Dvanced treatment of wastewater can include any of the following except

1. reverse osmosis.
2. sand and gravel filtration.
3. phytoremediation.
4. charcoal filtration.

2. sand and gravel filtration.

Explanation:

Sand and/or gravel filters are made at home usually comprising of a pipe or tub filled with sand and gravel, while the advanced commercial systems usually filters contain other filtration media and processes such as charcoal filtration phytoremediation reverse osmosis

Wet oxidation

Activated sludge systems

Upflow anaerobic sludge

Vacuum evaporation

blanket digestion

Anaerobic filter

Urine-diverting dry toilet

Vermifilter

Activated sludge model