Effluent treatment
First Claim
1. A process for purifying industrial effluent from a plant where dithiocarbamates are made or used and which contains at least 200 p.p.m. dissolved dithiocarbamate consisting essentially of, before discharging the effluent, adjusting the pH, if necessary to a pH of 6 to 8, mixing the effluent at a pH of 6 to 8 with an excess of up to 200% of the stoichiometric amount of at least one soluble heavy metal salt selected from the group consisting of iron and copper and thereby precipitating heavy metal dithiocarbamate, separating the precipitated heavy metal dithiocarbamate from the effluent, discharging the effluent and the said of said precipitate by dumping or incineration.
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Abstract
A purification process for industrial effluent containing dissolved dithiocarbamate is described. Before discharging the effluent, it is mixed at pH 6 to 8 with a soluble heavy metal salt and heavy metal dithiocarbamate thereby precipitated and the precipitate is separated from the effluent. By the process poisoning of fish in water courses into which the effluents are discharged can be avoided as can malfunctioning of sewage treatment processes handling the effluents.
27 Citations
15 Claims
- 1. A process for purifying industrial effluent from a plant where dithiocarbamates are made or used and which contains at least 200 p.p.m. dissolved dithiocarbamate consisting essentially of, before discharging the effluent, adjusting the pH, if necessary to a pH of 6 to 8, mixing the effluent at a pH of 6 to 8 with an excess of up to 200% of the stoichiometric amount of at least one soluble heavy metal salt selected from the group consisting of iron and copper and thereby precipitating heavy metal dithiocarbamate, separating the precipitated heavy metal dithiocarbamate from the effluent, discharging the effluent and the said of said precipitate by dumping or incineration.
- 14. A process for purifying industrial effluent from a plant where dithiocarbamate is made or used and which contains at least 200 p.p.m. dissolved dithiocarbamate consisting essentially of, before discharging the effluent, adjusting the pH if necessary to a pH of 6 to 8, mixing the effluent at a pH of 6 to 8 with an excess of up to 200% of the stoichiometric amount of soluble iron and copper salts, either simultaneously or first with the iron salt and then with the copper salt, thereafter adding an aqueous solution of a high molecular weight polyacrylamide flocculating agent, and thereby precipitating iron and copper dithiocarbamates, separating the precipitated dithiocarbamates froms the effluent, discharging the effluent having a dithiocarbamate content of not more than 2 p.p.m., and incinerating the separated copper and iron dithiocarbamates.
Specification