Application of successive projections algorithm for variable selection to determine organic acids of plum vinegar

Visible and near infrared (Vis/NIR) spectroscopy was investigated to determine the acetic, tartaric and lactic acids of plum vinegar based on a newly proposed combination of successive projections algorithm-least squares-support vector machine (SPA-LS-SVM). SPA, compared with regression coefficients (RC), was applied to select effective wavelengths (EWs) with least collinearity and redundancies. Five concentration levels (100%, 80%, 60%, 40% and 20%) of plum vinegar were studied. Multiple linear regression (MLR) and partial least squares (PLS) models were developed for comparison. The results indicated that SPA-LS-SVM achieved the optimal performance for three acids comparing with full-spectrum PLS, SPA-MLR, SPA-PLS, RC-PLS and RC-LS-SVM. The root mean square error of prediction (RMSEP) was 0.3581, 0.0714 and 0.0201 for acetic, tartaric and lactic acids, respectively. The overall results indicated that Vis/NIR spectroscopy incorporated to SPA-LS-SVM could be applied as an alternative fast and accurate method for the determination of organic acids of plum vinegars.     

常减压蒸馏装置工艺防腐蚀技术进展

简述了原油蒸馏塔顶工艺防腐蚀的基础工艺措施,分析了各项工艺措施的利弊,阐述了从“一脱四注”向“一脱二注”的进展及新型高效电脱盐技术。     

Characterization of humified substances in organic fertilizers by means of analytical electrofocusing (EF): A first approach

The objectives of the study were to test the electrofocusing technique to determine its suitability as a method for the characterization of organic fertilizers from a qualitative point of view and identification of the organic matrix in an unknown fertilizer; no laboratory methods for this purpose are presently available.Analytical electrofocusing (EF) is shown to fulfill these objectives and may be easily adopted as a routine manual procedure. A solution of sodium hydroxide was chosen as the extractant because it allows comparisons between various types of humified materials and permits the evolution of organic matter to be followed during maturation of the fertilizer itself. The organic fertilizers considered included many nitrogen-rich waste materials, mostly of animal origin. They are divided into different groups according to origin and EF profiles.     

Ozonation of Several Organic Compounds Having Low Molecular Weight under Ultraviolet Irradiation

Ozonation of several low molecular weight organic compounds under ultraviolet irradiation was studied. Nine compounds were identified as reaction products of the ozonation of phenol which was promoted by the simultaneous use of ozone and ultraviolet irradiation. In the case of several organic compounds having carbon numbers from one to six, the removal of total organic carbon (TOC) by this simultaneous use was higher than by either the ozone oxidation method or the ultraviolet irradiation method for all the compounds.     

Effects Of Ozone On The Production Of Biodegradable Dissolved Organic Carbon (BDOC) During Water Treatment

This article deals with the oxidation effect of ozone on the increasing fraction of biodegradable organic matter with the “ozotest” method, a laboratory technique which simulates the effect of ozonation and allows a complete oxidation assessment. Ozone treatment was performed on river water samples and sand filter effluent samples. Ozone consumption, reduction of UV absorbance and BDOC formation were monitored with applied ozone doses from 0 to 10 mg/L and with contact times from 0 to 60 min. The BDOC formation was optimum at an applied ozone dose of 0.25-0.5 mg O₃ per mg DOC (contact time = 5 min) corresponding to apparition of traces of residual ozone and maximum UV reduction. Maximum ozone consumption, UV reduction and BDOC formation occurred simultaneously during the first two minutes of treatment. Concerning BDOC formation, applied ozone dose showed a greater effectiveness than contact time. For the same quantity of consumed ozone, a short contact time associated with a high ozone dose was preferable to a long contact time and a low ozone dose.     

Comparative Efficiency Of Three Systems (O3, O3/H2O2, and O3/TiO2) For The Oxidation Of Natural Organic Matter In Water

CATAZONE is a new process of heterogeneous catalytic ozonation in which water is ozonated in the presence of a solid catalyst composed of titanium dioxide. The efficiency of this O₃/TiO₂ system has been compared to the two well-known oxidant systems: ozone alone and ozone combined with hydrogen peroxide.

This comparison was undertaken on three models of natural organic compounds : an aquatic fulvic acid, a protein and a disaccharide. The first results showed the following order of relative efficiency: O₃/TiO₂ > O₃/H₂O₂ > O₃ as far as Total Organic Carbon (TOC) removal was concerned.     

The Chemistry of Water Treatment Processes Involving Ozone,Hydrogen Peroxide and Ultraviolet Radiation

Advanced oxidation processes are defined as those which involve the generation of hydroxyl radicals in sufficient quantity to affect water purification. The theoretical and (practical yield of OH from O₃ at high pH, 0₃/H₂0₂, O₃/UV and H₂O₂/UV systems is reviewed. New data is presented which illustrates the importance of direct photolysis in the O₃/UV process, the effect of the H₂0₂:0₃ ratio in the O₃/H₂O₂ process, and the impact of the low extinction coefficient of H₂O₂ in the H₂0₂/UV process.     

Oxidation by UV and Ozone of Organic Contaminants Dissolved in Deionized and Raw Mains Water

Organic contaminants dissolved in deionized pretreated and raw mains water were reacted with ultraviolet light and ozone. Ozone first was used for partial oxidation followed by ozone combined with ultraviolet radiation to produce total oxidation. The reduction of TOC level and direct oxidation of halogenated compounds were measured throughout the treatment process. The rate of TOC reduction was compared for ozone injected upstream and inside the reactor.     

Ozonation of Drinking Water: A Design Methodology

The formation of potentially carcinogenic organic halides has been shown to result from drinking water disinfection with chlorine. xidative treatment of organic halide precursors with ozone prior to chlorination has surfaced as an attractive technique for reducing the formation of these compounds. In addition to reduction of precursor levels, preozonation has been reported to effect other beneficial results in water treatment. This paper presents design methodologies to optimize the implementation of the ozonation process for water treatment applications. Pre-design considerations common to all ozonation design processes are discussed. Subsequently, design procedures for the ozone generation and contacting systems are reviewed.