METHOD FOR STENCH SUPPRESSION AND EROSION CONTROL IN WASTE/RAINWATER CONDUITS AS WELL AS IN PUMP STATIONS WITH USE OF AMMONIA NITRATE OR CALCIUM NITRATE SOLUTIONS

摘要

Method for the suppression of stench produced by H2S production or by other compositions such as skatol under non-aerobic conditions in rainwater /waste networks as well as in pump stations, which method is based on the controlled addition of the ammonia nitrate (NH4NO3) or calcium nitrate solution (Ca(NO3)2)) both ensuring the permanent presence of the azote nitrate into pump stations and conduits. The addition of nitrates increases the oxidation-reduction potential and provides soluble oxygen impeding the creation of non-aerobic conditions. In septic wastes the addition of nitrates oxidizes the H2S into sulphates while the quantity of the nitrates remaining after oxidation suspend the further production of the H2S, the absence of which abolishes the consequential modification thereof into sulfuric acid having high erosive effects on the concrete of the conduits. The required supply of the solution is determined by the hydraulic characteristics of the rainwater/wastes network; this supply should guarantee a minimum concentration of nitrogen nitrate (1mg/lt) even at the most remote point of the network; indicatively, the proportion is 0,02-0,06 mg/lt of nitrate ammonia or nitrate calcium by m3 of wastes, the waste being under 25deg. Celcius temperature.