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5 - The Portuguese Technology

The Portuguese technology is a vertical flow system (figure 2) where the traditional water plants have been replaced by bamboo species able to bring the required oxygen through existing air canals (Ding yu-Long,1993) In the frame of the EEC supported research project “Bamboo for Europe”, a demonstration unit of 8 m² have been implemented and tested comparing the traditional water plant Phragmites Australis with 2 bamboo species: Phyllostachis Nidularia and Phyllostachis heteroclada.

The unit is in operation since August 1998 (figure 3) with full concordance concerning the regulation imposed by European standard.

Bamboo represents some advantages versus the traditional water plants

-  Same level of treatment
-  Lower density for plantation (1 plant/m² instead of 6-11 plants/m²)
-  Maintain green all the year round. Phragmites Australis becomes brown in the winter period
   and give a bad aspect to the unit during 4-5 months/year
-  No competition of other plants when in south Europe, Phragmites Australis can be
   dominated by other grasses
-  Less maintenance

First step treatment: big bag for units until 100 HE- septic tank or tank imhoff for higher capacities 

6 -7 - second step treatment by special adapted areas with bamboo
8 - Double found for the improvement of oxygenation
9 - Discharge to a maturation tank for the reduction of nitrates

The first treatment step is a septic tank or a tank Imhoff or a big bag in function of the capacity of the unit. European rules prevent that the first step reduce mainly the total solid in suspension by 50 % and  the CBO5 by 20 %.

The second treatment step is realised by a constructed wetland with bamboo. The European requirements for the treatment level depends of the areas where the final effluents is discharged: normal, sensitive or no sensitive areas.

For normal areas (75 % of the cases) primary and secondary treatments steps are required with following maximum limits after the treatment: 
Solids in suspension : Max 35 mg/l
COD( Chemical oxygen demand) : 125 mg de o²/l
BOD 5( biological oxygen demand after 5 days): 25 mg de o² /l

For very sensitive areas ( 15 % of the cases) also a tertiary treatment is required with the need to reduce nitrogen and phosphor contents.
For no sensitive areas ( 10 % of the cases) only a primary treatment is required with a reduction of 50 % of the solids in suspension and a 20 % BOD 5 reduction. 


7 - Present applications and future developments

The present experiences of phytoremediation with bamboo are limited to Portugal. A high potential of further development exist  in Europe and abroad (figure 4)
In Portugal three units are in operation for the treatment of Urban wastewaters and one for vintage effluents. ( figure 5)

Our proposal is  to develop landfarming systems where a bamboo forest is irrigated by the effluents after of the secondary treatment. This solution is particularly interesting for agricultural practises with any intensive animal breeding. Such solution will avoid any water contamination and will at the same time produce a valuable biomass even suitable for industrial purposes. A very high added value will be obtained for the whole system.

A practical project is in study for  he treatment of 10m³/day effluents coming from a small pig breeding unit. After physical separation solid/liquids and after a secondary treatment, the final effluents will be spreaded on a 5000 m² bamboo forest aiming a zero emission during the summer period avoiding any risk of underground water pollution.

8- Bibliography

1-2000- Joris De Vos -  “Bamboo for Europe” - final report EEC Brussels- part 2-pp 1-35

2-1996 - Economic research service, USDA- Industrial uses / IUS-6/ September  1996 pp 32-36

3-2001 - David Glass- 2001- U.S. and International Markets for fitoremediation 1999- 2000,pp 266

4-1998- API, The use of treatment wetlands for Petroleum Industry effluents, Publication number 4672, Brochure prepared for the API biomonitoring task force by CH2M hill, Washington, DC

5-1993 - Ding Yu-Long;  Dietger Grosser; Walter Liese; Xiong Wen-Yu- Anatomic studies on the Rhizomes of some monopodial bamboos - pp 122-127

Last scientific activities in bamboo

1 –coordinator of EEC project AIR3-ST94-012- 1995- Feasibility study for the introduction of bamboo in Europe

2 – Coordinator of EEC projects Fair3- CT96 – 1747 “Bamboo for Europe

3 – Partner in EEC project Fair5-CT97-3784- Light natural sandwich development

4 – Partner in the EEC- INCO Asia project-IACA –CT 2001- 10089 (Nov 2004)

5 – Partner in two new EEC projects submitted on September 11 and October 6 -2003

6 – Preparation of EEC funded AIDCO projects with Chile, India and Bangladesh. Call issued in December 2003 for proposals to be submitted end of March 2004

Last commercial activities in phytoremediation:

1 – Main contractor of two constructed wetlands for the treatment of waste waters utilizing bamboo instead of the traditional water plants:
        -  12 HE for domestic wastewaters in the municipality of Odemira
        -  50 HE for a wine production in the Municipality of Sétubal

2 – Sub contractor in 22 constructed wetlands for the treatment of urban wastewaters. (Delivery of special water plants all over Portugal)

3 – Main contractor for a tertiary treatment in the Municipality of Évora. Successful reduction of the total phosphor content from 25 mg/lit to less than 0,5 mg/lit.(authorized limit = 3 mg/lit

4 – Preparation of a project for the treatment of stable effluents by algae’s ( Donkey’s , horses and  ponies)

5 – Sub contractor in a constructed wetland with bamboo (30 HE) for the Portuguese Bank syndicate (under Construction in Ferreira do Zêzere). Delivery of process equipments and bamboo

6 – Sub contractor in two constructed wetlands for Águas do Zêzere e Côa. Delivery of special water plants

7 – Preparation of a project for the treatment of  6 lagoons  polluted by ducks (amusement park in Algarve)