Nanometer manganese dioxide/active aluminum oxide compound adsorbent and method for preparing same

Abstract

The invention discloses a nanometer manganese dioxide / active aluminum oxide compound adsorbent. The compound adsorbent is a granular material, the grain size is 4 to 6 meshes, the surface of the compound adsorbent has a nanometer pore structure, and the pore size is 5 to 10 nanometers. Compared with the conventional manganese dioxide / active aluminum oxide compound adsorbent, the nanometer manganese dioxide / active aluminum oxide compound adsorbent of the invention has the advantages that: in the grain size is large; the pore size is smaller as the surface has the nanometer pore structure; the adsorption rate is higher; the adsorption capacity is as high as to reach an adsorption equilibrium within 20 minutes in 20mg / L chromium-containing solution, the adsorption equilibrium can be achievedwithin 20 minutes; and the chromium adsorption capacity is as high as 12mg / g and reduces the chromium content of the solution to below 0.001mg / L, which is much lower than the national limit value which is 0.05mg / L. When the compound adsorbent of the invention is used for reducing heavy metal chromium content of a source of drinking water, the out-factory water is guaranteed to meet the standards;simultaneously, because a surface active agent is added when the compound adsorbent is prepared, the manganese dioxide content of active aluminum oxide spheres is higher and the manganese dioxide is dispersed more uniformly; and thus, the load manganese dioxide is insusceptible to falling off, and the secondary pollution is not caused to the water body.

Description

Technical field [0001] The invention relates to a nano manganese dioxide / activated alumina composite adsorbent capable of effectively removing metallic chromium in micro-polluted water bodies and a preparation method thereof, and belongs to the technical field of water treatment. Background technique [0002] In recent years, due to social production and living activities, the amount of heavy metals released into drinking water sources has gradually accumulated, seriously threatening human health and life safety. Among them, chromium is the most common pollutant that endangers residents' health the most. [0003] Chromium is a heavy metal element that is widely used and harmful to the human body. Chromium can invade the human body through the digestive tract, respiratory tract, skin and mucous membranes, and induce lung cancer and nasopharyngeal cancer. All chromium compounds are toxic, and hexavalent chromium is almost 100 times more toxic than trivalent chromium. [0004] The ca...

AI Technical Summary

Problems solved by technology

In the conventional technology, activated alumina is usually used as the adsorbent, because it has a large specific surface area, and the chromium removal effect is relatively stable, but the adsorption capacity of activated alumina is not high, and when the chromium content in water is high, the effect is not obvious enough For this reason, manganese dioxide-activated alumina composite materials are currently used more

However, in long-term use, the existing manganese dioxide-activated alumina composite material still exposes the following disadvantages: due to the small particle size of the material, the large surface voids, and the content of manganese dioxide on the activated alumina pellets Low (less than 5%), and the dispersion is uneven, resulting in small adsorption capacity of the material, low chromium removal efficiency, and prone to manganese dioxide shedding, resulting in secondary pollution of water bodies