Study on Catalytic Oxidation, Flocculation and Sedimentation of Acidizing and Fracturing Wastewater

The acidizing and fracturing waste fluid in a wellsite in northern Shaanxi was treated by catalytic oxidation and flocculation precipitation. It investigated the effect of different coagulants and their dosage and the wastewater pH on coagulation precipitation. As for chemical oxidation experiment, it investigated the effect of oxidant dosage and reaction time on its treatment effect. The results showed that when 30% hydrogen peroxide (volume percentage) was added at the dosage of 0.3% and oxidized for 50 min, the pH was adjusted to 7.5 and 350 mg/L polyaluminum chloride (PAC) and 4 mg/L polyacrylamide were added (PAM); after processing the waste liquid, total iron, chemical oxygen demand (COD), chromaticity, and average corrosion rate were reduced from 252.75 mg/L, 3427.50 mg/L, 624.15°, and 0.1226 mm/a to 0.12 mg/L, 275.18 mg/L, 125° and 0.0217 mm/a, respectively; effective removal of iron and color, reduced COD, and controlled corrosion was achieved.

A Study on the Removal of Fluorescent Whitening Agent by Pretreatment Ozone Oxidation for MBR Process Application

In this study, ozone oxidation experiment was carried out for the removal of fluorescent whitening agent which is widely used in textile dyeing and paper industry. The stilbene fluorescent whitening agent has been industrialized since the earliest, and the amount of current production is the highest. Due to the characteristics of the fluorescent whitening agent that cannot be removed by conventional wastewater treatment methods, the fluorescent whitening agent in wastewater treatment has difficulty in using as recycled water in the process. Pre-treatment ozone oxidation experiment was conducted prior to the introduction of Membrane Bio Reactor (MBR) treatment process by converting biodegradable materials into biodegradable materials. The removal efficiencies of fluorescent whitening agents, a diaminostilbene disulfonic acid derivative by ozone oxidation were evaluated by UV254 Scan, COD, T-N and color using a synthetic wastewater sample (COD=433.0 mg/ℓ) and paper and paper mill wastewater (COD=157.2 mg/ℓ).

Preserving Climacteric Fruits by Ripening Hormone Oxidation using nano-KMnO4 Confined within Nanoporous Carbon

Climacteric fruits naturally can be over-ripened because of ripening hormone composed of ethylene gas. Removal of ethylene gas by potassium permanganate (KMnO4) has successfully preserved the fruit, but there is still a room for improvement through nano-confinement process. This study was conducted to compare the ethylene oxidation rate and fruit preservation ability of KMnO4 and nano-KMnO4. Ethylene oxidation experiment was conducted in a gas-tight vial filled with ethylene gas (~20%v) and either KMnO4 or nano-KMnO4. Ethylene gas concentration inside the vial was periodically measured using gas chromatography (GC). The result revealed that ethylene oxidation rate by nano-KMnO4 is higher than KMnO4. The ethylene oxidation rate kinetic was modeled with a gas-solid reaction model, which is fundamentally more accurate than first-order reaction model. Fruit preservation experiment was conducted in sealed containers filled with banana (Musa acuminata) samples and either KMnO4 or nano- KMnO4, and stored at room temperature. The result revealed that banana preservation duration by nano-KMnO4 is remarkably longer than KMnO4, where unpreserved fruit was ripened after 7 days and fruit preserved by KMnO4 and nano-KMnO4 were ripened after 13 and 16 days respectively.

Effect of graphene oxide coatings on the structure of polyacrylonitrile fibers during pre-oxidation process

In this paper, GO is mainly applied in the pre-oxidation experiment process of PAN fibers, and the exothermic heat in the PAN fiber pre-oxidation process is taken away by the GO with super-high thermal conductivity to accelerate the pre-oxidation progress.

Active iron bound to SOM catalyzes the oxidization of alkanes in soil by H2O2

To explore the oxidation effects and mechanisms for the oxidation of alkanes by H2O2 in a Fenton system catalyzed by two types of iron bound to soil organic matter (Fe-SOM) in crude oil-contaminated soil, an oxidation experiment was performed in active Fe-SOM and Fe-SOM systems.

Improvement and Evaluation of Copper Oxidation Experimental Procedure for the Introduction of the Law of Definite Proportion

In Science classes, students usually learn about the law of definite proportions by the oxidation of copper. However, common procedures usually do not lead to proper results. This leads to confusion among the students because their experimental results do not fit to the theoretical values. Therefore, we invented a new procedure for this experiment to improve the introduction of the law of definite proportions. The new procedure can also be done by the students, it is done within 15 minutes and provides theoretical data written in the textbook. To evaluate this improved procedure, we let 8th year students (n = 133) do the copper oxidation experiment in the traditional and the improved way. The oxidation ratio doing the improved method was 98%, while the traditional way was only 55%. Student's individual feedback indicates that the new method might be able to improve the understanding of the law of definite proportions.