However, the GSBR with only primary treatment cannot meet the present effluent standards for municipal wastewater, mainly because of exceeding the suspended solids effluent standard caused by washout of not well settleable biomass.
Con todo, os sistemas GSBR soamente con tratamento primario non poden alcanzar os actuais estándares de depuración de augas residuais urbanas, principalmente debido ao exceso de sólidos en suspensión no efluente que superan os valores límite de emisión.