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.

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.

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 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.

An apparatus includes a process chamber, a controllable compressor for pressurizing a fluid, a pressure reducing member, an inlet for a processing agent and a controller. The process chamber is a pressure chamber. The controllable compressor pressurizes a fluid and introduces the pressurized fluid into the process chamber from a source. Further the controllable compressor controls a predefined pressure in the process chamber to reach a supercritical state of the fluid. An inlet for a processing agent facilitates introduction of the processing agent into the process chamber prior to, during, or subsequent to pressurization of the fluid. The pressure reducing member reduces the pressure of the fluid at least to reach a gaseous state subsequent to processing the leather object such that the time for reduction of pressure exceeds a predefined reduction period or the reduction of pressure does not exceed a predefined leather pressure reduction gradient.

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.

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.

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.

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.

A process of chemical cleavage of leather or skins containing chromium The process using sodium, potassium or calcium methylates (CH.sub.3O.sup.?) or ethylates (CH.sub.3CH.sub.2O.sup.?), producing chromium hydroxide (green paste), ammonium sulfate and liquid fertilizer. The chromium trioxide III (Cr.sub.2O.sub.3) obtained was used in the production of FeCr alloy. The liquid fertilizer was applied to strawberry, violet and acerola crops, and can be applied to other types of crops. The fertilizer is also compatible with pesticides, being able to compose a composition containing fertilizer and pesticide or even used to obtain products containing fertilizers and pesticides, which allow application in a single step, exempting the process in the field A solid NPK fertilizer formulation obtained by combining N recovered from waste and homogeneously mixed with K and P salts.