Reactive surface functional groups of the [email protected] are strongly important factor for removing of dyes from wastewater

Reactive surface functional groups of the [email protected] are strongly important factor for removing of dyes from wastewater; the Boehm titration method provides evidence for the existence of acidic and basic sites (Boehm, 1994). The acidic and basic sites of [email protected] were 0.87 and 0.47 mmol/g, this result show that the [email protected] has mainly acidic character.
The DC electrical conductivity (?DC) values of SVT-PUF, [email protected] and ZnONPs were measured at room temperature and found to be 1.23×10-8, 7.1×10-8 and 5.8×10-6 ?1 m-1, respectively. The conductivity of [email protected] is greater than PUF. This can be attributed to additional new groups due to the interaction between PUF and ZnONPs. Also, the higher conductivity could be due to the uniform distribution of zinc oxide on PUF, as the ZnONPs have excellent electric conductivity.
The surface charge of [email protected] was zero at pHZPC 7.3 (Fig, 3A). The surface charge become positive at pH 7.3.The maximum values of ?pH for [email protected] are +3.43 and -1.64 at pH 3.3 and 9.3, respectively. Figure 3B shows that the pHf of [email protected] is little change from pH 3 to pH 9. Due to the buffering effect of water on the [email protected] surface, the pH measurements would only be considered in a pH range of 3-9. Figure 3C shows that the maximum of removal percentages of Br.G, To.B and Tr.B dyes are achieved at pH 8-10, 3-11 and 3-11, respectively. Although the surface of [email protected] was positive charge at pH 85%. Due to illustrate this result, the figure 3b shows that the surface [email protected] has buffering effect from pH 3-11 therefore not repulsion occurs between the dyes and [email protected]