Treatment of DSD acid wastewater using a weak basic resin

Use of 4,4′-Dinitrostilbene-2,2′-Disulfonic Acid Wastewater As a Raw Material for Paramycin Production

“…Generally, the DNS yield from the oxidation of NTS is only 85% or less, and about 15% of the reactants are transformed into various byproduct through three main routes (Section 1 in the Supporting Information) , . Therefore, the concentration of ASAs remains high in the wastewater and, as a result, is extremely toxic to organisms , . Direct discharge of the wastewater will cause serious environmental problems.…”

“…More than 15 kilotons of NTS are therefore transformed into various ASAs, which are dissolved in water forming 2 million m 3 of DNS wastewater (COD∼2 × 10 4 mg L −1 ) . There are several methods for treating this wastewater on an industrial scale, including biological degradation, oxidation with Fenton’s reagent, ozonation, resin absorption, and incineration − . However, biological processes cannot degrade the ASAs in wastewater effectively; resin absorption produces mixtures that require further treatments; the Fenton’s reagent and ozone oxidation methods are more effective but are still unable to recycle ASAs (Scheme , Route I).…”

A novel method for the recovery of 4,4′-dinitrostilbene-2,2′disulfonic acid from the wastewater obtained from 4,4′-diaminostilbene-2,2′-disulfonic acid production

“…Moreover, since DNS, ANSD and DSD constitute the major proportion of the organic compounds dissolved in the wastewater (Fig. 3b), recovery of those compounds would also facilitate subsequent wastewater treatment [16][17][18].…”

Solubility of Na2CO3 and NaHCO3 in Aqueous Sodium Sulfate Solutions and Its Application to Separating Na2CO3 and Na2SO4 Salt Mixtures

“…As a consequence of the low reaction efficiency of the oxidation process, the wastewater produced in the oxidation process contains high concentrations of various substituted derivatives of aromatic compounds as well as inorganic substances (mainly Na 2 SO 4 ) and cannot be discharged directly. Over the past decades, several methods have been investigated for treating this wastewater and recovering the valuable resources, including oxidation with Fenton’s reagent, complexometric extraction, and resin absorption. ,− However, some deficiencies restrict their wide application in industry. Fenton’s reagent is an efficient oxidizing agent to degrade the organic substances, but it has a high cost and is better used in dilute solution.…”