A process for leather production from a raw animal hide includes the steps of pre-soaking, soaking, unhairing and liming, re-liming, deliming and bating, pickling and tanning, degreasing, re-tanning, neutralizing, dyeing and fatliquoring, and washing the processed hide. Waste liquid is collected from at least one of the foregoing steps is recycled to at least one of the foregoing steps. The collected waste liquid can be recycled to the same step, to a different step, or to two of more steps in the process.

A system and method for a chromium recovery process for recovering chromium from byproducts resulting from a tannery process. A system and process for solubilizing chromium contained in the oil byproduct into the remaining water content within the oil and extracting the water from the oil with the chromium sufficiently solubilized in the water such that the chromium content in the oil is sufficiently reduced below hazardous levels.

Water treatment systems and associated methods are generally described. Certain embodiments of the water treatment systems and methods described herein may be used to treat water comprising one or more contaminants (e.g., oil, grease, suspended solids, scale-forming ions, volatile organic material) to remove at least a portion of the one or more contaminants. In some embodiments, at least a portion of the treated water may be used directly in certain applications (e.g., oil and/or gas extraction processes). In some embodiments, at least a portion of the treated water may undergo desalination to produce substantially pure water and/or concentrated brine.

A metal removal system and method are disclosed. An example method includes providing a sorptive media and providing a primary ligand having an affinity for the sorptive media, the primary ligand being an amphipathic, heterocyclic metal-coordinating compound. The method also includes providing a co-ligand having an affinity for the sorptive media. During a treatment process, a metal removal response is observed to be non-proportional between expected metal removal ability based on individual metal coordination abilities of the media alone and of all ligands, and actual net metal removal capacity resulting from a heterogeneous cooperation of the primary ligand and the sorptive media and activated by the co-ligand.

A plant for the disposal of wastes includes a supercritical water oxidation reactor, a supercritical water gasification reactor, and a feeding system configured for feeding at least two organic currents of wastes to the supercritical water oxidation reactor and supercritical water gasification reactor and configured for feeding at least one aqueous flow within said plant. The feeding system is configured for feeding the at least one aqueous current with a series flow through the supercritical water oxidation reactor and supercritical water gasification reactor. The feeding system is configured for feeding the at least two organic currents of wastes with a parallel flow through the supercritical water oxidation reactor and supercritical water gasification reactor and so as to selectively feed each of the organic currents of wastes to the supercritical water oxidation reactor or to the supercritical water gasification reactor.

The invention relates to a process for the purification of water and/or dewatering of sludges and/or sediments, to the use of a combination of a phyllosilicate and a surface-treated calcium carbonate for water purification and/or dewatering of sludges and/or sediments, as well as to the use of a combination of a phyllosilicate and a surface-treated calcium carbonate for reducing the amount of polymeric flocculation aids in water and/or sludges and/or sediments and to a composite material comprising at least one surface-treated calcium carbonate, at least one phyllosilicate and impurities originated from different sources obtainable by said process.

This invention provided a preparation method of the composite which was immobilized Paracoccus denitrificans on modified graphene oxide and its application. The composite was obtained by following the steps below: 1) Synthesis of graphene oxide; 2) Synthesis of modified graphene oxide; 3) Acclimatization and immobilization of Paracoccus denitrificans. In this invention, the raw materials were low-cost and easily obtained used in the preparation process; easy operation, convenient, and no expensive instruments during the whole process; this invention of the composite could remove DMF from wastewater completely, and with the advantages of high efficiency, good recycle performance, economical, environmentally friendly, better feasibility.

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

The present invention provides a low pressure anion exchange chromatographyturbidimetric method for simultaneous online analysis of trace S.sup.2 and Cl.sup. in water samples using an apparatus comprising a low pressure pump, a sample valve, a sample loop, a low pressure anion chromatographic column, a reactor, an optical flow cell, an optical detector, a computer system, a mixer, a sample flow path, a propelling solution flow path, and a color developer solution flow path, the method comprising: (a) mapping a baseline; (b) mapping spectrogram of S.sup.2 and Cl.sup. in test samples; (c) mapping standard working curves; and (d) calculating the concentrations of S.sup.2 and Cl.sup. in the test samples based on the peak heights of S.sup.2 and Cl.sup. in the spectrogram and the regression equations of standard working curves. In this method, a chromatography method is combined with a turbidimetric method for the first time to realize simultaneous online analysis of trace S.sup.2 and Cl.sup. in water samples, and the method is endowed with the advantages of fast analysis speed, high analysis efficiency and low analysis costs.

A recycling process for achieving near-zero emissions of tannery effluent is characterized in that effluent recycling is carried out independently in soaking, liming, re-liming, de-liming bating, pickling chrome tanning, re-tanning, neutralizing, and dyeing procedures. The effluents in the above procedures can be recycled in each step. This process greatly reduces effluent discharge and helps solve the problem of tanning pollution. The process also improves the quality of the finished leather, effectively decreases loose grain rate and increases compactness and fullness of the finished product. The project can reduce chemical material consumption by 15%-55%. For example, the consumption of chromium powder can be reduced up to 65%. Consumption of other chemical materials can be reduced by more than 90%, while certain chemical materials can be essentially completely conserved.