Study On Adsorption Of Modified Water Hyacinth Cellulose To Heavy Metals

With the development of society and the increasing degree of industrialization,the discharge of sewage is also increasing significantly.A large number of sewage with poor treatment effect or even without any treatment is directly discharged,causing serious pollution of water bodies and seriously affecting people's health and the sustainable development of society.Among them,heavy metal pollution is a very serious problem.In this paper are common water hyacinth invasion species as raw material,using its contains a lot of cellulose,lignin,etc.The characteristics of effective components,chemical modification,preparation of three kinds of modified water hyacinth biological adsorbent,studied them for adsorption of heavy metal ions in water,the water common heavy metal ions include Cu²⁺and Cd²⁺,Pb²⁺and Zn²⁺,including the solution pH,temperature,time,and solid-liquid ratio on the adsorption.The results showed that the pH value of the solution had a great influence on the adsorption of Cu²⁺,Cd²⁺,Pb²⁺and Zn²⁺,and the pH value with the best adsorption effect was about 5.At the same time,the adsorption effect of the change of water temperature on heavy metal ions was studied.The results showed that the adsorption rate of the three modified water hyacinth biological adsorbents on the four metal ions decreased with the increase of temperature at 30⁶0?.The whole adsorption process is fast,and the equilibrium of ions can be basically reached within 20min.After the adsorption of heavy metal ions of water hyacinth can make use of nitric acid or hydrochloric acid elution regeneration,regeneration loss rate of water hyacinth cellulose,citric acid ester>chlorate modified water hyacinth>water hyacinth cellulose xanthate salt,citric acid water hyacinth cellulose ester and regenerated cellulose xanthate salt water hyacinth adsorption properties have no obvious drop,chlorate modified regenerated water hyacinth adsorption performance has a certain decline,but the decline is also small.Under the optimal conditions,namely pH between 4.5 and 5.5,temperature at 25?,solid-liquid ratio of 5g/L,the adsorption rates of cellulose citrate of water hyacinthus cellulose citrate to Cu²⁺,Cd²⁺,Pb²⁺and Zn²⁺were 23.87%,21.43%,26.64%and 19.36%,respectively.The adsorption rates of cellulose xanthate on Cu²⁺,Cd²⁺,Pb²⁺and Zn²⁺were93.14%,87.6%,93.33%and 88.24%,respectively.The adsorption rates of Cu²⁺,Cd²⁺,Pb²⁺and Zn²⁺to water hyacinth modified by chloride were 89.62%,84.38%,95.15%and 91.17%,respectively.Overall adsorption performance:water hyacinth cellulose xanthate>chloride modified water hyacinth cellulose>water hyacinth citrate,which water hyacinth cellulose citrate adsorption performance is poor,the preparation process is complex,takes a long time,the cost of regeneration is high.Water hyacinth cellulose xanthate has good adsorption performance for heavy metal ions,relatively simple preparation process,simple regeneration conditions,low loss rate after regeneration,and no significant decline in performance.The properties of water hyacinth modified by chloride are slightly weaker than that of water hyacinth cellulose xanthoate.The regeneration conditions are similar,and the properties of water hyacinth modified by chloride are not significantly reduced after regeneration.Moreover,compared with water hyacinth cellulose xanthoate,there will be no peculiar smell during preparation,which will not affect the production environment.Compared with other biological adsorbents prepared by other materials,water hyacinth cellulose xanthate and chloride modified water hyacinth has the advantages of excellent adsorption performance,wide material sources and relatively simple preparation process.