Unsteady-state membrane operation process for treating high-concentration wastewater

Abstract

The invention discloses an unsteady-state membrane operation process for treating high-concentration wastewater. The process comprises the following steps: treating high-concentration wastewater through a hollow fiber nanofiltration membrane system, carrying out operation continuously at a constant pressure for 1-300 seconds, closing a water production pump, slowly increasing the pressure to a preset pressure at a rate of 1-30kPa / s, stably producing water for 1-300 seconds after the pressure reaches 30-300kPa, closing the pump again, and so on. After the unsteady-state operation process is adopted, the same membrane assembly can tolerate higher concentration, so that the pretreatment process can be reduced, and the sewage treatment flow can be shortened.

Description

technical field [0001] The invention relates to the field of wastewater treatment, and more specifically relates to an unsteady-state membrane operation process for treating high-concentration wastewater. Background technique [0002] In the treatment of industrial sewage, the traditional membrane operation process adopts a steady-state operation mode, that is, a fixed system inlet or outlet pressure (constant pressure mode), or a fixed influent, concentrated return or product water flow rate (constant flow mode). The water quality of industrial sewage is usually poor, and the membrane fouling will be more serious, which is manifested by a significant decrease in water production or an increase in operating pressure, accompanied by varying degrees of water quality degradation. In the constant pressure mode, the permeated water will continue to decrease with the increase of membrane fouling; while in the constant flow mode, in order to keep the flow constant, the operating pr...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, the water production has dropped significantly for a long time before the membrane module is cleaned, resulting in a decrease in the performance of the membrane module and a decrease in the quality of the produced water.

Moreover, the cleaning process is time-consuming, takes up a lot of manpower, and wastes energy and water resources.

For high concentration wastewater, the operating efficiency is lower