How to select correct parameters for designing an industrial wastewater treatment work?

Hi everybody, 

I am working on my master thesis about designing a wastewater treatment system for a pulp and paper mill using waste paper as raw materials. All of the streams are mixed into only one stream to be treated. The influent profile is shown as follows: 

-Design flow rate: 167 m3/h, maximum flow rate at the collection pits: 334 m3/h

-BOD5: 2600-7000 mg/L

-COD: 5000-12000 mg/L

-TSS: 300-4200 mg/L 

-Color: 3000 Pt-Co

-AOX: 20 mg/L

-Dioxin: 12 pgTEQ/L 

I have some questions as follows:

1. Large variations in flow rate: 

I am planning to have an equalization basin to equalize the flow rate. As my understanding, I should use Qmax for the units before the equalization basin (such as primary sedimentation) and Q average for units after the equalization basin. However, as I know, the flow record for at least 24h is needed to calculate the volume for the equalization basin. The company only gives me the maximum and average flow. Are there any simple approaches  to calculate the equalization basin? 

2. Large variations in contaminants concentration (BOD, COD, TSS):

Should I use the average concentrations or the maximum ones for design and calculation? 

3. Are there anything else I should take into account? 

Any practical experience shares are appreciated. 

Thank you very much for your time!