S.N. Name of adsorbent Adsorption capacity (mg/g) Time pH Ref. 1. Silica 1.5 - 2-4 24 2. HDTMA-Modified Zeolites Cowlesite 0.763 - 7 25 3. Clinoptilolite HDTMA 0.844 - 7 26 4. Red clay 1.3 - 4 - 6.5 27 5. ZnO2 nanomaterial 4.98 15 6.5-7.3 Present study

Table 1: Adsorption comparision of PVP functionalized ZnO2 nanomaterial for chromium.