In domestic wastewater, the problem of wastewater odors in sewage network is mainly attributed to H2S evolution and less often to ammonia (depending on the pH of the wastewater). The main source of H2S is the reduction of sulfates by anaerobic bacteria following the reactions:
MgO provides the system with a buffer solution of 9-9,5, prohibits the formation of H2S, which, based on reaction [2]. It is performed through two mechanisms: on one hand, they provide Hydroxide (OH) groups which neutralize the hydrion (H) groups. And on the other hand they prevent the formation of H2SO4 since in values of pH < 9-9.5, the ionised form of H2S is created [reaction 2].
Protection of the sewage network and collection tanks
The corrosion of the sewerage network and tanks is attributed to the formation of H2SO4 through the reaction [3].
pH<7 corrosion of cement
So the protection may be performed in two ways: either with continuous addition of MgO / Mg(OH)2 in parts of the network for pH adjustment or through coating the free surface of the pipes with Mg(OH)2 slurry.