a wastewater treatment process providing nitrogen , phosphorus , biochemical oxygen demand and suspended solids removal comprises the steps of : passing wastewater containing ammonia nitrogen , phosphate , bod and suspended solids , said wastewater mixed with recycled activated sludge from a subsequent step , into a first anoxic zone therein reducing nitrate nitrogen from the recycled sludge to molecular nitrogen ; passing effluent from the first anoxic zone to a first aerobic zone therein oxidizing at least a portion of the bod and oxidizing at least a portion of the ammonia nitrogen to nitrate nitrogen ; recycling a portion of the contents at the end of the first aerobic zone back to the first anoxic zone ; passing the effluent of the first aerobic zone to a second anoxic zone ; introducing volatile fatty acid such as acetic acid into the second anoxic zone therein releasing phosphorus into a liquid phase ; passing effluent from the second anoxic zone including the volatile fatty acid to a second aerobic zone therein substantially absorbing phosphorus into biomass and removing and / or oxidizing ammonia nitrogen ; passing effluent from the second anoxic zone to a final settling zone therein separating : a purified wastewater having decreased nitrogen , phosphorus , bod and suspended solids and a sludge containing suspended solids , phosphate and bod ; and recycling at least a portion of the sludge to the first anoxic zone . in another embodiment , at least a portion of the sludge is also recycled to the second anoxic zone . in yet another embodiment , the second anoxic zone is divided into a first section and a second section . in the first section , anoxic conditions are established and in the second section , volatile fatty acid is added after anoxic conditions have been established .