Advanced oxidation processes for removal of organics from cooling tower blowdown: Efficiencies and evaluation of chlorinated species

One of the major challenges in reusing cooling tower blowdown water (CTBD) utilizing membrane processes is its remaining organic compounds, e.g., humic substances leading to biofouling. Besides, possible abundance chloride CTBD imposes concern formation chlorinated by-products. To choose a pre-treatment process for studied composition, various advanced oxidation (AOPs), including electrooxidation (EO), photocatalytic degradation (PCD), heat-activated persulfate (PS), UVC/vacuum UV (UVC/VUV), and UVC processes, were evaluated compared based on two main targets: i) highest removal mineralization organics, especially substances; ii) lowest by-products adsorbable halides oxychlorides. All conducted natural condition real CTBD, while solution pH was monitored. Based results chemical oxygen demand, total carbon, dissolved UV254 absorbance, liquid-chromatography–organic carbon detection (LC-OCD), fluorescence excitation-emission matrices (FEEM), it concluded that PS leads complete compounds along with low molecular weight acids neutrals. FEEM LC-OCD data also indicated EO, PCD, UVC/VUV brought about substantial broke down into building blocks organics. EO exhibited AOX oxychlorides formation, these limited when using other AOPs. Summarizing, PS, efficient organics without generating significant amounts