[Removal of mixed waste gases by the biotrickling filter].

A biotrickling filter (BTF) was designed for treating mixed waste gases, which contained hydrogen sulfide (H2S), tetrahydrofuran (THF) and dichloromethane (DCM) at the start-up and steady states. The removal efficiency of H2S and DCM could maintain about 99% and 60%, respectively, and the removal efficiency of DCM was reduced from 90% to 37% with the shortening empty bed retention time (EBRT) form 50 to 20 seconds when the inlet concentrations were 200, 100, 100 mg x m(-3) of H2S, THF, DCM, respectively. In the theoretical study, the biodegradation efficiency of contaminants was H2S > THF > DCM by analyzing the Michaelis-Menten Dynamic model.

[Mechanism of catalytic ozonation for the degradation of paracetamol by activated carbon].

The degradation of paracetamol (APAP) in aqueous solution was studied with ozonation integrated with activated carbon (AC). The synergistic effect of ozonation/AC process was explored by comparing the degradation efficiency of APAP in three processes (ozonation alone, activated carbon alone and ozonation integrated with activated carbon). The operational parameters that affected the reaction rate were carefully optimized. Based on the intermediates detected, the possible pathway for catalytic degradation was discussed and the reaction mechanism was also investigated. The results showed that the TOC removal reached 55.11% at 60 min in the AC/O3 system, and was significantly better than the sum of ozonation alone (20.22%) and activated carbon alone (27.39%), showing the great synergistic effect. And the BOD5/COD ratio increased from 0.086 (before reaction) to 0.543 (after reaction), indicating that the biodegradability was also greatly improved. The effects of the initial concentration of APAP, pH value, ozone dosage and AC dosage on the variation of reaction rate were carefully discussed. The catalytic reaction mechanism was different at different pH values: the organic pollutions were removed by adsorption and direct ozone oxidation at acidic pH, and mainly by catalytic ozonation at alkaline pH.

[Studies on the degradation of paracetamol in sono-electrochemical oxidation].

A novel lead dioxide electrodes co-doped with rare earth and polytetrafluoroethylene (PTFE) were prepared by the electrode position method and applied as anodes in sono-electrochemical oxidation for pharmaceutical wastewater degradation. The results showed that the APAP removal and the mineralization efficiency reached an obvious increase, which meant that the catalytic efficiency showed a significant improvement in the use of rare-earth doped electrode. The effects of process factors showed that the condition of the electrode had the best degradation efficiency with doped with Ce2O3 under electrolyte concentration of 14.2 g x L(-1), 49.58 W x cm(-2), 50 Hz, pH = 3, 71.43 mA x cm(-2). The APAP of 500 mg x L(-1) removal rate reached 92.20% and its COD and TOC values declined to 79.95% and 58.04%, the current efficiency reached 45.83% after degradation process for 2.0 h. The intermediates were monitored by the methods of GC-MS, HPLC, and IC. The main intermediates of APAP were p-benzoquinone, benzoic acid, acetic acid, maleic acid, oxalic acid, formic acid etc, and the final products were carbon dioxide and water. The goal of completely degradation of pollutant was achieved and a possible degradation way was proposed.

[Preparation and electro-catalytic characterization on La/Ce doped Ti-base lead dioxide electrodes].

Ti-base lead dioxide electrodes (Ti/PbO2) doped with rare earth La, Ce were prepared by the electrode position. The surface morphology and crystal structure of the electrodes was analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), the results showed that, microstructure and crystal orientation of electrode surface changed after doping rare earth La, Ce, which made the electrode surface more dense and uniform. The electrochemical properties of the electrodes were tested by linear sweeping (LS) and cyclic voltammogram (CV), the experimental results show that, La, Ce doping improved the electrode overpotential of oxygen evolution and the peak current density, promoted the catalytic performance of the electrode. Different doping amount of modified electrodes were used to degrade methylene blue simulative dyeing wastewater, the results showed that, electrodes doped La and Ce respectively 8.0 g x L(-1) and 5.0 g x L(-1) have the best degradation efficiency and catalytic activity, for example, the removal of MB and its COD respectively researches 83.85%, 79.95% and 79.18%, 76.21%. The possible degradation pathways and mechanisms were also discussed.

[Effects of shikonin on the proliferation and apoptosis of HL-60 cells].

OBJECTIVE: To explore the mechanism of shikonin for inducing the apoptosis of human promyelocytic leukemia cell HL-60. METHODS: The effects of shikonin on the HL-60 cell proliferation were detected using MTT. The apoptosis rate was analyzed by Annexin-V/PI double staining. The expression level of the bcl-2 gene was detected using semi-quantitative reverse transcriptase PCR (RT-PCR), thus analyzing the correlation between the bcl-2 expression level and the apoptosis of HL-60. RESULTS: Shikonin could inhibit the proliferation of HL-60 cells with the concentration range of 1-8 microg/mL in a time- and concentration-dependent manner. Two microg/mL shikonin could induce the apoptosis of HL-60 cells in a time-dependent manner. The expression level of bcl-2 was obviously down-regulated at 2 microg/mL shikonin. CONCLUSIONS: Shikonin could induce the apoptosis of HL-60 cells. Its mechanism was correlated with down-regulation of the expression level of bcl-2.

Synergetic effects for p-nitrophenol abatement using a combined activated carbon adsorption-electrooxidation process.

A novel fluidized electrochemical reactor that integrated advanced electrochemical oxidation with activated carbon (AC) fluidization in a single cell was developed to model pollutant p-nitrophenol (PNP) abatement. AC fluidization could enhance COD removal by 22%-30%. In such a combined process, synergetic effects on PNP and COD removal was found, with their removal rate being enhanced by 137.8% and 97.8%, respectively. AC could be electrochemically regenerated and reused, indicating the combined process would be promising for treatment of biorefractory organic pollutants.