Method for treating cadmium ions in heavy metal waste water

Abstract

The invention discloses a method for treating cadmium ions in heavy metal waste water. The method comprises the following concrete steps: (1) initial concentration of cadmium ions in a solution is firstly detected, and nanometer magnesium oxide is added according to a certain mass ratio, and an empirical formula is used to infer time for treatment according to the temperature of the solution; (2) in secondary treatment, a complex and nanometer magnesium oxide are prepared according to a certain ratio, the materials are added into waste water, and treatment time is controlled at 30-45 minutes. In the process, cadmium ion / MgO=75-100 / 1000; the complex which is added is one of sodium hexametaphosphate, sodium tripolyphosphate and sodium pyrophosphate; the ratio of the complex to nanometer magnesium oxide in the secondary treatment is 1:40-50. The concentration of residual cadmium ions in waste water after treatment is far lower than the national discharge standard, and the method is environmentally friendly without pollution and has good practical value.

Description

technical field [0001] The invention belongs to the field of industrial wastewater treatment, in particular to a method for treating cadmium ions in heavy metal wastewater. Background technique [0002] Heavy metals refer to metals with a density greater than 4 or 5. Although heavy metals such as manganese, copper, and zinc are trace elements required for life activities, most heavy metals (such as mercury, lead, cadmium, etc.) are not necessary for life activities, and all heavy metals Exceeding a certain concentration is harmful to the human body. Due to the increasing mining, smelting, processing and commercial manufacturing activities of heavy metals, many heavy metals (such as lead, mercury, cadmium, cobalt, etc.) have entered the atmosphere, water, and soil environment, causing serious environmental pollution. Heavy metals that exist in various chemical forms will persist, accumulate and migrate after entering the environment or ecosystem, and are likely to cause harm...

AI Technical Summary

Problems solved by technology

[0003] Existing treatment methods for heavy metal wastewater include: chemical precipitation, ion exchange resin, and adsorption. These methods only convert pollution into sediment or a form that is easier to handle. The secondary pollution caused by this often requires a more expensive price

In addition, these methods often have certain defects in actual operation, especially for heavy metal wastewater with low concentration.