EUROPEAN-MEDITERRANEAN ENERGY CO-OPERATION PROJECTS (EUROMED)
Euro-Mediterranean Project – Technical File: RUE / IN / No. 08
a. General information
Project title:
Simultaneous nitrogen elimination and energy production for reclamation of waste-waters
and production of raw materials
Location:
Geographical area where the research activities are performed or where the project results will find their eventual
application.
Research activities were run in Spain, Italy, France and in two non-EU countries: Israel and
Morocco. The process was implemented in a pilot plant located in Italy (L'Aquila). Application may
be possible in all the Mediterranean region.
Code (identification of the project, reference programme, responsible official and DG):
AVI CT-94-0011; AVICENNE Initiative; DG XII
Area (RES, RUE, FF and sub-specifications):
Specific tasks and themes in the programme.
not specified
Year of approval:
1994
Sector (industry, building, tertiary, etc.):
Application sector in which the project results will find their eventual application.
Industry, environmental protection and sanitation. Small scale energy production.
b. Co-ordinator, partners and suppliers
Co-ordinator:
Name of the organisation or company.
University of Barcelona
Dept. Chemical Engineering
Martí i Franquès 1, Pta. 6, E-08028 Barcelona
Tel. +34 93 402 1305; Fax +34 93 402 1291
Contact person: Prof. J. Mata-Alvarez
Partner 1:
Name of the organisation or company.
Institut National de la Recherche Agronomique
Laboratorie de Biotechnologie de l'Environment des I.A.A
Bd General de Gaulle B.P. 429, Narbonne 11104 France
Partner 2:
Name of the organisation or company.
Universita di Venezia
Dipartimento Scienze Ambientali
Calle Larga, S. Marta 2137, 30123 Venezia, Italy
Partner 3:
Name of the organisation or company.
Technion – Israel Institute of Technology
Faculty of Agricultural Engineering, TECHNION – IIT
Haifa, 32000 Israel
Partner 4:
Name of the organisation or company.
Universite Abdelmalek Essaadi
Faculte des Sciences - Departement de Chimie
Tetouan, B.P. 2121 Morocco
Main suppliers:
Organisations or companies which are providing key technology, know-how or products for the successful
implementation of the project.
not applicable
c. Aims and objectives
Brief descriptions of the main objectives and tasks.
The project AVI-CT94-0011 was started with the main objective of setting up procedures able for
the reclamation of waste-waters (including nutrient removal) and, at the same time, producing
energy and raw materials. To accomplish this main objective, some specific tasks and sub-tasks
were devised also with several specific aims. Among them, the most important are:
- To study the optimal aeration pattern for optimal nitrification and de-nitrification
- To study the cycles of ion-exchange and biological regeneration of zeolites for ammonia
recovery and to establish optimal procedures to carry out the operation
- To study the production of Volatile Fatty Acids from highly COD loaded waste-waters. To
optimise this production and its conversion to useful products such as bio-gas or its application
to biological nutrient removal process.
- To set up different integrated process to remove/recover N and P from waste-waters with an
increased energy production.
d. Situation of the project
Synthetic but exhaustive idea about the main technical characteristics of the project in relation to the programme and
the general framework within which it has been developed.
Description:
The project activities were carried out within 4 main tasks, described in what follows.
Task 1. Was concerned with the preparation of the inoculum of nitrifying bio-mass using waste
sludge, the construction of reactors and purchase of equipment for nitrifying reactors, the set-up and
starting of anaerobic digesters populations.
Task 2. Was devoted to the construction of reactors, the establishment of anaerobic cultures in a
nitrifying reactor, the preparation of drawings for the final reactors. Different initial nitrate/nitrite
concentrations and C/N ratios were tested.
Task 3. Was focusing on the realisation of a pilot plant, exploring different reaction parameters in
order to assess the optimum process.
Task 4 and 5. These tasks were mainly devoted to scientific investigation and search in the available
literature.
Phase of advancement:
Concluded
Date of beginning and conclusion:
01-02-1995 / 31-01-1998
Innovative technology (if foreseen):
not applicable
e. Results and achievements
Energy saving, substitution, power production:
A novel integrated process using an anaerobic reactor and an aerobic step has been set up to remove
N and carbon in an optimised way. The results have been tested treating pig manure. The
treatment includes an anaerobic section in which VFA are produced. These are later used to
denitrify the produced nitrates and once de-nitrification has finished they are methanised. Thus it is
possible to remove simultaneously nitrogen and to produce energy with low operation costs treating
for instance pig manure. The procedure could also be applied to any wastewater highly loaded with
ammonia and COD.
Establishment of a procedure to recover ammonia from waste-waters and, at the same time to
remove nitrogen from wastewater through a ion-exchange process using zeolite (chabazite and
clinoptilolite) as a carrier. “Adsorbed” ammonia is recovered using a nitrification process. Final
effluent is a water loaded with nitrates which can be used as a rich fertiliser. Waste-waters free
from ammonia are much better treated anaerobically with a significant increase in energy
production, as was demonstrated using pig manure as substrate (1). For nitrification and denitrification, optimum aeration patterns have been established . These patterns can be used for
clinoptilolite/chabazite regeneration Finally the use of VFA for removal of nutrients has also been
studied using a SBR system with results similar to the ones that can be obtained using a
conventional C-source such as acetate.
Environmental and social impact:
A novel process has been developed to overcome the drawbacks associated with the simultaneous
carbon and nitrogen removal by separating these two operations and concentrating the ammonium
from wastewater into a small volume reactor in which high nitrifying bio-mass concentrations and
optimal conditions for nitrification (temperature, oxygen, pH etc.) can easily be maintained.
Recovery of nitrogen takes place through ion exchange, using zeolites (chabazite). Regeneration of
zeolites takes place by nitrification, using accelerated patterns of aeration.
Experiments to
determine the affinity sequence of the major cations present in sewage to the chabazite yielded the
following K+>Ca2+>NH4+>Na+>Mg2+. Breakthrough curves showed that in the presence of these
counter ions in the sewage a breakthrough value of 4 mg/l is achieved after 220 bed volumes, at
which point the ammonium occupies only about 20% of the chabazite’s capacity. The process was
tested with simulated and real secondary effluents in a bench scale plant.
An inventory of botanical species has been carried out in a zone of interest in Morocco
Finally some studies have been carried out to test the metal tolerance of two species Lemma Gibba
and Lemma Minor. Both are capable to accumulate Cu and Cr, specially the last.
In a pilot plant level, it has been established a procedure to recover volatile fatty acids from wastewaters through fermentation process involving the organic fraction of municipal wastes. More than
40 g/L as VFA and light alcohol and lactic acid (5) have been obtained, representing a very high
yield. In the same pilot plant, de-nitrification is then achieved with a remarkable rate from 0.01 to
0.06 kgN-NO3/kg VSS.d. and with nitrate uptake rates using methanol of 0.28 kg N-NO3/kg
VSS.d. P removal also takes place with a 3% in the Waste Sludge. However there is room enough
to improve the biological removal of P using VFA as the sole carbon source.
Results of this pilot plant have been used to design a demonstration unit at the wastewater treatment
plant of Treviso (Italy).
Economic data:
not applicable
f. Co-operation data
Role of the partners (host, supplier and key enabler):
Partner 1, at the University of Barcelona, has studied the nitrification and de-nitrification process, at
high concentrations of ammonia and nitrate respectively. The process has been optimised in what
refers to the cycles of aeration and non-aeration in order to obtain a better yield and better
settlement characteristics. In a parallel study, technology has been developed to improve the
removal of COD from highly loaded wastewater by removing the ammonia using zeolites (process
studied mainly by Partner 4) The COD removal process has improved the production of bio-gas by
around 30%. The zeolite bio-regeneration process has also optimised by the results obtained
during the previous activity. Finally an integrated process has been set up using a SBR for
simultaneous N and P removal using the VFA produced by the fermentation of wastes (accordingly
with the process developed by Partner 3).
Partner 2 at the INRA-Narbonne, has studied the simultaneous removal of nitrogen and energy
production in a novel integrated process at laboratory level. Wastewater in a first step produces
volatile fatty acids (VFA), (as in the studies of Partner 3). These VFA are subsequently used to
remove nitrogen (via de-nitrification) and to obtain energy through bio-gas in a second
methanisation stage. The process has been studied with simulated and real waste-waters.
Partner 3 at the University of L’Aquila has studied the production of VFA from waste-waters and
the optimisation of the fermentation process. The studies have been carried out at a pilot plant
level. VFA are used for the biological nutrient removal of wastewater in different reactor
configurations. A design of a demonstration plant has also been carried out, using data from the
pilot plant.
Partner 4 at Technion, Haifa has studied and optimised at laboratory level the recovery of
ammonium from waste-waters through an ion-exchange operation, using zeolites as a carrier.
These zeolites are biologically regenerated via a nitrification process using the same carrier for
nitrifying bio-mass immobilisation. Ion-exchange behaviour of other anions such as potassium,
magnesium, etc. has also been studied to favour the recovery of ammonium. Resulting nitrate-rich
waters can be used in agricultural applications for fertilisation purposes.
Partner 5 at University of Tétouan has devoted his studies to the development of an botanical
inventory in a given zone of Morocco and to develop a basic technology to use macrophytes to treat
waste-waters polluted with some metal ions.
Technology transfer (description of the technology, name of the provider):
not applicable
Localisation of the applied technology/plant:
The pilot plant developed during the project is located at L'Aquila (Italy). Based on the results
obtained, a new and larger implementation is being realised in Treviso (Italy).
Characteristics of the non-EU area (short description):
Non-EU partners were not involved in on-site practical activities. They have mostly been
performing lab experiments. However the Morocco partner performed a preliminary investigation
of botanical species present around Tètouan.
Relevant aspects of the co-operation (management, technical, economic):
The programme has serve to establish durable links between partners, including establishment of a
network of communication, sharing equipment and student stays.
Best practices and lessons learned:
In addition to the usual scientific and technical gain of knowledge, communication with other
different cultures and establishment of useful relationships can be included in this section.
Employment observations:
not applicable
g. Potential applications
Potential application of the results obtained are in the area of integrated waste management
(municipal solid wastes and domestic waste-waters). Soil decontamination by phyto-remediation.
h. General comments
not applicable
i. Contact person for further information
Prof. J. Mata-Alvarez
Dept. Chemical Engineering
University of Barcelona
Martí i Franquès 1, Pta. 6
E-08028 Barcelona
Tel +34 93 402 1305
Fax +34 93 402 1291
E-mail: jmata@medicina.ub.es
h. Photos and graphic material
not applicable