Preparation And Appilication Of Cellulose Membrane Prepared From Solidago Canadensis

In1935, Solidago Canadensis was introduced into our country (Shanghai, Nanjing) as garden plants. After a long period of latent, in the late1980s, it spreaded in more than10coastal provinces and cities. In this paper Solidago Canadensis was used as the raw material to produce cellulose pulp, cellulose diacetate and cellulose acetate membrane. Characterizations, performance testings, wastewater treatment of products were studied at the same time. It was an effective way to control and manage this invasion plant when getting the products. The main contents of this study include several parts as follows:(1) Used cerolipoid determination of ramie standard to measure Solidago Canadensis component content. The result showed that, in Solidago Canadensis sterm, the cellulose content was46.29%, the hemicellulose content was22.28%, the lignin content was19.44%, the pectin content was0, the Water Solubles content was6.41%, the cerolipoid content was5.58%.(2) The mechanical disruption pretreatment and formic acid/hydrochloric acid pretreatment was used to prepare high purity, high degree of polymerization, high whiteness of cellulose pulp. The best process conditions were that the solid-to-liquid ratio of Solidago Canadensis and formic acid/hydrochloric acid was5:60(g/ml), the reaction temperature was90℃， the reaction time was75min, the H2O2concertration was11%, the bleaching temperature was80℃, the bleaching time was2.5h. The degree of polymerization of prepared cellulose pulp was713, the whiteness was87.3%ISO, the α-cellulose concertration was97.23%.(3) Solidago Canadensis L. was used as the raw material to prepare cellulose diacetate(CDA). Result shows that the best liquid-solid ratio during activation is1:7, the optimum dosage of catalyst and acetic anhydride respectively is9-11%and550%during acetified reaction, and the best AA concentration is70%during saponification. The prodction’s degree of substitution is2.31. The result of FT-IR and XRD analysis shows that the cellulose from Solidago Canadensis L. is acetylated partly, and the crystal linity of the production is decreasing.(4) The viability of Solidago Canadensis L. for cellulose acetate membrane production was tested. The result showed that the cellulose acetate membrane with desirable pure water flux and rejection ratewas obtained from cellulose diacetate by solution casting. The membrane showed favorable hydrophilic property so that it had good anti-pollution performance. The maximize pure water flux of the membrane was27.21ml/cm2·h and the maximize rejection ratewas80.39%. The results demonstrated that the membrane gotten from herbaceous plant:Solidago Canadensis L. had good performance of ultrafiltration.(5) In order to obtain high flux, high rejection rate of cellulose acetate membrane, we studied the preparation of SiO2/CA membrane by the method of immersion-precipitation phase transformation. The effect of the SiO2dosage on the structure and property of the membrane was tested by SEM, ATR-IR and UF experiments. The result showed that the number of pores was obviously increased after modified. When the addictive amount of SiO2was30wt.%, the water flux is23.7ml/cm2·h, while10.1ml/cm2·h without SiO2, the porosity is73.04%, and the rejection rate is80.3%, while83.1%without SiO2.(6) In order to solve the problem of poor result of single membrane technology, we studied the preparation of biochar produced from Solidago Canadensis L and its application on the pretreatment of ultrafiltration. The results showed that the biochar had many microporous. When the dosage of biochar is100mg/L, the the membrane flux decline velocity is lower than10%,the removal rate of TOC increased about50%; the removal rate of UV254increased about40%; the removal rate of turbidity increased about10%.