Method for treating nickel-containing wastewater by using composite adsorbent

Abstract

The invention discloses a method for treating nickel-containing wastewater by using a composite adsorbent. The method comprises the following steps: mixing the nickel-containing wastewater with the composite adsorbent, carrying out oscillating at room temperature, carrying out solid-liquid separation to obtain preliminarily-treated wastewater, adjusting the pH value of the preliminarily-treated wastewater to 4-5, adding sodium hypochlorite, carrying out a stirring reaction, adding the composite adsorbent, conducting oscillating at room temperature, and carrying out solid-liquid separation to obtain secondarily-treated wastewater; adjusting the pH value of the secondarily-treated wastewater to 10.5-11.5, performing standing for precipitation, taking supernatant liquid, adding polyaluminum chloride, conducting stirring, adding polyacrylamide, performing stirring and standing, and carrying out solid-liquid separation to obtain tertiarily-treated wastewater; and mixing the tertiarily-treated wastewater with the composite adsorbent, conducting oscillating at room temperature, and carrying out solid-liquid separation, wherein the composite adsorbent is prepared by uniformly mixing modified sepiolite, acid-modified fly ash and cross-linked chitosan. The method for treating the nickel-containing wastewater by using the composite adsorbent provided by the invention is simple in process,has a better treatment effect on various forms of nickel in a water body, and is high in nickel removal rate.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a method for treating nickel-containing wastewater by using a composite adsorbent. Background technique [0002] Nickel is one of the most widely used and expensive heavy metal elements. In recent years, it has been widely used in electroplating, electronics, alloys, steel, catalysts and other fields. These fields will discharge a large amount of nickel-containing wastewater. Nickel and its compounds in nickel-containing wastewater are highly toxic substances. In the field of wastewater treatment, nickel-containing wastewater is a high-concentration and refractory toxic wastewater. If it is not treated properly, it will not only waste nickel metal resources, but also It is easy to produce secondary pollution, and can enter the human body through the food chain, causing serious harm to the human body. Therefore, according to the regulations of the environmental protec...

AI Technical Summary

Problems solved by technology

Although there are many methods for treating nickel-containing wastewater, including chemical methods, electrolysis methods, and physical isolation and filtration methods, the existing treatment methods generally have the defects of complicated operation process and low removal rate of nickel metal.