Ammonium recovery in wastewater treatment plants for agricultural valorization.
Type of activity
AGAUR. Agència de Gestió d'Ajuts Universitaris i de Recerca
Funding entity code
2017 DI 088
Nitrogen compounds (organic and inorganic) are typical pollutants in sewage which need to be removed from wastewater to comply with discharge regulation according to the 91/271/EC Directive. At industrial-scale level in Europe, nitrogen is usually biologically oxidized to N2(g) which is emitted to the atmosphere in aerated reactors, contributing to 30 – 60% of the total wastewater treatment costs. Within the context of circular economy, new and innovative technologies to recover N from sewage instead of removing it are being developed.
The objective of this PhD thesis is the development and optimization of a technology for the production of nitrogen salts from ammonium-rich effluents at wastewater treatment plants (WWTP). The technology should be economically competitive with nitrogen removal technologies and conventional N fertilizer production methods based on the Haber-Bosch process. A treatment train combining adsorption materials and membrane technologies will be used for nitrogen recovery at a relevant pilot-scale level in a urban WWTP.
Specific sub-objectives of the PhD thesis would be the following:
· Understand N species concentration mechanisms in the adsorption unit; subjected to subsequent cycles of adsorption-desorption with different eluent agents. In-depth characterization of virgin and exhausted adsorbent materials
· Understand N species and water mass transfer at the membrane unit under different process conditions (membrane material and pore size, operating pH and temperature, G/L ratio, liquid phase composition, etc.) to maximize the concentration of the recovered salts and develop strategies to minimize inorganic scaling and organic fouling and biofouling. In-depth characterization of virgin and exhausted membranes
· Select and validate the most adequate pre-treatment unit to minimize impact of matrix macro-interferences (such as Chemical Oxygen Demand, suspended solids, phosphorus species, organic nitrogen, etc.) in the treatment train
· Assess the fate of micro-interferences (such as heavy and light metals, organic micro and nano-pollutants) in the treatment train and develop strategies to improve the quality of the recovered N salts
· Develop a suitable control system for N recovery in WWTP adapted to the developed treatment train
· Conduct technical, economic and environmental assessment of the developed technology and compare with other technologies used for the same application such as air/steam stripping systems; and N removal
V Pla de Recerca i Innovació de Catalunya (PRI). 2010-2013
Agència De Gestió D'ajuts Universitaris I De Recerca (agaur)