Selenium-Laden Substrate for Water Remediation

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Solution Overview

Problem

Conventional methods for removing selenium from water are inefficient, often requiring high waste volumes, being slow, expensive, and leaving a large carbon footprint, and are typically effective for only one form of selenium, with selenium removal systems being interfered with by competing anions and producing high volumes of sludge.

Innovation Solution

A method and system involving a selenium-laden substrate, initially prepared at an elevated temperature greater than 600°C, is introduced into a selenium-containing solution with a pH less than 10, allowing for the removal of selenium through a process system, where the substrate can be in the form of powder, particles, or pellets, and is arranged to pass through a bed in-line with the process system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional methods are used to remove selenium from water, then selenium removal is achieved, but high volumes of waste are generated and sludge is produced

Engineering Contradiction:
Improveselenium removal effectivenessVSAvoidwaste volume and sludge production
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The invention changes the chemical form of selenium on the substrate from soluble salts to elemental selenium through thermal decomposition at elevated temperatures (600-1000°C). This parameter change in selenium's chemical state transforms it into an insoluble, non-sludge-forming elemental form that can be easily removed without generating waste sludge.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention extracts selenium from aqueous solution by adsorption onto a substrate, then thermally decomposes the substrate to release elemental selenium. This two-step extraction process removes selenium from the water phase and converts it to a recoverable elemental form, eliminating the need for sludge disposal.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If conventional selenium removal methods are used, then selenium is removed from water, but the process is slow and inefficient

Engineering Contradiction:
Improveselenium removal effectivenessVSAvoidremoval rate and process speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention changes the selenium species from various soluble forms (selenides, selenites, selenates, selenocyanates) to elemental selenium through thermal decomposition. This parameter change in oxidation state and chemical form dramatically accelerates the removal process by converting multiple slow adsorption steps into a single rapid thermal decomposition step.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The substrate is pre-loaded with selenium compounds during its preparation phase. This preliminary accumulation of selenium on the substrate allows for rapid bulk removal when the substrate contacts contaminated water, followed by quick thermal decomposition to release concentrated elemental selenium, thereby increasing overall process productivity.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If conventional methods are used for selenium removal, then selenium is removed, but the cost is high and environmental impact is large

Engineering Contradiction:
Improveselenium removal effectivenessVSAvoidoperational cost and environmental footprint
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention recovers elemental selenium from the substrate through thermal decomposition instead of discarding the substrate as waste. This recovery process converts the selenium burden into a valuable product, reducing both operational costs and environmental impact by eliminating the need for expensive waste disposal and sludge management infrastructure.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The invention converts the harmful selenium contamination into beneficial elemental selenium product through thermal decomposition. By transforming the toxic dissolved selenium into recoverable elemental form, the process turns an environmental liability into an economic asset, reducing both treatment costs and environmental footprint.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Reliability

If conventional selenium removal systems are used, then selenium is removed, but competing anions interfere with the removal process

Engineering Contradiction:
Improveselenium removal effectivenessVSAvoidsusceptibility to interference from competing anions
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention changes the selenium form to elemental selenium through thermal decomposition, which fundamentally alters the removal mechanism from chemical adsorption (susceptible to anion competition) to thermal decomposition (insensitive to anion interference). This parameter change in chemical form and removal mechanism eliminates vulnerability to competing anions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention extracts selenium from the complex aqueous environment containing competing anions by adsorption onto substrate, then separates it through thermal decomposition. This two-stage extraction process isolates selenium from interfering substances, allowing the final decomposition step to proceed without anion interference.

Inventive Principle:
Principle #2Taking out (Extraction)

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 effectively removes selenium from the solution, achieving higher removal rates and efficiencies compared to traditional methods, with the selenium-laden substrate remaining effective for extended periods and reducing operational costs and environmental impact.

Implementation Method 1

introducing the substrate to the selenium-containing solution, or passing the selenium-containing solution through a bed comprising the selenium laden substrate so as to remove selenium from the solution

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2394737B1Method and system for removal of selenium
Publication Date: 2016.02.17 PHILLIPS 66 CO
  • EP2394737B1 patent drawingFigure 1~2

AI summary

Described herein is a cost effective means for selenium recovery and refining relying on an impregnated substrate. The substrate is impregnated with selenium and provides a system and method for the environmentally safe discharge of previous selenium-contaminated solutions and an environmentally safe discharge of industrial waste water.