Research On Preparation & Application Of Water Treatment Agent With Orange Peel Residues

The water treatment agent from orange peel is prepared by chemical method and microwave method, and its adsorption characterristics are researched in this paper.The research results indicates, the production with chemical method has good adsorption capability to Cr(Ⅵ). The influences of activation agent concentration, carbonization temperature and carbonization time on adsorption capacity are getting weaken to turn, and the reasonable condition of preparing adsorption is following: orange peel residue soaked 12h in 10% sulphuric acid solution and carbonized 2.5h at 110℃. The specific surpace area (BET) and iodine value of this sample is respectively 378 m2/g and 408.5 mg/g, and contains 3.94% ash. The physical properties of production that is made by microwave are poorer than that of chemical method. The specific surpace area (BET) was 285 m2/g, and its iodine value was 376 mg/g, but the ash content is only 2.59%.The absorbent is used to hold wastewater-containing chromium. The influences of temperature, solution pH and contact time on adsorption speed and equilibrium time are tested, and the feasible conditions of adsorption to Cr(VI) were gained: the tempereture is 40℃and pH is 4.0 for 0.5g adsorbent when the K2Cr2O7 concentration is 200 ug/cm3and the volume is 50.00 cm3. The removing rate for 0.2g adsorbent may achieve 87.3% as the initial concentration of K2Cr2O7 solution was 60 ug/cm3, and it is discovered that the adsorption speed reduces along with the increase of time. Moreover, the adsorption characteristics to Cr (VI) accords with Bangham formula within 16h, the adsorption isotherm shows that Freundlich and Langmuir model can describe the adsorption to Cr (VI) when the concentration of K2Cr2O7 solution was 60μg/cm3 to 200μg/cm3, and its maximal amount adsorbed was 24.92mg/g. When the concentration of K2Cr2O7 solution was less than 140μg/cm3, the process is described by Freundlich model, the linearity correlation coefficient R2 is 0.995, and 1/n was 0.189. Thus, it is concluded that the adsorbent to Cr(Ⅵ) is effective.