Method for treating cadmium-containing waste water by intensified ultrafiltration of hollow fiber ultrafiltration membrane and foam floatation

Abstract

The invention provides a method of disposing waste water containing cadmium with hollow fiber hyperfiltration membrane intensive hyperfiltration and floating foam, which comprises the following steps: 1) adding anionic surfactant sodium dodecyl sulfate into the waste water containing cadmium, intimate mixing, and stewing reacting, pumping the water into hyperfiltration membrane assembly for filtering with peristaltic pump, then flowing into air-float column; 2) blowing air from aeration head in the bottom of air-float column with air compressor, making yielding water obtained from step 1)flow into from the intermediate section of air-float column, with foamability of sodium dodecyl sulfate, making rudimental sodium dodecyl sulfate form bubble with adsorption capacity, to adsorb low-concentration cadmium ion remaining in water, 3) the bubble with cadmium ion obtained from step 2) floating upward, and issueing from the top of air-float column, and the water discharging from the bottom of air-float column after reaching the standard. The invention has the following merits: good removal effect, small energy consumption, simple operation, less dosage of surfactant, low cost.

Description

technical field [0001] The invention belongs to a membrane treatment method for heavy metal wastewater, in particular to a method for treating cadmium-containing wastewater by utilizing hollow fiber ultrafiltration membranes to strengthen ultrafiltration and foam air flotation. Background technique [0002] With the continuous growth of my country's economy, the scale of investment in heavy industries such as iron and steel, electric power, cement, and electrolysis has increased, the output of products has increased rapidly, and heavy metal pollution has become increasingly serious. At present, the treatment methods of heavy metal wastewater mainly include chemical precipitation method, adsorption method, ion exchange method, biological method, membrane separation method and so on. The precipitation method is simple in process, convenient in operation, economical and practical, and is widely used in wastewater treatment, but it cannot realize the recovery and utilization of ...

AI Technical Summary

Problems solved by technology

The precipitation method is simple in process, convenient in operation, economical and practical, and is widely used in wastewater treatment, but it cannot realize the recovery and utilization of heavy metals, and the stacking of sediments may also cause secondary pollution

The adsorption method to treat heavy metal wastewater is controlled by various factors such as the type of adsorbent, the amount of adsorbent added, the composition of the wastewater, the concentration of the wastewater, the pH value, and the adsorption time. The actual operation is difficult and the selectivity is not high.

The ion exchange method treats heavy metal wastewater, which has a high degree of purification, can be recycled, and has no secondary pollution, but the actual treatment cost is very high

Biological method is not widely used because there are many problems to be solved in the process, and its load impact resistance is not high

Membrane separation methods to treat heavy metal wastewater mainly include electrodialysis, reverse osmosis, nanofiltration, etc., which have the outstanding advantages of high pollutant removal rate, ability to recover heavy metal salts in wastewater, and simple process. However, due to electrodialysis membrane, The cost of reverse osmosis membrane and nanofiltration membrane itself is high, and the required operating pressure is relatively high, resulting in high investment and operating costs for membrane treatment of heavy metal wastewater, which affects its application in large-scale industrial wastewater treatment