Studies Of Magnesia Modification And Oily Wastewater Disposal

Adsorption has already been used widely in treating wastewater because it is simple, convenient and efficient. The exploitation of cheap and high effective sorbents has attracted the interests of many scholars. In this study, the light-burned magnesia was used as a raw material and was modified by microwave. Preparation, characteristics and regeneration of modified magnesia were investigated. Furthermore, the sorption behaviors for modified magnesia to adsorb oil form wastewater was studied as well. It promotes the use and benefits of magnesium in environment protection and oily wastewater treatment.The experiment covered proportion of magnesia and glycol, and desorption conditions about different export powers and operation times. The influences of factors on sorption capability of modified magnesia were measured by the removal rate of oil from wastewater. Results indicated the best condition that the proportion of magnesia and glycol of 2 to 1, export power of microwave of 560W, and operation time of 8 minutes. Sorption capability of magnesia after modification was much better than the raw material, so that, the amount of sorbents reduced obviously. More over, specific surface area of modified magnesia was more than to 2 times larger than the raw material.The paper researched the sorption behavior for modified magnesia to sorb oil from wastewater. Results of mono-factor experiment and orthogonal test proved that the optimum reaction conditions for light-burned magnesia to treat oily wastewater may be obtained with the addition of adsorbent about 7.5g/L, churning time of 60 minutes, churning rate of 150rpm and reaction temperature of 50℃. Modified magnesia depended little on pH and it could be used in broad pH area, that was 2 to 12. Speculation of adsorption mechanism proved that Langmuir adsorption dominated the reaction and went with Freundlich adsorption.The paper discussed elementarily that tradition heat regenesis and microwave regenesis on modified magnesia. Compared to tradition heat regenesis, microwave regenesis had the characters of high regenesis adsorption efficiency, quickly decalescence and short regenesis cycle. When modified magnesia exposed to air, it would be aging. However, calcination could solve the problem of hydration and resume its activity.