Chemical Oxygen Demand Measurements Research Articles

Synthesis, characterization of Bi/ZnO and its photoactivity towards TB, AR 27 & RR 120 degradation under UV-A light

Bare and hexagonal wurtzite Bismuth loaded ZnO (Bi/ZnO) nanostructures have been prepared successfully by a simple solvothermal method. The structure and composition of the samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectrum (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), cyclic voltammograms (CV) and BET surface area measurements. In the present work, the photocatalytic degradation of Trypan blue (TB), Acid Red 27 (AR 27) and Reactive Red 120 (RR 120) dyes with prepared heterogeneous photocatalyst under the UV-A light. Bi/ZnO was found to be more proficient in the degradation of TB, AR 27 and RR 120 dyes than bare, commercial ZnO and Bi2O3. The mineralization of these three dyes have been confirmed by Chemical Oxygen Demand (COD) measurements. A possible mechanism was proposed for Bi/ZnO under UV light. This catalyst can be reused and it provides more stability.

Optimization of Chemical Oxygen Demand Determination in Seawater Samples Using the Alkaline Potassium Permanganate Method

Chemical oxygen demand (COD) is a practical parameter that is used to estimate the amount of organic pollutants in aqueous systems. It is generally used as a guideline to control the quality of waste treatment effluent globally and is a management tool to evaluate the total pollution load in the highly developed coastal regions of Korea. It is a preferred method because of the speed and simplicity of the analysis and because there are fewer instrumentation requirements. The Ministry of Oceans and Fisheries (MOF) of the Republic of Korea developed a standard procedure for the measurement of COD. It has been revised several times, and the most recent revision was made in 2013 (MOF 2013–230). In this study, we modified the standard COD measurement procedure (MOF 2013–230), especially the sample digestion apparatus, to enhance analytical efficiency for a large sample number (batch), which is called a Korea Institute of Ocean Science and Technology (KIOST) modified MOF 2013–230. We examined uncertainty related to each experimental step and optimized laboratory conditions to reduce such uncertainties. The detection limit and estimated expanded uncertainty related to the KIOST modified MOF 2013–230 was 0.18 and 0.11 mg O2/L at a 95% confidence level (k = 2), respectively. This study also provides several tips to maintain consistent COD measurements in seawater using the alkaline potassium permanganate method.

Nanoparticles augmentation on biogas yield from microalgal biomass anaerobic digestion

This study evaluates the influence of metal and metal-oxide nanoparticles (NPs) on biogas production from green microalgae Enteromorpha. The concentration of metallic NPs (Ni, Co) was 1 mg/L and oxides NPs (Fe3O4, MgO) was 10 mg/L. An anaerobic digestion was carried out batch-wise with working volume, operating temperature, mixing rate and hydraulic retention time as 500 ml, 37 °C, 150 rpm and 170 h, respectively. The measurements of chemical oxygen demand (COD), volatile fatty acids (VFAs), reducing sugar and biogas production were observed to monitor effectivity of nanoparticles. The results showed that NPs has moderate positive influence in biogas production until 60 h of retention time but significantly improve afterward. The maximum total biogas yield of 624 ml was achieved by Fe3O4 NPs whereas highest biohydrogen, 51.42% (v/v) was achieved by Ni NPs. The cumulative increase in biogas production for Fe3O4, Ni, Co and MgO NPs was 28%, 26%, 9% and 8%, respectively. A modified Gompertz and Logistic function model were used to determine kinetic constants of the reaction. The logistic model has the better predicting ability for microalgae anaerobic digestion.

High nitrite concentration accelerates nitrite oxidising organism's death.

High nitrite is a known operation parameter to inhibit the biological oxidation of nitrite to nitrate. The phenomenon is traditionally expressed using a Monod-type equation with non-competitive inhibition, in which the reaction associated with the biomass growth is reduced when high nitrite is present. On the other hand, very high nitrite is also known to slay nitrifiers. To clarify the difference between the growth inhibition and the poisoning, cell counting for living microorganisms in the nitrite oxidiser-enriched activated sludge was conducted in batch conditions under various nitrite concentrations together with measurements of biomass chemical oxygen demand (COD) concentration and oxygen uptake rate. The experiments demonstrated that these measureable parameters were all decayed when nitrite concentration exceeded 100-500 mgN/L at pH 7.0 in the system, indicating that nitrite poisoning took place. Biomass growth was recognised in lower range of nitrite which was expressed with growth inhibition only. Based on the response, a kinetic model for the biological nitrite oxidation was developed with a modification of IWA ASM1. The model was further utilised to calculate a possibility to wash out nitrite oxidiser in the aeration tank where a part of the return activated sludge was exposed to high nitrite liquor in a side-stream partial nitritation reactor.

Statistical Exposé of a Multiple-Compartment Anaerobic Reactor Treating Domestic Wastewater.

Mainstream anaerobic treatment of domestic wastewater is a promising energy-generating treatment strategy; however, such reactors operated in colder regions are not well characterized. Performance data from a pilot-scale, multiple-compartment anaerobic reactor taken over 786 days were subjected to comprehensive statistical analyses. Results suggest that chemical oxygen demand (COD) was a poor proxy for organics in anaerobic systems as oxygen demand from dissolved inorganic material, dissolved methane, and colloidal material influence dissolved and particulate COD measurements. Additionally, univariate and functional boxplots were useful in visualizing variability in contaminant concentrations and identifying statistical outliers. Further, significantly different dissolved organic removal and methane production was observed between operational years, suggesting that anaerobic reactor systems may not achieve steady-state performance within one year. Last, modeling multiple-compartment reactor systems will require data collected over at least two years to capture seasonal variations of the major anaerobic microbial functions occurring within each reactor compartment.

Soft-sensing modeling of chemical oxygen demand in photo-electro-catalytic oxidation treatment of papermaking wastewater

Photo-electro-catalytic (PEC) oxidation has been widely recognized as an effective technology for advanced treatment of papermaking wastewater. To optimize the oxidation process, it is important of monitor continuously the chemical oxygen demand (COD) of inflow and outflow wastewater. However, online COD sensors are expensive difficult to maintain, and therefore COD is usually analyzed off-line in laboratories in most cases. The objective of this study is to develop an inexpensive method for on-line COD measurement. The oxidation-reduction potential (ORP), pH, and dissolved oxygen (DO) of wastewater were selected as the key parameters, which consists of four different types of artificial neural network (ANNs) methods:multi-layer perceptron neural network (MLP), back propagation neural network (BPNN), radial basis neural network (RBNN) and generalized regression neural network (GRNN). These parameters were applied in the development of COD soft-sensing models. Six batches of papermaking wastewater with different pollution loads were treated with PEC technology over a period of 90 minutes, and a total of 546 data points was collected, including the on-line measurements of ORP, pH and DO, as well as off-line COD data. The 546 data points were divided into training set (410 data, 75% of total) and validation set (136 data, 25% of total). Four statistical criteria, namely, root mean square error (RMSE), mean absolute error (MAE), mean absolute relative error (MARE), and determination coefficient (R²) were used to assess the performance of the models developed with the training set of data. The comparison of results for the four ANN models for COD soft-sensing indicated that the RBNN model behaved most favorably, which possessed precise and predictable results with R²=0.913 for the validation set. Lastly, the proposed RBNN model was applied to a new batch of PEC oxidation of papermaking wastewater, and the results indicated that the model could be applied successfully for COD soft-sensing for the wastewater.

Anchoring N-Halo (sodium dichloroisocyanurate) on the nano-Fe3O4 surface as “chlorine reservoir”: Antibacterial properties and wastewater treatment

A novel retrievable bifunctional magnetic nano-structure (sodium dichloroisocyanurate immobilized on the Fe3O4@SiO2@Si(CH2)3Cl surface) was synthesized. Its antibacterial performance as water disinfectant successfully evaluated. The value of Minimum Bactericidal Concentration (625 ppm) and Minimum Inhibitory Concentration (314.5 ppm) show that magnetic nano-structure is a very effective antibacterial structure against the E. coli bacteria. In addition the viability of bacteria (%) was evaluated at different contact time against magnetic nano-structure. The disinfection procedure is very clean without any residual cyanuric acid in water. In other hand, oxidizing performance of nano-structure against the azo dye (acid red-18) was evaluated which attributed to the releasing HOCl in water. Kinetic of dye removal was measured at 0.01, 0.05, 0.1, and 0.5 g of nano-structure. Reducing pH and increasing temperature leads to increased Acid Red 18 degradation. Chemical oxygen demand (COD) measurement shows the effectiveness of nano-structure in acid red-18 degradation.The nano-structure turns to be magnetically retrievable, clean disinfectant, wastewater treatment agent, and its chlorine can be regenerated simply by exposure to household bleach such as Ca(OCl)2.

Poly(styrene–divinyl benzene)‐immobilized Fe(III) complex of 1,3‐bis(benzimidazolyl)benzene: Efficient catalyst for the photocatalytic degradation of xylenol orange

ABSTRACTA polymer‐supported Fe(III) complex of 1,3‐bis(benzimidazolyl)benzene [PS–Fe(III)BBZNH] was used in the photodegradation of xylenol orange (XO) dye with H2O2 under UV irradiation. The catalyst was synthesized and characterized by elemental analysis, and Fourier transform infrared, far‐infrared, and UV–visible–diffuse reflectance spectroscopy, Scanning electron microscopy, Brunauer–Emmett–Teller surface area measurements, thermogravimetric analysis, and magnetic measurements. An octahedral coordination around Fe(III) was confirmed by electronic spectral data, and a decrease in the intensity of the νCH2Cl peak in PS–Fe(III)BBZNH was observed compared to the polymer support; this indicated the binding of the ligand to the support. An array of experiments were carried out to assess the influence of various reaction parameters on its photocatalytic performance to ensure maximum dye degradation. The maximum photocatalytic activity was observed at pH 8 with 125 mg of catalyst, 300 ppm of XO, and 200 ppm of H2O2 with complete mineralization after 90 min, as confirmed by chemical oxygen demand measurements. Furthermore, the reactions were repeated under sunlight and under dark conditions to check the photocatalytic efficiency of PS–Fe(III)BBZNH. It displayed better catalytic performance compared than the unsupported complex, PS–Cu(II)BBZNH [Cu(II) complex of 1,3‐bis(benzimidazolyl)benzene], and PS–VO(IV)BBZNH [VO(IV) complex of 1,3‐bis(benzimidazolyl)benzene]. PS–Fe(III)BBZNH could be recycled for up to seven runs. A tentative mechanism involving ·OH radical was proposed. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46480.

Enhanced photocatalytic activity of Ag-ZnO nanoparticles synthesized by using Padina gymnospora seaweed extract

In this present study, reported the Padina gymnospora seaweed extract mediated synthesis of Ag-ZnO nanoparticles by the chemical co-precipitation method. Thus synthesized SW/Ag-ZnO nanoparticles were characterized by FTIR, UV–Visible, HR-SEM and TEM analysis. The strong chemical bonding interactions of Zn2+ and Ag+ ions on the seaweed biomolecules were confirmed by FTIR and UV–Visible spectroscopy. The spherical and grain shaped morphology of Ag, ZnO particles intercalated on the seaweed polymer component was verified by HR-SEM and TEM analysis and their average size of the particles was obtained in 20–40 nm range. In addition, the surface area and pore volume distribution of SW/Ag-ZnO (55.14 m2 g−1 and 0.1830 cm3/g) was found to be higher than SW-ZnO nanoparticles. Photodegradation and decolorization performances of the catalyst nanoparticles were tested by cationic (Methylene Blue) and anionic (Reactive Blue 198) dyes under the direct sunlight irradiations. The photocatalytic degradation activity of SW/Ag-ZnO nanoparticles were fitted to the first order reaction kinetics, the rate constant values of 0.026 and 0.024 min−1 obtained for the MB and RB198 dyes and the removal of 85 and 95% degradation was achieved within the irradiation period of 30 min exposure than the other nanoparticles. The mineralization of MB and RB198 dyes were confirmed by Chemical oxygen demand (COD) measurements.

PENGURANGAN GAS RUMAH KACA DARI LIMBAH CAIR DI PABRIK KELAPA SAWIT PINANG TINGGI, JAMBI DENGAN CDM

Waste water produced from Crude Palm Oil’s process in Palm Oil Mill (POM) is usually treated using water treatment ponds that consist of anaerobic ponds and aerobic ponds. It is known well, methane gas is generated from degradation of organic matter in anaerobic ponds. The methane gas results global warming impacts. Regarding to tackle the global warming impact, the methane gas generated from POM can be captured and flared to convert methane gas tocarbon dioxide. This study was conducted in one of the big capacity of Pinang Tinggi POM owned by PT Perkebunan Nusantara 3. Methane gas potential was investigated by using pH, COD (Chemical Oxygen Demand) and waste water measurement. And from these result the methane gas potential was predicted. In this study, using Clean Development Mechanism (CDM), capturing methane gas generated from anaerobic pond gave a result that the project can be an economically feasible based on the condition measured.Keywords : oil palm industry, methane gas, gas rumah kaca, CDM project(CleanDevelopment Mechanism), COD (Chemical Oxygen Demand)

Applicability of electrochemical methods to paper mill wastewater for reuse. Anodic oxidation with BDD and TiRuSnO2 anodes

The electrochemical oxidation of paper mill wastewater belonging from Halfa industries (Tunisia) was performed by galvanostatic electrolysis using boron-doped diamond (BDD) anodes and Ti-Ru-Sn ternary oxide (TiRuSnO2). The effect of several operating parameters, such as applied current density, flow rate, temperature, initial pH value and addition of NaCl was evaluated. Chemical oxygen demand (COD) and ammonium measurements were carried out to study the treatment of the actual wastewater. The energy consumption analysis has been also discussed. The experimental results exhibited that galvanostatic electrolyses with BDD always allowed efficient COD removal in any conditions thanks to the reaction with hydroxyl radicals electrogenerated on BDD surface during electrolysis. On the contrary, using the TiRuSnO2 anode, the complete COD removal was only obtained in the presence of chloride ions. Comparison of the results of the two electrodes showed that BDD provided a faster removal with higher efficiency and lower energy consumption, while TiRuSnO2 was more efficient for ammonium removal.

Effect of pure and REM: (Nd, Ce)-doped Dy2O3 NPs via hydrothermal method and their magnetic, optical, electrochemical, antibacterial and photocatalytic activities

Pure Dysprosium oxide (Dy2O3) with the spherical-morphology based material, and the rare earth metal (REM) - doped Dy2O3 nanoparticles (NPs) were synthesized using the reaction of dysprosium (III) nitrate pentahydrate, neodymium (III) nitrate hexahydrate and cerium (III) nitrate hexahydrate by the simple cost-effective hydrothermal method, which exhibits high antibacterial effects and photocatalytic activity. The antibacterial effect of pure and (5 mol% of Nd, Ce) - doped Dy2O3 NPs, on Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi were studied by using various concentrations. The photocatalytic activity of pure and 5 mol% of cerium doped Dy2O3 NPs were assessed by degrading the methyl orange (MO) dye under UV irradiation. The characterization results indicated that the XRD and TEM studies confirms the size of the prepared Dy2O3 NPs decreased with Nd and Ce insertion into dysprosium oxide. The particle size calculated from the Williamson-Hall (W-H) plot was consistent with TEM results. From VSM analysis, cerium doped NPs shows high saturation (Ms) magnetization than that of pure Dy2O3 NPs. The emission spectra and electrochemical properties are found to be dopant dependent. 5 mol% of Ce-doped Dy2O3 NPs shows good antibacterial effect compared to that of pure and Nd doped sample. From the above, it is observed that cerium doped NPs exhibit high photocatalytic activity than pure NPs. The mineralization of MO dye solution for pure and 5 mol% of Ce-doped samples has been confirmed by chemical oxygen demand (COD) measurements. In addition, the rate of decolorization is also confirmed by the total organic carbon (TOC) study. From the results, cerium doped sample enhances the photocatalytic performance compared to pure Dy2O3 NPs due to the lower recombination rate of electron-hole pairs and the presence of large surface area of the samples act as reactive facets for adsorption of MO dye molecules.

Veratric acid removal from water by electrochemical oxidation on BDD anode

The efficiency of boron doped diamond (BDD) in the electrochemical treatment of synthetically contaminated water with veratric acid (VA), one kind of polyphenolic type compounds, is investigated in this work. A BDD electrode was practically fabricated using hot filament chemical vapor deposition (HFCVD). Later on, the BDD electrode was implemented as an anode in a batch electrolytic reactor. The effect of operating factors such as the initial concentration of VA, NaCl addition, and supporting electrolyte type (H2SO4, H3PO4 and Na2SO4) was studied. The chemical oxygen demand (COD) measurements were conducted to study the VA electrolysis kinetics. The experimental data suggested that sodium sulfate was the best supporting electrolyte as the COD removal reached a percentage of 100% using 1 mmol/dm3 as VA concentration. The kinetics of the COD decay of the VA electrolysis were found to obey the pseudo-first order model. Remarkably, the electrolysis process is significantly speeded up once chloride is added to the reaction. The complete COD removal was achieved in 60 minutes of treatment.

How do sulfamethoxazole and tetracycline affect the utilization of short chain fatty acids under anaerobic conditions?

The study focused on acute inhibition mechanism and effect of sulfamethoxazole (SMX) and tetracycline (TET) on the carboxylic acid utilization and the methanogenic activity. Duplicate batch reactors were operated in a range of 1–1000 mg/L for each antibiotic. Short chain fatty acid removal was determined in terms of soluble Chemical Oxygen Demand (COD) and specific fatty acid measurements together with methane generation. Additionally, seed sludge was characterized by Fluorescent in situ Hybridization (FISH).The inhibitory impacts of two antibiotics were variable with the initial dose. While in the lower sulfamethoxazole dosage, inhibition was observed in methanogenesis step. 35.8% and 46.8% inhibition in methane production were observed at 25 mg/L and 50 mg/L of SMX amended reactors. In higher SMX doses, short chain fatty acid utilization was inhibited even no acetate produced in the system. Inhibitory effect of tetracycline started at lower dose. 25% inhibition in methane production started at 1 mg/L of TET concentration. Additionally, it affected utilization of butyrate, propionate and acetate together. Tetracycline inhibited total microbial metabolism in terms of substrate utilization and methane generation between 500 mg/L and 1000 mg/L. FISH results showed that the dominant methanogenic group in the sludge was acetoclastic methanogens in term of Methanosarcina and Methanosaeta spp.

Oxidative degradation of phthalic acid using TiO2 photocatalyst

TiO2 is one of the well-known multipurpose material for different applications such as gas sensors, catalysis, solar cells, optoelectronic devices, etc. TiO2 is widely used as photocatalyst due to interest optical and electrical properties. In the present work, TiO2 photocatalyst is used to study the degradation of phthalic acid under ultraviolet light illumination. The prepared TiO2 photocatalyst is characterized by different characterization techniques such as X-ray diffraction, Raman spectroscopy, scanning electron microscopy. The end result shows that the degradation percentage of phthalic acid using TiO2 photocatalyst has reached 41.93% after 320 min. under ultraviolet light illumination. The amount of mineralization of phthalic acid is confirmed by chemical oxygen demand measurements.

Improved UV/O3 method for measuring the chemical oxygen demand.

We improved the ultraviolet (UV)/O3-based method for measuring chemical oxygen demand (COD) in water. An on-line COD monitoring device was developed and the UV/O3 method was used to oxidize sample solutions. A model was established by using support vector machines (SVM) algorithm to estimate dissolved oxygen and CO2 in solutions. Based on the measured data by each sensor during the oxidation process and the estimated dissolved oxygen and CO2, the UV/O3-based COD test accuracy was improved. This approach overcomes many problems associated with the conventional COD determination techniques such as long analysis time, consumption of expensive and toxic reagents, and production of secondary toxic waste. The effect of important parameters on the measurement of COD was systematically investigated. The improved method was successfully applied to determine the COD of real samples from environmental water. Compared with the standard dichromate method, our UV/O3-based COD test method is more effective. The assay time of 10-15 min/sample can be readily achieved. A practical detection limit of 0.89 mg/L COD with a linear range of 1-300 mg/L was achieved under the normal conditions.

Online monitoring and conditional regression tree test: Useful tools for a better understanding of combined sewer network behavior

A good knowledge of the dynamic of pollutant concentration and flux in a combined sewer network is necessary when considering solutions to limit the pollutants discharged by combined sewer overflow (CSO) into receiving water during wet weather. Identification of the parameters that influence pollutant concentration and flux is important. Nevertheless, few studies have obtained satisfactory results for the identification of these parameters using statistical tools. Thus, this work uses a large database of rain events (116 over one year) obtained via continuous measurement of rainfall, discharge flow and chemical oxygen demand (COD) estimated using online turbidity for the identification of these parameters. We carried out a statistical study of the parameters influencing the maximum COD concentration, the discharge flow and the discharge COD flux. In this study a new test was used that has never been used in this field: the conditional regression tree test. We have demonstrated that the antecedent dry weather period, the rain event average intensity and the flow before the event are the three main factors influencing the maximum COD concentration during a rainfall event. Regarding the discharge flow, it is mainly influenced by the overall rainfall height but not by the maximum rainfall intensity. Finally, COD discharge flux is influenced by the discharge volume and the maximum COD concentration. Regression trees seem much more appropriate than common tests like PCA and PLS for this type of study as they take into account the thresholds and cumulative effects of various parameters as a function of the target variable. These results could help to improve sewer and CSO management in order to decrease the discharge of pollutants into receiving waters.

Investigation on the Heterogeneous Photocatalytic Remediation of Pyrene and Phenanthrene in Solutions Using Nanometer TiO2 under UV Irradiation

ABSTRACTPolycyclic aromatic hydrocarbons (PAHs) represent an important group of pollutants, which are known to be mutagenic, teratogenic, carcinogenic and relatively unwavering in the environment. The photocatalytic decomposition employing nano-based semiconductor photocatalyst has been a promising method for the elimination of organic pollutants in water and atmosphere. Photocatalytic remediation of pyrene (Py) and phenanthrene (Phe) by TiO2 in aqueous solutions was investigated under UV light irradiation along with chemical oxygen demand (COD) measurements. Moreover, UV–vis spectrophotometry and gas chromatography (GC) techniques were used to monitor the degradative reaction process. Fast and effective removal of pyrene and phenanthrene was achieved in this system. Catalyst TiO2 accelerated the photoremediation of Py and Phe significantly, with their half-lives being 40.005 and 60.0086 min−1, respectively. Statistical analysis showed high correlation coefficient and significant negative relation with COD and concentration of PAHs with time. All results indicated that the photocatalytic method in the presence of TiO2 nanoparticles is an advisable choice for the treatments of PAHs polluted wastewaters in nature.

Partial Least Squares Regression Calibration of an Ultraviolet-Visible Spectrophotometer for Measurements of Chemical Oxygen Demand in Dye Wastewater

Wastewater from the dye industry is typically analyzed using a standard method for measurement of chemical oxygen demand (COD) or by a single-wavelength spectroscopic method. To overcome the disadvantages of these methods, ultraviolet-visible (UV-Vis) spectroscopy was combined with principal component regression (PCR) and partial least squares regression (PLSR) in this study. Unlike the standard method, this method does not require digestion of the samples for preparation. Experiments showed that the PLSR model offered high prediction performance for COD, with a mean relative error of about 5% for two dyes. This error is similar to that obtained with the standard method. In this study, the precision of the PLSR model decreased with the number of dye compounds present. It is likely that multiple models will be required in reality, and the complexity of a COD monitoring system would be greatly reduced if the PLSR model is used because it can include several dyes. UV-Vis spectroscopy with PLSR successfully enhanced the performance of COD prediction for dye wastewater and showed good potential for application in on-line water quality monitoring.

Degradation of paracetamol in a bubble column reactor with ozone generated in electrolyte-free water using a solid polymer electrolyte filter-press electrochemical reactor

A porous anode composed of β-PbO2 was electrochemically deposited onto a carbon cloth substrate (e.g., CC/β-PbO2) aiming for the electrochemical ozone production (EOP) in electrolyte-free water using a solid polymer electrolyte (SPE) filter-press reactor. Scanning electron microscopy (SEM) images revealed the presence of a three-dimensional oxide structure necessary to obtain a fluid-permeable anode. X-ray analysis showed the predominance of the β-PbO2 phase. The maximum current efficiency for the EOP was 9.5% with an ozone production rate of 1.40 g h−1. Using a constant ozone production rate of 0.5 g h−1, the oxidative degradation of paracetamol (PCT) dissolved in water was accomplished as a function of the PCT concentration (20, 30, and 50 mg L−1) and the pH (acid, natural (without adjustment), and alkaline). The UV-Vis spectrophotometric analysis showed that the degradation process is more pronounced in alkaline media with a strong reduction in the electrical energy per order (E EO). A reduction of the chemical oxygen demand (COD) of up to 80% was observed. A linear correlation between data referring to COD and HPLC measurements with the UV absorbance measured at 243 nm (UV243) was verified indicating that these different techniques can be complementary to each other. The nuclear magnetic resonance (NMR) study of the ozonation by-products revealed that the oxidation of PCT occurred through the rupture of the aromatic ring. The major part of phenol’s ring was oxidized to CO3 2− while no reaction occurs in the acetamide group of paracetamol during the ozonation reaction.