Method for treating heavy metal wastewater by superconductive HGMS-NZVI (high gradient magnetic separation-nanoscale zero valent iron) coupled technique

Abstract

The invention relates to a method for treating heavy metal wastewater by a superconductive HGMS-NZVI (high gradient magnetic separation-nanoscale zero valent iron) coupled technique, belonging to the fields of resources and environments. The result proves that the optimal technological parameters of the superconductive HGMS-NZVI coupled technique are as follows: the addition amount of NZVI is 0.05-0.5 g / ml, the magnetic gradient is 3-5T, the standing time is 1-15 minutes, and the distance i between the reaction tank diameter d / magnetic field generator and the reaction tank wall is less than 3. The 4878.62ml of arsenic can be removed from every liter of high-concentration arsenic wastewater, and the removal ratio of arsenic ions in the wastewater is up to 99.56%. The operating method comprises the following steps: adding a right amount of NZVI into the heavy metal wastewater, uniformly stirring, injecting the wastewater in the reaction tank in a superconductive high-gradient magnetic field, and standing for some time. Before the treatment, no pretreatment is needed, and the pH value of the wastewater is not regulated. Under the technological conditions of the superconductive HGMS-NZVI coupled technique, the saturation adsorption quantity of NZVI is 16-18 mg / g (the arsenic ion adsorption quantity of 1g of NZVI), and the technological parameters can be properly regulated according to the arsenic ion concentration characteristic of wastewater.

Description

Technical field: [0001] The invention belongs to the field of resources and environment, and relates to the use of superconducting HGMS (High Gradient Magnetic Separation) technology. The coupling process of nano-zero valent iron (NZVI) can realize waste treatment and resource utilization. It is especially suitable for the treatment and reuse of acidic high-concentration arsenic-containing heavy metal wastewater. Background technique: [0002] Heavy metal wastewater mainly comes from electroplating, cold-rolled steel and non-ferrous metal smelters. [0003] Superconducting high-gradient magnetic separation (HGMS) technology shows advantages in the fields of resources and environmental protection due to its low investment, small footprint, low energy consumption, low cost, and high efficiency. The processing speed is 5 times that of conventional methods. However, this technology is not effective for the separation and removal of high-concentration ionic substances. The int...

AI Technical Summary

Problems solved by technology

However, the adsorption of heavy metal ions by nano-zero-valent iron is affected by the pretreatment effect and the concentration of competing ions, and nano-zero-valent iron itself has strong self-agglomeration and magnetic properties of iron itself, resulting in reduced activity, high consumption and high operating costs when used alone

Images