**1. Introduction**

To meet the increasing demand for fresh water under growing environmental awareness and constraints, necessity of desalination techniques are being felt strongly. Potable water by desalination can be produced either by thermal process or membrane processes. Membrane application is an emerging area of interest, as membrane processes operate at ambient temperature and offer one step separation for dissolved constituents on molecular level. Reverse Osmosis (RO) is long established as a large scale industrial membrane process. According to International Desalination Association (IDA) report, the cumulative global installed capacity is now 92.5 million m3 /day with 19,372 Reverse Osmosis (RO) plants around the world. By 30th June 2018, this number has increased to 20,000. The large desalination market in recent years has resulted in increased waste generation associated with this technology, which has led to the disposal of more than 840,000 End-of-Life (EoL) membranes (>14,000 tonne/year) every year worldwide. Literature shows that these membranes can be repaired in order to reuse them for secondary and tertiary purposes. **Figure 1** shows Installed and projected desalination capacity including mostly applied process. Wide variety of polymers such as cellulose acetate; poly acrylonitrile; polyamide and polysulfones are used for RO modules and ultra filtration processes [1].

In most of the cases membranes are deployed in spiral configuration. Depending on the process and operating conditions, these modules have design life and needs to be replaced after 3 to 5 years. This generates lot of spent RO module as waste. With growing market of membrane technologies the disposal of these spent modules going to be serious issues. Review of status of technologies is briefly highlighted. Keeping this in mind, the various schemes/protocols [2] can be planned and accordingly exploratory studies have been initiated on primary techniques which are based on hydro thermal processes.

**Figure 1.**

*Installed and projected desalination capacity including mostly applied process.*

Hence eco-friendly disposal of spent membranes is an important issue for desalination industry. In our initial approach, we have carried out lab scale studies to study the various hydrothermal process techniques on mineralisation of polyamide thin film composite membrane and as well as poly sulfone membrane. The low temperature AOP processes requires mild chemical duty conditions and in turn helps in bringing down the capital costs of waste treatment plants.
