6. Future perspectives
Water treatment by adsorption using low cost adsorbent is a demanding area as it has double benefits i.e. water treatment and waste management. As discussed in this article various waste products have been converted into low cost adsorbents and used for water treatment. The reported data is very interesting and growing interest in water treatment. Therefore, there are greater chances of the applications of low cost adsorbents for water treatment in near future. Besides, the universal and inexpensive natures of adsorption technology are other assets for bright future of low cost adsorbents. Moreover, it is believed that the future of low cost adsorbent is quite bright in developing and under developed countries.
In spite of bright future of low cost adsorbents, there are some issues related to their success in near future. The management of the exhausted adsorbent is an important issue and has not been not been taken care completely. Besides, there is no report available on the issue related to the management of removed pollutants. In our views, the removed pollutants should be recycled or dumped deep into soil. The removed pollutants should be filled in steel containers and treated as in case of nuclear wastes. Some adsorbents are not capable to work under natural conditions. Therefore, there is great need to develop such adsorbent that can work at pH 7.0, normal temperature with short contact time. Normally, low cost adsorbents are effective for removing pollutants at mg/mL concentration. Attempts should be made to module them for working at μg/mL concentration too. Besides, these adsorbents should be prepared eco-friendly and used in a controlled way to avoid any environmental hazards. Various papers discussed herein describe adsorption by batch mode. But there are few researches describing water treatment at pilot and industrial scales. Therefore, future is seeking for the design and development of effective columns for treating water at large scale. There is a need to develop more efficient, selective, inexpensive and eco-friendly low cost adsorbents for water treatment. Briefly, there is demand to module low cost adsorbents for making them inexpensive, fast and eco-friendly in nature.