This document discusses using sodium alginate to remove heavy metal ions from wastewater. Sodium alginate is obtained from brown algae and can adsorb heavy metal ions while not producing secondary pollution. It has some downsides like low thermal stability and poor mechanical strength. These downsides can be overcome by adding polymers or nanocomposites to sodium alginate to improve its properties. The document also discusses detecting heavy metals in wastewater, various removal methods, why removal is important, and the future focus on developing more effective and sustainable adsorbents.