Shewanella xiamenensis BC01 (SXM) was isolated from sediment collected off Xiamen, China and was identified based on the phylogenetic tree of 16S rRNA sequences and the gyrB gene. This strain showed high activity in the decolorization of textile azo dyes, especially methyl orange, reactive red 198, and recalcitrant dye Congo red, decolorizing at rates of 96.2, 93.0, and 87.5%, respectively. SXM had the best performance for the specific decolorization rate (SDR) of azo dyes compared to Proteus hauseri ZMd44 and Aeromonas hydrophila NIU01 strains and had an SDR similar to Shewanella oneidensis MR-1 in Congo red decolorization. Luria-Bertani medium was the optimal culture medium for SXM, as it reached a density of 4.69 g-DCW L(-1) at 16 h. A mediator (manganese) significantly enhanced the biodegradation and flocculation of Congo red. Further analysis with UV-VIS, Fourier Transform Infrared spectroscopy, and Gas chromatography-mass spectrometry demonstrated that Congo red was cleaved at the azo bond, producing 4,4'-diamino-1,1'-biphenyl and 1,2'-diamino naphthalene 4-sulfonic acid. Finally, SEM results revealed that nanowires exist between the bacteria, indicating that SXM degradation of the azo dyes was coupled with electron transfer through the nanowires. The purpose of this work is to explore the utilization of a novel, dissimilatory manganese-reducing bacterium in the treatment of wastewater containing azo dyes.

Heterogenous catalytic ozonation of 2-chlorophenol (2-CP) in the presence of gamma-alumina as a solid catalyst has been investigated in this research. It showed that the rate for degradation of TOC could increase from 21% to 43%. The pseudo-first reaction constants of 2-CP could increase from 0.8688 min-1 to 0.1270, increasing by approximately 40%. At the same time, the consumption of ozone was only half that of ozone alone. This research also explored the effects of the catalyst dosage, pH values and removal kinetics of 2-CP. In addition, three consecutive running with the same catalyst revealed insignificant reduction of the activity. Furthermore, the elimination of toxicity was evaluated by Microtox analysis. The detoxification was more stable and with good results.

This research is mainly to explore functional improvement by adding various kinds of metallic ions in the ozonation of 2-chlorophenol solution. During the experiment, various kinds of metallic ions (Pb+, Cu2+, Zn2+, Fe2+, Ti2+, and Mn2+) were added; it was found that the reaction rate increased in all cases. The best result was obtained by using manganese ions, followed by iron and titanium ions. At pH = 3 and 1 ppm Mn2+ concentration, the reaction rate was increased by three times. TOC removal rate was also increased from 12.6% to 38% at 60 min reaction time. Ozone self-decomposition with various kinds of metallic ions alone was tested. It was found the ozone self-decomposition coefficient is highly dependent on the reaction rate constant for ozonation of 2-chlorophenol. The improvement of reaction was relevant to the mechanism of reaction between ozone and metallic ions. Furthermore, the effect of adding manganese ions was studied. With the initial manganese concentration at 0-2 ppm, after gas exposure for 20 min the removal rate can be increased from 38% to 93%. TOC removal rate was increased from 11% to 38%. The reaction rate was improved more greatly at the initial pH = 3.

This research focused on the biological treatment of high-strength organic nitrogen wastewater, and presented the results from the nitrification and denitrification of an actual industrial wastewater using anoxic/aerobic process. The opto-electronic industrial wastewater often contains a significant quantity of organic nitrogen compounds and has a ratio over 95% in organic nitrogen (Org-N) to total nitrogen (T-N). In this study, a 2-stage anoxic/aerobic process was established and evaluated the efficiency of wastewater treatment. Raw wastewater from an actual TFT-LCD manufacturing plant was obtained as the sample for looking into the feasibility of opto-electronic industrial wastewater treatment. After toxicity identification evaluation (TIE) test of raw wastewater. the inhibition was related to organic nitrogen (TMAH, MEA) and unionized ammonia (free ammonia, NH3) with high pH. Therefore, pH control is important for biological treatment of high-strength organic nitrogen industrial wastewater. Besides. hydraulic retention time (HRT) and mixed liquor recycled rate (MLR) were controlled independently to distinguish between the effects of these two factors. Under suitable HRT ( > 1.7 d) and mixed liquor recycled rate (< 4Q), effluent of NH4-N. NO3-N + NO2-N, and COD can fall below 20 mg/L, 30 mg/L, and 80 mg/L. The anoxic/aerobic process removed 92-98% of the carbon source, and approximately 80% of TKN, 70% of T-N.

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