Wang, LK, Wang, MHS (2022). Laboratory Procedures and Apparatus for Chemical Coagulation/Precipitation, Sedimentation, Dissolved Air Flotation, Dispersed Air Flotation, and Filtration. In: “Environmental Science, Technology, Engineering, and Mathematics (STEM)”, Wang, LK, Wang, MHS, and Pankivskyi, YI (editors). Volume 2022, Number 1, January 2022; 51 pages.. Lenox Institute Press, MA, USA. 2022……….ABSTRACT: This publication has been used as one of the lecture materials at the Lenox Institute of Water Technology (LIWT) for the humanitarian environmental education of LIWT , for the continuing education of New England Water Works Association (NEWWA) for both the licensed professional engineers (PE) and the certified water and wastewater operators, and for the technology transfer program of the United Nations Industrial Development Organization (UNIDO) in developing countries. The publication covers the subjects of: (a) chemical coagulation/precipitation simulation; (b) dissolved air flotation (DAF) simulation full flow pressurization systems; (c) DAF simulation partial flow pressurization systems; (d) DAF simulation recycle flow pressurization system; (e) dispersed air flotation simulation batch system; (f) dispersed air flotation simulation continuous systems; (g) simulation of chemical coagulation/precipitation, sedimentation and filtration system; (h) simulation of chemical coagulation/precipitation, flotation and filtration system; (i) experiment of coagulation and flocculation with hydrolyzing metallic salts; (i) experiments of coagulation and flocculation with organic polymers; (k) experiment of batch laboratory flotation test; (l) experiment of dispersed air flotation and foam separation; and (m) pilot plant operation of a dissolved air flotation cell.