鸡粪生物炭对萘的吸附性能研究

Adsorption of naphthalene by chicken manure-derived biochar

以鸡粪为生物质原料,采用热分解法在管式炉中氮气氛围下分别于300、500、700℃温度下及在马弗炉中限氧500℃温度下制备生物炭,采用XRD、SEM和FTIR等对所制备的鸡粪生物炭进行表征,研究不同条件下所制备的鸡粪生物炭对萘吸附特性的影响,并探讨鸡粪生物炭对萘的吸附机理。结果表明,鸡粪生物炭具有凹凸不平、不规则表面的无定形炭结构,表面具有—COOH、—OH等多种含氧官能团;随着热解温度的升高,萘在鸡粪生物炭上的吸附量先减小后增加,其中,在700℃热解温度下制备的鸡粪生物炭对萘的吸附量最大;鸡粪生物炭对萘的吸附过程主要为化学吸附,而且是多层吸附,其中,700℃热解温度下制备的鸡粪生物炭对萘的吸附机制主要是疏水作用,而300℃热解温度下制备的鸡粪生物炭对萘的吸附机制主要为分配作用。

With chicken manure as the raw material,biochar was prepared by pyrolysing method at temperatures of 300,500 and 700℃ under the protection of the nitrogen atmosphere of a tube furnace and at temperature of 500℃ with limited oxygen in a muffle furnace.The chicken manure-derived biochar prepared were characterized by XRD,SEM and FTIR.The effects of different chicken manure-derived biochars on naphthalene adsorption performance were researched.The adsorption mechanism of chicken manure-derived biochar was also discussed.The results show that the chicken manure-derived biochar has an uneven carbon structure with uneven and irregular surfaces,and has various functional groups such as—COOH,—OH on the surface.With the increase of pyrolysis temperature,the adsorption capacity of chicken manure-derived biochar on naphthalene decreases first and then increases.The maximum adsorption capacity is had by chicken manure-derived biochar prepared at 700℃ pyrolysis temperature.The adsorption of naphthalene by chicken manure-derived biochar is mainly chemical adsorption,and also multilayer adsorption.Hydrophobic interaction is the main mechanism for the adsorption of naphthalene by chicken manure-derived biochar prepared at 700℃ pyrolysis temperature,while distribution effect is the main mechanism for the adsorption of naphthalene by chicken manure-derived biochar prepared at 300℃ pyrolysis temperature.