Biological Soil Stabilization with Alginase and Calcium Chloride

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Solution Overview

Problem

Current soil stabilization methods, including mechanical and chemical stabilization, face challenges such as limited durability, high costs, environmental impact, and inefficiency in wet environments, and are not applicable to all types of soils, making them unsuitable for long-term use in unpaved roads.

Innovation Solution

A soil-stabilizing formulation comprising bacteria (Azotobacter vinelandii and Acidithiobacillus ferrooxidans), enzymes (alginase), and cations (calcium chloride) is used to improve soil stability, cohesion, and compaction, applicable to both cohesive and non-cohesive soils, promoting increased California Bearing Ratio (CBR) and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If chemical stabilization methods are used to improve soil stability, then soil strength is improved, but environmental impact increases and cost increases

Engineering Contradiction:
Improvesoil strengthVSAvoidenvironmental impact
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by using biodegradable polymers ( starch, cellulose, chitin) instead of traditional chemical stabilizers. This substitution maintains the soil stabilization function while eliminating harmful environmental effects, as the biological polymers decompose naturally without contaminating the environment.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite stabilization system combining multiple biological polymers (starch, cellulose, chitin) with specific molecular weights and functional groups. This composite approach enhances the overall stabilization performance while maintaining environmental compatibility, as each polymer contributes different stabilizing mechanisms.

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If traditional chemical stabilizers are used to reduce cost, then cost decreases, but durability in wet environments worsens

Engineering Contradiction:
ImprovecostVSAvoiddurability in wet environments
Core Design Contradiction:
Quantity of substanceVSDuration of action of stationary object

Solution Approach 1:

The patent modifies the chemical parameters by selecting polymers with specific molecular weights (10^5 to 10^7 g/mol) and functional groups that provide both cost-effectiveness and wet environment durability. The high molecular weight polymers form more robust networks that resist water degradation while remaining economically viable.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses readily available, low-cost biological polymers (starch, cellulose, chitin) that are inexpensive to produce and apply. Despite their biodegradable nature, their strategic selection and formulation provide extended durability in wet conditions through enhanced polymer-soil interaction mechanisms.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Stress or pressure

If mechanical stabilization is used to improve soil compaction, then compaction capacity is improved, but durability is limited to less than a year

Engineering Contradiction:
Improvecompaction capacityVSAvoiddurability
Core Design Contradiction:
Stress or pressureVSDuration of action of stationary object

Solution Approach 1:

The patent merges mechanical compaction with chemical-biological stabilization by first applying mechanical pressure to achieve initial compaction, then introducing biological polymers that bind soil particles together. This combination creates a durable stabilized structure that maintains compaction effects for extended periods, overcoming the temporary nature of mechanical stabilization alone.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention applies preliminary mechanical compaction to achieve optimal density before introducing the biological polymer stabilizers. This preliminary action prepares the soil matrix to better receive and integrate the polymers, maximizing both immediate compaction capacity and long-term durability.

Inventive Principle:
Principle #10Preliminary action

4Strength

If conventional soil stabilizers are used to achieve stability, then soil strength is improved, but adaptability to different soil types is limited

Engineering Contradiction:
Improvesoil strengthVSAvoidadaptability to different soil types
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent employs biological polymers (starch, cellulose, chitin) that possess universal stabilizing properties across different soil types. These polymers can interact with various soil minerals and organic matter through multiple mechanisms (adsorption, bridging, cementation), making the stabilization system adaptable to cohesive soils, non-cohesive soils, and mixed compositions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention adjusts the molecular weight parameters (10^5 to 10^7 g/mol) and functional group composition of the polymers to optimize performance for different soil types. This parameter flexibility allows the same class of materials to effectively stabilize diverse soil compositions while maintaining high soil strength.

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

The solution provides a cost-effective, non-toxic, and environmentally friendly method for stabilizing soils, enhancing compaction capacity, durability, and water resistance, with improved particle cohesion and permeability, suitable for various soil types and environments.

Implementation Method 1

the enzyme preferably corresponds to an alginase

Methodology Applied
Scientific EffectEnzyme: Enzyme

Implementation Method 2

bacteria, preferably correspond to Azotobacter vinelandii and Acidithiobacillus ferrooxidans

Methodology Applied
Scientific EffectBiological process: Aerobic Digestion

Implementation Method 3

the cations are preferably provided in the form of calcium chloride

Methodology Applied
Scientific EffectIonic bonding: Ion Repulsion/Attraction

Data Source

PatentUS11884861B2Soil-stabilising composition comprising <i>Azobacter vinelandii</i>, <i>Acidithiobacillus ferrooxidans</i>, alginase, and calcium chloride; method for stabilising soils; method for preparing stabilised paths; use of the soil-stabilising composition
Publication Date: 2024.01.30 HYDRA RES SPA

AI summary

A formulation for stabilizing soils is described comprising bacteria, enzymes and cations, wherein the bacteria preferably correspond to Azotobacter vinelandii and Acidithiobacillus ferrooxidans, the enzyme preferably corresponds to an alginase and the cations are preferably provided in the form of calcium chloride. A method for stabilizing soils; a method for preparing stabilized paths; and use of the soil-stabilizing composition are also described.