Sodium Dithionite

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• Product Name: Sodium Dithionite
• CAS: 7775-14-6
• Catalog: HG-BULK005
• Applications: Textile Industry, Paper Industry, Chemical Industry, Food Industry.

Known for its ability to reduce various compounds, sodium dithionite plays a crucial role in industrial processes that require bleaching, dyeing, and chemical reduction. This white, crystalline powder serves as a powerful reducing agent with diverse applications in textile, paper, chemical, and food industries.

Key Features

Odor

• Odorless or slightly smells of sulfur dioxide (SO₂), which is typical of its decomposing nature.

Solubility

• It is soluble in water, making it suitable for a variety of aqueous processes.

Reducing Agent

• It acts as a powerful reducing agent, ideal for applications in textile dyeing, chemical synthesis, and various bleaching processes.

Technical Data

Items	Type I	Type II	Type III	Type IV (Food Additive)
Na2S2O4	≥90%	≥88%	≥85%	≥85%
Fe	≤20ppm	≤20ppm	≤20ppm	≤20ppm
Zinc (Zn)	≤1ppm	≤1ppm	≤1ppm	≤1ppm
Other heavy metal (calculated as Pb)	≤1ppm	≤1ppm	≤1ppm	≤1ppm
Water insoluble matters	≤0.05%	≤0.05%	≤0.05%	≤0.05%
Shelf life(month)	12	12	12	12

Applications

Alfa Chemistry's sodium dithionite has a wide range of industrial applications due to its strong reducing properties. It plays a crucial role in:

Textile Industry

• Reduction Dyeing: Used as a reducing agent to facilitate dyeing with reduction dyes, it ensures effective color absorption.
• Bleaching: Ideal for wool and silk, enhancing brightness and cleanliness.
• Dyeing Auxiliaries: It assists in the printing of reduction dyes, improving adhesion.
• Color Stripping & Cleaning: It removes dye stains and cleans dye vats.

Paper Industry

• Pulp Bleaching: It effectively bleaches mechanical and thermomechanical pulps, improving paper whiteness.
• Deinking: Used to remove ink from recycled paper pulp, ensuring high-quality recycled paper.

Chemical Industry

• Reducing Agent: Utilized in synthetic chemistry and metal extraction processes, promoting chemical reduction.

Food Industry

• Preservative: It extends shelf life for products like dried fruits and noodles.
• Whitening Agent: Used in mushrooms, bamboo shoots, and candied fruits to maintain freshness.

Storage and Packaging

• Storage: It should be stored in a cool, dry place away from moisture and high temperatures to prevent decomposition.
• Packaging: Carefully packed in iron drums or plastic bags with a net weight of 15-200 kg.
• Transportation: During transportation, appropriate safety measures should be followed due to the product's sensitivity to moisture and air, which can lead to the release of sulfur dioxide (SO₂).

Alfa Chemistry's sodium dithionite stands out as a versatile and effective chemical used across various industries, from textile and paper production to food preservation and chemical synthesis. For more information, please feel free to contact us.

Case Study

Sodium Dithionite for Selective Copper(II) Recovery from Ligand-Containing Wastewater

Chou, Yi-Hsuan, et al. Chemosphere 141 (2015): 183-188.

Sodium dithionite (Na₂S₂O₄) acts as an efficient reducing agent for recovering Cu(II) from industrial wastewater containing ligands (EDTA, ammonia), addressing the challenge of poor metal removal caused by chelation.

Experimental Protocol: Synthetic wastewater (2.25 mM Cu(II)) with EDTA (1:1 molar ratio) or ammonia (1:8 molar ratio) was treated with Na₂S₂O₄ (Cu:dithionite = 1:3). Reactions were conducted at pH 5–11 under N₂ purging (oxygen-depleted) for 30 min. Real PCB production wastewater (4450.9 mg/L Cu(II), 115.4 mg/L Ni(II)) was treated without pH adjustment.

Performance Evaluation: EDTA-containing systems achieved 96.6–99.6% Cu(II) removal (pH 5–11), while ammonia systems reached near-100% removal (except pH 9.0, due to nano-sized particles). XRD confirmed Cu₂O (ammonia system) and CuO (EDTA system) as products. Real wastewater treatment yielded ~100% Cu(II) removal (residual: 2.9 mg/L, meeting discharge limits) but only 10% Ni(II) removal. Na₂S₂O₄ avoids ligand degradation, enabling potential reuse, making it suitable for electroplating/PCB wastewater treatment.

Sodium Dithionite-Mediated Decarboxylative Sulfonylation for Tertiary Sulfone Synthesis

Li, Yaping, et al. Angewandte Chemie International Edition 59.23 (2020): 8907-8911.

Sodium dithionite (Na₂S₂O₄) serves as a dual-functional reagent (SO₂ source and radical initiator) in multicomponent decarboxylative sulfonylation, enabling efficient access to sterically bulky tertiary sulfones—key motifs in pharmaceuticals—without extra initiators.

Experimental Protocol: Redox-active esters (carboxylate-derived N-hydroxyphthalimide esters), Na₂S₂O₄ (1:2 molar ratio to ester), and electrophiles (alkyl halides/phosphates) were reacted in DMF/CH₃CN (2:1) with DIPEA (base), ZnCl₂ (additive), and TBAB (phase transfer catalyst) at 120℃ under N₂ for 15 h. Diverse carboxylic acids (natural products, drugs like ibuprofen) were tested.

Performance Evaluation: The reaction afforded tertiary sulfones in 32–79% yields, tolerating heteroatoms and sensitive functional groups. Kinetic studies confirmed decarboxylation (via single-electron transfer) as the rate-determining step. Na₂S₂O₄'s dual role simplified the process, avoiding toxic SO₂ handling. Natural acids (abietic acid) and drug derivatives (naproxen) converted efficiently, with diastereoselectivity up to 13:1. This green, scalable method is ideal for drug discovery and fine chemical synthesis.