I'd further request that you give us more information on what exactly you're looking at, what type of wastewater are you interested in or it's just any wastewater in general and probably the water quality parameters of interest.
It depends on what kind of wastewater are you trying to treat, its amount as well as its characteristics. Identification of those vital factors will help you to find the series of option under categories of physicochemical and biological . In many cases you may need to apply a combined system to reduce the cost and improve the final discharge efficiency.
The European commission selects the best available technology (BATs) for every industrial sector and sets emission limits values based on the capabilities of those BATs. Please visit the EIPPCB webpage and more specificaly the CWW reference document
The main Criteria in more than 90% of all cases is the technology that will give the lowest Capex. and still fulfill the demanded effluent criteria. All other Criteria follow afterwards like Low Opex, Energy Self sufficiency, Ease of operation, Space savings, No Hear-No see-No smell.
A few other thoughts you can find in my publication:
Conference Paper Resource recovery – It should be good money
It depends on your target, such as removal of BOD, COD, etc., of course, the availability and cost of technology, the purpose of effluent (irrigation, reuse, or back to water body) are also considerations.
@Leroy Jia : We always suppose to reuse as underground water recharge after treatment but I want to know the list with what technology we can achieve what level of treated effluent ....... please enlist something if you have ....
It depends on the EPA requirement of your local government, if you want to recharge treated water underground, according to our years experience, TN,TP, Salinity must under certain level, and chlorine must be removed if you use it, hope this helps. If you want to know more, send me a message,
@Leroy Jia: Thank you........... I want to know that what will be different different reuse scenario... if we treat urban sewage to a certain level, to a medium level and to the maximum level. We use all technologies whichever is applicable.... if we go for reuse what caution should I take..... using all these I want to generate different scenario...... Kindly give some suggestion