摘要:
The present invention in one embodiment, is a process that uses a chemical treatment to remove arsenic, organic acids, and heavy metals from antifreeze solutions. In one aspect such a method includes adding an iron salt, to an antifreeze solution containing arsenic and heavy metals with adequate mixing for dispersion throughout the solution. Then, a base is added to increase the pH to a level from about 8 to 10. As the base is added, a precipitate forms and is then removed by standard filtration techniques. The arsenic, organic acids, and heavy metals co-precipitate with the iron and are removed by filtration. The process may either be a batch process or a continuous process.
摘要:
A process for treating acid wastewater containing heavy metals has been invented, the process including adding fly ash to the acid wastewater to reduce heavy metals content of the acid wastewater. In one aspect the acid wastewater contains soluble iron and adding fly ash reduces the level of soluble iron. In one aspect the acid wastewater contains sulfate ions and adding fly ash reduces the sulfate ion level. In one aspect solid silicate salts are added to the acid wastewater. Preferably undesirable very hydrous iron hydroxide precipitate is not formed. In certain aspects the pH of the acid wastewater is raised to an environmentally acceptable level. In one aspect the process is a batch process. In another aspect the process is a continuous process.
摘要:
The present invention, in certain embodiments, teaches a process for treating ammonia or ammonium-sulfate-containing waste effluent from an acrylonitrile, caprolactam or acetonitrile manufacturing facility. In one such process the effluent is fed to a deep well oxidizer, e.g. a water oxidizer vertical tube reactor (super critical or subcritical), to degrade organic contaminants. Certain embodiments of the deep well oxidizer have, according to this invention, an oxygen inlet tube movable by a coil tubing system. The output stream from the vertical tube reactor is, preferably, filtered, and then it is fed to an electrodialysis unit. In one aspect the electrodialysis unit produces an output stream at a pH of about 5 with a concentration of ammonium sulfate at least, preferably, of about 15% by weight, and most preferably between about 20% and about 26% by weight. This output stream may be neutralized and then further treated to remove ammonia and/or ammonium sulfate solids, e.g. by a downstream ammonia stripper, evaporator, and/or crystallizer system or combination thereof.