摘要 |
<p>A purification process for waste water and/or waste water sludge, comprising a methane fermentation and subsequent oxidation of the reduced compounds present in the effluent of the methane fermentation by means of aeration, whereby the sulphide from the effluent of the methane fermentation is used as electron donor by the denitrification and whereby the residual reduced compounds from the liquid effluent from the methane fermentation not until the subsequent next step are oxidized by aeration. <??>In this way the suiphldes, produced by the methane fermentation, are used in appropriate way and simultaneously converted in non troublesome or innocent sulphate. <??>In the liquid effluent, remaining after denitrification, the ammonia, which was occurring in the effluent is still present; this ammonia is subsequently oxidized into nitrate at the aeration, whereby the sulphide cannot interfere with, as this sulphide was converted in sulphate with the denitrification. As no sulphide is more present, the aeration is demanding less air and aeration may moreover be more simple. <??>The hydrogen suiphide from the gas formed by the methane fermentation also may be used for this purpose, giving in this way the greatest utility of the products formed with the methane fermentation, while the gas is purified in a simple way. </p> |