Extraction And Modification Of Natural Polysaccharide Flocculant From Herbal Plants

Fresh water resources suffer from serious pollution,which has become a serious impact on the harmonious development in China’s main problem,and put forward reasonable and effective management measures and management means is the key to solve the problem of fresh water pollution in China.Sewage treatment is an important means to ensure China’s water resources,and the use of flocculant can effectively treat sewage.The following work were studied:(1)A polysaccharide flocculant was extracted from a herbaceous plant,and the best extraction temperature was 50 ℃,and the extraction time was 1.5 hr;(2)The storage time of the extracted polysaccharide flocculant was continuously monitored,and the polysaccharide content in the extracted polysaccharide flocculant decreased with time;(3)The natural polysaccharide flocculant was acidic and alkaline,and the acid-base change on flocculant flocculant was studied;(4)The natural polysaccharide flocculant was compounded with inorganic flocculant and organic flocculant respectively,and the flocculation effect of compound was studied;(5)The effect of alkalinity and etherification conditions on flocculating effect was investigated by the modification of grass residue after extraction of polysaccharidest,according to the experimental results,optimum etherification conditions as follows:the alkalization time is 1.5 hr,the alkali temperature is 50 ℃,he mass fraction of sodium hydroxide is 10%,the time is 2 hours,the etherification temperature is 40 ℃,and the amount of etherifying agent is 3 ml;(6)The extracted polysaccharide flocculant has good coagulant effect;(7)The effect of polysaccharide flocculant in alkaline condition is better than that in pickling condition,whether used alone or in combination with other flocculants;(8)A good flocculation effect was also obtained after the modification of grass residue by etherification.