Composite Biochar Stabilizes Heavy Metals via Sintering

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Solution Overview

Problem

Current methods for heavy metal pollution control, such as phytoremediation, face challenges in stabilizing heavy metals in biomass, leading to potential secondary pollution and environmental risks due to differences in adsorption capacities among plants and the difficulty in harmless disposal of enriched biomass.

Innovation Solution

A composite biochar is developed by enriching centipede grass with arsenic and lead, then sintering it with hydroxyapatite, sepiolite, and chitosan, and compounding it with microorganisms to create a stable form that reduces the environmental hazard of these metals, utilizing a process that includes the use of chicken feces, polyacrylamide, and diethylenetriaminepentaacetic acid to enhance heavy metal absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If plant remediation technology is used to enrich heavy metals in plant body, then heavy metal removal from contaminated site is achieved, but large amounts of polluted biomass cannot be degraded and may cause secondary pollution of soil and groundwater

Engineering Contradiction:
Improveheavy metal removal quantityVSAvoidsecondary pollution risk
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical and chemical parameters of heavy metals in biomass through sintering treatment. The sintering process transforms organic biomass into inorganic biochar, fundamentally altering the state of heavy metals from organic-bound to inorganic-bound forms, thereby preventing degradation and secondary pollution while maintaining heavy metal removal effectiveness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system by combining biochar with hydroxyapatite, sepiolite, and chitosan. This composite structure stabilizes heavy metals through multiple mechanisms (adsorption, complexation, precipitation), effectively preventing heavy metal leaching and secondary pollution while maintaining high heavy metal removal capacity

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If different plants are used for phytoremediation, then adsorption capacity varies, but defining which plants can effectively adsorb specific heavy metals and how to dispose of biomass becomes challenging

Engineering Contradiction:
Improveheavy metal adsorption capacityVSAvoidplant selection and disposal complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent extracts the plant biomass after heavy metal enrichment and transforms it into biochar through sintering. This extraction separates the heavy metal-containing biomass from the natural degradation pathway, allowing for controlled stabilization and simplified disposal through land application of the stable biochar composite

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sintering process fundamentally changes the chemical parameters of the biomass, converting organic material into stable inorganic biochar. This parameter change eliminates the need for complex plant selection and disposal protocols, as the biochar composite can be safely applied to land with minimal environmental risk

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If heavy metals are enriched in plant biomass, then soil heavy metal risk is reduced, but the enriched biomass becomes difficult to degrade and may return to environment causing pollution

Engineering Contradiction:
Improvesoil heavy metal riskVSAvoidbiomass stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent applies sintering treatment to change the physical and chemical parameters of the biomass, transforming it from an organic, biodegradable state to an inorganic, stable biochar state. This parameter change simultaneously reduces soil heavy metal risk and ensures long-term stability, preventing the biomass from degrading and returning heavy metals to the environment

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material combining biochar with stabilizing agents (hydroxyapatite, sepiolite, chitosan) that enhance the stability of heavy metals. This composite structure ensures both reduced soil risk and long-term compositional stability, preventing heavy metal release back into the environment

Inventive Principle:
Principle #40Composite materials

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 composite biochar effectively stabilizes and coats heavy metals, prolonging their migration time, reducing environmental risk, and providing a new approach for treating heavy metal biomass, thereby addressing the challenges of secondary pollution and environmental contamination.

Implementation Method 1

stable enrichment or coating heavy metals such as arsenic and lead

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

exploiting the synergistic action of microorganisms, hydroxyapatite, sepiolite and chitosan to increase the stability and decrease the dissolution rate of heavy metal

Methodology Applied
Scientific EffectSurface complexation: Chemisorption

Implementation Method 3

centipede grass is sintered with hydroxyapatite, sepiolite and chitosan

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 4

sintering it with hydroxyapatite, sepiolite, and chitosan

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 5

chitosan 5-20 parts... exploiting the synergistic action of microorganisms, hydroxyapatite, sepiolite and chitosan to increase the stability

Methodology Applied
Scientific EffectComplexation: Chemisorption

Data Source

PatentUS20240139790A1Composite biochar for preventing and treating heavy metal pollution and preparation method therefor
Publication Date: 2024.05.02 CHINESE RES ACAD OF ENVIRONMENTAL SCI

AI summary

A composite biochar for controlling heavy metal pollution and a process for producing the same, in particular enrichment of heavy metals such as arsenic and lead in soil with centipede grass, thereafter centipede grass is sintered with hydroxyapatite, sepiolite and chitosan, and compounded with microorganisms to produce said composite biochar; through the process of the present invention, heavy metals such as arsenic and lead are stably enriched or coated in said composite biochar, significantly reducing the potential hazard of arsenic and lead to the environment, and also providing new developmental ideas for treating heavy metal biomass.