11 Water and waste water treatment apparatus, installations and plants, namely, reverse osmosis units, forward osmosis units, water filtration units, membrane filtration units, water sterilization units, water purifying apparatus, water and wastewater concentration units, water recovery units, water desalination plants, sewage treatment plants; desalination apparatus, installations and plant, namely, water desalination units and plants, intake systems, pre-treatment systems, membrane desalination units, thermal desalination units and post-treatment systems; sewage treatment apparatus, installations and plant, namely, thickening and dewatering machines for use in treatment of liquids including water, industrial effluent and sewage, apparatus and installations for decomposing toxic substances in water, sewage treatment plants, biological treatment units, chemical treatment units, filtration units, aeration units and membrane treatment units; water supply apparatus, namely, water purification, sedimentation and filtration apparatus for clarification, thickening and filtration of water, waste water and industrial water, regulating accessories for water supply, namely, metered valves and pipes