Hi Sudarat. I agree with ...

Hi Sudarat.

I agree with all the comments below, therefore, before to decide what to do you have to check which type of wastewater do you have (domestico or industrial?), if there are some specific regulation in your country for reuse of treated wastewater, and for which plantation are you aimed to reuse the treated wastewater. 

Anyway, a interesting low cost solution is constructed wetlantd+ disinfection unit (such as UV lamp). The disinfection unit can be used or not depending on the final plantation. Indeed, if you follow the WHO guidelines, you can reuse the treated WW for processed food plantation with a limit of E.coli of 10000 cfu, which is deliverable with only nature-based solutions.