Inhibition of mineralization on nitrogen compounds from leachate of aquatic macrophyte: methodological adequacy - DOI: 10.4025/actascibiolsci.v30i3.3610

Abstract

This study aimed at establishing the adequate concentrations of nitrapyrin for effective inhibition of oxygen demand required by nitrogen compounds oxidation during aerobic mineralization of the leachate. The aquatic macrophyte Myriophyllum aquaticum was used as dissolved organic matter (DOM) source. The leachate was incubated in several chambers which contained different composition and treatments: (i) treatment with leachate (DOM), (ii) treatment with DOM plus nitrapyrin in different concentrations (10 mg L^-1; 25 mg L^-1 and 50 mg L^-1), aiming at finding the right concentration that inhibits nitrification process, (iii) treatment with DOM plus NH₄SO₂ (iv) treatment containing DOM and nitrapyrin plus NH₄SO₂ and (v) treatment with DOM plus azide. The dissolved oxygen amount in each treatment of incubations was periodically measured. The results indicated that the ratio of 10 mg L^-1 of nitrapyrin for each 10 mg C of leachate is efficient in inhibition of the oxidation of nitrogen compounds from aquatic macrophytes.