Like our teeth, placoid scales have an inner core of pulp (made up of connective tissues, blood vessels, and nerves), which is covered by a layer of dentine (hard calcareous material). This dentine is covered by enamel-like vitrodentine.Scales in bony fish grow as the fish gets larger, but placoid scales stop growing after they reach a certain size, and then more scales are added as the fish grows.his dentine is covered by enamel-like vitrodentine. Scales in bony fish grow as the fish gets larger, but placoid scales stop growing after they reach a certain size, and then more scales are added as the fish grows.
Wet air oxidation is a promising technology for the treatment of refractory organic pollutants in the effluent from various industries in view of high pollutant removal efficiency at mild conditions and environmental friendliness not involving any harmful chemical reagent.
drain line: A pipe line which is used to carry water from the water treatment system to a waste system. drinking water: A water treated or untreated which is intended for human use and consumption and considered to be free of harmful chemicals and disease-causing bacteria, cysts, viruses or other microorganisms.