The IWA-MTC 2019 was attended by 410 attendants from 49 different countries with a strong representation from Asian countries, particularly China. More than 200 oral and 120 poster presentations were devoted to many aspects of membrane filtration in water and wastewater treatment. It was concluded that membrane technology progressively permeates all fields of water and wastewater treatment by replacing existing technology. Furthermore, membrane technology has the potential of becoming the best available technology to recycle, reuse and recover materials (resources) from water.
Membrane filtration is increasingly applied in all aspects of water and wastewater treatment and replaces existing more conventional treatment processes. Examples given during the conference include sand filters replaced by ultrafiltration in drinking water production, thermal processes replaced by membranes in seawater desalination and settlers replaced by microfiltration in activated sludge processes. This trend is due to the diversity and the flexibility of membrane technology and its capacity of being included in hybrid processes (such as UV and adsorption). Also recent developments in membrane synthesis and novel membrane concepts play an important role in this.
Recycle, reuse and recover materials from membrane concentrate streams
Membrane filtration is a separation process which results in a concentrated brine stream. Recovering valuable products from this concentrate stream from reverse osmosis seawater desalination was presented by different research groups (e.g. University of Technology Sydney, University of Calabria). Another route is to transform the conventional wastewater treatment plant into a circular water reclamation plant including reuse of treated water and sludge valorisation by energy production and/or valuable products recovery (PUB, Singapore). This philosophy is very close to our own CoRe Water project which was briefly presented by Lex van Dijk (BlueTec).
Membranes key technology in decentralized water treatment
In California 20% of electricity produced is spent on water transport and treatment. Decentralization is a key issue to decrease the carbon footprint of clean water production, which is also a key strategy of our multi-source 1-step RO project. Decentralization also applies for wastewater treatment, for example in sewer mining, i.e. the withdrawal of wastewater from sewer systems to be locally treated and used, which enables the decrease of the carbon footprint of wastewater treatment. In all these concepts membrane technology plays a pivotal role, which is particular relevant for the urban water supply chain.
Membrane technology increasingly applied in industry
The industrial sector is increasingly improving their water management strategy as an integral part of their overall business strategy and sustainability goals. The zero-liquid discharge concept is steadily applied to comply with regulations set by authorities and as a viable strategy to mitigate water stress in different regions in the world. Membrane technology is more and more prevalent in these strategies, not only in the scientific context but also on pilot and full-scale in different industrial sectors. An in-house example is the zero-liquid discharge project for the agricultural sector.
Membrane technology is becoming the key technology to elevate pressures in water stress, raw material stress (e.g. phosphorus,..) and energy consumption. During the 9th IWA-MTC in Toulouse from 23th–27th July there were many examples of these directions.