Cationic Coagulant Pre-treatment for Microfiltration Fouling

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Solution Overview

Problem

Microfiltration systems in water treatment processes experience significant fouling due to colloidal and particulate solids and dissolved organics, leading to reduced membrane flux and frequent cleaning or replacement, especially during high organic loading conditions.

Innovation Solution

The use of cationic coagulants, particularly organic and inorganic polymer blends, is introduced at the early stages of the water treatment process to coagulate and flocculate contaminants, reducing fouling and increasing membrane permeability, with specific examples including Klaraid CKP 1348™ and polyaluminum chloride.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If microfiltration systems are used to filter water, then water quality is improved, but membrane fouling increases and flux decreases

Engineering Contradiction:
Improvewater qualityVSAvoidmembrane flux
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies preliminary action by using chemical coagulants (such as alum, ferric chloride, or polyaluminum chloride) to treat the water before it reaches the microfiltration membrane. This pre-treatment step removes colloidal particles and organic matter that would otherwise cause fouling, allowing the membrane to maintain higher flux over time while still producing high-quality filtered water

Inventive Principle:
Principle #10Preliminary action

2Productivity

If microfiltration systems operate continuously, then water production increases, but cleaning frequency must increase

Engineering Contradiction:
Improvewater productionVSAvoidcleaning frequency
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

By implementing chemical coagulation as a preliminary treatment step, the system prevents the accumulation of fouling materials on the membrane surface during continuous operation. This allows for extended periods between cleanings, reducing the time lost to maintenance while maintaining high water production levels

Inventive Principle:
Principle #10Preliminary action

3Productivity

If high organic loading conditions occur, then water treatment capacity is maintained, but fouling rate increases

Engineering Contradiction:
Improvewater treatment capacityVSAvoidfouling rate
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent uses chemical coagulants as an intermediary substance between the high organic loading water and the microfiltration membrane. The coagulants bind with organic matter and colloidal particles, forming larger aggregates that are easier to remove and less likely to cause pore plugging, thus protecting the membrane during high-loading conditions

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This approach significantly reduces fouling, increasing membrane flux and extending the time between cleanings by up to 95%, while also improving color removal, turbidity reduction, and minimizing aluminum carryover, as demonstrated with Klaraid CDP 1348™ showing better results than polyaluminum chloride.

Implementation Method 1

cationic coagulant is used to treat water in the early stages of a water treatment system, and to coagulate and flocculate the contaminants

Methodology Applied
Scientific EffectCoagulation: Coagulation

Implementation Method 2

coagulate and flocculate the contaminants, and thereby resulting in reduced fouling

Methodology Applied
Scientific EffectFlocculation: Flocculation

Data Source

PatentEP2137113B1Method for reducing fouling in microfiltration systems
Publication Date: 2019.07.17 BL TECHNOLOGY INC
  • EP2137113B1 patent drawingFigure 1~2

AI summary

A process has been found which increases the efficiency and effectiveness of the overall filtration system, b> i educing the fouling of the microfilUatiop system, thereby increasing its permeability and reducing the frequency of cleanings necessary According to one embodiment of the inv ention, cationic coagulant is used to treat water in the ear!) stages of a water treatment system, and to coagulate and flocculate the contaminants, and thereby resulting m reduced fouling of the microfiltration system, resulting in inciease flux, less deposit of colloidal and particulate solids and dissolv ed organics on the surface of the microfiltration membrane, therein reducing the frequency and duration of the membrane cleaning and ultimate replacement