Preparation, Characterization And Dye Adsorption Performance Of Carrageenan Activated Carbon

Due to the vigorous development of industry now,the dyes discharged in the production process have caused serious pollution,posing a huge threat to the environment and human health.Activated carbon is a commonly used adsorbent to deal with dye pollution.Due to cost issues,activated carbon gradually tends to be prepared from biomass and waste materials.Chondrus crispus is an economic seaweed,a raw algae produced by carrageenan,and is often used in various fields such as food and medicine.In this paper,Chondrus crispus was used as a raw material to prepare activated carbon and its adsorption performance was studied.On this basis,the special adsorption performance of activated carbon for triphenylmethane dyes and the dye adsorption performance of Chondrus crispus activated carbon after water washing?desalting?were also studied.?1?Preparation of Chondrus crispus activated carbon and dye adsorption characteristicsThe marine material Chondrus crispus was prepared into activated carbon by high-temperature carbonization.The surface morphology of Chondrus crispus activated carbon?CCAC?was characterized by scanning electron microscope?SEM?.In addition,CCAC was characterized by FTIR,Raman and BET analysis.Several factors affecting the performance of CCAC dye adsorption capacity were studied including the amount of adsorbent,pH of the dye,adsorption contact time,initial dye concentration and temperature.Experimental results show that CCAC can effectively adsorb methylene blue?MB?as a cationic dye,methyl orange?MO?as an anionic dye,oil red O?ORO?as an oil-soluble dye,and eight other dyes.The adsorption capacities of CCAC for methylene blue,methyl orange and oil red O are 132.81,49.48 and 33.17 mg g^?1,respectively.The adsorption process of CCAC conforms to the pseudo-second-order kinetic model.The adsorption isotherm fitting model of CCAC conforms to both Langmuir and Freundlich equations.CCAC is ideal for the recycling of three dyes,and it can maintain a removal rate of more than 89%after 5cycles.Finally,it is analyzed that the adsorption mechanism of dyes by CCAC mainly depends on the?-?interaction between activated carbon and dyes.?2?Special adsorption properties of Chondrus crispus activated carbon for triphenylmethane dyesThrough the research process of the adsorption of activated carbon on various dyes,it was found that there is an ultra-fast adsorption rate for triphenylmethane dyes?3 min>99%?.Three cationic dyes malachite green?MG?,fuchsin basic?FB?,anionic dye acid fuchsin?AF?three triphenylmethane dyes were selected.pH,initial dye concentration.The surface morphology of activated carbon was also characterized by scanning electron microscopy;the metal ion concentration of the aqueous solution of activated carbon was characterized by inductively coupled plasma emission spectrometry?ICP?.The experimental results exclude the influence of the dosage,dye concentration,pH and other factors on the adsorption rate.The adsorption capacity of activated carbon is mainly related to the?-?interaction.?3?Preparation of water-washed?desalted?Chondrus crispus activated carbon and dye adsorption propertiesIn order to increase the porosity of activated carbon,thereby increasing its adsorption capacity.Water-washed Chondrus crispus activated carbon?WCCAC?was prepared by soaking in deionized water.According to several factors that affect the adsorption performance of dyes,including the dosage,time and temperature of the adsorbent,it is concluded that the adsorption capacity of WCCAC for methylene blue,methyl orange and oil red O are 199.40,99.99 and 49.99 mg g^?1,compared with the adsorption capacity of CCAC for the three dyes 132.81,49.48 and 33.17 mg g^?1.WCCAC has better adsorption effect.The adsorption kinetic data shows that the WCCAC adsorption process conforms to the pseudo-second-order kinetic model.And the adsorption isotherm is more consistent for Langmuir model.