adsorbent’s effectiveness for each type of pollutant, and mainly
depends on experimental conditions. The use of waste materials
as low-cost adsorbents for removing various pollutants from water
and wastewater presents many attractive features especially their
contribution in the reduction of costs for waste disposal, therefore
contributing to environmental protection. Although the amount of
available literature data on the use of low-cost adsorbents in water
and wastewater treatment is increasing at a tremendous pace, there
are still several gaps which need to be filled. Some of the important
issues can be summarized below: