Sludge Conditioning Agent for Reproducible Dewatering

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Solution Overview

Problem

Existing sludge dewatering technologies face challenges in achieving consistently good and reproducible results due to varying sludge composition, leading to non-optimal dewatering and increased disposal costs.

Innovation Solution

A sludge conditioning agent comprising 20-80% alkaline earth metal salts (MgX or CaX) and 2-50% carboxylic acid solution, along with 2-20% iron-based components, is added to the sludge before dewatering, enhancing flocculant binding and penetration, and promoting the formation of shear-stable sludge flocs through alkaline earth metal ions and citric acid-induced structural changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional dewatering methods are used, then the dewatering process can be operated continuously, but the dewatering results are inconsistent and suboptimal due to varying sludge composition

Engineering Contradiction:
Improvereproducibility of dewatering resultsVSAvoiddewatering efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the chemical parameters of the sludge by adding a conditioning agent containing magnesium or calcium salts and carboxylic acid. This modifies the sludge composition and properties to create ideal and nearly constant conditions for the dewatering device, ensuring consistent and reproducible dewatering results regardless of variations in incoming sludge composition.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The sludge conditioning agent acts as an intermediary substance between the variable sludge input and the dewatering device. It mediates the interaction by altering the sludge structure and charge balance, enabling the dewatering device to operate consistently under ideal conditions despite variations in sludge composition.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If manual readjustment of flow rate and polymer settings is performed continuously, then dewatering results can be optimized, but the operational complexity and labor requirements increase

Engineering Contradiction:
Improvedewatering efficiencyVSAvoidoperational simplicity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The sludge conditioning agent is added to the sludge before it enters the dewatering device, performing the optimization action in advance. This preliminary chemical treatment creates ideal conditions for dewatering automatically, eliminating the need for continuous manual readjustment of flow rate and polymer settings during operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The conditioning agent enables the dewatering system to self-optimize by automatically creating ideal dewatering conditions through chemical modification of the sludge. The system becomes self-regulating, maintaining consistent performance without requiring continuous manual intervention or monitoring.

Inventive Principle:
Principle #25Self-service

3Reliability

If sonication systems are installed upstream, then sludge dewatering is improved, but the equipment complexity and investment costs increase

Engineering Contradiction:
Improvedewatering consistencyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The chemical conditioning agent serves as an intermediary that achieves dewatering improvement without requiring complex sonication equipment. It modifies the sludge properties to enhance flocculant binding and penetration, providing consistent dewatering results through a simpler chemical addition system rather than complex mechanical sonication systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical sonication system with a chemical conditioning approach. Instead of using ultrasonic waves to improve sludge dewatering, the method uses chemical agents to modify sludge structure and promote floc formation, achieving similar or better results with simpler equipment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If more flocculant is added to achieve better dewatering, then the dewatering result improves, but the flocculant consumption and costs increase

Engineering Contradiction:
Improvedewatering efficiencyVSAvoidflocculant consumption
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The conditioning agent is added before the flocculant to pre-modify the sludge structure and charge balance. This preliminary action enhances the effectiveness of the subsequently added flocculant, allowing achieve better dewatering results with lower flocculant consumption by optimizing the sludge-flocculant interaction in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The conditioning agent changes the chemical parameters of the sludge, including charge balance and surface properties, to improve flocculant binding efficiency. This parameter modification allows the flocculant to work more effectively at lower concentrations, reducing overall flocculant consumption while maintaining or improving dewatering performance.

Inventive Principle:
Principle #35Parameter changes

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 results in improved and reproducible dewatering outcomes, reduced flocculant consumption, and increased gas yield in digestion towers, while minimizing undesirable side reactions and enhancing sludge dewatering efficiency.

Implementation Method 1

By adding alkaline earth ions contained in the sludge conditioning agent according to the invention, such as calcium or magnesium, an improved charge balance can be achieved between the sludge structure and the typically polymeric flocculant

Methodology Applied
Scientific EffectIon Repulsion/Attraction: Ion Repulsion/Attraction

Implementation Method 2

allows the flocculant to bind better to the sludge, or to penetrate the sludge suspension more effectively

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

citric acid-induced structural changes

Methodology Applied
Scientific EffectSolvation: Solvation

Implementation Method 4

the complexing properties of carboxylic acids prevent the rapid and effective precipitation of dissolved pollutants from the wastewater to be treated

Methodology Applied
Scientific EffectComplexation:

Implementation Method 5

The active surface area in the sludge is altered, which allows the flocculant to bind better to the sludge, or to penetrate the sludge suspension more effectively

Methodology Applied
Scientific EffectSurface modification:

Data Source

PatentEP3567013B1Sludge conditioning agent and process for optimizing the dewatering of sludge
Publication Date: 2022.12.14 KUBINGER ULRICH

AI summary

A sludge conditioning agent for optimizing sludge dewatering from a biological treatment process is proposed. To achieve advantageous sludge conditioning conditions, it is proposed that the agent be composed of MgX or CaX, where X is either a nitrate, a sulfate, and/or a chloride, at least one carboxylic acid, and FeY, where Y is either a nitrate, a sulfate, and/or a chloride.