SU0003122 - Laserfiche WebLink

Home Browse Search

Technical Description NH3 +HOCI NH2Cl (monochloromine) +H2O NFV1 +HOCI NHC12 (dichloromine) +Hz0 NHCl2 +HOCI NCI (nitrogen trichloride) +H2O These reactions are extremely important, as the. disinfecting power of a unit of chlorine as hypochlorous acid is between 25-100 times as great as that of a unit of chlorine as monochloramine. Ifthe effluent has not gone through a quality nitrification/denitrification process,the levels of ammonia at the chlorine contact stage will be high enough to convert the potent chlorine to a less-than-potent monochloramine.In addition to combining with ammonia,hypochlorous acid reacts with amino acids, proteins, and other organic matter to produce chlorine compounds which have very low disinfecting power, and it combines with sulfites, nitrates, and ferrous or manganous ions to produce chlorine compounds which have absolutely no disinfecting power. For this reason, it is very important that if chlorine is to be used, the chlorine receiving effluent be of the highest quality possible. Although the Bio-Pure system is perfectly capable of producing this high-quality effluent at the chlorine contact stage, AquaClear recommends the use of ozone as the preferred method of dis- infection. Should chlorine be required by local ordinance,it is advisable that an ozone generator follow chlorine contact. This will accomplish two things: In virtually all cases it will assure a 99.999% pathogen kill and, at the same time,will convert the chlorine residual to a chlorate which will be taken up by plant life without harm. This conversion is expressed as: 3C1-+03 —)� 3C1+302 --> C1+503 After the SNT pump transfers the supernatant from the clarifier,the clarifier sludge return(SLR)pump returns the sludge, and any floatables which surfaced during the clarification stage, to the aeration chamber for reprocessing. This sludge,along with the fresh incoming waste,becomes the food source for new cell growth and a carbon source for denitrification. Because of this 100% returned-sludge;process, the Bio-Pure system is capable of removing an average of 96%of nitrates. The 100%returned activated sludge(RAS) provides dead bacterial cells as the carbon source for new cell growth.These new cells utilize the NO along with the PO 41 causing removal of nitrates and phosphorus. The dead cells also provide a food source for the incoming bacteria. Upon completion of the sludge return, the MLT pump can again fill the clarifier. Upon completion of the second quiescent settling :period in the chlorine contact chamber, the supernatant is then pumped through tertiary filters, and finally the tertiaried effluent may be dechlorinated and further sterilized by optional ultraviolet light prior to discharge. Settled sludge from each stage,and filter backwash,are returned to the aeration chamber and recycled. If physical pretreatment is incorporated in a buffer tank, settled sludge and backwash may be selectively returned to the buffer tank or to the aeration chamber. ADDITIONAL PRETREATMENT(may not lbe required) DISINTEGRATION. If required, influent may be disintegrated by pretreatment prior to entering the aeration chamber by one of three methods: J