Abstract: This invention relates to an improvement in a process for the production of dinitrotoluene and particularly to the recovery of dinitrotoluene and organic by-products from the wastewater and wash waters generated in the process. Wastewater and wash water streams contaminated with residual levels of mononitrotoluene, dinitrotoluene, and organic by-products, formed in the purification process, are contacted with toluene. An organic phase and an aqueous phase are generated. The phases are separated and the dinitrotoluene recovered from the organic phase.

Abstract: A single step wet oxidation process for treating wastewaters containing organic species, with or without heteroatoms, and anions of strong acids, e.g. sulfate or phosphate ion, or cations of strong bases, e.g., sodium, potassium or calcium ions, and which may contain ammonium ion and/or nitrate ion in addition to added ammonium ion and/or nitrate ion was developed which on thermal treatment near the critical temperature of water removes substantially all the COD and nitrogen through conversion to water, carbon dioxide or carbonate species, nitrogen gas and small amounts of nitrous oxide. Key to the success of the process is the balancing of all reducing species with an equivalent amount of oxidizing species and the balancing of all strong acid anions with strong base cations and including at least 0.06 acetate ion for moles of nitrate in the wet oxidation process.

Abstract: A single step wet oxidation process for treating wastewaters containing organic species, with or without heteroatoms, and anions of strong acids, e.g. sulfate or phosphate ion, or cations of strong bases, e.g., sodium, potassium or calcium ions, and which may contain ammonium ion and/or nitrate ion in addition to added ammonium ion and/or nitrate ion was developed which on thermal treatment near the critical temperature of water removes substantially all the COD and nitrogen through conversion to water, carbon dioxide or carbonate species, nitrogen gas and small amounts of nitrous oxide. Key to the success of the process is the balancing of all reducing species with an equivalent amount of oxidizing species and the balancing of all strong acid anions with strong base cations. The former ensures good removal of organic species, ammonium ion and nitrate ion. The latter ensures maintaining the pH in the range of from 1.