Brucite was employed as a natural adsorbent to explore its capacity of removing Cu2+ from an acidic solution. Experimental results indicate that brucite has a good neutralization capacity for acidity. The final pH of brucite suspensions rises to 3.47 and 7.91 respectively with initial pH of 1.49 and 2.09, and Cu2+ adsorption on brucite is 1.85% and 96.31% accordingly. The adsorption of Cu2+ on brucite increases sharply from 9.23% to 82.00% with increasing final pH from 5.01 to 6.75. It is concluded that the removal of Cu2+ from a brucite suspension is ascribed to the synergism of neutralization and adsorption capacities of brucite.

The effect and mechanism of the removal of Pb2+from an aqueous solution by using brucite as the adsorbent were studied.It was revealed that the increase in pH of brucite suspension, as a result of the release of magnesium hydroxide into the suspension,leads to a sharp rise of the adsorption amount of Pb2* on brucite. The synergism of buffering and adsorption capacities of brucite isresponsible for the removal of Pb2+from the aqueous solution. The coexistence of Cu2+ with Pb2+ causes a decrease of their adsorp-tion on brucite due to a competition for surface sites and brucit exhibits a higher adsorption capacity for Pb2+than for Cu2+. The per-centage adsorption of Pb2+ on brucite could reach 96.38%, 97.20% and 94.09% respectively with the initial pH of the suspension pHi=1.76 (initial Pb2+ concentration [Pb2]i=20gmol/L), 1.82 ([Pb2+]i=100gmol/L) and 1.84 ([Pb2+]i=500gmol/L). It was concludedthat brucite is a very efficient mineral adsorbent for Pb2+ removal from polluted acidic water.

Silica nanotubes were synthesized and used as enzyme immobilization carriers. The immobilization profiles were described by the adsorptionof lysozyme molecules from aqueous solution onto the hydrophilic silica surface. The driving force of the adsorption, structurechanges in the immobilized lysozyme molecules, and enzymatic activities were investigated. A study of the zeta potentials of silica withand without the immobilized lysozyme showed that there was an increase in the isoelectric point with the increase in the loading amount oflysozyme. FTIR spectra indicated that protein secondary structure was maintained well in the immobilized molecules. It was observed thatenzymatic activities first increased and then decreased with increasing surface coverage of silica nanotubes by lysozyme, which suggestedthat the overlap and aggregation of lysozyme molecules reduced enzymatic activities of the adsorbed lysozyme molecules at high surfacecoverage.

Porous hollow silica nanoparticles (PHSNP) with a diameter of 60-70nm and wall thickness of approximately10 nm weresynthesized by using CaCO3 nano-particles as the inorganic template. The characterization of PHSNP byTEM and BET indicatedthat PHSNP were uniform spherical particles with good dispersion, and had a specific surface area of 867m2/g. The as-synthesizedPHSNP were subsequentlyemploy ed as drug carrier to investigate in vitro release behavior of cefradine in simulated bodyfluid. UVspectrometryandTG analyses were performed to determine the amount of cefradine entrapped in the carrier. The BJH pore sizedistribution of PHSNP before and after entrapping cefradine was examined. Cefradine release profile from PHSNP followed a threestagepattern and exhibited a delayed release effect.

This paper presents a route of synthesizing nano-#brillar aluminum hydroxide (AH) by carbonation in a novel rotating packed bed (RPB)reactor and thermal hydrolysis. Carbonation of sodium aluminate (SA) is conducted by introducing CO2 into RPB at room temperatureto form AH gel which is subsequentlytreated bythermal hydrolysis for an optimum time of 30min and temperature of 85◦C to yieldnano-#brillar pseudoboehmite (PB) of 1-10nm in diameter and 50-300nm in length. Factors a<ecting carbonation process such as highgravitylevel, Gas/Liquid ratio and SA solution concentration are discussed. Experimental results reveal that operating conditions havesigni#cant in=uences on the properties of PB and the morphologyof PB is closelyrelated to the unit structure of AH gel. The as-preparedPB is characterized byTEM and XRD and compared with those synthesized byconventional Stirred Tank Reactor (STR). Reaction timein RPB shortens for approximatelya half compared with that in STR. It is proven that this route has obvious advantages over STR.