Urea-Modified Cleaning Agent for RO Membrane Amide Protection
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Solution Overview
Problem
Cleaning agents used for reverse osmosis (RO) membranes often degrade the rejection property of the membranes, particularly when aromatic polyamide membranes are cleaned with high-pH solutions, leading to a reduction in rejection rate.
Innovation Solution
Incorporating a urea derivative, such as urea or biuret, into the cleaning agent to protect the RO membrane from degradation by adsorbing onto the amide bond portions and preventing damage from high-alkaline conditions, combined chlorine agents, and oxidizing agents, while maintaining a high cleaning effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-pH cleaning agents are used to clean aromatic polyamide RO membranes, then cleaning effectiveness is improved, but rejection rate of the membrane is reduced
Solution Approach 1:
Urea acts as a protective intermediary substance that adsorbs onto the amide bonds of the aromatic polyamide membrane, forming a protective layer that prevents direct contact between the high-pH cleaning agent and the membrane polymer, thereby preventing membrane degradation while allowing effective cleaning
Solution Approach 2:
Urea is applied to the membrane before or during the cleaning process to preemptively protect the amide bonds from alkaline degradation, counteracting the harmful effects of high-pH cleaning agents before they can damage the membrane structure
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The use of urea derivatives in the cleaning agent effectively prevents the degradation of the rejection property of RO membranes during cleaning, allowing for a high cleaning effect without reducing the rejection rate, even under harsh conditions.
Implementation Method 1
Incorporating a urea derivative, such as urea or biuret, into the cleaning agent to protect the RO membrane from degradation by adsorbing onto the amide bond portions
Data Source
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AI summary
Provided are a cleaning agent and a cleaning liquid that prevent a reduction in the rejection rate of an RO membrane which may occur when the RO membrane is cleaned and a method for cleaning an RO membrane with the cleaning liquid. The agent for cleaning an RO membrane includes a urea derivative. The urea derivative preferably includes urea (H2N-CO-NH2) and/or biuret (H2N-CO-NH-CO-NH2). The cleaning liquid is an aqueous solution produced by diluting the cleaning agent. The method for cleaning an RO membrane uses the cleaning liquid. Urea and biuret have a structure analogous to amide bonds included in aromatic polyamide RO membranes, and have a strong affinity for amide bond portions. Urea and biuret adsorb onto the amide bond portions, and prevent the amide bonds from being broken by the cleaning liquid.