A new type of benzene adsorption material was prepared by using the airtight heat treatment method.This method can directly transform the organic impurities of the activated alumina waste into carbon with adsorption capability.The microstructure and carbon content of materials were characterized by scanning electron microscope(SEM),X-ray diffraction(XRD),BET(Brunauer Emmett Teller) surface area analysis and elemental analysis.The influences of heat treatment temperature on the properties of the composite materials were discussed.The benzene adsorption capability of the material was investigated.The experimental results show that the optimal heat treatment process condition is airtight heating at 400 ℃ for 2 h.The resulting sample has carbon mass fraction of 3.57%,specific surface area of 234.70 m 2 /g,pore volume of 0.41 m 3 /g,and average pore size of 6.59 nm.The samples show excellent benzene adsorption capability with an adsorption rate of 21.80%.
In this paper, the powdered activated carbon is taken as the main raw material to develop a new material of inorganic activated charcoal gel by using silicate cement as the gelling agent. The micro-structure of this material is characterized by XRD, BET, SEM, EDS and so on; and the adsorption and cyclic regeneration characteristics of formaldehyde on the material are primarily studied. The experimental results show that this material is an adsorbent on the basis of micropores distributed between 0.60-1.12 nm, with specific surface area of 452.86 m2/g, average pore size of 2.62 nm and total pore space of 0.30 m3/g. The samples have excellent formaldehyde adsorption ability with saturation adsorption of 268.00 mg/g; after 20 times of cyclic adsorption and desorption, the formaldehyde adsorption rate of the samples can remain 49% of the original value, showing good cyclic regeneration of the samples.
AlCl3,NH3·H2O,HNO3 and activated carbon were used as raw materials to prepare one new type of activated alumina-activated carbon composite material.The influence of heat treatment conditions on the structure and property of this material was discussed;The microstructures of the composite material were characterized by XRD,SEM,BET techniques;and its formaldehyde adsorption characteristic was also tested.The results showed that the optimal heat treatment temperature of the activated alumina-activated carbon composite material was 450 ℃,iodine adsorption value was 441.40 mg/g,compressive strength was 44 N,specific surface area was 360.07 m2/g,average pore size was 2.91 nm,and pore volume was 0.26 m3/g.According to the BET pore size distribution diagram,the composite material has dual-pore size distribution structure,the micro-pore distributes in the range of 0.6-1.7 nm,and the meso-pore in the range of 3.0-8.0 nm.The formaldehyde adsorption effect of the activated alumina-activated carbon composite material was excellent,much better than that of the pure activated carbon or activated alumina,and its saturated adsorption capacity was 284.19 mg/g.
A novel wastewater purification material was prepared by a hydrothermal method. It was mainly made from oyster shells with the merits of long service time, large surface area, high lead removal efficiency and excellent recyclable properties. The technological conditions were decided respectively based on the lead removal efficiencies. At pH = 5 and 30 ℃, for the wastewater with the initial concentration of Pb2+ to be 5 mg/L, adsorption time 24 h, and 1 mg to 40 mL of mass ratio between adsorbent and Pb2+, the maximum adsorption capacity can reach 0.19 mg/g. The lead removal material prepared by hydrothermal method has excellent recycle performance. The equilibrium adsorption capacity can get to 9.71 mg/g and the average Pb2+ removal rate is as high as 66.39%. After reusing for 60 times, the SEM observation shows that the hydrates of reticular formation is formed after hydrothermal modification, which provides a good attachment position for Pb2+, indicating the physical adsorption is dominant.
