A method for cleanup of circulated rolling oil including gravity separation followed by size separation. The method includes supplying the circulated roiling oil to a separation chamber of a rotating centrifugal rotor and separating water and solid debris from the circulated rolling oil by centrifugal force. Oil, oil-water emulsion, and some residual debris may be recovered and supplied to a ceramic membrane having a pore size of 1.5 micron or smaller. A purified oil sample is recovered from the membrane, along with a reject including the oil-water emulsion and residual debris. The reject may be further concentrated by gravity separation and recycled to the membrane to recover further amounts of oil.

A system and process for recycling machining waste into a solid/scrap material component and a recyclable machining coolant. The system and process comprise collecting the waste machining waste and mechanically separating the machining waste into a solid/scrap material component and a machining waste liquid component. The machining waste liquid component is decanted to separate oils and solids from the recyclable machining coolant. The machine recyclable machining coolant is then filtered through at least a first filter and preferably a second, finer mesh filter. The recyclable machining coolant is then exposed to UV light to kill bacteria and microorganisms. Lastly, ultrapure water is added to dilute the recyclable machining coolant and form the recycled machining coolant. If desired, a virgin machining coolant can be added to the recycled machining coolant, to replenish any additive(s) stripped during the recycling process, prior to resale of the recycled machining coolant.

A method for eliminating legionellae from water of a cooling circuit of industrial plants, in particular of a hot rolling mill, is disclosed. The water is loaded with organic substances and inorganic particles. In a further aspect, the use of bacteria for eliminating legionellae from a water of a cooling circuit of an industrial plant is disclosed.

A method for eliminating legionellae from water of a cooling circuit of industrial plants, in particular of a hot rolling mill, is disclosed. The water is loaded with organic substances and inorganic particles. In a further aspect, the use of bacteria for eliminating legionellae from a water of a cooling circuit of an industrial plant is disclosed.

A purification system and a method for purification of slop oil and industrial emulsions, wherein the purification system can handle two processes in parallel, a slop oil purification process and an industrial emulsion purification process, said system comprising: —at least one slop oil centrifugal separator (5) into which slop oil is provided for separation of water and oil; —at least one emulsion centrifugal separator (25) into which an industrial emulsion is provided for separation of oil and water; —a first redirecting fluid connection (37, 37′) arranged for transferring oil separated from the industrial emulsion in the emulsion centrifugal separator (25) to the slop oil centrifugal separator (5) possibly via a slop oil tank (3).

A purification system and a method for purification of slop oil and industrial emulsions, wherein the purification system can handle two processes in parallel, a slop oil purification process and an industrial emulsion purification process, said system comprising: —at least one slop oil centrifugal separator (5) into which slop oil is provided for separation of water and oil; —at least one emulsion centrifugal separator (25) into which an industrial emulsion is provided for separation of oil and water; —a first redirecting fluid connection (37, 37′) arranged for transferring oil separated from the industrial emulsion in the emulsion centrifugal separator (25) to the slop oil centrifugal separator (5) possibly via a slop oil tank (3).

A method of treating cooling circuit water of industrial plants (2) contaminated with organic substances and inorganic particles, comprises the following steps: a) separating the organic substances and inorganic particles from the cooling circuit water to obtain precleaned cooling circuit water; b) cooling the precleaned cooling circuit water by an open cooling tower (11) to obtain cooled precleaned cooling circuit water; c) desalinating at least a partial volume flow of the cooled precleaned cooling circuit water by an desalination plant (14) to obtain cleaned cooling circuit water; and d) adding bacteria capable of degrading organic substances present in the cooling circuit water. The bacteria are added to the cooling circuit water before the separation in accordance with step a), before the cooling in accordance with step b) and/or before the desalination in accordance with step c), to form a biological cleaning stage.

A purification system and a method for purification of slop oil and industrial emulsions, wherein the purification system can handle two processes in parallel, a slop oil purification process and an industrial emulsion purification process, said system comprising: at least one slop oil centrifugal separator (5) into which slop oil is provided for separation of water and oil; at least one emulsion centrifugal separator (25) into which an industrial emulsion is provided for separation of oil and water; a first redirecting fluid connection (37, 37) arranged for transferring oil separated from the industrial emulsion in the emulsion centrifugal separator (25) to the slop oil centrifugal separator (5) possibly via a slop oil tank (3).

A purification system and a method for purification of slop oil and industrial emulsions, wherein the purification system can handle two processes in parallel, a slop oil purification process and an industrial emulsion purification process, said system comprising: at least one slop oil centrifugal separator (5) into which slop oil is provided for separation of water and oil; at least one emulsion centrifugal separator (25) into which an industrial emulsion is provided for separation of oil and water; a first redirecting fluid connection (37, 37) arranged for transferring oil separated from the industrial emulsion in the emulsion centrifugal separator (25) to the slop oil centrifugal separator (5) possibly via a slop oil tank (3).

A system and process for recycling machining waste into a solid/scrap material component and a recyclable machining coolant. The system and process comprise collecting the waste machining waste and mechanically separating the machining waste into a solid/scrap material component and a machining waste liquid component. The machining waste liquid component is decanted to separate oils and solids from the recyclable machining coolant. The machine recyclable machining coolant is then filtered through at least a first filter and preferably a second, finer mesh filter. The recyclable machining coolant is then exposed to UV light to kill bacteria and microorganisms. Lastly, ultrapure water is added to dilute the recyclable machining coolant and form the recycled machining coolant. If desired, a virgin machining coolant can be added to the recycled machining coolant, to replenish any additive(s) stripped during the recycling process, prior to resale of the recycled machining coolant.