Mao Guozhu

The denitrification of nitrate contained wastewater in a gas–liquid–solid three-phase flow airlift loop bioreactor

Denitrification of nitrified effluent with high concentration of nitrate, low COD in fertilizer plant was carried out in a 12-1 gas-liquid-solid three-phase flow airlift loop bioreactor, in which biological membrane replace the activated sludge. The influences of pH, temperature, C/N ratio, gas-liquid ratio and HRT on the removal of nitrate-nitrogen were investigated and discussed. The optimum operation conditions were obtained as pH value of 6.5-7.5, temperature of 20-35 °C, C/N ratio of 0.95-1, gas-liquid ratio of 62.5 and HRT of 2.5 h. Under optimum operation conditions, the average removal efficiencies of COD and NO x -N are higher than 93 and 96%, corresponding to the effluent concentrate of nitrate <20 mg/l and COD <40 mg/l. The radial and axial positions have little influence on the local profiles of COD and NO x -N.

THE SURFACE MODIFICATION OF ZEOLITE 4A AND ITS EFFECT ON THE WATER-ABSORPTION CAPABILITY OF STARCH-G-POLY (ACRYLIC ACID) COMPOSITE

The surface modification of Zeolite 4A using cetyl trimethyl ammonium bromide (CTAB) as a modifier via an ultrasonic method was carried out and the surface physicochemical properties measured. Response surface methodology (RSM) was developed with CTAB concentration, handling time, and handling temperature as variables, to help predict the performance of the modified zeolite under particular conditions. The influence of organic-modified surface treatment and of the amount of modified zeolite on the water-absorption capability of starch-g-poly (acrylic acid) hydrogel composites was also assessed. The results showed that the channels and skeleton structure of zeolite 4A were unchanged after organic modification by CTAB and the surface modification was effective. The results suggest that organic-modified zeolite 4A has improved the water-absorption capability.

Building fire rescue with evacuation management information system and its application

Building Fire Rescue with Evacuation Management Information System (BFREMIS) is established. And the evacuation model of BFREMIS was analyzed and presented in this paper. Based on the constructed network model, the evacuation of the teaching building in the university was analyzed by using the software EVACNET4. The analysis items included: the total evacuation time, the floor clear time, evacuation bottleneck, and the visual path of the evacuation on MAPGIS platform. BFREMIS is valuable in building safety assessment and building fire rescue.

LOCAL LIQUID SIDE MASS TRANSFER MODEL IN AIRLIFT LOOP REACTOR AND SELF-ASPIRATED REVERSED FLOW JET LOOP REACTOR

ABSTRACT Combining Higbies penetration theory and Kolmogoroffs theory of isotropic turbulence, a small-scale isotropic mass transfer model for the local liquid side mass transfer coefficients in a gas-liquid two-phase airlift loop reactor and a self-aspirated reversed flow jet loop reactor has been developed. Good agreement with the experimental data suggests a general applicability of the proposed model in these reactors.