[en] The removal effects of main toxic organic pollutants in semi-coking wastewater by combined treatment process were investigated, while the genotoxicity relevance of wastewater from different treatment units were monitored by using Vicia faba bioassays. Results showed that 37 kinds of toxic organic pollutants were detected in the crude sewage, most of them were removed by physicochemical pretreatment, and the total concentration of organic pollutants decreased from 4826 mg L⁻¹ to 546 mg L⁻¹. After pretreatment, benzenes, phenols, quinolines and indoles in the wastewater were mainly removed by anaerobic/aerobic biodegradation, but the polycyclic aromatic hydrocarbons (PAHs) were removed mainly by advanced treatment, total concentration of toxic organic pollutants was lower than 0.5 mg L⁻¹ in the effluent. Genotoxicity evaluation results showed that the wastewater from coagulating sedimentation unit or foregoing had significant mutagenic properties. However, the micronuclei (MN) frequency (‰, which was calculated by observing 1000 cells) induced by wastewater after adsorption with modified coke was only 8.06‰, it was no significant difference compared with negative control (7.43‰). It could be concluded that the adsorption treatment was required for the safety of effluent, and the physicochemical-biochemical combined process in this study was suitable for high concentration semi-coking wastewater treatment. - Graphical abstract: Removal effects and genotoxicity relevance of the toxic organic pollutants in semi-coking wastewater by combined treatment process were investigated. Display Omitted - Highlights: • Main toxic organic matters in the semi-coking wastewater were identified. • Most of toxic organic matters in semi-coking wastewater were removed by extraction unit. • Benzenes, phenols, quinolines and indoles were removable at biochemical treatment phase. • Advanced treatment process was efficiency and necessary for PAHs reduction. • Adsorption treatment process was required for the safety of effluent.

[en] The fate of cyclic and linear volatile methylsiloxanes (VMSs) was evaluated in a wastewater treatment plant (WWTP) using constant water level sequencing batch reactors from Dalian, China. Influent, effluent, and sewage sludge samples were collected for seven consecutive days. The mean concentrations of cyclic VMSs (cVMSs) in influent and effluent samples are 1.05 μg L"−"1 and 0.343 μg L"−"1; the total removal efficiency of VMSs is > 60%. Linear VMS (lVMS) concentration is under the quantification limitation in aquatic samples but is found in sludge samples with a value of 90 μg kg"−"1. High solid-water partition coefficients result in high VMS concentrations in sludge with the mean value of 5030 μg kg"−"1. No significant differences of the daily mass flows are found when comparing the concentration during the weekend and during working days. The estimated mass load of total cVMSs is 194 mg d"−"1 1000 inhabitants"−"1 derived for the population. A mass balance model of the WWTP was developed and derived to simulate the fate of cVMSs. The removal by sorption on sludge increases, and the volatilization decreases with increasing hydrophobicity and decreasing volatility for cVMSs. Sensitivity analysis shows that the total suspended solid concentration in the effluent, mixed liquor suspended solid concentration, the sewage sludge flow rate, and the influent flow rate are the most influential parameters on the mass distribution of cVMSs in this WWTP. - Highlights: • A mass balance model for siloxanes was developed in sequencing batch reactor. • Total suspended solid in effluent has the most influence on removal efficiency. • Enhancement of suspended solid removal reduces the release to aquatic environment

[en] Highlights: • Metal work function was first used in hydrogen production by plasma reforming. • Metals with low work function as plate electrode can increase the hydrogen yield. • Energy efficiency was enhanced with low work function metal electrode. • The OES was used to analyze the process of hydrogen production. • Electron temperature and density were estimated. - Abstract: Hydrogen production from an ethanol solution by pulsed high voltage spark discharge was optimized by varying the material of plate electrode. It is the first time that metal work function has been used in hydrogen production by plasma reforming. With low work function metal plate electrode, both energy efficiency and hydrogen yield can be increased. The flow rate and the percentage concentration of hydrogen were achieved 1.3 L/min and 75% respectively while discharging with zinc plate electrode for hydrogen production, which is much better than traditional stainless steel electrodes at the same conditions. The analysis of emission spectra was also accomplished in this work. All the intensity of existing spectral lines showed a decline with higher work function metal as plate electrode, and H"· may be the key to the process of hydrogen production. Additionally, electron temperature and density were also estimated. Both of which were increased with lower work function metal plate electrodes. The electron temperature and density can reach 24,000 K, 7.5 × 10"1"8 cm"−"3 respectively.

[en] Highlights: • Hydrogen produced by pulsed spark discharge in ethanol solution was first studied. • A reactor for on-board hydrogen production was designed. • The influence of many factors on hydrogen production was studied. • Energy consumption was reduced to 1.69 kW h/m"3, better than many others. - Abstract: Hydrogen production from ethanol solution by pulsed high voltage spark discharge was investigated in this work. It is the first time that pulsed high voltage spark discharge in ethanol solution has been used for hydrogen production in the existing documents. A needle–plate reactor for on-board hydrogen production was also designed, which is small-scale and portable for automobiles. By optimizing the reaction conditions, the flow rate of hydrogen can reach 422 mL/min at peak voltage = 30 kV, discharge frequency = 30 Hz, electrode distance = 15 mm, initial ethanol concentration = 50%. It was also found that energy consumption of this method is about 1.69 kW h/m"3, which is better than most existing methods.

[en] The liquid-phase oxidation of phenol induced by plasma that was generated from direct glow discharges at the tip of a platinum anode in aqueous electrolyte was investigated. Various influencing factors such as the initial pH, the concentration of reactants and the catalytic action of Fe²⁺ were examined. The results suggest that the reaction is a pseudo-first-order kinetic reaction; the initial pH significantly affects the degradation velocity and ferrous ions displayed a remarkable catalytic effect on the oxidation. The major oxidation intermediates were identified with high-performance liquid chromatograph and ion chromatograph analysis. It was found that the degradation proceeded differently in the presence and absence of catalysts and consequently two degradation pathways were proposed

[en] Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that the degradation followed the first order kinetic law; Fe²⁺ had a remarkable catalytic effect on the removal rate of o-chlorophenol. In the presence of Fe²⁺, 2-CP underwent an exhaustive degradation, from which the major intermediates included o-dihydroxybenzene, p-hydroxybenzene, p-benzoquinone and carboxylic acids

[en] A simple gas-liquid diaphragm discharge reactor was designed and characteristics of the discharge and its application on decolorization of brilliant red B in an aqueous solution were investigated. The results showed that strong oxidizing agents such as ·OH and ·O radicals were generated. Average electron temperature of the discharge was 0.72 eV, 1.15 eV and 0.83 eV with air, oxygen and argon as the discharge gas, respectively. Solution pH and conductivity changed little when oxygen or argon was used as the discharge gas; however, these two parameters changed significantly when the discharge was performed in air. During the discharge treatment, the characteristic absorption peaks of brilliant red B gradually decreased where the decolorization followed the first-order kinetics. With 10 min of discharge, the decolorization of brilliant red B (30 mg L⁻¹) can reach 96%, 81% and 62% in the cases of oxygen, argon and air, respectively. The analysis of by-products showed that the brilliant red B molecule can be effectively destroyed in this discharge mode. (paper)

[en] One detecting method for young child being left on school bus based on the FSR (Force Sensing Resistor) sensor array was put forward and the alarm system was designed, which aimed at the frequent occurrence of safety accidents of young children being left on school bus in summer. Four square or circular FSR sensors were combined parallel together and placed on one seat of school bus as one module. Two strip shape FSR sensors were combined parallel together and placed on the ground between seats and on the aisle of school bus as one module. A certain number of modules placed on seats or aisle were combined parallel together and then connected with one input terminal of microcontroller. The resistance of each FSR module is inversely proportional to the pressure being applied. So, whether the young children were left on school bus alone or not can be detected by the resistance of the FSR module. To protect the FSR sensors were not damaged, the FSR sensors were wrapped in two soft silicone cushions. When the young children being left on the school bus alone was detected, the microcontroller would drive the speaker to play the alarm voice for warning the people nearby the school bus to recuse. The FSR sensors could detect the left child on the school bus accurately and the alarm system can warn timely. The detection method and the alarm system can be used for young children school bus to improving the safety of children riding. (paper)

[en] The degradation of aniline by plasma which was generated in a localized zone between an electrolytic solution and an anode was reported. The influence of the initial concentration, temperature, pH value and different mediums of aniline on the reaction kinetic was investigated. The results showed that temperature had a remarkable effect on the degradation of aniline, but the concentration had no appreciable effect on the degradation. There is a maximum elimination rate on the degradation of aniline in neutral condition. Iron (II) and other cations had a remarkable catalytic action on it. On the basis of the detailed analysis of the kinetic consideration, it was demonstrated that the oxidative degradation would be a first-order reaction. Some of the intermediate products of the degradation process in the solution were detected by HPLC

[en] Contact glow discharge electrolysis of some chloroanilines in sodium sulfate was investigated in different initial concentrations. Each of them underwent the dechlorination, deamination through oxidative degradation, and were eventually decomposed into hydrogen carbonate and carbon dioxide. It was testified that the chlorine atom and amidogen could be transformed into chloride ion and nitrite ion, respectively. Fe²⁺ has a remarkable catalytic effect on the degradation of them. On the basis of the detailed analysis of the intermediate products and kinetic behaviors, the reaction pathway was proposed, in which the attach of hydroxyl radical on the benzene ring of starting material might be a key step