, and equilibrium
was achieved after 40 and 80 min for modified and unmodified sawdust, respectively. The Langmuir and Freundlich equations
for describing adsorption equilibrium were applied to data. The constants and correlation coefficients of these isotherm models
were calculated and compared. The adsorption isotherms obey the Freundlich equation. The thermodynamic parameters like free
energy, enthalpy, and entropy changes for the adsorption of phosphate ions have been evaluated, and it has been found that
the reaction was spontaneous and endothermic in nature. The low value of activated energy of adsorption, 3.088–3.540 kJ mol−1, indicates that the phosphate ions are easily adsorbed on the sawdust. Results suggest that the prepared chemically modified
Aleppo pine sawdust has potential in remediation of contaminated waters by phosphate. 相似文献
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The calcination/carbonation cycle using calcium-based sorbents appears to be a viable method for carbon dioxide (CO?) capture from combustion gases. Recent attempts to improve the CO?/SO? uptake of a calcium-based sorbent modified by using rice husk ash (RHA) in the hydration process have succeeded in enhancing its effectiveness. The optimal mole ratio of RHA to calcined limestone (M(Si/Ca)) was adjusted to 0.2. The cyclic CO? capture characteristics and the SO? uptake activity of the modified sorbent were evaluated in a calcination/pressurized carbonation reactor system. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) spectrum of the sorbent were also taken to supplement the study. The results showed that the carbonation conversion was greatly increased for the sorbent with M(Si/Ca) ratio of 0.2. For this sorbent formulation the optimal operating conditions were 700-750 °C and 0.5-0.7 MPa. CO? absorption was not proportional to CO? concentration in the carbonation atmosphere, but was directly related to reaction time. The CO? uptake decreased in the presence of SO?. SO? uptake increased, and the total calcium utilization was maintained over multiple cycles. Analysis has shown that the silicate component is evenly or well distributed, and this serves as a framework to prevent sintering, thus preserving the available microstructure for reaction. The sorbent also displayed high activity to SO? absorption and could be used to capture CO? and SO? simultaneously. 相似文献
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Transesterification of a mixture of vegetable oils with methanol using metal oxide catalysts derived from snail shell (SS) for biodiesel production was investigated. The metal oxides obtained from calcined snail shells in the temperature range of 650°–950 °C and modified by loading different potassium salts were used as a catalyst in the process. The catalysts were characterized by FT-IR, XRD, SEM-EDS, XPS and TGA. Catalytic activities of developed catalysts were also tested by Hammet indicator method and ion exchange method. The best calcination conditions were observed at 850°C for 4 hours based on biodiesel yield. The KF loaded snail shell gave highest biodiesel yield of 98 ± 1% in a batch reactor with highest basicity (15.9 mmoles/g) and basic strength measured by Hammet method. The optimized reaction conditions were: reaction temperature 65°C, reaction time 3 hours, methanol to oil molar ratio 9:1 and catalyst concentration 3wt%. Leaching and reusability tests confirm the stability of the catalyst as it encounters only 3% of leaching and small changes in catalytic activity up to five runs in terms of biodiesel yield. 相似文献
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Lingmei Yang Pengmei Lv Zhongming Wang Zhenhong Yuan Wen Luo Huiwen Li 《International Journal of Green Energy》2017,14(9):784-791
A series of heterogeneous KF/CaO catalysts modified with transition metals (lanthanum, cerium, and zirconium) were prepared via wet impregnation method and applied to the trsansesterification process of waste cooking oil (WCO) as feedstock with methanol to biodiesel production. The structure, performance of the solid catalysts was characterized by X-ray diffraction (XRD), temperature programmed desorption of CO2 (CO2-TPD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The effect of methanol/oil molar ratio, 1reaction time, reaction temperature, catalyst amount, and stability was investigated. The results showed that 10 wt% of lanthanum, cerium, and zirconium improved the catalytic activity of KF/CaO catalyst. The maximum catalytic activity using the lanthanum doping of 10wt% on KF/CaO catalyst was reached 98.7% under the optimal reaction condition of methanol/oil molar ratio of 12:1, reaction for 1 h at reaction temperature of 65°C, and 4% (wt/wt oil) catalyst amount. In addition, the FAME yield of KF/CaO/La catalyst remained higher than 95% after 10 cycles. The promotional effect of lanthanum doping could be attributed to the enhancement of the basicity strength of KF/CaO catalyst and block the leach of Ca2+ in the transesterification reaction. 相似文献