Studies On Adsorptive Property Of Sawdust Loaded With MnO₂ To Heavy Metal And Dye

Heavy metal wastewater and printing and dyeing wastewater which are the common of the wastewater,not only make the water worse,but also harm people healthy causing human and biology carcinogenic,teratogenic and mutagenic through other ways.At present,adsorption method is the most usual way to treat two waste water and paid attention by human,because of its high efficiency simple and inexpensive.The important part of the adsorption method is the adsorption material selection,and the usual of the adsorption method is forestry and agricultural residues.The forestry and agricultural residues is widely used,because of its distribution wide and inexpensive.The study based on the characteristic of potassium permanganate which is reacted MnO2 to the organic matter in the neutrality condition,and combining with potassium permanganate's strong oxidizing property,researches that the sawdust is modified.On the one hand,taking advantage of the MnO2 which contains lots of hydroxyl and the large specific surface area,on the another hand,take advantage of potassium permanganate's oxidation,so sawdust is able to be improved its number of functional group and its adsorption capacity.Combining with above effects,modified sawdust is improved the adsorption capacity of heavy metal and the dye.Finally,the study explores the mechanism and performance about the heavy metal and the dye,then gets to know the adsorption mechanism.The main research contents and the conclusion are described as follows.1.the research of the sawdustThe optimal modified conditions of one sawdust are researched.The modified methods employs orthogonal experiment,single factor(the size of sawdust,the concentration of potassium permanganate,solid-liquid ratio of potassium permanganate and sawdust,reaction time,reaction temperature).The result indicates:when the condition of sawdust size is 60-80,the concentration of potassium permanganate is O.lmol · L-1,the liquid-solid ratio of potassium permanganate liquor is 60:1,the reaction temperature is 30 ? and the reaction time is 5h,and the modified sawdust reach the maximum adsorption amount of Cu2+,Pb2+,Cd2+.When the condition of sawdust size is 60-80,the concentration of potassium permanganate is 0.2mol·L-1,the liquid-solid ratio of potassium permanganate is 60:1,the reaction temperature is 30 ? and the reaction time is 5h,the modified sawdust reach the maximum adsorption amount of acid red and methylene blue.2.The adsorptive property research of modified sawdust to Cu2+?Pb2+?Cd2+The adsorptive property research of modified sawdust to heavy metal,has been main exploring modified sawdust about the adsorptive property effect of pH,time and temperature;Adsorption situation of modified sawdust is investigated that adsorb heavy metal wastewater and printing and dyeing wastewater through changing different diameter high levels ratio.The result indicate:in the optimal conditions,through simulating Langmuir and Freundlich models,Langmuir equation has better described the adsorption behavior about modified sawdust adsorbing Cu2+?Pb2+?Cd2+,and the adsorption behavior accord with endothermic process,and the adsorption behavior accord with second order kinetics model,and the maximum adsorption amount is 73.86mg · g-1,98.04mg · g-1,and 90.33mg · g-1;with the diameter high levels ratio increasing,modified sawdust have more time to adsorb Cu2+?Pb2+?Cd2+,and the adsorbing ability obtain improvement.3.The adsorptive property of modified sawdust to acid red and methylene blueThe adsorptive property research of modified sawdust to acid red and methylene blue,the adsorbing result indicates:in the optimal conditions,through Langmuir and Freundlich models simulating the adsorbing way on modified sawdust to acid red and methylene blue,and the adsorption behavior accord with endothermic process,and the adsorption behavior of acid red and the adsorption behavior of methylene blue accord with second level mechanical model;the adsorbing capacity of acid red and methylene blue are 90.09mg · g-1 and 136.05mg · g-1,respectively.With the diameter high levels ratio increasing,modified sawdust have more time to adsorb and touch acid red and methylene blue,and the adsorbing ability obtain improvement.4.the preliminary mechanism research of modified sawdust to heavy metal wastewater and printing and dyeing wastewaterThe modified sawdust have better adsorbs Cu2+?Pb2+?Cd2+?acid red and methylene blue.Comparing with form of sawdust and modified sawdust,the size of sawdust is large,and its'surface is smooth.After potassium hypermanganate oxidizing,the surface of sawdust appears lots of fine particle,and its' surface become coarse.After adsorbing metal wastewater and printing and dyeing wastewater,the size of fine particle becomes large,and fine particle huddles together,and then form bridge role,so adsorption capacity of the the modified sawdust improves.Above effects,the modified sawdust is improved its' ability on treatment of heavy metal waste water and printing and dying waste water.After X-ray,the result indicates,modified sawdust obtains MnO2 and MnO(OH).After sawdust is modified,the broad peak of O-H and C=O enhance higher than the peak of sawdust,and the peak of modified sawdust which adsorbs heavy metal and dye,appear lots of burr peak.It indicates that the charge digits of the modified sawdust which adsorbs heavy metal and dye have changed,so improves the modified sawdust active group,and have changed the interior structure of modified sawdust,then improving the adsorptive property on sawdust to heavy metal and dye.