Nitrogen Removal and complete purification in raw and digested zootechnical manures

The Bioflottazione system has been applied successfully for some years to the treatment of zootechnical manures (pigs, calves, cattle, poultry, etc.) either as raw or after anaerobic digestion. The system is applied for the nitrogen removal (>70%) of such manures, in order to reduce the land surface necessary for their fields spreading so to respect  the European Directive 91/676/CEE (Nitrates Directive), or for the complete purification within the law limits when associated to micro/ultrafiltration systems (MBR).

As confirmed in pilot tests, applying the Microbioflottazione process to the new plants in the zootechnical fields for the nitrogen removal, important advantages, in terms of plant and running costs reduction, are obtained.

Function basis

NITROGEN REMOVAL
The plant for the nitrogen_removal contained in raw zootechnical manures and/or in the digested manures after anaerobic digestion of raw manure mixed with “green” wastes utilizes a particular Nitro-Denitro process in alternative sequence in a single tank CSRT (Completely Stirred Reactor Tank), named Microbioflottazione, whose efficiency is based on the high breathing capacity of the biomass formed in the treatment tank, thanks to the unique oxygenization system installed.

What follows is a fast and important transformation of the organic load and nitrogen in carbon dioxide, elementary nitrogen and water, allowing to this treatment technology to avoid excess biological sludge production to be disposed in the nitrogen_removal case for the  field spreading.

The high oxygen transfer capacity from the gas to the liquid phase due to the peculiarity of the technology installed in the tank supports, in fact, an extremely efficient biological activity. 

PHOSPHOROUS AND POTASSIUM REMOVAL
The plant is already predisposed to meet the future law limits for the parameters Phosphorous and Potassium in the manure to be spreaded on the fields.

In order to accomplish the removal of such parameters, in the range of 40 – 90% according to the necessities, the plant must be up-graded with a second treatment phase, which can vary from a simple or advanced biomass separation (sedimentation or micr/ultrafiltration) to a chemical-physical-biological section, before the storage/spreading.

Automation
All the plant are equipped with PLC and control panel with grafic interface for the complete automation of the whole process and with continuous control system of the fundamental parameters  such as OD, pH, Temperature, RedOx and, according to necessities, of some advanced parameters such as SST, NH4, NOx etc. The automation system, furthermore, verifies and automatically runs transfer flow rates, HRT, oxygenization, levels, process times, etc. All the plants can be equipped with tele-service system for the remote control and operation of the whole process.