[A Time-Spatial Resolvable High Speed Spectrograph and Its Application on Spectrum Measurement of a Nanosecond Pulsed Underwater Spark Discharge].

Recently, the diagnosis of the characteristic of pulsed underwater electrical discharges plasma have received significant attention. The measurement of a time-spatial resolved spectrum emitted from a single discharge pulse is important for understanding the time-spatial evolution characteristics of plasma generated by a pulsed high-voltage discharge in water. In this paper, a high speed time-spatial resolvable spectrograph for measuring the emission spectrum of a single electrical discharge pulse was reported. The high speed time-spatial resolvable spectrograph has been constructed by combining an ultrahigh-speed frame camera system with monochromator. Software for the spectral analyzing was also developed. The performance of the spectrograph was tested by using a 632.8 nm He-Ne laser beam at a 1 200 g x mm(-1) grating. The pixel resolution for 632.8 nm spectra is 0.013 nm. The instrument broadening for 632.8 nm spectra is (0.150 ± 0.009)nm when the exposure.time of the camera is 20 ns and the width of entrance slit is 0.2 mm, and increases with increasing the slit width. The change of exposure time of the camera has no influence on the instrument broadening, ensuring the spectrograph in a steady performance while adjusting the exposure time of the camera. With the spectrograph, time-spatial resolved spectra emitted from a single discharge pulse of an underwater nanoseconds spark discharge were obtained. It provides good data for investigating the time-spatial evolution characteristics of the discharge plasma during a single discharge pulse. The spectrograph developed in this work provides a technical approach for studying the time-spatial evolution characteristic of, plasma generated by a single electrical discharge pulse.

[Evaluation and choice of PCR-DGGE primers in analyzing the microbial community structure of activated sludge in traditional Chinese medicine wastewater].

In the study of traditional Chinese medicine wastewater, it was discussed for the effect of different sets of 16S rDNA universal primers on DGGE fingerprinting and microbial community diversity of aerobic and anaerobic activated sludge from one traditional Chinese medicine wastewater treatment. The genome DNA of activated sludge was isolated, and eleven sets of primers were used to amplify the four variable regions of 16S rDNA, the resolution of DGGE fingerprinting and community diversity was analyzed. The results indicated that community diversity with different sets of universal primers by DGGE was obviously different. Separated patterns of the V3 and V6-V8 regions were better than of V1-V3 and V3-V5. In the DGGE profiles, bands and diversity from V3 were most, bands and diversity from V3-V5 and V6-V8 were a little worse than those of V3. According to the length of targeted sequence and the resolution of DGGE fingerprinting, V6-V8 (B968F/B1401R) are recommended to be used to do the DGGE analysis. Mix I341F/I534R and B341F/B534R PCR product equally to make DGGE analysis can get more community diversity information.

Feasibility and simulation model of a pilot scale membrane bioreactor for wastewater treatment and reuse from Chinese traditional medicine.

The lack and pollution of water resource make wastewater reuse necessary. The pilot scale long-term tests for submerged membrane bioreactor were conducted to treat the effluents of anaerobic or aerobic treatment process for the high-strength Chinese traditional medicine wastewater. This article was focused on the feasibility of the wastewater treatment and reuse at shorter hydraulic retention time (HRT) of 5.0, 3.2 and 2.13 h. MLSS growth, membrane flux, vacuum values and chemical cleaning periods were also investigated. The experimental results of treating two-phase anaerobic treatment effluent demonstrated that the CODfilt was less than 100 mg/L when the influent COD was between 500-10000 mg/L at HRT of 5.0 h, which could satisfy the normal discharged standard in China. The experimental results to treat cross flow aerobic reactor effluent demonstrated that the average value of CODfilt was 17.28 mg/L when the average value of influent COD was 192.84 mg/L at HRT of 2.13 h during 106 d, which could completely meet the normal standard for water reuse. The maximum MLSS and MLVSS reached 24000 and 14500 mg/L at HRT of 3.2 h respectively. Membrane flux had maximal resume degrees of 94.7% at vacuum value of 0.02 MPa after cleaning. Chemical cleaning periods of membrane module were 150 d. A simulation model of operational parameters was also established based on the theory of back propagation neural network and linear regression of traditional mathematical model. The simulation model showed that the optimum operational parameters were suggested as follows: HRT was 5.0 h, SRT was 100 d, the range of COD loading rate was between 10.664-20.451 kg/(m3xd), the range of MLSS was between 7543-13694 mg/L.