DIFFERENT WORKS HAVE BEEN PERFORMED ON QUINOLONE TREATMENT [1] AND USING PERIODATE [2]. AN EFFICIENT PHOTO-OXIDATION SYSTEM IS INTRODUCED HERE FOR DEGRADATION OF QUINOLINE (QU) USING PERIODATE SALT (KPI) WITH THE ASSISTANT OF UV LIGHT IRRADIATION. FOR DEPTH EVALUATING THE SYSTEM, CENTRAL COMPOSITE DESIGN (CCD) METHODOLOGY WAS EMPLOYED, IN DESIGNING THE EXPERIMENTS, MODELING AND OPTIMIZATION OF THE PROCESS. DEGRADATION OF QU VIA UV/KPI SYSTEM WAS MUCH SUPERIOR TO THE ONLY PHOTOLYSIS AND CHEMICAL OXIDATION PROCESSES. A QUADRATIC MODEL WAS ESTABLISHED TO DESCRIBE THE DEPENDENCY OF THE DEGRADATION EFFICIENCY (DE), AS THE MODEL RESPONSE, TO THE EFFECTIVE OPERATIONAL PARAMETERS, I.E. THE INITIAL CONCENTRATION OF KPI, INITIAL PH AND TEMPERATURE. UNDER THE OBTAINED OPTIMUM CONDITIONS (PH=4.34, [KPI]=3.02 MM, T=35.6OC) AND WITH 40 MG/L INITIAL QU CONCENTRATION, 95.5% DE AND 71.5% REMOVAL BASED ON COD ANALYSIS WERE ACHIEVED AFTER 70 MIN. AS PRESENTED IN THE FIGURE 1, NO SIGNIFICANT DEGRADATION WAS RELEVANT WITH ONLY UV LIGHT APPLICATIONS I.E. WITH NO PERIODATE REAGENT.

IN THIS STUDY, FOR THE FIRST TIME, ADVANCED OXIDATION PROCESSES (AOPS) SUCH AS UV/S2O8 2- AND UV/H2O2 HAVE BEEN INVESTIGATED AND COMPARED FOR DEGRADATION OF SALICYLIC ACID (SA) MOLECULES IN AQUEOUS MEDIA. SALICYLIC ACID HAS BEEN WIDELY USED AS AN INTERMEDIATE IN THE MANUFACTURE OF PHARMACEUTICALS AND COSMETICS AND IT IS INTRODUCED INTO THE ENVIRONMENT BY A VARIETY OF INDUSTRIAL AND NATURAL SOURCES. IT IS A KEY INGREDIENT IN MANY SKIN-CARE PRODUCTS FOR THE TREATMENT OF ACNE, PSORIASIS, CALLUSES. THIS AROMATIC ORGANIC COMPOUND IS VERY TOXIC AND IT IS WIDELY PRESENT IN PHARMACEUTICAL INDUSTRIAL EFFLUENTS [1]. ALL THE EXPERIMENTS WERE PERFORMED IN A STAINLESS STEEL RECTANGULAR CUBIC REACTOR WITH THREE LITERS CAPACITY. THE LIGHT SOURCE WAS A UV-C (6 W, PHILIPS) WHICH WAS PLACED HORIZONTALLY IN A QUARTZ TUBE AT THE CENTER OF THE REACTOR [2]. THE CREATED DECLINES IN THE UV REGION ABSORBANCE RELATED TO THE SA SPECTRUM AT 298 NM WERE MEASURED DURING THE TIME USING A UV-VIS SPECTROPHOTOMETER TO ASSESS THE AROMATIC CONTENT DEGRADATION OF THE SOLUTIONS. THE EFFECTS OF SOME OPERATIONAL PARAMETERS ON THE DEGRADATION EFFICIENCY WERE EXPLORED AND IT WAS FOUND THAT FOR TREATMENT OF THE SOLUTIONS CONTAINING 30 MG/L OF SA, THE OPTIMUM CONDITIONS ARE: THE OXIDANT DOSAGE OF 4.16MM AND PH=4 FOR THE UV/H2O2 PROCESS AND AS WELL, THE OXIDANT DOSAGE OF 5.2MM AND PH=6 FOR THE UV/S2O8 2- PROCESS. UNDER THESE CONDITIONS AND AT THE CONSTANT REACTION TEMPERATURE OF 25◦C, THE OBTAINED DEGRADATION EFFICIENCIES FOR THE UV/H2O2 AND UV/S2O8 2- PROCESSES EXCEED 92% AND 94% AFTER 120 MIN RESPECTIVELY. AT THE EACH OPTIMUM CONDITION, USING A HPLC INSTRUMENT (UNDER THE APPROPRIATE WORKING CONDITION [3]) THE CONCENTRATION OF SA WAS MEASURED DURING THE EACH PROCESS. THEN, THE TRENDS OF SA DEGRADATION VIA UV/S2O8 2- AND UV/H2O2 PROCESSES WERE FORMULATED ADEQUATELY WELL ON THE BASE OF PSEUDO-FIRST-ORDER KINETIC MODEL, WITH A RATE CONSTANT OF 0.06 MIN-1 AND 0.03 MIN-1, RESPECTIVELY. ALSO FOR THE CASE OF UV/S2O8 2- PROCESS, THE RESULTS OF ADDITION OF RADICAL SCAVENGERS (SUCH AS ETHANOL AND TERTIO BUTYL ALCOHOL) INTO THE REACTION MEDIA SHOWED APPROXIMATELY EQUAL CONTRIBUTION FOR THE HYDROXYL AND PERSULFATE RADICALS IN THE DEGRADATION OF THE SA MOLECULES. FINALLY; DESPITE OF THE SIMILAR ABILITY OF THE TWO APPLIED PROCESSES FOR THE DEGRADATION OF SA MOLECULE, THE RESEARCH PREFERS THE UV/S2O8 2- PROCESS BECAUSE OF THE SUITABLE PERFORMANCE UNDER THE MORE MODERATE PH CONDITION AND ALSO THE STABILITY BENEFIT OF THE SOLID POWDER OF PERSULFATE SALTE RATHER THE H2O2 SOLUTIONS.

A COMPREHENSIVE 3D COMPUTATIONAL FLUID DYNAMICS (CFD) MODEL WAS DEVELOPED TO SIMULATE THE FLOW BEHAVIOR AND PHOTO-BIOCATALYTIC DEGRADATION REACTION OF ACID ORANGE7 (AO7), IN A OPEN-CHANNEL PHOTO-BIORECATOR. THE NOVEL PROCESS IS COMPOSED OF PHOTOCATALYST (TIO2 IMMOBILIZED ON POLYURETHANE (PU)) AND GLUCOSE OXIDASE (GOX) AS BIOCATALYST IMMOBILIZED ON TIO2/PU. THE OPEN-CHANNEL PHOTOBIOREACTOR SIMULATION COMBINED THE POROUS MEDIUM CFD WITH A REACTION KINETICS MODEL. MOREOVER, THE KINETIC OF LANGMUIR-HINSHELWOOD WAS APPLIED FOR THE PHOTO-BIODEGRADATION OF AO7. THE OBTAINED CFD MODEL COMBINED WITH THE ABOVE KINETIC LAW WAS VALIDATED WITH EXPERIMENTAL DATA.