Typically bench scale is in a laboratory and uses systems that can't handle more than 50L at a time (often much more per day depending on flow rates).

Pilot scale is proof of concept at a scaled up size for treating up to 50% of a total actual flow for the application. Usually these are on-site at the eventual place where full scale will be built and operated.

Full scale is the final design, construction, operate system. It's the result of incorporating outcomes at the bench and pilot scale to optimize the final design. 

As above although pilot scale can be as low as 10% of the flow

I agree with Dr. Kelly, but I suppose that also bench scale (which according to my understanding means more or less a laboratory scale) could be smaller than Dr. Mcmartin described above.

Regards

Vit

I agree with Dena W Mcmartin about the quantity of flow trough a scale, pilot and a full scale Constructed Wetland Operation...However another consideration is the kind of plants do you use for the CW, because if the Scale and pilot is too small, the plants will not grow well and that will affect yours results and the possibility to scale to a full Scale Station.

Best regards

Endorsing all the views expressed, I add that for design of CW, HRT is considered to be 6 to 10 days for total treatment , The inflow into CW to be limited to 300-500 BOD with pH around 7.0, DO to be appropriate. well wishes. 

I agree with them, however bench scale usually use laboratory glass wares as reactors

Are you seeking an answer for a Masters or PhD  proposal????  The answer to YOUR question is much more complex.  There are a series of questions you may have to sort out first: Is it a Free Water Surface (FWS) constructed wetlands or a Vegetated Submerged Bed (VSB) system that you wish to model?  Then: what variables are (or may be) involved?  Are you interested in the system hydraulics? Or the organic loading? Or both?  If you wish to establish a relationship (scale-up/down), geometric similitude between systems as well as loadings (hydraulic and organic) come into play.  Or is it organic similitude? Then if vegetation comes into play you will open Pandoras' Box!  A data acquisition strategy requires much thought.  and the questions go on and on.........  Any research must be built on a  solid, extensive literature review.  Your interpretation will guide you in arriving at a research proposal which will be a significant contribution to the existing knowledge base.

Dear C A. Your question is more than a year ago.Its best that a summation on the answers are done and that summation is suggested to be deliberated.. well wishes to all Respondents..

Dear Researcher Dr A Dhaundiyal,

Nicely explained

1. Bench Scale-

Can it be called "Lab- scale "

Say within 200 litres per day 45gallon drum type

Can introduce in 1st & 2nd stage anaerobic tanks

In Tertiary 3rd stage use -

Phyto Remediation with cayhna, napier- grass saplings

Can assess plant- beds to be float type

2. In the last stage, have processed water for Re use option under C & M mode.

3. Have recycled water passed thro phytoR for a few days.. drip irrigation type.

Well wishes

Prof Ajit Seshadri

The Vigyan Vijay Foundation

Ngo at New Delhi and

Vels University, Chennai

Tamil Nadu India