Novel and green materials are needed to reduce operating and maintenance costs of treatment systems and to enable conversion of active treatment processes to engineered passive treatment approaches. New materials that have greater or more selective affinity towards heavy metals and organic molecules are needed. Similarly, novel materials that can be synthetized to enhance the performance of existing treatment processes such as microlenses to improve photodegradation of water contaminants should be investigated. Such materials should allow for operational stability under variable process conditions and should be available at low costs.
Traditional adsorbents, such as activated carbon and polymers, have been widely used in water and wastewater treatments to remove heavy metals, organics, and biological contaminants. However, they are not always efficient in contaminant removal and their production is high cost and high energy input. Producing activated carbon from sludge from municipal wastewater treatment has potential to be a cost effective alternative to waste management and production of low cost adsorbents. Similarly, cellulose nanofibers (CNFs) are promising alternatives to the current water treatment adsorbents because of their large surface area, hydrophilicity, broad surface chemical modification capacity, and lack of toxicity.
Recent advances in nanotechnologies have facilitated synthesis of new nanomaterials for photocatalysis. In recent years, solar or natural sunlight driven photocatalysis is becoming the revolutionary method for degrading organic contaminants. However, major drawbacks of traditional photocatalysts include the high requirement of the solar source and the side effects of the catalyst nanomaterials. Further research is necessary to develop efficient, environmentally friendly and real time treatment methods for better environmental adaptability.