Reusable Nanoadsorbent for Dye Removal
Official patent title
Method for purifying polluted water
Arabic title: طريقة لتنقية المياه الملوثة
Invention
Invention
Problem
Industrial dyes can be poorly biodegradable and difficult to remove using biological treatment. Silver tungstate is attractive for remediation but can have low surface area and suffer photochemical instability and reduced efficiency during reuse.
Why it matters
A regenerable nanoscale adsorbent for dye-contaminated water could complement membrane, oxidation, coagulation, and biological systems, particularly for wastewater streams containing persistent colorants.
Approach
Sulfur-doped Ag2WO4 nanoparticles are mixed with polluted water to adsorb dyes and then removed by filtration. The particles contain 5–30 wt.% sulfur, are 2–40 nm in diameter, and can be acid-washed and water-rinsed for reuse.
Who may benefit
Potential beneficiaries include textile and dye-industry wastewater operators, advanced water-treatment firms, adsorbent manufacturers, environmental laboratories, and industrial facilities seeking reusable polishing media.
Potential value
The method combines nanoscale sulfur modification, room-temperature adsorption, simple filtration, and acid regeneration, with claimed removal efficiencies of at least 90% for indigo carmine and methyl red under specified laboratory conditions.
Background
Background
Wastewater may contain dyes, pesticides, mineral ions, and other pollutants from municipal and industrial sources. Many dyes resist biodegradation, so adsorption, filtration, coagulation, electrochemical treatment, and oxidation are used for color removal. Silver tungstate has useful optical and catalytic properties but may be unstable under prolonged intense illumination, and its reuse can be limited by photocorrosion. The disclosed method instead emphasizes adsorption with sulfur-doped nanoscale Ag2WO4, aiming to improve dye capture and enable regeneration after treatment.
Technology overview
Technology overview
Dry sulfur-doped Ag2WO4 particles containing 5–30 wt.% sulfur are added to a stirred pollutant solution, mixed, and filtered. The spherical particles average 2–40 nm and may be amorphous by XRD. For indigo carmine, claims specify pH- and concentration-dependent capacities and up to at least 95% removal after 80 minutes near neutral pH. The material retains at least 90% indigo-carmine removal after three regeneration cycles using 0.1 M HCl followed by water rinsing, and also removes methyl red.
Potential applications
Potential applications
- Removal of indigo carmine from dye-contaminated water.
- Removal of methyl red from aqueous streams.
- Polishing of textile and colorant-industry wastewater.
- Reusable nanoscale adsorbent research for industrial water treatment.
Evidence-supported advantages
Evidence-supported advantages
- Uses 2–40 nm sulfur-doped silver tungstate particles.
- Reports at least 95% indigo-carmine removal under a specified condition.
- Reports at least 90% removal for both indigo carmine and methyl red in selected tests.
- Retains at least 90% indigo-carmine removal after three acid-regeneration cycles.
- Operates through mixing and filtration without requiring illumination in the claimed method.
Development stage
Development stage
Nanoparticle characterization and laboratory batch adsorption and three-cycle regeneration tests are described; continuous operation, real-wastewater performance, leaching, and pilot-scale validation were not established. The development stage was not independently verified.
Commercial opportunity
Commercial opportunity
The adsorbent may interest textile-water, specialty-chemical, and advanced-treatment companies. Deployment requires fixed-bed or continuous-flow testing, real-effluent validation, silver and tungsten leaching assessment, regeneration and waste-acid management, ecotoxicity, nanoparticle containment, manufacturing cost analysis, and comparison with activated carbon and other commercial media.
Patent classifications
Patent classifications
WIPO IPC
- C02F1/28Treatment of water, wastewater, sewage or sludge
- B01J20/06Chemical or physical processes, e.g. catalysis or colloid chemistry; their relevant apparatus
- C02F101/30Treatment of water, wastewater, sewage or sludge
CPC
- B01J20/06Chemical or physical processes, e.g. catalysis or colloid chemistry; their relevant apparatus
- B01J20/3085Chemical or physical processes, e.g. catalysis or colloid chemistry; their relevant apparatus
- B01J20/3433Chemical or physical processes, e.g. catalysis or colloid chemistry; their relevant apparatus
- B01J20/3071Chemical or physical processes, e.g. catalysis or colloid chemistry; their relevant apparatus
- C02F1/288Treatment of water, wastewater, sewage or sludge
- B01J20/28007Chemical or physical processes, e.g. catalysis or colloid chemistry; their relevant apparatus
- B01J20/28019Chemical or physical processes, e.g. catalysis or colloid chemistry; their relevant apparatus
- B01J20/3475Chemical or physical processes, e.g. catalysis or colloid chemistry; their relevant apparatus
- C02F2101/308Treatment of water, wastewater, sewage or sludge
- C02F1/281Treatment of water, wastewater, sewage or sludge
- C02F2303/16Treatment of water, wastewater, sewage or sludge
- C02F2305/08Treatment of water, wastewater, sewage or sludge
Inventors
Inventors
- First inventorMohamed Khairy Abdel Fattah Omran
- InventorMohamed Mokhtar Mohamed
- InventorSalah Ahmed Ibrahim Eid
- InventorBabiker Yagoub Elhadi Abdulkhair
Keywords
Keywords
- silver tungstate
- sulfur doping
- Ag2WO4
- indigo carmine
- methyl red
- adsorption
- water purification
- regeneration
Patent document and drawings
Patent document and drawings
The patent publication is mapped to this record. Patent drawings remain within that publication; no separately cleared public media package has been supplied.