Study On The Adsorption Of Aqueous Phthalate Ester (Dibutyl Phthalate) On Bamboo-Derived Biochar

In recent years, a lot of artificial syntheses of organic compounds were discharged into the environment with the rapid development of industry. Some of them have the endocrine disruption effect after been detected. More and more attention has been paied on this gradually and Endocrine Chemicals became a global social problem. Bamboo biochar is a new kind of adsorbent. High specific surface area and rich pore distribution structure make it possess excellent adsorption performance.Two kinds of partical bamboo biochars were selected to adsorb the typical endocrine disrupting chemicals dibutyl phthalate in this paper. The bamboo biochar samples were characterized by N2 adsorption. The BET surface area, pore volume and pore size distribution were analyzed.It was found that both of the bamboo biochars were mainly composed of micropore. The BET surface area and pore volume of the bamboo biochar after been activated were greatly optimized, having higher surface area and abundant pore size distribution. The adsorptive removal behavior of dibutyl phthalate (DBP) onto bamboo biochar (BC) has been investigated in tthis work through a series of batch experiments under different research conditions, such as adsorption time, initial DBP concentrations, various pH value, ionic strength, nature organic material concentrations and temperature. These factors were used to evaluate the influence of removing DBP from aqueous by bamboo biochars. The results indicated the DBP removal rate was getting slower and slower along with the increase of adsorption time. With the increase of the initial DBP concentration, the adsorption removal rate was decreased from 85.2% to 61.3% and 97.9% to 94.1% for two typles of bamboo biochars, respectively. The maximum DBP adsorption removal rate occurred at pH value 3, reaching 90.2% and 98.1% for two typles of bamboo biochars. The ionic strength has a positive influence on the DBP adsorbed onto BC, increasing ionic strength was found to increase the DBP removal rate in the present work. The existence of NOM can cause a slight reduction of the DBP removal rate. The rising temperature can also reduce the DBP adsorption capacity by bamboo biochar.Based on the adsorption theory, adsorption thermodynamics and kinetics natures of DBP on bamboo biochars were investigated. The results showed that the Freundlich isotherm was more applicable for the adsorption systerm. The adsorption of DBP on bamboo biochars was exothermic and spontaneous. The adsorption process can also be well described by the pseudo-second-order kinetics model and the intra-particle diffusion model.Thus, bamboo biochar, as an available, low cost and renewable biomaterial, can be efficiently used as an excellent adsorbent for the adsorptive removal of aqueous phthalate ester.