Multifunctional Floculant Powders (MFP)
New Application Fields on Wastewater

By Dr. Federico Rivalta
November 2003

The Author is General Manager at Intecna Srl in Peschiera Borromeo, Italy. He is a specialist in water treatment additives such as polyelectrolites and multifunctional flocculant powders. → See also:

Multifunctional flocculants powders (MFP) application is addressed to the wastewater depuration process in small and medium dimension plants (less than 20 cubic meters/day).
The powders are "all in one" products and contain primary flocculants, polymers, dispersants, wetting agents, anti-caking agents, activated carbon and absorbing clays : all these components in micronized form.
MFP must be added as it and stirred in a period of 3 - 5 minutes in a pH range 8 - 9.
No pre-dilution, pre-dispersion, or other previous operation is required.
After such period it occurs the formation and sedimentation of big flocks and the liquid becomes clear without residual solids in suspension. By this method itīs possible to obtain the following advantages:

Multifunctional flocculants powders are suitable for the wastewater difficult to be treated by alternative treatments, produced by the following industries:

The feeding devices are automatic and requires the use of a screw connected to a timer to allow a suitable dosage, a stirred vessel and a filtration equipment by means draining bags or a paper filter.

The use of such products allows a treatment without storage tanks, pH control, dosing pumps etc, so the depuration cycle is easier and can be carried out in batches or in continuous, depending on the volume of the wastewater.

Application Method

  1. pH CONTROL
    Before to use HYPOL PWD range, itīs necessary always to control pH value.
    The best pH value range is between 7,8 - 8,5.
    PH adjustment is carried out with lime in slurry
    An acidic pH range does not allow the first flocks formation and a to basic pH leads to opalescent water at the end of the treatment.
     
  2. Dosing Devices
    HYPOL PWD range must be added as it. Usually in the plant the dosage feeding devices is a screw connected with a timer to calculate a working time more suitable for the wastewater characteristics. The product is mixed with the wastewater in a batch or continuous process.
    The water to be treated must be well stirred to avoid the formation of product caking and lumps formation.
     
  3. Reaction Time
    A stirring time of 3/4 minutes is usually adequate to complete the reaction.
    At the beginning, it occurs the formation of small dimension flocks. In few minutes the flocks increase the dimension and a fast sedimentation occurs.
     
  4. Time of Sedimentation
    After the reaction time, the stirring is stopped to allow the sedimentation.
     
  5. Sludge Filtration
    After sedimentation the settled sludge is collected in various plant options : draining bags, paper belt, press filter. Usually the plants suitable for this application are automatic and have a treatment capacity from 500 lt to 20,000 lt/day.

In this paper are reported some application examples for wastewater showing a strong difficulty to be treated in conventional way.

Application 1 :
Wastewater from Resins and Glues

Water Characteristics
AspectMilky
pH6,8 - 7,5
COD10 - 12000
OdourAcrylic resin - PVA
TSS2000 ppm
Emulsionstable without settling tendency

Type of Treatment

Satisfactory results have been obtained by such way:

Step 1 : Dosage of 1500 – 2000 ppm flocculant PA 8700 (Ferric / polyamine mixture)
Step 2 : Multifunctional Floculant Powder HYPOL PWD 100 SA 9, 2000 ppm
A practically limpid water is obtained and a contemporarily COD reduction 70%.

In the photo 1 are reported the wastewater before and after the treatment

Photo 1

Application 2 :
Wastewater from Metalworking and Penetrating Fluids

Water Characteristics
AspectOpalescent/fluorescent
pH7,5 - 10
COD2000 - 4000
Odourcharacteristic of cutting oil
TSS4000 ppm
Emulsiontendency to natural settling

Type of Treatment

Very satisfactory results have been obtained by treating the wastewater in a single Step with Multifunctional Flocculants Powder HYPOL PWD 100 AD (2500 ppm).

Limpid water and colourless water is obtained as in Photo 2.

Photo 2

Application 3 :
Treatment of Wastewaters Containing Inks

Water Characteristics
AspectBrown strong coloured
pH7,5 - 10
COD20000 - 40000
Odoursolvents
TSS> 5000 ppm
Emulsionpresence of bottom deposits

Type of Treatment

Satisfactory results have been obtained by such way :

Step 1 : Dosage of 1500 – 2000 ppm flocculant PA 8700 (Ferric / polyamine mixture)
Step 2 : Multifunctional Floculant Powder HYPOL PWD 100 SA 10, 2000 ppm
A practically limpid water is obtained and a contemporarily COD reduction 60%

Limpid water has been obtained as in photo 3

Photo 3

Application 4 :
Wastewater Treatment of Water Based Paint Washing Equipment

Water Characteristics
AspectGreen - Blue strong coloured
pH7 - 7,5
COD4500
Odourresin
TSS> 3500 ppm
Emulsionno sedimentation tendency

Type of Treatment

Satisfactory results have been obtained by by treating the wastewater in a single Step with Multifunctional Flocculants Powder HYPOL PWD 100 ADC/L (2500 ppm).
The product allows a complete destabilization of the emulsion and it occurs a floatation of the paint layer which can be easily removed in floatation equipment of by filtration

Application 5 :
Treatment of Wastewater of Aluminium Moulds

Water Characteristics
AspectOpalescent white
pH7 - 7,5
COD> 18000
OdourGlycols
TSS> 1500 ppm
Emulsionno sedimentation tendency

Type of Treatment

Satisfactory results have been obtained by by treating the wastewater in a single Step with Multifunctional Flocculants Powder HYPOL PWD 100 SC (strong cationic) (2500 ppm).

A practically limpid water is obtained suitable to be reused. (Photo 4)

Photo 4

Conclusions

A wide range of formulations in Multifunctional Floculants Powders allow to apply such technology in many wastewater depuration cycles. Contemporarily, the high automation in plant increases the possibility to use an additive in powder form in a process without storage, dosing pump, complex instrumentation.

Such method is a technological advancement of the classical sedimentation plant and by such way the removal of COD, Tenside, Colours, oils etc can be strong increased.

The final result is usually satisfactory and can be optimised depending on the opportunity or necessity to save the water by a complete reuse.

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