an antiwear additive found in many types of hydraulic and
lubricating fluids. Zinc dialkyldithiophosphate.
The temperature of pure melting ice under standard atmospheric
pressure on the Centigrage and Réaumur scales.
Zero discharge water
A discharge limit applied to manufacturing and commercial establishments in
which only normal human sanitary wastewaters may be discharged to the municipal
sewerage system. All other types of wastewater, such as that water used in
manufacturing processes, are not included in zero discharge water; these
wastewaters must be recycled, and the resulting waste products must be taken to
an alternate and approved disposal facility.