DP 4 ELECTRO
ELECTROCOAGULATION TECHNOLOGY
BASIC PRINCIPLES
For complete wastewater treatment, electro-cell is followed by
the usual separation processes. In INTECNA plant is installed a
filtration device.
Electro-coagulation and Electro-floatation are well known
method for wastewater treatment
Basically , in a electrolytic – cell, are placed plates of
participative electrodes ( Aluminum or Iron) . By application of
suitable electrical current, regulated by Faraday Law, there is
a slow dissolution of metals ( Anodic Oxidation) .
INTECNA DP4 ELECTRO
Purification plant General view is reported in photo
Metallic ions, under form of Hydrates, absorb pollutant material
and precipitate. At Cathode there is formation of Hydrogen gas
( Cathodic Reduction) , so, formed flocks have tendency to
float.
FLOCULATION VESSEL
ELECTROCELL
PANELBOARD
FILTER
TREATED WATER COLLECTION VESSEL
INTECNA designed and developed a specific plant : DP4
ELECTRO by using this principle,
In this plant, direct current is passed through aluminium plates
suspended in a electro cell.
Undesirable contaminants are removed either by chemical reaction
and precipitation or by causing colloidal materials to coalesce. They
are then removed by sedimentation and filtration.
Compared to water treatment with aluminium sulphate or polyaluminium chloride, electrochemical aluminium generation has
several distinct advantages. Aluminium is introduced without
corresponding sulphate ( or chloride) ions. Also there is no
need for a alkalinity supply to give a reaction. By eliminating
competing anions using a highly pure aluminium source, lower
metal residuals are obtained and less sludge is produced (50-70
per cent). The adjustment of aluminium ion dose in the water can
be done easily by manipulating the dial for control of current.
The following physic- chemical reactions take place in the
electrode cell:
• Anodic oxidation and cathodic reduction of impurities present
in waters.
• Solution of metallic anodes, discharge and coagulation of
colloidal particles.
• Flotation of solid particles by gas bubbles produced on
electrodes.
The following electrode reactions occur in this process:
Anode:
Al0 = Al3+ +3eCathode:
H20+2e- = 2 OH + H2
The quantity of dissolved Aluminium depends on the quantity of
electricity passing through the water, and can be found by
Faradays Law.
Therefore
m = 1/96500 × A/V × It
where m = mass of dissolved Aluminium
V = valence of aluminium (Al +++ = 3).
A = atomic mass of aluminium (27).
I = current in amperes.
t = time in seconds.
Additionally, both the anode and the cathode will be dissolving
chemically in water.
MAIN COMPONENTS
Electrolysis vessel
Electrolysis vessel ha a particular design (photo). In the vessel
are placed the electrodes who release Aluminum Hydroxide
under the effect of the flowing current
In the vessel is installed a electrodes package with a cleaning
system. Dimensions and design are calculated on the base of
required flow rate. In photo is reported a manufacturing detail.
SYSTEM FOR COMB TRANSLATION
COMB FOR ELECTRODES CLEANING
0
AI + 3H2 = Al (OH)3 + 1.5H2
The nascent Al +++ reacts with the water to form insoluble
hydroxides and the colloid destablilization process is therefore
analogous to that obtained with traditional metal salts.
ELECTRODE
Electrodes are connected by means aluminum bars placed
on the vessel border . Connection allows to send the
electrical current to the single electrode. By such way is
created the unit cell
Basic principle is as follows :
To four electrodes package is applied a current by means four
generators able to supply a current 12- 20 volt / 60
System will absorb a current proportional to wastewater
Conductivity. Under Faraday Law, absorbed Amperes will
dissolve a proportional Aluminum quantity.
On such base feeding pump will send a consequent
wastewater flow
Dimensions and treatment capacity
Dimensions : 2500x1700x2800 mm
Applied maximum current : 12 volt /240 Ampere
Electrodes : 34 = 13,6 square meter
Production capacity : 750-1000 Liter/hour
(depending on wastewater quality)
Sludge formation : 25 Kg/hour
Sludge humidity average : 75 %
Polymer consumption : 20 grams/hour
Electro- cell power maximum consumption : 2,88 Kw/h
Floculation vessel
By overflowing, treated wastewater will pass to flocculation
vessel, where is added a polymer to allow flocks aggregation
Sludge filtration
By overflowing, a filter paper roll will receive the suspension
water/flocks and will allow the filtration. In the photo is
reported the filtration device.
When the level of the suspension will arrive to touch the
upper level, it means that the filtration rate becomes too low ,
so, automatically the paper will advance in order to increase
the filtration rate. Paper and sludge will be collected
TOGHETER in a plastic container.
Filtered, treated water will be collected into the backwater
tank. This tank has a level control that will allow for the
discharge pump to send the filtered water to a storage tank
for the re-use.
TECHNOLOGY AVDANTAGES
This plant
is addressed to process strong polluted
wastewater, especially when water re-use is required.
The main advantages of this method are :
Panel board
In the photo is reported the panel board installed
LOW INVESTMENT if
technology (evaporators)
compared
with
competitor
NO CHANGE IN TREATED WATER PARAMETERS :
pH and Conductivity don’t change
NEGLIGIBLE USE OF CHEMICALS
SMALL SLUGDE PRODUCTION
LOW MAINTENANCE COSTS
LOW ENERGY CONSUMPTION
NO HAZARDOUS BY PRODUCTS
TECHNICAL SUPPORT
INTECNA is well skilled to support the customer by previous
laboratory tests and pilot plant available for customers for a
previous economic evaluation of cost/benefit balance.
TECHNICAL NORMES
DP4 ELECTRO manufactured by INTECNA meets the
following Technical Standards
UNIEN
UNIEN
UNIEN
UNIEN
UNIEN
UNIEN
EN
EN
EN
EN
EN
EN
EN
CEI EN
CEI EN
EN
CE
CE
EN
292 – 2
292 – 1
294
349
418
811
894 - 3
894 – 2
894 – 1
963
964
1050
50099 – 1
60204 – 1
60439 – 1
61000-6-4
2006/95
2004/108
61010 - 1
INTECNA