Complex sentence: Coarse material such as beach sand is removed in sand traps, finer residue is settled in raking thickeners along side synthetic flocculants, and solids in the thickener overflow are removed by cloth filters.
Split into simpler sentences: Coarse material such as beach sand is removed in sand traps. Finer residue is settled in raking thickeners with the addition of synthetic flocculants, and solids in the thickener overflow are removed by cloth filters.