TiO2 photocatalysis of naproxen: Effect of the water matrix, anions and diclofenac on degradation rates

The TiO2 photocatalytic degradation of the active pharmaceutical ingredient (API) naproxen (NPX) has been studied using a laboratory-scale photoreactor equipped with a medium pressure mercury lamp. UV/TiO2 photocatalysis proved highly efficient in the elimination of NPX from a variety of water matrices, including distilled water, unfiltered river water and drinking water, although the rate of reaction was not always proportional to TiO2 concentration. However, the NPX degradation rate, which follows first-order kinetics, was appreciably reduced in river water spiked with phosphate and chloride ions, a dual anion system. Addition of chloride into drinking water enhanced the TiO2-photocatalysed degradation rate. Competitive degradation studies also revealed that the NPX degradation was greatly reduced in the presence of increased concentrations of another API, diclofenac (DCF). This was established by (i) the extent of mineralization, as determined by dissolved organic carbon (DOC) content, and (ii) the formation of intermediate NPX by-products, identified using liquid chromatography and electrospray ionization (positive and negative mode) mass spectrometry techniques. This study demonstrates that competition for active sites (anions or DCF) and formation of multiple photoproducts resulting from synergistic interactions (between both APIs) are key to the TiO2-photocatalysed NPX degradation

Titanium dioxide photocatalysis for pharmaceutical wastewater treatment

Heterogeneous photocatalysis using the semiconductor titanium dioxide (TiO2) has proven to be a promising treatment technology for water purification. The effectiveness of this oxidation technology for the destruction of pharmaceuticals has also been demonstrated in numerous studies. This review highlights recent research on TiO2 photocatalytic treatment applied to the removal of selected pharmaceuticals. The discussions are tailored based on the therapeutic drug classes as the kinetics and mechanistic aspects are compound dependent. These classes of pharmaceuticals were chosen because of their environmental prevalence and potential adverse effects. Optimal operational conditions and degradation pathways vary with different pharmaceutical compounds. The main conclusion is that the use of TiO2 photocatalysis can be considered a state-of-the-art pharmaceutical wastewater treatment methodology. Further studies are, however, required to optimize the operating conditions for maximum degradation of multiple pharmaceuticals in wastewater under realistic conditions and on an industrial scale

Photo-fenton treatment of sago wastewater: RSM optimization and toxicity evaluation

Due to the fact that organic matter in sago wastewater is not effectively removed by current traditional methods, this study was designed to systematically investigate the performance of photo-Fenton treatment. Despite being ratified for its high efficiency in improving wastewater quality, there remains a paucity of evidence on its performance on sago wastewater. Thus, the objective of this study was to optimize the conditions of the photo-Fenton process by employing the response surface methodology (RSM) using the chemical oxygen demand (COD) removal as the target parameter. Fenton’s reagent (Fe2+ and H2O2 concentration) and pH were used as the independent variables to be optimized. Under optimum conditions, 90.0% of COD removal efficiency was obtained when the wastewater sample was treated at pH 2.66 in the presence of 4.01 g/L of H2O2and 5.07 g/L Fe2+ion. Despite the high COD removal, the total organic carbon (TOC) removal under the same optimized condition was lower, only 48.0% indicating incomplete mineralization of stable intermediates present in the solution. Toxicity evaluation revealed that the mortality of Artemia salina was less than 50%, which means that the treated sago wastewater can be considered as non-toxic. The regression value (R2> 0.99) of the models indicates a high degree of correlation between the parameters evaluated. The results obtained indicate the feasibility of photo-Fenton treatment to the sago wastewater as an appealing alternative approach

A COMPLEX STRUCTURE TO INTEGRATED ELECTRIC ENERGY WITH RENEWABLE ENERGY

The suggested electricity micro grid connects having a wind turbine via a current-source ripper tools (VSC), a wave generator via a VSC, a power storage battery via a bidirectional electricity/electricity ripper tools, a resistive electricity load via a load electricity/electricity ripper tools, as well as an ac power company via a bidirectional grid-tied inverter. To be able to read the uncertainty and intermittent qualities of wind power and wave, this paper proposes a built-in wind and wave generation system given for an ac power company or of an isolated load utilizing a electricity micro grid. The analyzed integrated wind and wave system became a member of using the electricity micro grid is modeled and simulated while using written program according to MATLAB/Simulink. Root-loci plots from the analyzed system under various speeds from the wave generator are examined. Comparative simulation and experimental results demonstrate that the analyzed integrated system can maintain stable operation to provide power under different operating conditions while using suggested electricity micro grid. To look at the essential operating qualities from the analyzed integrated system became a member of using the electricity micro grid, a laboratory- scale platform can also be established

TiO2 photocatalysis of naproxen : effect of the water matrix, anions and diclofenac on degradation rates

The TiO2 photocatalytic degradation of the active pharmaceutical ingredient (API) naproxen (NPX) has been studied using a laboratory-scale photoreactor equipped with a medium pressure mercury lamp. UV/TiO2 photocatalysis proved highly efficient in the elimination of NPX from a variety of water matrices, including distilled water, unfiltered river water and drinking water, although the rate of reaction was not always proportional to TiO2 concentration. However, the NPX degradation rate, which follows first-order kinetics, was appreciably reduced in river water spiked with phosphate and chloride ions, a dual anion system. Addition of chloride into drinking water enhanced the TiO2-photocatalysed degradation rate. Competitive degradation studies also revealed that the NPX degradation was greatly reduced in the presence of increased concentrations of another API, diclofenac (DCF). This was established by (i) the extent of mineralization, as determined by dissolved organic carbon (DOC) content, and (ii) the formation of intermediate NPX by-products, identified using liquid chromatography and electrospray ionization (positive and negative mode) mass spectrometry techniques. This study demonstrates that competition for active sites (anions or DCF) and formation of multiple photoproducts resulting from synergistic interactions (between both APIs) are key to the TiO2-photocatalysed NPX degradation

Advanced oxidation process-mediated removal of pharmaceuticals from water: A review

Pharmaceuticals, which are frequently detected in natural and wastewater bodies as well as drinking water have attracted considerable attention, because they do not readily biodegrade and may persist and remain toxic. As a result, pharmaceutical residues pose on-going and potential health and environmental risks. To tackle these emerging contaminants, advanced oxidation processes (AOPs) such as photo- Fenton, sonolysis, electrochemical oxidation, radiation and ozonation etc. have been applied to remove pharmaceuticals. These processes utilize the high reactivity of hydroxyl radicals to progressively oxidize organic compounds to innocuous products. This review provides an overview of the findings from recent studies, which have applied AOPs to degrade pharmaceutical compounds. Included is a discussion that links various factors of TiO2-mediated photocatalytic treatment to its effectiveness in degrading pharmaceutical residues. This review furthermore highlights the success of AOPs in the removal of pharmaceuticals from different water matrices and recommendations for future studies are outlined

DISINFECTANTS AND CORONAVIRUS DISEASE 2019 (COVID-19) : A MINI REVIEW

The 2019 novel corona virus (2019-nCoV), now known as coronavirus disease (COVID-19), is a major public health threat, impacting both health of populations and economies worldwide, since its emergence in a city called Wuhan, China in December 2019. Known to be highly infectious via human-to-human transmission, the virus can cause severe respiratory infections, resulting in mortality. Because of the current lack of effective drugs to treat or a vaccine to prevent COVID-19 or the SARS-CoV-2, which causes it, disinfectant use is encouraged at a personal level and especially in healthcare and residential settings to control the spread of the virus. The current knowledge of available disinfectants commonly used, their active ingredients and effectiveness in combating COVID-19 will be discussed in this mini review

Heterogeneous photocatalysis for pharmaceutical wastewater treatment

Environmentally sustainable solutions for wastewater management including the improvement of water quality and water recycling are considered key priority areas globally. The challenges facing our water resources are unprecedented due to the presence of organic and inorganic pollutants derived from numerous anthropogenic activities. This situation has been further complicated by emerging persistent contaminants such as pharmaceuticals which possess low biodegradability and resistance to chemical and biological treatments. Excretion of pharmaceuticals and their metabolites via human waste, improper disposal and veterinary applications is recognized as the principal sources of pharmaceuticals ending up in various compartments of the environment. Heterogeneous photocatalysis using semiconductor titanium dioxide (TiO₂) has proven to be a promising treatment method for the degradation of pharmaceuticals. \ud \ud Here, we review recent research concerning the application of TiO₂ photocatalysis for the removal of selected pharmaceuticals belonging to different therapeutic drug classes. These classes of pharmaceuticals were chosen based on their environmental prevalence and potential adverse effects. The highlighted conclusions from this review are that (1) TiO₂ photocatalysis may play a major role in the degradation of pharmaceuticals; (2) various factors such as catalyst loading, initial concentrations, and water matrices significantly influence both the degradation rate and kinetics of degradation; (3) mineralization remains incomplete, despite complete abatement of the parent pharmaceutical due to the formation of stable byproducts; (4) structures or number of intermediates formed differ due to the variation of photocatalytic experimental parameters, and (5) laboratory-scale experiments with artificial pharmaceutical solutions, in particular single compounds, are more common than pilot-scale or real wastewater samples. The main conclusion is that the use of heterogeneous photocatalysis can be considered a state-of-the-art pharmaceutical wastewater treatment. Further studies are needed to optimize the operating conditions for maximum degradation of wastewater containing multiple pharmaceuticals under realistic conditions and on industrial scales

Solar photolysis versus TiO2-mediated solar photocatalysis: a kinetic study of the degradation of naproxen and diclofenac in various water matrices

Given that drugs and their degradation products are likely to occur as concoctions in wastewater, the degradation of a mixture of two nonsteroidal anti-inflammatory drugs (NSAIDs), diclofenac (DCF) and naproxen (NPX), was investigated by solar photolysis and titanium dioxide (TiO2)-mediated solar photocatalysis using an immersion-well photoreactor. An equimolar ratio (1:1) of both NSAIDs in distilled water, drinking water, and river water was subjected to solar degradation. Solar photolysis of the DCF and NPX mixture was competitive particularly in drinking water and river water, as both drugs have the ability to undergo photolysis. However, the addition of TiO2 in the mixture significantly enhanced the degradation rate of both APIs compared to solar photolysis alone. Mineralization, as measured by chemical oxygen demand (COD), was incomplete under all conditions investigated. TiO2-mediated solar photocatalytic degradation of DCF and NPX mixtures produced 15 identifiable degradants corresponding to degradation of the individual NSAIDs, while two degradation products with much higher molecular weight than the parent NSAIDs were identified by liquid chromatography mass spectrometry (LC-MS) and Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS). This study showed that the solar light intensity and the water matrix appear to be the main factors influencing the overall performance of the solar photolysis and TiO2-mediated solar photocatalysis for degradation of DCF and NPX mixtures