Dear Munir, agricultural and waste water treatment are possible with a bio-digester  which can give you a clear water, gas and humus as by-product. The benefits of these by-products far outweigh the cost of no treatment

Dear Banson, many thanks, however I suppose it is good for a small scale but what method is more appropriate for commercial hydroponicddiscarded weather of RO and of recipe 

The agricultural and RO waste waters are highly saline. However, these can be put to many uses, especially for growing of salt tolerant crops, halophytes, landscaping plants, fisheries, grasses of high salt tolerance (like golf courses), desert soils (sandy soils with very high drainage) and etc.    

 Dear Nazir sahib, many thanks for great options. No doubt that these uses can be great for the discarded RO water and of recipe after use. Is there possible economical way like using two to three sand filters with or without BAC units to make this water even usable for coolong pad supply if not for the irrigation to get maximum benefit where water is scarce.