Transcript a cura del prof. Paolo Broglio direttore scientifico di

High Efficiency Biological Removal Process
over Nitrogen and Carbon
through a Single Stage System
in Waste Waters
produced by Zootechnical Management
A SOLUTION TO NITRATE PROBLEM
(In compliance with the Decree of Italian Ministry for Agriculture and Forest Policy, dated 7th
April 2006 and titled “Nitrates Directive”, according to Council Directive 91/676/EEC of
12.12.1991 concerning the protection of waters against pollution caused by nitrates from
agricultural sources)
Paolo Broglio
Scientific Director of Ecologia Applicata S.R.L.
Scientific Organization on Environmental Research
via N.A.Porpora , 9 - Milan - Italy
Italian National Research Anagraphic Nr. 602910X9
 The Operation Plan (approved by the
Executive Commission of Regione Lombardia),
regulating the usage of nitrogen sources in
agriculture is causing serious worries to the
entire zootechny in this Italian Region.
 According to the New Area Division, more than 59%
of the low-land in Regione Lombardia is to be
considered vulnerable to Nitrates. This involves 62%
of the utilizable farming area where you find greater
zootechnical tendency not only in Lombardia but also
in the entire Italian country with a strong trend to high
quality products. As a matter of fact both Grana
Padano and Prosciutto of Parma, well known all over
the world, are only the two symbol products of Italian
Agro-Food System
 Regarding the pigs to fatten up, the limit changes from 112 kg/t-l.w.
to 110 kg/t-l.w., corresponding to 17 heads/ha and to 17,3 heads/ha
respectively. This means a reduction of about 3% of heads per each
hectare, whereas the reduction, in the case of cattle to fatten up,
reaches 10% and with dairy cattle even 30%.
(Note: l.w.= living weight)
 The Ministry Decree rappresents the latest Legal Act aiming at the
protection of the Po River low-land against the Nitrate Pollution
increasing. Day by day this pollution has been growing worse and
worse during for the last decades.
 The reduction of Nitrogen loading into the vulnerable areas (56% in
the low-land area and about 70% in Zootechny load) has been
becoming an absolute priority.
KNOWLEDGE UP-DATING
Technicians and operators have always considered the
Removal of Nitrogen from zootechnic waste water as a
less important target untill they discovered the heavy
presence of Nitrate content in the first water bed of our
low-land.
It is appened mainly due to the widespread agronomical
usage of Nitrate fertilization and partly due to the usage
of fertilizing irrigation with zootechnical waste water.
The high N/C ratio, characteristic of a large number of
animal faeces, has generally caused a difficult approach
to the sewage treatment with the use of simple and
economically convenient methods.
Different Research Institutes, among them the Italian CNR
and CRPP, have been publishing Scientific Literature [1],
[2], [3], [4] in which they suggested different systems in
order to lessen, under any form, the presence of Nitrogen
in waters, specially in the surface water body. Besides
they proposed even a different better solution such as
fertilizing irrigation, by now in bad performance because of
the soil saturation in Nitrogen.
[1]
[2]
[3]
[4]
Piccinini, S. ,( 1990 )
Olanda: Il Trattamento dei liquami zootecnici in impianti consortili.
Rivista di Suinicoltura Ed. Edagricole
Bortone, G., Piccinini, S., ( 1991)
Nitrification and denitrification in activated sludge plants for pigslurry and
wastewater from cheese
Bioresource Technology
Bonazzi, G., Piccinini, S.,( 1997 )
Come gestire i liquami suinicoli.
CRPA. Rivista di Suinicoltura Ed. Edagricole
Bonazzi G. ( 2007)
Sempre più difficile gestire e smaltire le deiezioni
L'Informatore Agrario. 1/2007
Due to the unbalance among feeding substances,
Waste Water Treatment results particularly difficult and
unefficient using the Biological Water Treatment
Process called “active sludge”, both in the single stage
and in the double stage.
The farmers are obliged either to use a lot of water to
dilute substantially waste water or to manage very
complex and expensive post-treatments or to buy
nitrogen-free lands at high costs or even to give up the
cattle breeding.
Excess of Ammonia and organic Nitrogen partially
inhibit biological process, limiting the plant performance
and the Nitrogen reduction-oxydation as N2 gas.
The widely recommended mixing system between civil
and zootechnic waste water rappresents however an
exception to the ordinary situation in which the cattlebreeding are placed far from civil buildings, depending
also upon the unpleacent smell outlet which becomes
particularly heavy in certain cases.
However the biologic treatments, also for nitrification and
denitrification, have always been preferred to other
process which are considered not only expensive but
also difficult to control.
(combined treatment, chemical treatment or psysicalchemical treatment)
Biological Nitrogen Removal from waste water normally
follows a metabolic way that transforms organic
nytrogen into ammonia (generally through hydrolysis
otherwise by enzymatic way).
The ammonia will be subsequently transformed into
nitrates (by Nitrobacter and Nitrosomonas SPP) and
finally into gaseous nitrogen due to peculiar anaerobic
bacteria. The complete reaction is shown in the
following scheme:
(N org.) NH4+ + O2 → NO2- + H2O + H+ →
NO3- + H2O + H+ → N2 + H2O
It is obvious that a great amount of energy will be
consumed by the oxidation from Ammonia to Nitrite
and from Nitrite to Nitrate into oxidative stage and in
this way it reduces the Nitrate up to gaseous
Nitrogen into anaerobic stage.
Each phase requires suitable tanks and proper
controls, leading the well functioning of the process.
It will be somtimes against the simple and easy
plant management, that is certainly a very important
aspect within the cattle-breeding farm
Due to the plant complexity to use the nitrificationdenitrification process, most of the farmers desist
from providing with Waste Water Treatment and
consequently they have mainly adopted the
method of controlled spreading within their field.
Although this is a managing system controlled by
specific regional rules, it has become inadequate
to practical application in agriculture due to the
excessive presence of Nitrate in the waterbed,
that is successively necessary to produce drinking
water.
TECHNOLOGY DATA BASE
 Within this general setting, some tests have recently
demonstrated that it is possible to obtain best
results in the treatment of zootechnic waste water
with very high organic and nitrogenous load. This
peculiar waste water, produced by intensive pig
farms, could be treated using special operating
procedures, based on the knowledge of other
processes that have already obtained particular
efficiency in the Nitrogen Removal.
 As a matter of fact, all the problems concerning overload
Nitrogen production in the Waste Water Treatment is not
only exclusive of the zootechnic farm plant, but we also
find it in the percolates, produced in the urban waste
disposal site, and in the supernatant of the thickening
sludges, produced in the biological depuration plant.
Since 1990 some researchers have elaborated a process in
order to mitigate this problem. This High Ammonia
Removal Process as waste water treatment was named
SHARON [5].
In adequate conditions of pH, dissolved oxygen and
temperature, it can produce only Nitrites (about 50% of
Ammonia Input) without oxidation up to Nitrates and
saving energy up to 25÷30%.
Later these Nitrites will be reduced into gaseous Nitrogen
through a secondary traditional anaerobic stage.
All of this is summarized in the following equation :
NH4+ + HCO3- + 0.75 O2 →
→ 0.5 NH4+ + 0.5 NO2- + CO2 + 1.5 H2O.
[5]
Hellinga,C., Schellen, A.A.J.c., Mulder,J.W.,
van Loosdrecht, M.C.M. and Heijnen,J.J. (1998)
The SHARON process : an innovative method
for nitrogen removal from ammonium-rich waste water.
Water Science Technology, 37 (9), 135-142.
This important innovation however was not
completely utilizable as it provided two distinct
Aerobic and Anaerobic Stages.
In 2002 a team of researchers focused on a
process called CANON [6] where they succeeded
to transform Ammonia into gaseous Nitrogen
through only one stage (using one reactor alone),
providing aeration times alternate to
anaerobiosys steps.
As this process was rather unstable, applications
on large scale were really few and they regarded
mainly the treatment of supernatant in the
thickening plant for biological sludge.
[6]
Sliekers ,A.O., Derwort,N., Gomez,J.L.C.,
Strous, M., Kuenen, J.G. and Jetten, M.S.M. ( 2002).
Completly autotrophic nitrogen removal over nitrite in one single reactor.
Water Research, 36, 2475-2482.
An efficient Engineering Technic knows how to
activate the SHARON process first (weakly aerobic)
and the ANAMMOX process later (anaerobic)
obtaining almost a complete Nitrogen Removal from
the Waste Water with a result of energy saving about
25÷30% in comparison with the traditional
Nitrification-Denitrification System.
Even in the realized plants two reactors are needed.
Altogether the two reactions are well simplified in the
following scheme :
100 % N-NH4+  SHARON

95% N2

50% N-NH4+ + 50% N-NO2-  ANAMMOX

5% N-NO3-
It has been tested in Laboratory the capacity of a
single reactor to carry out Ammonification of organic
nitrogen, partial Nitrification and Denitrification in the
same room, where Waste Waters carry particulary
heavy organic loads, both Carbon ratio
(20.000÷40.000 mg/l of COD) and Nitrogen ratio
(3.500÷4.000mg/l Ntot).
Details of this process has been published under the
name of SNAP [7] ( Single-stage Nitrogen removal
using Anammox and Partial nitritation ), which shows
the possibility to carry out 60÷80% Nitrogen Removal
in respect of the initial Nitrogen input.
[7]
Furukava,K.,Lieu, P.K., Tokitoh,H. and Fujii,T. ( 2006 )
Development of single-stage nitrigen removal using anammox
and partial nitritation ( SNAP ) and its treatment performance.
Water & Science Technology. 53 (6), 83-90.
SNAP = Single-stage Nitrogen removal using Anammox and Partial nitritation
Conventional nitrogen removal process
aerobic autotrophic nitrification and anoxic heterotrophic denitrification.
Novel nitrogen removal processes:
shortcut biological nitrogen removal (SBNR) process
- to denitrify from nitrite
- saves 25% oxygen and 40% organic matter.
wholly autotrophic processes
- removal of ammonium in absence of organic carbon
- saves 100% organic carbon source and more than 50% oxygen
- can be separate or single-reactorseparate processes:
sequent SHARON-ANAMMOX, sequent partial nitritation-ANAMMOX
single-stage process:
OLAND
(Oxygen-Limited Autotrophic
Nitrification-Denitrification)
CANON
(Completely Autotrophic
Nitrogen removal
Over Nitrite)
However the literature shows the Ammoniacal
Nitrogen value quite low (max. 500÷600mg/l)
and in the case of SNAP Process it becomes
very low, under 150mg/l.
Zootechnic Waste Waters naturally present
special characteristic: high COD, particularly
rich load of total and Ammoniacal Nitrogen,
large amount of suspended solids.
A Simple Process could be reproduced on wide scale,
with easy management and without great expenditure, and
it should enable to remove high percentage of total
Nitrogen, up to 80÷90%. This solution might better the
quality of the Waste Water and, so indirectly, the quality of
the underlying water bed, the pollution of which has
caused the “Nitrate Problem”.
Our target is to verify
the possible application
of SNAP Process, with
suitable modification, in
the Zootechnic Waste
Water, bearing those
characteristics listed in
the Table 1.
Table 1
_____________________________________________
Raw Input
Filtered Input
_____________________________________________
COD
(mg/l)
63.891
60.930
N Tot.
(mg/l)
4.952
4.702
N-NH4+ (mg/l)
2.911
2.900
N-NO2- (mg/l)
61
57
N-NO3- (mg/l)
n.r.
n.r.
_____________________________________________
The process undergoing
an adequate period of
seeding (30÷60 days)
should assure the
removal of total Nitrogen
around 80%, reaching
even up to 95%.
Organic Carbon Compounds may be or may
not be removed in consequence of the
Waste Water Reuse
( for example Anaerobic Digestion with
Biogas Production ).
The main purpose of the applied research is
focused on the Codification of Biological
Nitrogen Removal for at least 90% of the
Zootechnic Waste Water.
It should be realized over a true scale or at
least over a semi-true scale and consequently
demonstrate its technological reliability and
its reproducibility.
As a side-issue it should be fixed the characteristic of the
process, through which it will be possibile to maintain a
residual COD, with equal Nitrogen Removal.
This target in COD should be still so high as useful for
biogas production in anaerobic digestion.
The best practical result of this
project is shown in the possibility
to overpass the obstacles, hidden
in the technical law on Nitrates
Pollution Control Directive
(91/676/EEC of 12 December 1991).
Consequently it should help to by-pass
the Directive limitations, which could
force the farmers in peculiar situations
to close the cattle-breeding farm.
The possibility to apply the modified SNAP process has
successfully been tested both in laboratory and
partially also in the practice.
The experiments have been executed in anoxy alternate
condition for sufficient period and the process resulted
considerably stable.
Analysis have shown a total Nitrogen Removal of about
80%, measuring a minimum Nitrite concentration (never
recorded before and indicating a bad functioning in the
traditional plant) and obtaining a substancial Nitrate
absence [8].
[8]
Stefano Franco, Dario Pagani – GB. Odobez Srl, Varese;
Paolo Broglio – Ecologia Applicata, Milano.
“Applicazioni al trattamento di reflui industriali
e di reflui zootecnici del processo di Bioflottazione® :
abbattimento di tensioattivi, coloranti diretti ed alti carichi di azoto”.
Ecomondo. Rimini - 9 novembre 2006
OUR NITROGEN
REMOVAL PROCESS
On the basis of the
obtained results, an
applied research took
form, already ratified in
main lines as process,
which brought to codify
on industrial or real scale
a new type of process
called :
PRiBioAC 3S
Biological Removal Process
over Nitrogen and Carbon
through a Single Stage System
The proposed project for an applied
research could be realized by setting up
a pilot plant having capacity of few net
cubic meters or by rewamping an
existing sewage tank, transforming it in
a biologic reactor, placed in a cattlebreeding farm that supports the project.
Some air baffle diffusors should be settled at
the bottom of the tank enabling to regulate
the blowing air from minimum to maximum.
There should also exist the possibility to stop
at fixed interval the air flow and somehow to
keep the sewage in mixing and suspension.
The system will also be
provided with a partial
regulation of pH,
using CO2 as acidifying agent.
Oxymeters and pHmeters
will record the flows and a
mobile laboratory will be
set up in the site.
Some samples will be
carried to our Institute for
further thorough tests.
The aim of the research is to
obtain Biological Nitrogen
Removal through a
sufficiently simple process
to be automatically
controlled by using PLC and
certainly capable to remove
the Organic Carbon
Compound Load (COD) in
connection with an eventual
further anaerobic digestion
with energy recovery.
An already existing structures could be used or
however a low cost prefabricated structures.
All this assures a wide success of the process
and its application on large scale.
The result indicators
are rappresented by the
removal percentage
both of the Organic
Carbon Compounds
and of Total Nitrogen
with relative specific
loads.
( kg Ntot-rem / m3 * d )
or
( kg COD-rem / m3 * d )
They indicate the
process efficiency and
its market value.
Also the total cost
of the treatment
(sinking cost excepted)
is supposed
to be oscillating
between 0,8÷1,2 €/m3
(per treated cubic meter).
Let us consider it
as an important
result indicator.
FOLLOW UP AND CUSTOMERS
FOR OUR RESULTS
The result of the project is
generally addressed to
Zootechnic farmers and
specially to pig breeders, who
face with the restrictions laid
down by the Laws of Ministry
for Agriculture and Forest
Policy dated 7th April 2006
(named Nitrate Limitation
Directive).
All farmers, indirectly even private citizens,
would obtain an advantage due to the
diminished risk to find more amount of Nitrate
than the one allowed in the drinking water.
This aspect holds a
particolar importance as the
removal from drinking water
of concentrated substances
not in acordance with the
law, turns out to be
technically very difficult or
even impossibile.
Moreover such a process will allow to
obtain a perfectly suitable waste water
for a further utilization in Anaerobic
Digestion in order to obtain Biogas.
USEFULLNESS,
APPLICATION AND
IMMEDIATE BENEFITS
OF THE RESULTS
Technical Application Immediately follows the Experimental Research.
When we encode the process creating a Start-up Procedure and a Plant
Management Procedure, our goal is to obtain a undoubted stability in the
Process. With this stable point each farmer is able to approach this
technology, which substantially is more a Process than a Plant.
In other words, once you know how to start PRiBio AC3S measuring
correctly alternative Oxic and Anoxic periods togetherwith a rigorous
control on pH, hydraulic retention time and feeding substance balancing,
the Process can be set going with the use of any tank or other aeration
device.
The process could be registered by the farmer’s association; the latter may
give the Patent User-Right to different Engineering Companies in order to
build the plants.
EXPECTED ADVANTAGES
A rapid diffusion of the PRiBioAC 3S System
is considered as a real advantage inside each
cattle-breeding farm facing with Nitrate Risk.
Taking into consideration the quick setting up of this Plant
(3÷6 months) in a span of 5 years, if the great part of the cattle
breeders adopt this Process, there will not be any more Nitrate
Problem, at least in terms described up to now.
All Cleaned Waste Waters might regularly flow together into
the ducts within the limits prescibed by Italian Law Decree
152/2006 and consequently contribute to better the quality of
the surface water body.
( as per Water Protection Plan by Regione Lombardia definitely approved
with the Delibera di Giunta n. 2244 dated 29.03.2006 )
WORK PLANNING
Once we have optimized the “starting
phase”, we should proceed with the
support of an operation procedure to verify
the reliability of the process through
medium and long endurance tests.
We will proceed both to record the involved
process parameter and to register the
obtained results as total Nitrogen removal
and COD removal or stabilization.
To this stage we will dedicate the entire
second year of the applied research.
_____________________________________________________________
Times
Stages
Descriptions
_____________________________________________________________
1st month
A
Activity Organization and System Planning
2nd month
B
Setting up of the System and Electromechanical Testing
3rd÷12th months
C
Engineering-Analitical-Procedural Activity
( start-up tests )
with intermediate control report
12th÷23rd months
D
Engineering-Analitical-Procedural Activity
( system reliability tests )
activity dead line with final report
E
Publishing and popularizing of result presentation
_____________________________________________________________
24th month
COST - BENEFIT ANALYSIS
Cost-Benefit Valuation Analysis turns
to be extraordinarily positive
The Applied Research should permit a
widespread application of the
PRiBioAC 3S Process,
using different engineering equipments (pumps,
diffusors, piping, control systems) … and
furthermore.
If we consider that this system overpass the
Nitrate Directive, the limitations of
“breederheads per hectares of agricultural
land” cause heavy expenditures for at least two
billions of Euros per year (as calculated by
Italian Associations Confagricoltura and
Coldiretti).
Thank you for your kind attention !
July 2007
Ecologia Applicata SRL.
Ecological Service
Scientific Organization on Environmental Research
Stipulated-Conventional with University of Studies in Milan
Milan: Via Porpora, 9
Tel. +39 - (0)2 - 2895978
Telefax : +39 - (0)2 - 2871159
e-mail : [email protected]
website : www.ecologia-applicata.it
Italian National Research Anagraphic Nr.602910X9
Part.IVA 09453070154
N.Reg.Soc.2876/7334/26/MI - N. Reg. Ditte 1294361