The current work demonstrates the feasibility of polystyrene (PS) immobilized TiO₂ (PS-TiO₂) as a floating catalyst for the photocatalytic reduction of nitrate in aqueous solution with formic acid as a hole scavenger. The synthesized PS-TiO₂ was characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM), Fourier transform infrared spectroscopy (FT-IR), and the Brunauer–Emmett–Teller (BET) surface area analysis. The experimental conditions including initial pH of the solution, formic acid concentration, and catalyst dosage were varied to demonstrate their effect on the denitrification efficiency and nitrogen selectivity. The complete denitrification of water with 40 mg L^-1 nitrate (as N) was observed within 135 min of irradiation at initial pH of 2.5, catalyst dosage of 15 g L^-1, and 16 mM formic acid concentration. The floating nature of the catalysts allowed for their easy recovery with ≥ 98 % catalyst recovery after 5 cycles of denitrification experiments. A potential mechanism for photocatalytic denitrification in the process is also discussed.

当前的工作证明了固定有聚苯乙烯（PS）的TiO ₂（PS-TiO ₂）作为浮式催化剂的可行性，该浮式催化剂可以用甲酸作为空穴清除剂来光催化还原水溶液中的硝酸盐。合成的PS-TiO ₂通过X射线衍射（XRD），扫描电子显微镜（SEM），傅里叶变换红外光谱（FT-IR）和Brunauer-Emmett-Teller（BET）表面积分析进行了表征。改变了溶液的初始pH，甲酸浓度和催化剂用量等实验条件，以证明它们对反硝化效率和氮选择性的影响。40 mg L ^-1对水进行完全脱硝在初始pH为2.5，催化剂剂量为15 g L ^-1，甲酸浓度为16 mM的情况下，在辐射135分钟内观察到硝酸盐（以N计）。催化剂的浮动特性使其易于回收，经过5次反硝化实验后，催化剂的回收率≥98％。还讨论了该过程中光催化反硝化的潜在机理。