Dear Giacomo.

I want to expand with one example the notings in my last paragraph of earlier reply Dtd. 5th Feb 2019.

When the wwt system is working fine and the effluent is well compliant, then the pond is used for growing Elephant Grass sp. in floats.

This sp. produce is used as feed for live stock, poultry and others.

One Self Help Group - SHG takes care of harvesting regularly the fodder/ feed and sells to another SHG who rears them for commercial consideration in communities.

This mechanism is self sustaining and could be under care of parent Voluntary Organisation- VO.
VO takes due care of this venture in toto incl. testing and monitoring standards of water. feed all produces.

This ensures that the produces are safe and communities well secure.

Well wishes .
Prof Ajit Seshadri .

Dear Elisabeth and Pr. Seshadri,
thank you for your answer.

Hi Giacomo,
As already indicated by Elisabeth, a pond system can be used for remedying the incidence of high BOD loading upto 500-1000ppm.

Deep pond can be evolved to contain sludges, and made to pass to the next process. A HRT of around 4 days is given with flow rate not more than 0.5m/sec. This deep pond of depth 3-5m can be kept as primary stage of the treatment.

This can be followed by also an anaerobic deep pond or a tank pf depth 3.0m with big boulders, followed by small stones to fix solid sludges at the bottom level of the secondary level, pond.
Flows are led by gravity flow and if led to the bottom level, then the effluent can have up-flow process,

Next phyto-remediation process can be planned to provide apt waste water treatment as the effluent flows by gravity flow to the last stage.
The total flow in the process of all the stages of treatment can have a HRT of 8 to 10 days, applied on Dewats design.

The treatment system is best worked, when the effluent is re-used for lower level duties viz. flush water in toilets, watering plants, others.
When the effluent is recycled, the system enjoys full confidence and the also saving in costs of providing water for secondary purposes.

Pl feel free to be in touch for any queries on the process etc.

with well wishes,
Prof. Ajit Seshadri

Hi Giacomo,

A pond system should be fine for your application (if you have the space available). But do you have more specific questions or issues you'd like to discuss about this case?

Regards,
Elisabeth

Dear forum,

I am doing a theoretical study on possible wastewater treatment with the following characteristics:
-location: north east Brazil, semi arid climate, village of around 6500 people
- considering high BOD loading usually a UASB solution would be proposed but we were wondering if a pond technology could still be used.

Do you have direct experience with high rate anaerobic ponds?
here (link to a paper entitled "High-rate anaerobic pond concept for domestic wastewater treatment: Results from pilot scale experience")


Thank you very much,
Giacomo