Technology of anaerobic-aerobic purification of wastewater from nitrogen compounds after obtaining biogas

Abstract

The technological parameters, by which the concentration of nitrogen containing compounds can be reduced to 75 % in the process of purification of the waste water from methane tanks after the process of the anaerobic fermentation of the poultry remainder were determined. The influence of the co-substrate structure on the change of the concentration of nitrogen compounds in wastewater in the process of obtaining biogas from the remainder was shown. The co-substrate, which contains more lignin, contributes to double increase in the content of ammonium ions, in relation to the substrates, the content of lignin in which does not exceed 25 %; besides, it does not increase the content of organic compounds in wastewater. The lower content of lignin leads to the fact that the content of organic substances in wastewater is 70 % higher. The technological parameters (time of hydraulic retention, the ratio of the flows in the process of wastewater purification) of the anaerobic-aerobic process of wastewater purification were defined. The obtained laboratory results provide an opportunity to develop the technology of the anaerobic fermentation of the wastes of livestock breeding industry with wastewater reusing in the technological process of anaerobic waste processing. This technology is attractive in cases when in the process of fermentation it is necessary to add water for bringing the content of the methane tank to the optimum humidity; the fermentation of poultry breeding wastes is a good example of such use.