A kind of magnetic heavy metal adsorbent with shell-core structure and preparation method thereof

Abstract

The invention relates to application of water treatment, in particular to a magnetic heavy metal adsorbent with a casing-core structure and a preparation method thereof. The magnetic heavy metal adsorbent with the casing-core structure uses a magnetic nano Fe-Mn compound MnxFe3-xO4(x=0-1) as a core, and uses a manganese oxide as a casing. The prepared magnetic heavy metal adsorbent is aggregate of nano particles, is 10-250 nm in particle size range and 70-120m<2> / g in specific area, has excellent performance of adsorbing ions of heavy metals including lead, cadmium, mercury, copper, nickel, zinc, cobalt and the like in a water body, is high in adsorption speed and adsorption capacity, still has a good removing effect when the heavy metals are lower in density, has good magnetism, is 35-55 A.m<2> / kg<-1> in saturatation magnetization, meanwhile magnetic separation can be performed, the separation speed is high, the operation is simple, the efficiency is high, the energy consumption is low and secondary pollution cannot be caused.

Description

technical field [0001] The invention relates to water treatment applications, in particular to a shell-core structure magnetic heavy metal adsorbent and a preparation method thereof. Background technique [0002] Heavy metals are enriched and difficult to degrade in the environment. During the mining, smelting, and processing of heavy metals, many heavy metals such as lead, mercury, cadmium, and cobalt enter the atmosphere, water, and soil, causing serious environmental pollution. Heavy metals discharged with wastewater, even if the concentration is small, can accumulate in algae and sediment, be absorbed by the surface of fish and shellfish, produce food chain concentration, and cause public nuisance. For example, public hazards such as Minamata disease (mercury pollution) and bone pain disease (cadmium pollution) that occurred in Japan are all caused by heavy metal pollution. [0003] At present, the methods of heavy metal wastewater treatment can be roughly divided into...

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Problems solved by technology

(2) Chemical methods, including chemical precipitation methods, redox methods, electrochemical methods, etc., are mainly suitable for the treatment of wastewater containing high concentrations of heavy metal ions. They have high efficiency, but consume a lot of energy and are prone to secondary pollution

[0004] At present, the adsorption materials for heavy metals include bentonite, zeolite, red mud, coconut shell, coated sand, activated alumina, activated carbon, and natural or synthetic metal oxides and their hydrated oxides, among which manganese oxides have isoelectric properties. It has the characteristics of low point, large specific surface area, and rich surface hydroxyl groups. It has strong heavy metal adsorption characteristics and can effectively adsorb and remove heavy metal pollutants in water. However, its particle size is small. In practical applications, traditional filtration separation methods have Problems of easy loss, difficult separation and low efficiency

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