Papers by Keyword: Ozone

Abstract: In this study, the micro-polluted water of a reservoir filled with Yellow River water in Shanxi was used as the raw water. The removals of chemical oxygen demand (COD_Mn), ammonia nitrogen, petroleum substances, and volatile phenol were investigated by ozone-activated carbon process. Results showed that ozone-activated carbon process had a good removal of the pollutants mentioned above. The optimum dosage of ozone for each pollutant was 2.0 mg/L, 2.5 mg/L, 3.0 mg/L, 3.0mg/L, with the corresponding removal efficiency of 59.36 %, 88.01%, 79.31%, and 88.16%, respectively. The treated water quality could meet the standards for Drinking Water Quality (GB5749-2006) in China.

Abstract: This paper reports a design proposal of a sonochemical setup for pesticide wastewater degradation. Multi-parameters obtained by multi-sensors of the setup were utilized to control experimental variables and analyze degradation effect. Based on the setup and method designed, degradation experiments of deltamethrin were set up. In the work, treatments using ultrasonic, ozone, and the combination of them were carried out respectively, and parameters including ultrasonic frequency, pH, electrical conductivity, temperature as well as mass were taken into consideration. Results indicated that deltamethrin could be degraded efficiently under the irradiation of 589 kHz US/O₃ combined and the degradation rate could reach 91%.

Abstract: In this study, three kinds of catalysts for ozone catalytic were fabricated and their effects on organic removal were investigated, moreover the influencing factors in manufacturing were investigated by orthogonal experiments. The prepared Cu/Al₂O₃, Mn/Al₂O₃ and Fe/ Al₂O₃ improved UV₂₅₄ removal of ozone by 12%, 3% and-2%, when ozone was combined with activated carbon filtration, the removal of UV₂₅₄ was improved by 16%, 14% and 8% respectively. Cu/Al₂O₃ was chosen as a model catalyst and its effluencing factors in preparation, including impregnation concentration, impregnation time and calcinations temperature, were analyzed in orthogonal experiments. The orthogonal experiments showed that impregnation time has the biggest effluence in catalytic effect, which followed by calcinations temperature and impregnation concentration.

Abstract: Night-soil pollution is a serious environmental and public health problem in highly populated and developing countries. Static and dynamic experiments were carried out to study the chroma and COD removal effect of night-soil sewage by ozone oxidation technique. The results show that, both the chroma and COD of night-soil sewage decrease with the growth of ozone dosage, and the chroma removal rate can be up to 90%, while the COD removal rate is less than 50%. The utilization efficiency of ozone decreases with the chroma reduction or the reactor diameter increasing. The appropriate diameter of ozonization reactor used in eco-friendly toilets is 150mm, and the optimal ozone dosage is 400mg/L.

Abstract: Comparative study on permanganate and ozone as pre-oxidation agents were performed on pilot scale with traditional drinking water treatment process, chemical oxygen demand (COD), total organic carbon (TOC), UV₂₅₄, turbidity, trihalomethane formation potential (THMFP) were examined at each reactor’s effluent. The results show that at pre-oxidation reactor, the total organic remained stable after by the two agents, while for UV₂₅₄, pre-ozonation has a removal rate of 34%, comparing that of 17% by permanganate. At the sedimentation process, 0.4 mg/L permanganate improves the removal rate of turbidity and COD by 0.99 % and 8.4%, respectively; while a positive COD removal of 11.8 % was achieved by 0.9 mg/L pre-ozonation, and an average of-10.08% turbidity removal was achieved at applied dosage (0.5, 0,9 and 1.5 mg/L), which can be made up for in the followed sand filtration reactor. Both permanganate and pre-ozonation show higher removal rate of THMFP for the finished water.

Abstract: The aim of this study was to investigate the ozone treating effects on wool scales and wool mechanical property through experiments and observation. For this purpose, a detailed investigation on the role of mechanical properties surfacing topography, changes in component and membrane structure were investigated. After this, a micro explanation was given to discuss the mechanism of wool shrinkage. For the scales is the element factor for shrinking, so this study is of great significance to the work of shrinkproofing.

Abstract: In order to control pesticide pollution, the degradation of dicamba in aqueous solution was investigated in a bubble reactor in laboratory using separate UV, separate O₃, O₃/UV systems. The experimental results show that UV has a synergistic effect on ozonation. The synergy factor of O₃/UV system is calculated to be 1.96. The degradation of dicamba follows pseudo-first-order kinetics. Considering that the composition of actual water is complex, chloride, nitrate, carbonate and bicarbonate ions, common ions appeared in actual water, were selected to add to reaction solution in O₃/UV system. Chloride and nitrite ions have inhibiting effect. Carbonate and bicarbonate ions have promoting effect. In O₃/UV system, different impurity ions have different influence on dicamba degradation with small amount addition.

Abstract: In the zinc hydrometallurgy process, iron is usually present in leach solutions and its elimination is a major operational problem. The first step of iron removal is iron oxidation by MnO₂, but this process have some disadvantages such as the cost is relatively high and decreased the current efficiency in the electro-winning stage. In this paper, a new iron oxidation process in zinc leaching solution by ozone oxidation was conducted and evaluated. The results showed that Fe²⁺ concentration decreased from 7.45 g/L to 0.51 g/L in 80min at pH 3. Oxidation of Fe²⁺ by O₃ is controlled by chemical reaction. O₃ dissolve rate, pH and initial iron concentration are key parameters for this process. Our finding indicated the potential application of O₃ oxidation in iron removal process of zinc hydrometallurgy.

Abstract: Silicon oxide thin film was formed using reaction of spin-coated dimethyl-silicone-oil and 5% ozone gas at low temperature of 300°C. Silicone oil is used for lubrication, insulation, and so on, and it is inexpensive and easy to deal with owing to its stability. FT-IR spectrum of the formed silicon oxide film was similar to that of the thermally oxidized film, and we hardly observed peaks of Si-CH₃ and C-H bonds originated in silicone oil. The Si-OH bonds in the film were observed. The Si-OH bond causes the degradation of the electric properties of the insulator. In order to remove the Si-OH bonds, the silicon oxide film was treated with an argon excimer light at room temperature. The wavelength of the light was 126 nm. The amount of Si-OH bond was drastically reduced by the UV annealing. The energy of the UV light is high and the value is 9.8 eV. The high energy light may cut the bond of Si-OH. Therefore, the amount of Si-OH bond could be reduced.

Abstract: Seedlings of Michelia macclurei, Cinnamomum camphora and Rhodoleia championii were placed in open-top chambers (OTC) with two ozonic treatments including E40 (nature air, 40 ppb) and E150 (150 ppb) and two water treatments. Physiological indexes such as chlorophyll, soluble sugar, soluble protein, proline, MDA and SOD of three seedling types were evaluated. With increasing experimental time, chlorophyll content generally decreased or remained steady, soluble sugar content increased followed by a decrease and SOD activity increased for the three seedling types in ozone treatment, drought treatment or ozone-drought intercross treatment. Contents of soluble protein and proline increased for the three seedling types in ozone treatment and drought treatment. The MDA content increased for M. macclurei and C. camphora in ozone treatment and drought treatment and for R. championii in the three stress treatments. Principal component analysis indicated that the resistance abilities of ozone, drought or intercross stress for the three seedling types was C. camphora seedlings > M. macclurei seedlings > R. championii seedlings.