A new method for sodium sulfide removal from an aqueous solution and application to industrial wastewater and sludge

Abstract

The catalyst activities for Na2S oxidation in aqueous solution were examined for various materials such as activated carbon, carbon black, ferric salts, hydroquinone, 1,4-naphthoquinone-2-sulfonic acid sodium salt, 1,4-naphthoquinone, and their mixed systems.The following conclusions have been drawn: (1) These catalyst systems are all active. (2) The effect of carbon black-ferric sulfate-system or hydroquinone-ferric chloride-system on oxidation efficiency is larger than that of carbon black or hydroquinone alone. (3) In case of carbon black system, the experimentally determined requirement of air is, respectively, about 40, 15, and 10 times larger than theoretical, corresponding to the runs of no catalyst, carbon black, and carbon black-ferric sulfate-system. In case of hydroquinone system, air requirements are, respectively, about 40, 15 and 8 times, corresponding to the runs of no catalyst, hydroquinone-ferric chloride-system and hydroquinone-ferric chloride-ammonium peroxydisulfate-system. (4) Application of the catalyst systems studied was made to wastewater and sludge treatments. These catalyst systems gave good results.

A catalyst based on 3,3′,5,5′‐tetra‐tert‐butyl‐4,4′‐stilbenequinone used in the liquid‐phase oxidation of sodium sulfide

“…It is known that reaction proceeds much faster than reactions and . Therefore, thiosulfate and sulfate ions are the main products of sulfide sulfur oxidation by oxygen.…”

“…As shown by previous studies, the most effective method of sulfide sulfur treatment in the wastewater involves its oxidation in atmospheric oxygen in the presence of a catalyst. Several heterogeneous and homogeneous catalysts have been employed to catalyze the reaction between toxic sulfide and oxygen, forming less harmful sulfur compounds such as thiosulfate and sulfate.…”

“…On another note, nontoxic and economical catalysts based on quinone compounds such as 1,4‐naphthoquinone, 1,2‐naphthoquinone‐4‐sulfonic acid sodium salt, polynaphthoquinone, benzoquinone, duroquinone have been recently applied to sulfide sulfur purification, particularly in petrochemical industry of both Japan and the UK. However, the disadvantages of these catalysts include low catalytic activity, high catalyst losses, and the complexity of the catalyst separation after oxidative treatments . With the view to overcoming these drawbacks, we propose a new quinone‐catalyst based on 3,3′,5,5′‐tetra‐tert‐butyl‐4,4′‐stilbenequinone (hereinafter referred to as stilbenequinone or C 30 H 42 O 2 ) that performs high catalytic activity, selectivity, and stability in alkaline media.…”

Sulphide removal from petroleum refinery wastewaters by catalytic oxidation

“…The oxidation of sulphide to sulfur is preferable since this requires the least amount of electrons and thus less energy input is needed [19]. Several researchers have also performed the catalytic oxidation of sulphide using sulphur black dye [24], carbon black, FeCl 3 [25,26] and hydrogen peroxide [27] as catalysts.…”

Remediation of Sulfidic Wastewater by Aeration in the Presence of Ultrasonic Vibration

“…Chemical oxidation involves the removal of electrons and removal or addition of hydrogen [7]. In water and wastewater engineering, chemical oxidation serves the purpose of converting putrescible pollutant substances to innocuous or stabilized products [11]. Reserachers in [9, [12][13][14][15][16] investigated the oxidation of sulfides in the presence of catalyst, however, catalytic oxidation suffers from certain drawbacks and it is not economically suitable for large continuous treatment processes.…”