Green synthetic magnetic composite nanomaterial, preparation method and application thereof

Abstract

The invention discloses a green synthetic magnetic composite nano material which is characterized by being prepared from the following components in parts by mass: ellipsoidal solid particles prepared by self-assembly, ferrous sulfate heptahydrate, a green tea extracting solution, tea residues and calcium alginate in a ratio of 1:(4-6):(0.6-0.8):(1.8-2.5). The invention also discloses a preparation method and application of the composite nanomaterial. According to the method, ferrous salt is taken as a raw material, calcium alginate is taken as a coating agent, a green tea extracting solution is taken as a reducing agent and a dispersing agent, and the calcium alginate-coated nano-iron composite material is synthesized in a green manner by controlling reaction conditions and the material adding amount and is applied to rapid removal of Cr<6+> and methylene blue in a water body. The nanomaterial has the advantages of being wide in raw material source, simple and convenient in synthesis method, stable in material performance, wide in application range, good in pollutant adsorption effect, free of secondary pollution and the like, can be suitable for emergency treatment of pollutants in large-volume environmental water bodies, and can also be used for deep purification of general domestic sewage, environmental water bodies and drinking water bodies.

Description

technical field [0001] The invention belongs to the technical field of nanomaterials and environmental protection, and in particular relates to a green synthetic magnetic composite nanomaterial, a preparation method and an application thereof. Background technique [0002] Due to its strong reducibility, large specific surface area, and high reactivity, nano-iron can effectively remove various organic pollutants and heavy metals. However, due to the high surface energy and magnetic properties of nano-iron particles, it is easy to agglomerate and reduce the reactivity when used alone, and the traditional nano-iron synthesis and modification methods such as improper selection of chemical reagents and modifiers may cause secondary pollution to the environment. It also increases the application cost. For this reason, the research on the synthesis technology of nano-zero-valent iron particles focuses on the utilization of green biomaterials, which not only realizes "turning wast...

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Problems solved by technology

[0005] However, the above-mentioned calcium alginate-coated nano-iron pellets have some disadvantages: (1) they cannot be used in the emergency disposal of water pollution accidents, and the nano-iron composite materials are mainly used in powder form, which has low strength, easy dispersion, Difficulty breaking out of water bodies and recycling issues

(2) After the reaction is over, solid-liquid separation by means of centrifugation and external magnetic field is required, the recycling rate of the material is low, and the recycling effect is poor; (3) Most nano-iron materials have the disadvantage of iron leaching in the process of removing pollutants, Especially after pollutants are removed under the condition of high pH, ​​it is easy to produce iron sludge, causing iron pollution, and the reaction is too fast, so it is difficult to control

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