A TiO2/Ti rotating disk photoelectrocatalytic (PEC) reactor has been developed and successfully applied to degrade Rhodamine B (RB) and other dyes in textile effluents. The innovative concept behind the reactor design is to simultaneously perform two processes on one electrode. These two processes are (1) highly effective thin-film PEC, in which the upper half of the round disk photoanode was coated with a thin layer of wastewater and exposed to UV radiation in air; and (2) the conventional PEC, in which the other half of the disk was immersed in bulk wastewater and irradiated by the same light source. The average aqueous film thickness was about 75μm. The disk electrode was kept rotating at 90 rpm to continuously refresh the thin aqueous film for the upper side of the electrode and to promote the mass transfer of the target pollutants and the degradation products on the lower part of the disk. Using 20-150 mg L-1 RB solutions as a model system, thin-film PEC removed total color and total organic carbon (TOC) by 27-84% and 7-48%, respectively, within 1 h,muchhigher than 3-55% and 0-30% removal by conventional PEC under the same treatment conditions. Results also suggest that the thinfilm process was especially superior for treating high concentration solutions. Application of the rotating disk PEC reactor in industrial textile effluents showed a satisfactory result. The recycle experiments demonstrated excellent stability and reliability of the rotating disk PEC electrode. This study proposed a new concept for designing a PEC reactor applicable to industrial wastewater treatment.

A surfactant-bound monolithic stationary phase based on the co-polymerization of 11-acrylaminoundecanoic acid (AAUA) is designed for capillary high performance liquid chromatography (HPLC). Using D-optimal design, the effect of the polymerization mixture (concentrations of monomer, crosslinker and porogens) on the chromatographic performance (resolution and analysis time) of the AAUA-EDMA monolithic column was evaluated. The polymerization mixture was optimized using three proteins as model test solutes. The D-optimal design indicates a strong dependence of chromatographic parameters on the concentration of porogens (1, 4-butanediol and water) in the polymerization mixture. Optimized solutions for fast separation and high resolution separation, respectively, were obtained using the proposed multivariate optimization. Differences less than 6.8% between the predicted and the experimental values in terms of resolution and retention time indeed confirmed that the proposed approach is practical. Using the optimized column, fast separation of proteins could be obtained in 2.5min, and a tryptic digest of myoglobin was successfully separated on the high resolution column. The physical properties (i.e., morphology, porosity and permeability) of the optimized monolithic column were thoroughly investigated. It appears that this surfactant-bound monolith may have a great potential as a new generation of capillary HPLC stationary phase.

A novel solid-phase microextraction (SPME) setup, circulating cooling solid-phase microextraction (CC-SPME), is developed for determining organochlorine pesticides (OCPs) in water. The linearity area of this method is 0.5-120g/l, its RSD value is less than 10% and detection limit is in the low ng/l when it is used to detect-hexachlorocyclohexane, which is better than traditional headspace SPME (HS-SPME) and direct immersion SPME (DI-SPME) methods. The influence of factors such as pH, ionic intensity, adsorption time, and adsorption temperature were also investigated, respectively.

Electrosorption-enhanced solid-phase microextraction (EE-SPME) based on activated carbon fiber (ACF) was developed for determination of aniline in aqueous solution. A porous ACF, served as working electrode in electrosorption procedure, was prepared and attached to a commercial manual SPME device. Parameters affecting the adsorption efficiency were investigated. Under optimized condition, whichwas 400mVelectrosorption potential, 0.01M Na2SO4 electrolyte, pH 7, and electrosorption at 40℃ for 10min, the method exhibited wide linear range (0.1-100gL−1, R2=0.9980), good repeatability of adsorption (RSD 6.15%, n=6), and low detection limit (0.02 gL−1). The feasibility of the method was evaluated by analyzing lake water spiked with aniline. Comparison was made with direct immersion (DI) ACF-SPME without electrosorption enhancement. The proposed procedure was demonstrated to be a simple, fast, sensitive sample preparation method for determination of aniline in water samples.

A bio-anode reactor and a bio-cathode reactor were developed to investigate the microenvironments around anodes and cathodes and their effects on denitrification. With an applied current of 40mA, the oxidation-reduction potentials (ORPs) in the bio-cathode and bio-anode reactors were 100-200 mV lower and 50mV higher, respectively, than that in the control reactor (a normal bio-reactor). The cathode reaction enhanced denitrification and the anode reaction inhibited denitrification. At 40 mA, the denitrification rate in the bio-cathode reactor was 55.1% higher than that in the control reactor. At 75mA, the denitrification rate in the bio-anode reactor was just 33.5% of that in control reactor. Electric current of less than 20mA had no effect on the most probable number (MPN) of denitrifiers, but at 75mA, the MPN of denitrifiers decreased by 90% in the bio-anode reactor. In the bio-cathode reactor, the MPN of denitrifiers increased more than 100% for the lower ORP environment produced by a cathode reaction at 75mA.