Preparation method for biochar composite adsorbent and repairing method for Cr(VI) containing wastewater

Abstract

The invention discloses a preparation method for a biochar composite adsorbent and a repairing method for Cr(VI) containing wastewater. The preparation method comprises the following steps: washing and cleaning Solidago decurrens, removing leaves from the Solidago decurrens, carrying out drying and pulverizing so as to obtain a powder, carrying out heating to 300 DEG C under the condition of nitrogen introduction, carrying out a reaction under the protection of the nitrogen for 2 hours until Solidago decurrens powder is completely cracked, then carrying out continuous cooling to a room temperature at a nitrogen flow rate of 100 ml/min, and carrying out sieving with a 100-mesh sieve so as to obtain Solidago decurrens biochar; and adding 10 g of the Solidago decurrens biochar into 200 mL ofdistilled water, carrying out stirring with a magnetic stirrer at a room temperature for 30 min, slowly adding 10 g of montmorillonite, introducing the nitrogen so as to maintain an anaerobic state, adding 5 g of ferrous sulfate heptahydrate, carrying out stirring for 30 min, adding an NaBH4 solution with a concentration of 15 g/L under same reaction conditions, and after completion of titration,continuing stirring for 30 min, centrifuging a mixed solution at a speed of 4000 rpm, removing a supernatant and freeze-drying a precipitate so as to obtain a nanometer zero-valent iron-montmorillonite-biochar composite adsorbent. The preparation method provided by the invention adopts a solution infiltration and reduction process and has the advantages of high efficiency, low cost, simple and convenient operation and easy promotion.

Description

technical field [0001] The invention relates to the technical field of preparation of biochar composite adsorbents, in particular to a preparation method of biochar composite adsorbents and a repair method for Cr(VI)-containing wastewater. Background technique [0002] Solidago canadensis is native to North America. It was introduced into my country as an ornamental plant in 1935. Because of its fast growth, strong reproductive ability and huge potential threat to the ecological environment, it was listed in the list of foreign invasive species in my country. According to statistics, in recent decades, goldenrod has caused the extinction of more than 30 kinds of native plants in China, causing economic losses of tens of billions of dollars. At present, many domestic scientific research institutes are conducting research on the prevention and control and resource utilization of Solidago canadensis. However, these studies are still in the theoretical and experimental stage, a...

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Problems solved by technology

[0003] Another important function of biochar is the adsorption of pollutants in the water environment. However, the biochar obtained by directly pyrolyzing Solidago sativa has small porosity and specific surface area, low adsorption capacity and long equilibrium time.

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