Wastewater is containing Phospho total very high

Wastewater system contain  Phospho total very high.

Level B of wasewater according with standard: P is 6 mg/l.

But the factory used STPP very much. So, Phospho total is very high to 200 mg/l.

We had  invited many wastewater company treatment to find measures but not to search results because Wastewater system contain  Phospho total very high so the cost very high.

 To P reduce, what do we do?

Thanks

Tina

Can anyone help Tina with this query?

Thanks,
Simon