Dear Jacky,

Toxicity Produced in the Biogas Plant Due to Excess Urine

Nitrogen is an essential major plant nutrient which is abundantly present in the animal and human urine. In the biodigester operated with human toilet, if urine is added in large quantity, there is every possibilities to produce toxicity because of the accumulation of ammonium. As indicated above, presence of HN4 greater than 200 mg/litre and NO3 (nitrate) above 50 mg/litre can cause toxicity thereby inhibiting the activities of the microbes. Therefore, in our plant at Pathari, urine collected particularly from three urinals of the male compartment were not added to the biodigester .

The excess urine that is not added to the biodigester can be collected in a separate tank to which dried plant materials can be added in large quantity to soak with the urine in order to make nitrogenous fertilizer so needed by the farming community.

Best regards!