钛基混凝所得富藻污泥的资源化回收

Resource utilization of algae-rich sludge obtained through titanium-coagulated

摘要:

污泥中含有大量的资源,如何实现污泥减量化、资源化处理是一个全球性的环保难题。采用一步煅烧法从钛基混凝后的富藻污泥中回收TiO₂纳米颗粒,并经光沉积得到Pt负载的二氧化钛光催化材料(Pt@TiO₂),可有效实现污泥的资源化回用。实验获得了具有纳米球状(介孔)结构的Pt@TiO₂,其禁带宽度与商用二氧化钛(P25)相比更窄。基于电子顺磁共振波谱仪(ESR)结果,回收的Pt@TiO₂在光照射下产生了羟基自由基和超氧自由基,这些自由基均可作为活性氧化物质参与氧化反应。考察Pt@TiO₂剂量、溶液pH、4-氯苯酚(4-CP)浓度、腐殖酸浓度等对Pt@TiO₂光催化性能的影响,结果表明,紫外光照射下,0.3% Pt@TiO₂可以在60 min内将20 mg/L的4-CP完全降解。回收反应后的Pt@TiO₂进行循环试验,Pt@TiO₂在循环五次后仍可降解92.5%的4-CP。本文提供了一种富藻污泥资源化回收再利用的方法,为实现环境可持续发展开辟了一种新途径。关键词：混凝；富藻污泥；资源化；光催化；Pt@TiO₂中图分类号：X703.1 文献标识码： A 文章编号：1003-5214 (2020) 01-0000-00

Abstract:

A significant amount of resources is contained within the sludge, and the achievement of sludge reduction and resource utilization is considered a global environmental challenge. High-value TiO₂ nanoparticles are recovered from the titanium-coagulated algae-rich sludge through the application of a one-step calcination method, and a Pt-loaded titanium dioxide photocatalytic material (Pt@TiO₂) is obtained through photodeposition, effectively enabling the resource utilization of the sludge.Pt@TiO₂ with nanospherical (mesoporous) structure, and lowband gaps (compared to P-25), were obtained. Based on the results of electron spin resonance spectroscopy (ESR), hydroxyl radicals and superoxide radicals are produced by the recovered Pt@TiO₂ under illumination, both of which can be utilized as active oxidative species involved in oxidation reactions. The impact of Pt@TiO₂ dosage, solution pH, 4-chlorophenol (4-CP) concentration, and humic acid concentration on the photocatalytic performance of Pt@TiO₂ was investigated. The results indicate that under ultraviolet light irradiation, 0.3% Pt@TiO₂ can completely degrade 20 mg/L of 4-CP within 60 minutes. Recycled Pt@TiO₂ was subjected to cyclic tests, and even after five cycles, 92.5% of 4-CP could still be degraded. This study offers a method for the resource recovery and reuse of algae-rich sludge, presenting a new avenue for achieving environmentally sustainable development.