Adsorption Of Parabens From Aqueous Solution Using Modified Bagasse Biochar By CTAB

Parabens are a class of compounds that have been used for nearly 100 years for their anti-microbial and anti-fungal properties.They are mainly used as preservatives in foodstuffs,cosmetics and pharmaceutical drugs.Considered as emerging contaminants,Parabens may lead to the potential suspected adverse ecological or human health effects of these compounds.It has been reported that these compounds have weakly oestrogenic activity and reproductive toxicity.Biochar is a widely source of raw materials of new environmental functional material,which has abundant micropore structure and large specific surface area,can be used as high performance adsorbents,and has a strong adsorption capacity for organic pollutants.Biochar is produced from the biomass pyrolysis under limited or in absence of oxygen conditions.Due to its porous structure,biochar has been used in many studies as an impressive adsorbent to remove different pollutants from aqueous solution.In this paper,biochars,which are BC and MBC,obtained from bagasse were prepared under 400 degrees and made into the modified biochar by CTAB.Paraben removal from aqueous solutions via adsorption by biochars.Then applied the biochars to study the adsorption of the simulate ethyl paraben waste water.The biochars was tested for its ability to remove ethyl paraben from aqueous solution by batch static adsorption and dynamic column adsorption,and the mechanism of the adsorption process was determined.Several main conchisions of this study are as follows:(1)With increasing temperature,the biochars provided more hydrophobic surfaces,and promoted the point of zero charge from 8.52 to 9.73.In addition,alkaline conditions(pH=8-12)decreased the adsorption capacity significantly.Decrease of adsorption capacity also came along with an increase of ionic strength.Sorption isotherm of ethyl paraben onto biochars agreed well with Langmuir isotherm model,and the order of maximum adsorption capacities is MBC>BC.Adsorption kinetics is well described by the pseudo-second-order model,and the thermodynamics constants show that the adsorption processes are endothermic and spontaneous.(2)After the modification,C16H33(CH3)3N+-Br-was mainly adsorbed on the surface of biochars,and only a few of them entered into the biochar.Moreover,the adsorption behavior of modified biochar on EP was mainly caused by C16H33(CH3)3N+ on the surface of biochar and biochar adsorption sites,and the internal adsorption of C16H33(CH3)3N+had little effect.After 4 cycles of adsorption-regeneration test,the regenerated biochars still maintained 70%of their initial adsorption capacitie.(3)Through the dynamic adsorption experiments of biochar,the effect of bed height,initial ion concentration,feed flow rate and other operating parameters on the cadmium adsorption characteristics was studied to show that the dynamic adsorption effect of modified biochar adsorption of EP depended on the experimental condition.The higher the height of the packing layer was,the greater the flow rate was.The higher the initial concentration was,the less the penetration time was.The less the column consumption time was,but the lower the adsorption efficiency was.