Method for absorbing and removing heavy metal and hexavalent chromium from waste liquid by using mangosteen slag

Abstract

The invention relates to a method for absorbing and removing a heavy metal and hexavalent chromium from waste liquid by using mangosteen slag. The method comprises the following steps of washing a certain amount of mangosteen pericarp, mangosteen fruit stems or juice-squeezed solid residues, mixing the above solid residues and alkali and water according to a mass ratio of 1 : 0.05-0.2 : 0.5-2 with stirring; reacting for 0.5-48 hours; washing the solid product, drying in a vacuum oven at a temperature of 60-100 DEG C; smashing and screening to obtain an absorbent material; preparing a metal ion water solution containing lead cadmium copper iron nickel zinc and hexavalent chromium, wherein the concentration of the metal ion water solution is 0.1-10 mmol / L; and adding the absorbent material obtained from the step 3 according to a proportion of the weight of the absorbent to the volume of the solution being 0.25-20 g / L, wherein the absorbent cam absorb the hexavalent chromium ions and heavy metal ions in the water solution. The method has the beneficial effects of reasonable design, simple operation and significant effect, can not cause secondary pollutions after adsorption treatment, and is easy to popularize.

Description

technical field [0001] The invention relates to a method for separating and purifying heavy metal ions in wastewater, especially hexavalent chromium ions, using mangosteen slag as a raw material to prepare an adsorbent material. Chromium deep purification. Background technique [0002] With the rapid development of industry, the pollution hazards caused by various waste water produced in the process of mining, smelting and using heavy metals to the environment have also attracted people's attention. In order to maintain the sustainable development of society, in addition to adopting more advanced and clean industrial technologies, the research and development of advanced technologies for efficient treatment of dangerous pollution sources caused by various heavy metals should also be strengthened. Among heavy metal pollutions such as lead, cadmium, arsenic, mercury, and chromium, the harm caused by chromium is very serious in some areas. Chromium and its salts are widely us...

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Problems solved by technology

The redox-precipitation method is to first reduce hexavalent chromium to trivalent chromium, and then precipitate or flocculate to separate. This method has a fast detoxification effect, but the consumption of chemical reagents is large, and a large amount of high-water chromium sludge needs further treatment, which is easy Cause secondary pollution, troublesome post-treatment, and poor purification effect on trace concentrations of hexavalent chromium wastewater

The microbial method needs to screen and find specialized strains for cultivation. It is troublesome to prepare the nutrient solution required for domestication or cultivation, and the period required for domestication or cultivation is long. The conditions for removing hexavalent chromium in wastewater are relatively harsh and the treatment time is relatively long. , the processing capacity is also limited, and it is not easy to realize large-scale industrial application for a large amount of chromium-containing poisonous residue

The removal of hexavalent chromium in wastewater by adsorption has the advantages of high efficiency, short time-consuming, thorough purification, and large treatment capacity. However, the existing ion-exchange resin-based adsorption materials often have poor separation selectivity, limited exchange capacity, and low There are strict requirements on the content of solid particles, and the price of ion exchange resin is relatively expensive, which makes the entire purification cost high. Therefore, it is necessary to develop new adsorbent materials with better selectivity and larger adsorption capacity.

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