Good day all,
Could anyone assist with the general rule of thumb when it comes to constructed wetland design in regard to size.

I know that there is a basic design requirment according to how much water will be passing through the system. i.e. what capacity does the wetland need to be in terms of m3 or m2.

The capacity needs to be for approx. 9,000 liters of water per day (approx. 2,400 gallons).

I know that there are a lot of variables such as what are the contents of the water to be treated etc, but I'm just looking for a basic rule of thumb.

TIA.

Unfortunately, there is no rule of thumb. Size depends on volume, climate, characteristics of the efluent to be treated, and desired outflow concentrations. It is quite likely that there will be one constituent in the wastewater that will act as the limiting factor in design volume. I recommend you pick up the Kadlec & Knight book and determine what sprt of expectations you can get based on different effluent constituents and go from there.

Thank you for your reply.
Will try and track down the book you mention.

The basic make up of the effluent will be waste water from a floriculture farm consisting of: shower rooms, post harvest water treated with a quaternary ammonium compound and aluminium sulphate and rinsing water from chemical spray tanks and lines (various pesticides and fungicides WHO class II, III & IV).

Thanks again for replying.

Andy,

You may run into some dificulties, particularly with regard to metals. It may be necessary to pass through some type of pre-treatment prior to the wetland, depending on your ultimate treatment goals.

Please feel free to contact me off the forum if you wish to discuss further.