Waste management - Collection, transport, processing, monitoring, recycling and disposal of waste materials.

Waste oil - Used cooking oil (mainly vegetable oil and animal fat) that can be converted into fuels such as biodiesel.

Waste separation and off-take - Sorting of solid wastes at the industrial facility to assist its exchange, recycling, incineration or disposal.

Waste vegetable oil biodiesel - Biodiesel produced from waste vegetable oil.

Wastewater sulfur stripping units - Mechanisms designed to remove hydrogen sulfide and ammonia from refinery wastewater.

Water grades - System designed by China to grade water quality that uses a scale ranging from I to V+, with grades I through III fit for human consumption.

Water productivity - The ratio of goods and services produced over the volume of water required for their production; measures the efficient use of water.

Water reinjection - Reinjection of water recovered at Gas Oil Separation Plants (GOSPs) back into oil reservoirs as a method of enhanced oil recovery.

Wide area management systems (WAMS) - Integrated systems that monitor and control elements of the electrical power grid to ensure availability and improve reliability and efficiency of the network.

Wind assessment - Process of assessing the quality of wind at a particular location for the purpose of estimating future potential energy production of a wind farm if it were to be installed at that location.