In this study, degradation of a pharmaceutical drug, Phenazone (PNZ) has been carried out via heterogeneous photocatalysis, photo-Fenton and in-situ dual process (photocatalysis + photo-Fenton) in suspension and fixed-mode under artificial UV-A as well as under natural solar radiations. Waste material such as foundry sand (FS) was exploited as a supplement for iron in case of photo-Fenton reaction. The distinct processes including photocatalysis and photo-Fenton were found to be competent for the degradation of PNZ as both processes revealed an almost 90–95% removal of PNZ after 180 min of UV irradiations. The degradation was improved to a great extent with remarkable reduction in treatment time of PNZ to almost 105 min when these two individual processes were combined together within the same unit. An almost 14% synergy of dual process over distinct processes was obtained. For fixed-bed studies, TiO₂ immobilized hollow circular composite disc already containing FS was utilized which yielded an almost 96% reduction in the concentration of PNZ after 4 h of solar irradiations. The disc was recycled 10 times and its stability and activity was confirmed through XRD, SEM/EDS, and DRS. The mineralization of PNZ was confirmed through significant reduction in COD and generation of anions during the treatment process. The transformation products were examined through GC-MS analysis. The novel technique of in-situ dual process especially in fixed-mode visualized in this study by employing renewable energy and durable catalyst can represent a viable solution to various industries for the treatment of wastewater comprising of bio-recalcitrant pollutants.

在这项研究中，Phenazone（PNZ）的降解是通过非均相光催化，光芬顿和原位双重过程（光催化+光芬顿）在人工UV-A下悬浮和固定模式进行的。以及在自然太阳辐射下。在光芬顿反应的情况下，废料如铸造用砂（FS）被用作铁的补充。发现包括光催化和光芬顿在内的独特过程可胜任PNZ的降解，因为这两个过程均表明，在紫外线照射180分钟后，PNZ的去除率接近90-95％。当这两个单独的过程在同一单元中结合在一起时，PNZ的降解时间得到了极大的改善，同时PNZ的处理时间显着减少了近105分钟。在不同的过程中，双过程获得了近14％的协同作用。对于固定床研究，TiO_使用2个已经包含FS的固定空心圆形复合材料圆盘，在太阳照射4 h后，PNZ的浓度降低了将近96％。圆盘被回收了10次，并通过XRD，SEM / EDS和DRS证实了其稳定性和活性。通过在处理过程中COD的显着减少和阴离子的生成，可以确认PNZ的矿化作用。通过GC-MS分析检查转化产物。通过使用可再生能源和耐用的催化剂，本研究中发现的原位双处理新技术，特别是在固定模式下可视化，可以为各种行业处理生物难降解污染物的废水提供可行的解决方案。