The present invention concerns a biochemical process for the denitrification of a hypersaline wastewater composition.

A method for chromium removal from post-tanning wastewater includes the following steps: (a) mixing pretreated post-tanning wastewater with an induction reagent to allow an induction reaction; and (b) adjusting a pH of a mixture obtained after the induction reaction to higher than 7.0 for precipitation; where the induction reagent includes a soluble metal salt. In the treatment method of the present disclosure, pretreated post-tanning wastewater is mixed with an induction reagent, a small amount of neutral chromium complexes remaining in the wastewater are converted into cationic chromium complexes under the action of the induction reagent (that is, a charge property of the chromium complex is changed), and then a pH is adjusted for precipitation to remove chromium, which greatly improves the removal efficiency of chromium in wastewater.

The present invention relates to a novel forward osmosis (FO) process for dewatering of a variety of feed solution using low water activity and high osmotic pressure deep eutectic solvent with and without dispersed magnetic nanoparticles as draw solution. In particular, choline chloride-ethylene glycol, choline chloride-glycerol, Fe.sub.3O.sub.4 dispersed in former and latter were utilized as draw solution in FO for one step desalination of brackish and seawater, water recovery from effluent of leather and dye industries, protein and DNA concentration at room temperature. Owing to very low freezing point, the diluted draw solution after FO was recovered through phase separation by chilling at Ca. 10 C. with concomitant production of usable water. Although the present invention focused on specific DES and dispersion of Fe.sub.3O.sub.4 as magnetic nanoparticles but use of other DES having high osmotic pressure and low freezing point and other magnetic nanoparticles dispersion are logical extension of present invention.

Processes are provided which utilize fiber conduit reactors/contactors to effect extraction from a fluid stream, particularly a fermentation broth, a waste stream of a fermentation process, a fluid comprising a dye, or a fluid comprising a pharmaceutical compound. In particular, methods are provided which include introducing a first stream comprising an extractant and a second stream which is substantially immiscible with the first stream into a conduit reactor proximate a plurality of fibers. The streams are introduced into the conduit reactor such that they are in contact with each other and the extractant of the first stream interacts with the second stream to extract a fermentation product, a fermentation byproduct, a dye or a pharmaceutical compound from the second stream into the first stream. The method further includes receiving the first and second streams in collection vessel/s and withdrawing separately the first and second streams from collection vessel/s.

A process of extracting metals from a wet mass includes a step A of concentrating the metals in a carbonaceous solid with a thermochemical treatment of the wet mass, with the ancillary production of a treatment gas; a step B of thermochemical decomposition of the carbonaceous solid in an atmosphere constituted by an operating gas which contains oxygen in substoichiometric quantity to carry out the thermochemical decomposition in order to promote a combination of the metals with substances present in the carbonaceous solid to form salts and others solid compounds and to concentrate the latter in residual ashes of the carbonaceous solid at the same time providing for the formation of a combustible synthesis gas comprising hydrocarbons from the carbonaceous solid; and a step C of extraction of the metals from the ashes produced.

A method of filtering tannery wastewater includes micro filtering a wastewater input of wastewater in at least one micro-filter, thereby splitting the wastewater input into a first retentate stream which includes organic compounds and a first permeate stream. The method further includes establishing, on the basis of the first permeate stream or a derivative thereof, a reverse osmosis input stream. The method further includes performing, on the basis of reverse osmosis input stream, a reverse osmosis filtering by a reverse osmosis filter, thereby establishing a reverse osmosis retentate stream and a reverse osmosis permeate stream. The wastewater includes one or more side streams of a tanning process.