Multiple modification on nanoporous silicon derived from photovoltaic silicon cutting waste for extraction of PbⅡ in industrial effluents

The post-processing and recycling of silicon cutting scraps in PV industry is of great importance both in environmental remediation and from an economic perspective. In this work, a novel organic-inorganic composite was synthesized by three-step surface modification of nanoporous silicon (NPSi) powder that was etched with Ag-assisted chemically of kerf loss silicon waste, which showed high-effective extraction of Pb Ⅱ in industrial effluents. The factors that have a decisive influence on its absorption performance, such as original pH value, absorption saturation time, and original concentration of Pb II , are studied in detail. The produced adsorbent has a maximum adsorption capacity of 253.3 mg/g for Pb II at the ideal circumstances of pH = 6, t = 10 min, and C 0 = 300 mg/L. Both the Langmuir isotherm and the pseudo-second-order model exhibit favorable agreement with the adsorption process . In addition, the adsorption mechanism is dominated by chemical chelation and ion exchange reactions between silanol groups and Pb II . The EDA-CC-APTES-NPSi still held fantabulous adsorption capacity even after undergoing a consecutive regeneration round. Hence, this study is about contributing to a new recycling idea of silicon cutting waste, as well as providing a potential adsorbent for efficient Pb Ⅱ removal.