ORGANO CLAYS ARE POWERFUL ADSORBENTS FOR A WIDE VARIETY OF ENVIRONMENTAL APPLICATIONS. THE SURFACE PROPERTIES OF BENTONITE CAN BE GREATLY MODIFIED WITH A SURFACTANT BY SIMPLE ION-EXCHANGE REACTIONS. THIS IS FAVOURED BY VANDERWAALS INTERACTION BETWEEN ORGANIC SURFACTANT CATIONS AND THE REDUCED SOLVENT SHIELDING OF THE IONS IN THE INTERAMOLECULAR ENVIRONMENT. LARGE ORGANIC CATIONS (CATIONIC SURFACTANTS) OF THE FORM (CH3)3N+R, WHERE R IS AN ALKYL HYDROCARBON, OCCUPY THE EXCHANGE SITES OF THE BENTONITE CLAY AND HENCE THE SURFACE AREA IS INCREASED. RAW BENTONITE WAS MODIFIES WITH CETYLTRIMETHYL AMMONIUM BROMIDE TO FORM ORGANIC-MODIFIED BENTONITE. THE PRODUCT INVESTIGATED BY ELEMENTAL ANALYSIS, FT-IR, X-RAY DIFFRACTION. THE RESULTS CONFIRMED THE PRESENCE OF CETYLTRIMETHYL AMMONIUM BROMIDE ON THE SURFACE OF BENTONITE. REMOVAL OF AN AZO DYE ONTO MODIFIED BENTONITE FROM AQUEOUS SOLUTIONS WAS INVESTIGATED [1-3].THE kinetic DATA WERE ANALYZED USING PSEUDO-FIRST ORDERAND PSEUDO-SECOND-ORDER kinetic MODELS. THE Adsorption kineticS CAN BE PREDICTED BY THE PSEUDO-FIRST-ORDER MODEL.

SILICA BASED MESOPOROUS MATERIALS HAVE ATTRACTED THE ATTENTION OF MATERIAL SCIENTISTS DUE TO THEIR HIGH SURFACE AREA. SILICA BASED MATERIALS STRUCTURES HAVE BEEN SYNTHESIZED BY MAKING USE OF SEVERAL SOURCES OF SILICA, SUCH AS SILICON ALKOXIDES (E.G., TEOS, TMOS), SODIUM SILICATE, LUDOX, FUMED SILICA, WATER GLASS ETC [1-3]. BENTONITE, ONE KIND OF WIDELY USED CLAY MINERAL, IS COMPOSED WITH SILICATE LAYERS [4]. IN THIS RESEARCH SILICA BASED MATERIALHAS BEEN SYNTHESIZED FROM NATURAL BENTONITE. CETYLTRIMETHYL AMMONIUM BROMIDE AND POLYETHYLENE GLYCOL HAVE BEEN EMPLOYED AS SURFACTANTS. SILICA COMPOSITES OF SCB AND SCS WERE CHARACTERIZED BY INFRARED SPECTROSCOPIC ANALYSIS (IR), X-RAY POWDER DIFFRACTION (XRD). REMOVAL OF 2-PICOLINE FROM AQUEOUS SOLUTION BY SILICA BASED MATERIAL WAS STUDIED. INFLUENCE OF VARIOUS PARAMETERS SUCH AS CONTACT TIME AND PH WERE STUDIED.THE Adsorption kineticS WAS EXAMINED. TOW COMMON kinetic MODELS, PSEUDO-FIRSTORDER AND PSEUDO-SECOND- ORDER WERE EMPLOYED TO DESCRIBE THE Adsorption MECHANISM.THE RESULTS SHOW THE Adsorption PROCESS OF 2-PICOLINE BY FOLLOWS SECOND-ORDER kineticS.

HYDROXYAPATITE (HA, CA5 (PO4) 3OH) IN PARTICULAR, APART FROM BEING IMPORTANT MATERIAL IN BIOLOGY AND CHEMISTRY [1], IS KNOWN FOR ITS Adsorption PROPERTIES FOR DIFFERENT BACTERIA AND NO2 [2]. RECENTLY, INCREASING INTEREST IN THESE MATERIALS AS ADSORBENTS CAN BE NOTICED DUE TO THEIR IONIC EXCHANGE PROPERTY, Adsorption AFFINITY, BONDING WITH ORGANIC MOLECULES, LOW WATER SOLUBILITY, AND HIGH STABILITY UNDER BOTH REDUCING AND OXIDIZING CONDITIONS, AVAILABILITY AND LOW COST [3]...

IN THIS RESEARCH, Adsorption OF MALIC ACID FROM AQUEOUS SOLUTION WAS STUDIED. BY THIS MEAN, BAX ZEOLITE MENTION AS ADSORBENT. SO, ADSORBENT DOSAGE AND TEMPERATURE WERE SELECTED FOR STUDY OF BAX BEHAVIOUR IN THIS PROCESS.  THE kinetic DATA FITTED THE DIFFERENT kinetic MODELS; PSEUDO-SECOND-ORDER MODEL HAS THE HIGHEST AFFINITY ON EXPERIMENTAL DATA. THE MAXIMUM REMOVAL PERCENTAGE OF MALIC ACID WAS DETERMINED 80.62% FOR 0.5 (G) OF ADSORBENT AT 303 (K) ...

INTRODUCTION: WASTEWATER CONTAININGP -TOLUENESULFONIC ACID (P-TSA) PRESENTS A SERIOUS DISPOSAL PROBLEM FOR ITS TOXICITY AND BAD BIODEGRADATION AS WELL AS GOOD SOLUBILITY IN WATER [1]. Adsorption OF P-TSA ON CONVENTIONAL POLYSTYRENE RESIN (PS) ALSO RESTRICTS BY HYDROPHOBIC SURFACE OF ADSORBENT. TO IMPROVE THIS DRAWBACK, ONE MAY MODIFY PS BY POLAR FUNCTIONAL GROUPS [2]. HERE, THE PS WAS FUNCTIONALIZED BY DIETHANOLAMINE (DEA) IN A SIMPLE MANNER. THE OBJECTIVE OF THIS RESEARCH IS TO EVALUATE THE VARIOUS kinetic MODELS TO DESCRIBE THE Adsorption kinetic DATA GENERATED FROM P-TSA Adsorption ON DEA-MODIFIED PS (DEA-PS), AND ALSO FIND THE Adsorption MECHANISM AS WELL AS RATE-LIMITING STEP.