Development Of A New Type Of Activated Carbon Monoliths With Inorganic Cementitious Materials For Water Purifier

In this paper, a new type of activated carbon monoliths with inorganic cementitious materials for water purifier was made by using powder activated carbon as main raw materials and inorganic cementitious materials as gelling agent. In the test, the influences of the selection of inorganic gelling agents, granulation technology and additive on the properties were tested, thus the optimal formula and process conditions of activated carbon monoliths prepared were decided; By discussing the influences of the autoclave curing temperature and time, thus the optimal system of steam pressure curing were decided. XRD, BET, SEM, EDS and other analytical methods were used to characterize the microstructures of materials. The formaldehyde adsorption characteristic and Cd2+ removal efficiencies of materials were tested; and the recycling method and effect of materials were also explored. At the same time, the preparation technology of inorganic gelling carbon filter material for water purifier was preliminary improved by using external wrapping granulation technology. Compared with the market water purifier filter materials, this method has many advantages, such as low costs, simple process, high strength, superior adsorption performance and recycling.Through a lot of experiments, we found that clinker was the optimal inorganic gelled materials and that the optimal processes of the samples by using clinker as gelling agent were as follows:firstly, the mass ratio of formula was controlled to be 70wt% of activated carbon 25wt% of clinker and 5wt% of silica powder, the optimum particle size of activated carbon monoliths could be controlled to between 16 and 20 mesh, and the optimum autoclave curing temperature was 195℃, holding for 6hrs. The corresponding properties of the optimal samples are listed below:iodine adsorption value is 551.72mg/g, compressive strength is 7.25MPa; carbon content is 58.48%; the porosity is 57.34%, water absorption is 69.42%, the permeable ratio is 1010mL/min; specific surface area is 452.86m2/g, average pore size is 2.62nm and pore volume is 0.30m3/g. The BET pore size distribution curves show that the sample is microporous adsorbent, the average pore size distribution of microporous are about 0.60 to 1.12 nm.XRD, SEM and EDS observation results show that inorganic gelling agents won’t affect the pore structure of activated carbon in the specimen.The more the gellants adding, the higher the compressive strength will be. The adsorption performance of the samples is proportional to the activated carbon content in the formula.Experiments show that the samples have excellent formaldehyde adsorption performance, their formaldehyde saturated adsorption capacities is 0.0148mg/g, and samples have good recycling effect on formaldehyde; The sample also has high Cd2+ removal efficiency, the average rate of cadmium is up to 83.8% after 20 cycle times adsorption.Outside wrapped granulation technology could further enhance the quality of filter, the optimal quantity of outside wrapped gelling agents(the mixture of tinker and silicon powder) is 10wt%, and compared with the performance of the optimal sample above:external wrapping process could improve the compressive strength, which is up to 8.25MPa, and also reduce the carbon loss.