DSD acid (4,4 diaminostilbene mono-2,2 bisulfonic acid) is an important dye intermediate, mainly used to manufacture fluorescent brighteners, direct frozen yellow G, direct yellow R, sunlight-resistant orange F3G and anti-moth-eating agents. The COD is 6000-8000mg/L, salinity is 6%-8%, and color is 50,000 times; the main components of wastewater are aromatic organic compounds with nitro, amino and sulfonic groups, and the ratio of BOD to COD is only 0.03, which is extremely difficult to biodegrade.

The water quality and water quantity of DSD acid production wastewater are stable, but the chromaticity and sulfate concentration are very high, the nutrients such as N and P are lacking, and the wastewater contains toxic and harmful substances, there is no successful treatment example in China. dsd acid is a light yellow paste or powder, soluble in ethanol and ether, insoluble in water, soluble in alkali solution. (2) It is easily oxidized to red, and has the properties of aromatic acids and amines at the same time.

3) Product quality and technical index: total amino value (according to the total amount of paste) ≥48%; dry product total amino value (according to the total amount of drying samples) ≥95.0%; alkali insoluble matter content (by the total amount of paste) ≤0.05%; alkali insoluble matter content (by the total amount of powder) ≤0.08%; benzyl matter (by the total amount of samples) ≤0.25% for the production of fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent, fluorescent whitening agent. Direct frozen yellow G and direct yellow R, and used as an insecticide.

Organic compound abbreviation. The full name is 4,4`-diaminostilbene-disulfonic acid. It can be used for the synthesis of fluorescent whitening agent and other dyes. CAS No.： 81-11-8 Molecular Formula：C14H14N2O6S2 Molecular Weight：370.4008 Quality Index（Specification） Appearance（Appearance）： light yellow powder/light yellow paste Content（Purity）： ≥95. 0 Packing（Package）： 25 mg/kg.

0 Packing (Package): 25kg/40kg/bag Physical Properties Molecular Weight: 370.4, yellow or light yellow crystal with hygroscopicity. It is easy to oxidize in air. This product is toxic and irritating to the skin, avoid direct contact with the human body.

Synthesis method: The current synthesis method is p-nitrotoluene sulfonated with fuming sulfuric acid, then precipitated with water, and the separated NTS is oxidized under alkaline conditions with air, and the DNS in the oxidation solution is precipitated with salt, then reduced with iron powder, and then precipitated with sulfuric acid. The powder is dried and dried. The powder is sold as a wet product for domestic sales, but is only sold in powder form for international trade.

Mit-ivy industry company mainly produces DSD ACID with an annual production capacity of 1,000,000 tons, and has an absolute market share of 97%.