Abstract: A process for removing selenium from water is described. Through a biological reduction process, selenium +6 species are reduced to selenium +4 species. A coagulant is mixed with the water and as a result, solids having complexation binding sites are formed. The reduced selenium +4 species is adsorbed onto the complexation binding sites of the solids. Thereafter, the solids having adsorbed selenium +4 species is separated from the water and ultimately separate from the process. The resulting effluent is subjected to a second biological treatment under aerobic conditions which converts residual selenium and organo-selenium to selenate.

Abstract: A self-locking system comprising a state selector for detecting the intent of an occupant to rise from a chair and then automatically causing a lock to block the mobility functions of the chair. The state detector is responsive to movement of an upper portion of the body of the occupant while the occupant is still supported in a normal seated position on the seat of the chair, thereby advantageously allowing the locking of the mobility functions of the chair to occur before the occupant starts to lift his weight from the seat of the chair.