| The continuous development of offshore oil and the widespread use of antibiotics have not only brought great harm to the marine environment,but also caused damage to the offshore aquaculture environment.Biomass resources are widely used in the removal of pollutants in the environment due to their abundant reserves and biodegradability.In view of the above-mentioned environmental problems,in order to achieve the efficient utilization of biomass resources,this topic took biomass resource loofah as the research object,and prepared three different loofah composite materials to explore their removal effect on organic pollutants.The main research results are as follows:（1）The loofah-chitin aerogel composite（MLCA）coated with methyltrimethoxysilane was synthesized using loofah as the skeleton material,and its microstructure was analyzed by various characterizations,and benzene series was selected as the representative organics,evaluating the adsorption capacity of MLCA for water-soluble components in oil spills.The adsorption experiment of benzene(100 mg·L-1)showed that the introduction of MTMS and aerogel increased the adsorption rate of benzene by about 23%compared with loofah（37.1%）.The adsorption kinetics followed the pseudo-first-order model and the adsorption isotherm model.It conforms to the Langmuir equation,and the thermodynamic parametersΔG>0,ΔH<0,ΔS<0.MLCA is a low-cost,green adsorption material with great potential for the removal of water-soluble benzene series.（2）ZIF-8@DLS composites were prepared by loading ZIF-8 nanoparticles on the surface of loofah by in situ synthesis with loofah as the carrier material.Characterization by FT-IR,XRD,XPS and SEM showed that ZIF-8 was successfully loaded on the surface of loofah.The adsorption capacity was increased by nearly 23 times as compared to MLCA.When the toluene concentration was 160 mg·L-1 and the material dosage was 0.5 g·L-1,the toluene adsorption capacity of ZIF-8@DLS was 153.6 mg·g-1.The adsorption of toluene by ZIF-8@DLS conforms to the pseudo-second-order adsorption kinetic model and Langmuir adsorption isotherm model.In addition,ZIF-8@DLS has a wide p H adaptation range（p H=3～11）,which can be applied to the adsorption and purification of organic pollutants in complex water environments.（3）In order to further degrade the adsorbed pollutant molecules,a semiconductor photocatalyst was loaded on the loofah.First,nano-ZnO was obtained by calcining ZIF-8 at high temperature,and then composited with BiOI to prepare BiOI/ZnO photocatalytic material.The photocatalytic degradation experiments of OFX showed that the optimum proportion of BiOI was 50 wt%.Secondly,BiOI/ZnO was loaded with loofah as a carrier to prepare BiOI/ZnO@luffa composites with adsorption-photocatalytic properties.The adsorption-photocatalytic experiments on OFX showed that when the dosage of BiOI/ZnO@luffa was 0.125 g·L-1and the concentration of OFX was 10 mg·L-l,the adsorption and removal rate of BiOI/ZnO@luffa for OFX was nearly 50%.The total removal efficiency of OFX after 180 min of UV irradiation was 88%.The recovery experiments showed that BiOI/ZnO@luffa had good stability and still maintained an OFX removal rate of 80%after 4times of use.Using loofah as a carrier,the cost is low and biodegradable,and the loss of photocatalytic materials in the recycling process is reduced,showing good economic practicability. |
PDF Full Text Request