Preparation Of Chitosan Sponge And Its Application In The Treatment Of Wastewater From Food Industry

With the development of food production and processing industry,more and more oily and organic wastewater is discharged,which causes serious ecological environment problems and greatly affects people's quality of life.How to effectively treat oil and organic matter in food industry wastewater has become a hot research project.After continuous attempts,various methods had been proposed,such as flotation,filtration,flocculation,absorption and combustion control.However,most of the solutions could not take into account the purpose of efficient treatment of wastewater and low-cost recovery of resources at the same time.Extraction and reuse of oil from water can not only solve the problem of oil pollution in water,but also achieve the purpose of resource recovery.It is one of the ideas for people to perfect the solution of oily wastewater in the future.In recent years,people began to explore adsorption materials with special wettability,which can remove one phase from oil/water mixture and repel the other phase at the same time by using the apparent opposite affinity to oil and water,thus achieving selective oil/water separation.As a low-cost natural alkaline polysaccharide,chitosan has the advantages of non-toxicity,biodegradability,biocompatibility and excellent plasticity.Derivatives obtained by modification and modification of chitosan as a matrix can simultaneously possess the special wettability of hydrophobicity and hydrophobicity,and the cost is low,and it will not cause secondary pollution.Chitosan is an ideal new type of green adsorbent material in oil-containing.Wastewater treatment has a wide application prospect.The results show that:(1)The chitosan air gel sponge was prepared by cross-linking chitosan with sodium tripolyphosphate and citral to form four new types of chitosan sponge.Sixteen kinds of chitosan sponge were prepared by single factor experiment.(2)By measuring and comparing the microstructures of four kinds of chitosan sponges,the effects of various crosslinking agents and modifiers on the preparation of chitosan sponges were proved.By comparing the wettability and mechanical properties of four kinds of chitosan sponges,a new type of adsorption material,modified cross-linked chitosan sponge,was screened out according to the actual requirements.The modified cross-linked chitosan sponge possesses 3-D porous structure and good mechanical properties through the cross-linking modification of sodium tripolyphosphate and citral.The surface wettability of the modified chitosan sponge is superhydrophobic/superlipophilic by the modification of Hexadecyl mercaptan.(3)The modified cross-linked chitosan sponge was used to adsorb a variety of oils and organic substances.It was proved that the modified cross-linked chitosan sponge had excellent absorption capacity to a variety of oils and organic substances,and its adsorption capacity and surface wettability remained basically unchanged under the conditions of recycling and long-term storage.At the same time,the adsorbate could be adsorbed by distillation and extrusion.Effective recycling.(4)Based on these characteristics of modified cross-linked chitosan sponge,a continuous oil-water separation model under two different conditions was established,and the application of this modified cross-linked chitosan sponge as adsorbent material in life and industry was explored.It was proved that this new type of environmental friendly adsorbent material could be used to treat wastewater containing oil and other organic substances from food production,processing and living diet.