Nitrogen recovery from wastewater and human urine with hydrophobic gas separation membrane: experiments and modelling

Abstract

In agriculture, the human urine could have been used as a natural fertilizer, although there are some problems with the direct utilization, such as the presence of micropollutants in urine, odour and storage of large volume of urine. Therefore, nutrients, such as nitrogen, can be recovered from urine. Continuous flow laboratory membrane reactor was built to investigate nitrogen recovery from wastewater and from human urine. Membrane gas separation method has not been investigated for ammonia recovery from human urine yet. Nitrogen as ammonia gas was recovered in acid using Zeus Aeos™ ePTFE gaspermeable hydrophobic membrane. Acid flux, operating pH, hydraulic retention time and effective membrane surface were experimentally determined. The aim of this work was to verify wastewater experiments in professional flowsheet environment, rigorously modelled with ChemCAD and optimized by dynamic programming optimization method: the membrane separation. Such nitrogen recovery membrane separation has not been published in this professional flowsheet environment yet. The objective function of the process is the ammonia harvesting efficiency. Eighty-five percentage ammonia harvesting efficiency can be reached with 60 membrane surface area/reactor volume ratio, at 35 °C feed temperature with 350 L/m 2 h acid and in 8 h' hydraulic retention time. It can be stated that this separation method is based on physical phenomena without any biological factors. The focus for nitrogen treatment in a wastewater treatment plant is removal instead of recovery. It can be determined that this system is capable for the nitrogen recovery from wastewater, and it can reduce the ammonia content of human urine too.

Ammonia recovery from human urine as liquid fertilizers in hollow fiber membrane contactor: Effects of permeate chemistry

“…In HFMC there is a high tendency of recovering any kind of volatile resources such as ammonia. This method generally requires less energy [14] and there is also a high tendency of being harmonized with green energy as less temperature and no aerations were required. Moreover, this technology is environmentally friendly, less chemical-intensive., much faster than normal stripping as it provides a large active surface area between the feed urine and stripping acid solutions [3].…”

“…There are a couple of studies who applied the hollow fiber direct contact membrane distillation process to recover nitrogen as a fertilizer [3,14,22]. Quite a considerable amount of study has been released so far regarding the effect of some of the most important parameters on the ammonia recovery performance of the hollow-fiber contactor.…”

Modelling and Optimisation of Multi-Stage Flash Distillation and Reverse Osmosis for Desalination of Saline Process Wastewater Sources

“…The Heat Input (or Briner Heater) Section consists of a heat exchanger and loop modules. The Loop module regulated the order of feed flows [ 37 ]: at first steam was flown and then PWW was pumped into the MSF plant. This part consists of two input streams and two output streams.…”

Pls-Based Soft-Sensor to Predict Ammonium Concentration Evolution in Hollow Fibre Membrane Contactors for Nitrogen Recovery

“…The main advantages of HFMC technology are: it is selective to free ammonia recovery; its energy consumption is lower than other technologies such as air stripping and it is appropriate for recovery of ammonium nitrogen to really low concentration [5]. High nitrogen recovery efficiencies (between 80% and 99%) have been obtained applying this technology to different streams such as chicken manure [6], reject water from anaerobic digestion [7,8], pig manure [9] or urine [10]. Although these studies were carried out at laboratory or pilot scale, recently, this technology has been implemented at the full-scale Munster WWTP [11] with recovery efficiencies close to those obtained at laboratory or pilot scale.…”