改性浒苔生物炭吸附水溶液体系中的Cd^(2+)

Adsorption of Cd^(2+) by Modified Enteromorpha Hupensis Biochar in Aqueous Solution

本研究运用NaOH浸渍法和合成硅源方法,采用NaOH和TMT-102(一种商用重金属捕捉剂)改性浒苔生物炭,研究两种改性产物NaOH-BC和TMT-BC的Cd^(2+)吸附效果。采用扫描电子显微镜(SEM)、傅里叶红外光谱仪(FTIR)、Brunauer-Emmett-Teller法(BET)测定比表面积等手段进行表征,探究了吸附时间、初始Cd^(2+)浓度、吸附剂投加量、初始溶液pH值、吸附温度、共存离子等因素对改性生物炭的Cd^(2+)吸附影响。结果显示未改性的生物炭表面光滑,NaOH-BC表面未见有明显的腐蚀痕迹,TMT-BC表面呈密集雪花状,且吸附后的两种改性生物炭比表面积相对于吸附前减小;改性和吸附处理后,生物炭的衍射峰位置发生了变化;改性浒苔生物炭的吸附属于均匀的单层化学吸附;在吸附300min,初始Cd^(2+)浓度为15mg·L^(-1),初始溶液pH值为6、吸附剂用量为0.8g·L^(-1)的条件下,上述两种改性生物炭对Cd^(2+)的最大吸附量分别为1.21和7.23mg·g-1。TMT-102负载改性法可有效提高浒苔生物炭吸附Cd^(2+)效果。

In this study,NaOH and TMT-102(a commercial heavy metal catcher)were used to modify enteromorpha biochar,and the adsorption of Cd^(2+)on both the modified products by NaOH-BC and TMT-BC were performed.The above two modified products were characterized by SEM,FTIR,BET and other means.Meanwhile,the effects of adsorption time,initial Cd^(2+)concentration,adsorbent dosage,initial solution pH,adsorption temperature,coexisting ions and other factors on the adsorption of Cd^(2+)by the modified biochar were investigated.SEM images showed that the surface of unmodified biochar was smooth,NaOH-BC surface had no obvious corrosion trace,TMT-BC surface was dense snowflake-like morphology,and the specific surface area of the two modified biochar after adsorption decreased compared to that before adsorption.FTIR analysis showed that the peak position of biochar changed after modification and adsorption.The results showed that the adsorption of modified enteromorpha biochar belonged to uniform single-layer chemical adsorption.Under the conditions of 300 min of adsorption time,15 mg·L^(-1)of initial Cd^(2+)concentration,6 of initial solution pH and 0.8 g·L^(-1)of adsorbent,the maximum adsorption capacity of the two modified biochar to Cd^(2+)was 1.21 and 7.23 mg·g-1,respectively.The results showed that TMT-102 could effectively improve the adsorption of Cd^(2+)by enteromorpha modified biochar.