Meta-Phenylenediamine-Derived Silver-Containing Nanoporous Hyper-Cross-Linked Polymer: An Innovative Fluorescence Probe for S2O32- ion Detection in Aqueous Media.

The meta-phenylenediamine polymer, when hyper-cross-linked, exhibits a minimal fluorescence intensity. However, the introduction of silver ions induces a significant increase in intensity, attributed to the plasmonic effect. This heightened intensity is selectively increased more upon the addition of thiosulfate ions. Capitalizing on this property, a fluorescence probe was developed. The correlation between fluorescence intensity reduction and S2O32- concentration follows a linear and consistent pattern. The precursor's response to diverse anions such as SO42-, CO32-, HPO42-, Cr2O72-, F-, Cl-, Br-, I-, H2PO4-, CH3COO-, NO3-, ClO-, and HCO3- was also examined. Under optimal conditions, the probe exhibited a linear range of 0.5-3 µM with a detection limit of 0.01 µM. Its effectiveness was demonstrated in measuring thiosulfate concentrations in aqueous media.

The role of hydrogen sulfide in the retina.

The discovery of the hydrogen sulfide (H2S) and the transsulfuration pathway (TSP) responsible for its synthesis in the mammalian retina has highlighted this molecule's wide range of physiological processes that influence cellular signaling, redox homeostasis, and cellular metabolism. The multi-level regulatory program that influences H2S levels in the retina depends on the relative expression and activity of TSP enzymes, which regulate the abundance of competitive substrates that support or abrogate H2S synthesis. In addition, and apart from TSP, intracellular H2S levels are regulated by mitochondrial sulfide oxidizing pathways. Retinal layers natively express differing levels of TSP enzymes, which highlight the differences in the metabolite and substrate requirement. Recent studies indicate that these systems are susceptible to pathophysiologies affecting the retina. Dysregulation at any level can upset the balance of redox and signaling processes and possibly upset oxidative stress, apoptotic signaling, ion channels, and immune response within this sensitive tissue. H2S donors are a potential therapeutic in such cases and have been demonstrated to bridge the gap, positively impacting the damaged retina. Here, we review the recent findings of H2S, how its multi-level regulation impacts the retina, and how its dysregulation is implicated in retinal pathologies.

Nitrogen-contained Nanoporous Hyper-cross-linked Polymer: A New Turn-on Fluorescence Probe for Detection of Ag+ Ions in Aqueous Media.

A fluorescence probe was designed using a nitrogen-contained mesoporous hyper-cross-linked polymer precursor (NH2-HCP) in order to selectively detect silver (Ag+) ions. NH2-HCP exhibits fluorescence intensity, but upon the addition of Ag+, a significant enhancement in fluorescence signal is observed. The relationship between fluorescence intensity enhancement and Ag+ concentration shows a linear and monotonic trend. The probe's response to various other cations such as Al3+, Fe3+, Cd2+, Ni2+, Cu2+, Fe2+, Hg2+, Mg2+, Zn2+, Pb2+, Mn2+, Co2+, Ca2+, Na+, and K+, as well as halogen anions like F-, Cl-, Br-, and I- was also investigated. Under optimal conditions, the probe demonstrated a linear range of 0.1-3 µM and a detection limit of 0.01 µM.

Fumed-Si-Pr-PNS as a Photoluminescence sensor for the Detection of Hg2+ in Aqueous Media.

Fumed silica was functionalized by piperazine followed by the reaction with 2- naphthalenesulfonyl chloride to prepare Fumed-Si-Pr-Piperazine-Naphthalenesulfonyl chloride (Fumed-Si-Pr-PNS), which was characterized to demonstrate the effective attachment on the surface of fumed silica. The optical sensing ability of Fumed-Si-Pr-PNS was studied via diverse metal ions in H2O solution by photoluminescence spectroscopy. The results showed that Fumed-Si-Pr-PNS detected selectively Hg2+ ions. The prepared sensor showed almost high absorption at different pH for Hg ion. After drawing various diagrams, The detection limits were calculated at about 12.45 × 10-6 M for Hg2+.

ZnO/black phosphorus/C3N4 composite: An effective photocatalyst for Cr (VI) reduction and degradation of rhodamine B.

The utilization of photocatalysts offers a promising approach for the removal of Cr (VI) and rhodamine dyes. Through the generation of reactive species and subsequent degradation reactions, photocatalysis provides an efficient and environmentally friendly method for the remediation of wastewater. In this study, we have synthesized an n-p-n heterojunction of carbon nitride (C3N4), zinc oxide (ZnO), and black phosphorus (BP) through the sonication-stirring method. The photocatalytic ability of this composite was examined for the decomposition rhodamine B (RhB) and detoxification of hexavalent chromium ion (up to 97% during 80 min) under Xenon irradiation. The results of trapper experiments indicated that the active species were hydroxyl radical (˙OH), electron (e-), and superoxide anion radical (˙O2-). Based on the obtained potential of the lowest unoccupied molecular orbitals (LUMO) and the highest occupied molecular orbital (HOMO) for the mentioned semiconductors, through Mutt-Schottky results, the double Z-scheme mechanism was proposed for the studied process. The electrochemical impedance spectroscopy data exhibited good charge transfer for the evaluated composite versus the pure compounds. The impressive separation of holes and electrons along with the low recombination were confirmed by the responses of photocurrent and quenching the photoluminescence (pl) intensity for the composite, respectively. The current density of the composite recorded 66.6%, 87.3%, and 92% higher than those of BP, C3N4, and ZnO, indicating an excellent electron-hole separation for the ternary composite compared to the pure semiconductors. Diffuse reflectance spectra (DRS) data revealed 2.9, 3.17, 1.15, and 2.63 eV as the band gap values for C3N4, ZnO, BP, and composite. The rate constant of the new composite to remove RhB and reduce hexavalent chromium were about 4.79 and 2.64 times higher than that of C3N4, respectively.

Black Phosphorus-based Photocatalysts: Synthesis, Properties, and Applications.

Photocatalysis is considered as an eco-friendly and sustainable strategy, since it uses abundant light for the advancement of the reaction, which is freely accessible and is devoid of environmental pollution. During the last decades, (nano)photocatalysts have gained broad industrial applications in terms of purification and detoxification of water as well as production of green fuels and hydrogen gas due to their special attributes. The degradation or remediation of toxic and hazardous compounds from the environment or changing them into non-toxic entities is a significant endeavor and necessary for the safety of humans, animals, and the environment. Black phosphorus (BP), a two-dimensional single-element material, has a marvelous structure, tunable bandgap, changeable morphology from bulk to nanosheet/quantum dot, and unique physicochemical properties, which makes it attractive material for photocatalytic applications, especially for sustainable development purposes. Since it can serve as a photocatalyst with or without coupling with other semiconductors, various aspects for multidimensional exploitation of BP are deliberated including their preparation via solvothermal, ball milling, calcination, and sonication methods to obtain BP from red phosphorus. The techniques for improving the photocatalytic and stability of BP-based composites are discussed along with their multifaceted applications for environmental remediation, pollution degradation, water splitting, N2 fixation, CO2 reduction, bacterial disinfection, H2 generation, and photodynamic therapy. Herein, most recent advancements pertaining to the photocatalytic applications of BP-based photocatalyst are cogitated, with a focus on their synthesis and properties as well as crucial challenges and future perspectives.

MOF-based composites as photoluminescence sensing platforms for pesticides: Applications and mechanisms.

Metal-organic frameworks (MOFs) have recently garnered considerable attention among reticular compounds due to their unique physicochemical properties and applications in sensing toxic compounds. On the other hand, fluorometric sensing has been widely studied for food safety and environmental protection among the various sensing methods. Thus, designing MOF-based fluorescence sensors for specific detection of hazardous compounds, especially pesticides, are incessantly needed to keep up with the continuous demands for monitoring these environmental pollution. Herein, recent MOF-based platforms for pesticide fluorescence detection are deliberated owing to sensors' emission origins and in terms of their structural properties. The influences of different guest incorporation in MOFs on pesticide fluorescence detection are summarized, and the future developments of novel MOF composites such as polyoxometalate@MOFs (POMOF), carbon quantum dots@MOFs (CDs@MOF), and organic dye@MOF are prospected for fluorescence sensing of assorted pesticides with a focus on mechanistic insights of specific detection techniques in food safety and environmental protection.

A miniaturized analytical system with packed epoxy-functionalized mesoporous organosilica for copper determination using a customized Android-based software.

A smartphone-assisted determination of copper ions is introduced by using a down-scaled microfluidic mixer. The system was coupled with a micro-column packed with a periodic mesoporous organosilica (PMO) material for preconcentration of copper ions. Copper ions were reduced to Cu(I) on-chip to selectively form an orange-colored complex with neocuproine. A novel Android-based software was made to determine the color change of the adsorbent by analyzing red-green-blue (RGB) components of images from the packed PMO material. Four porous framework materials with high porosity and chemical stability were synthesized and compared for the extraction of the Cu-neocuproine complex. The main parameters influencing the complex extraction efficiency were optimized. The analytical performance of the method showed limit of detection and quantification of 0.2 µg L-1 and 0.5 µg L-1, respectively. The accuracy and precision of the method were determined as recovery > 92% and relative standard deviations < 5.2% at medium concentration level (n = 5). Due to accumulation of the retained analyte in a single point and elimination of the stripping step, the RGB-based method showed sensitivity and precision higher than inductively coupled plasma-atomic emission spectrometry (ICP-AES) for determination of copper ions. To investigate the applicability of the method, six different water samples were analyzed. The t-test on the data showed that the method has no significant difference when compared with ICP-AES determination.

Altered transsulfuration pathway enzymes and redox homeostasis in inherited retinal degenerative diseases.

Retinal degenerative diseases result from apoptotic photoreceptor cell death. As endogenously produced gaseous molecules such as hydrogen sulfide (H2S) and nitric oxide (NO) play a key role in apoptosis, we compared the expression levels of genes and proteins involved in the production of these molecules in the retina of normal dogs and three canine models (rcd1, crd2, and xlpra2) of human inherited retinal degeneration (IRD). Using qRT-PCR, Western blot, and immunohistochemistry (IHC), we showed that mRNA and protein levels of cystathionine ß-synthase (CBS), an enzyme that produces H2S in neurons, are increased in retinal degeneration, but those of cystathionine γ-lyase (CSE), an enzyme involved in the production of glutathione (GSH), an antioxidant, are not. Such findings suggest that increased levels of H2S that are not counterbalanced by increased antioxidant potential may contribute to disease in affected retinas. We also studied the expression of neuronal and inducible nitric oxide synthase (nNOS and iNOS), the enzymes responsible for NO production. Western blot and IHC results revealed increased levels of nNOS and iNOS, resulting in increased NO levels in mutant retinas. Finally, photoreceptors are rich in polyunsaturated fatty acids (PUFAs) that can make these cells vulnerable to oxidative damage through reactive oxygen species (ROS). Our results showed increased levels of acrolein and hydroxynonenal (4HNE), two main toxic products of PUFAs, surrounding the membranes of photoreceptors in affected canines. Increased levels of these toxic products, together with increased NO and ROS, likely render these cells susceptible to an intrinsic apoptotic pathway involving mitochondrial membranes. To assess this possibility, we measured the levels of BCL2, an anti-apoptotic protein in the mitochondrial membrane. Western blot results showed decreased levels of BCL2 protein in affected retinas. Overall, the results of this study identify alterations in the expression of enzymes directly involved in maintaining the normal redox status of the retina during retinal degeneration, thereby supporting future studies to investigate the role of H2S and NO in retinal degeneration and apoptosis.

A new fluorescence probe for detection of Cu+2 in blood samples: Circuit logic gate.

A Fluorescence probe was designed based on 8-hydroxyquinoline chitosan silica precursor (HQCS) for selective detection of Al3+, Cu2+. The HQCS has no observable fluorescence signal, but after the addition of Al3+, a huge fluorescence signal appeared, and the selective quenching was absorbed after the addition of Cu2+. The effect of other different cations, including Cu2+, Mg2+, Ca2+, Pb2+, Zn2+, Hg2+, Ag+, Fe3+, and K+ was studied. The addition of Cu2+ to the probe (HQCSAL) decreased the fluorescence very repeatable, and the variation of the fluorescence vs. Cu2+ was monotonic and linear. Therefore, the prepared probe was used to determine Cu2+ ions in real samples. The mechanism of fluorescence variation by adding cations to the probe solution was studied using the Stern-Volmer equation. Under the optimum conditions, the linear range and detection limit were 3.5-31 µM and 1 µM, respectively. The probe accuracy on the copper determination in the blood and tap waters was comparable to the ICP-OES results. The circuit logic gate mimic was designed for the fluorescence behavior of the probe constituents.

Multicomponent Synthesis and Investigations Fluorescence Activity of Chromenone-Pyrazole Compounds.

A synthetic method is described to produce some chromenone-pyrazole derivatives through a one-pot multicomponent reaction using SrFe12O19 as a magnetic catalyst. This method provides quite a few merits, including the use of an effective and easy separable nanocatalyst, high yields of products, short reaction time, and easy work-up. Two of the products showed fluorescence properties, which have detected mercury ions without any interference with other ions. They can detect a tiny amount of mercury ions, which were comparable with other chemosensors. The detection limit is 4 × 10-7 and 3 × 10-8 M, respectively, for the compound I and II, respectively, which were considered very low amounts. The effect of mercury on health and environmental pollution is essential in medical science.

An On-off Supramolecular Fluorescence Switch for Detection of Pb2+ Ions and Vitamin C.

ß-cyclodextrin-hydroxyquinoline functionalized graphene oxide (GO-CD-HQ) was facilely fabricated to monitor and quantitatively analyze cations in aqueous media. The optical probe was notably selective enhanced toward Pb2+ ions over the other tested ions like Cu2+, Hg2+, Ca2+, Na+, K+, Zn2+, Fe2+, Fe3+, Ag+, Mg2+, and Cd2+ at 468 nm as an emission wavelength. The probe was shown the best performance in pH value, 5, and optimum time 1 min. Absorption spectra have clearly confirmed the static type fluorescence enhancement mechanism of GO-CD-HQ. Under the optimal conditions, the detection limit of it and linear concentration range for Pb2+ ions were obtained as 3.72 × 10-5 M and (5-60) × 10-5 M, respectively. Additionally, the developed assay exhibited logic gate behavior with Pb2+ ions and vitamin C as a masking agent for cited ions.

Ethane-bridge periodic mesoporous organosilica materials as a novel fiber coating in headspace solid-phase microextraction of phthalate esters from saliva and PET container samples.

The current study presents a periodic mesoporous organosilica (PMO) with a high surface area and uniform-porosity material. The PMO materials were successfully synthesized and modified. The resultant material was characterized by different characterization techniques. The prepared PMO was immobilized on a stainless steel wire surface and was evaluated for headspace solid-phase microextraction of the ultra-trace amount of phthalate esters from saliva and polyethylene terephthalate containers which were in contact with hot and cold water. Separation and determination of the phthalate esters (PEs) were performed by the GC-FID and GC-MS instruments. The key parameters affecting the extraction efficiencies, including extraction temperature, extraction time, ionic strength, and desorption temperature and time, were investigated and optimized. Under optimum conditions, the repeatability for one fiber (n = 7) was 4.8-8.7%, and fiber-to-fiber reproducibility (n = 3) was 7.5-10.6% for the extracted compounds. The limits of detection of the developed method for the studied compounds were between 0.01 and 1 µg L-1. The results showed suitable coefficients of determination (R2 ≥ 0.99) for all of the analytes in the 0.05-300 µg L-1 calibration range. Acceptable recovery values of 91-107%, 82-110%, and 98-104% were obtained in saliva, polyethylene terephthalate containers hot water, and cold water, respectively.

Electrospun composite nanofibers as novel high-performance and visible-light photocatalysts for removal of environmental pollutants: A review.

Environmental pollution caused by industries and human manipulations is coming a serious global challenge. On the other hand, the world is facing an energy crisis caused by population growth. Designing solar-driven photocatalysts which are inspired by the photosynthesis of plant leaves is a fantastic solution to use solar energy as green, available, and unlimited energy containing ∼50% visible light for the removal of environmental pollutants. The polymeric and non-polymeric-based electrospun composite nanofibers (NFs) are as innovative photocatalytic candidates which increase photocatalytic activity and transition from UV light to visible light and overcome the aggregation, photocorrosion, toxicity, and hard recycling and separation of the nanosized powder form of photocatalysts. The composite NFs are fabricated easily by either embedding the photocatalytic agents into the NFs during electrospinning or via their decorating on the surface of NFs post-electrospinning. Polyacrylonitrile-based, tungsten trioxide-based, zinc oxide-based, and titanium dioxide-based composite NFs were revealed as the most reported composite NFs. All the lately investigated electrospun composite NFs indicated long-term stability, high photocatalytic efficiency (∼> 80%) within a short time of light radiation (10-430 min), and high stability after several cycles of use. They were applied in various applications including degradation of dyes/antibiotics, water splitting, wastewater treatment, antibacterial usage, etc. The photogenerated species especially holes, O2∙-, and .OH were mostly responsible for the photocatalytic mechanism and pathway. The electrospun composite NFs have the potential to use in large-scale productions in condition that their thickness and recycling conditions are optimized, and their toxicity and detaching are resolved.

Nano-architectural design of TiO2 for high performance photocatalytic degradation of organic pollutant: A review.

In the past several decades, significant efforts have been paid toward photocatalytic degradation of organic pollutants in environmental research. During the past years, titanium dioxide nano-architectures (TiO2 NAs) have been widely used in water purification applications with photocatalytic degradation processes under Uv/Vis light illumination. Photocatalysis process with nano-architectural design of TiO2 is viewed as an efficient procedure for directly channeling solar energy into water treatment reactions. The considerable band-gap values and the subsequent short life time of photo-generated charge carriers are showed among the limitations of this approach. One of these effective efforts is the using of oxidation processes with advance semiconductor photocatalyst NAs for degradation the organic pollutants under UV/Vis irradiation. Among them, nano-architectural design of TiO2 photocatalyst (such as Janus, yolk-shell (Y@S), hollow microspheres (HMSs) and nano-belt) is an effective way to improve oxidation processes for increasing photocatalytic activity in water treatment applications. In the light of the above issues, this study tends to provide a critical overview of the used strategies for preparing TiO2 photocatalysts with desirable physicochemical properties like enhanced absorption of light, low density, high surface area, photo-stability, and charge-carrier behavior. Among the various nanoarchitectural design of TiO2, the Y@S and HMSs have created a great appeal given their considerable large surface area, low density, homogeneous catalytic environment, favorable light harvesting properties, and enhanced molecular diffusion kinetics of the particles. In this review was summarized the developments that have been made for nano-architectural design of TiO2 photocatalyst. Additional focus is placed on the realization of interfacial charge and the possibility of achieving charge carriers separation for these NAs as electron migration is the extremely important factor for increasing the photocatalytic activity.

Molecular docking and optical sensor studies based on 2,4-diamino pyrimidine-5-carbonitriles for detection of Hg2.

An organic chemical sensor based on pyrimidine was successfully produced through the green reaction between aromatic aldehyde, malononitrile, and guanidine carbonate using SBA-Pr-SO3H. This fluorescence intensity of chemosensor (2,4-diamino-6-(phenyl)pyrimidine-5-carbonitrile) decreases by the addition of Hg2+ and its detection limit is about 14.89 × 10-5 M, in fact, through the green synthesis, the ligand was yielded to detect Hg2+ and the importance of ligand was considered in docking studies. The molecular docking of 2,4-diamino-6-(phenyl)pyrimidine-5-carbonitrile compound has been done with the protein selective estrogen receptor 5ACC complexed with (Azd9496), Human Anaplastic Lymphoma Kinase Pdb; 2xp2 complex with crizotinib (PF-02341066) and human wee1 kinase Pdb; 5vc3 complexed with bosutinib. The ligands 2,4-diamino-6-(phenyl)pyrimidine-5-carbonitrile generate very good docking results with the protein Pdb; 2xp2, which is responsible for effective tumor growth inhibition.

Effect of the Nanoclay Treated Streptomyces sp. UTMC 3136 as a Bioformulation on the Growth of Helianthus annuus.

Biofertilizers based on plant growth-promoting actinobacteria are used as potential alternatives to chemical fertilizers for sustainable agricultural systems. However, successful application of PGPA to agricultural land is challenging. The present study was an attempt to develop and evaluate the effect of a low-cost biofertilizer named NCTS (nanoclay-treated-Streptomyces) based on Streptomyces sp. UTMC 3136 spores amalgamated in a hybrid material of nanoclay Na-montmorillonite K10-glycerol-water substrate. In addition, the effect of NCTS on sunflower growth was investigated. In vivo tests showed a statistically significant increase in the agronomic characteristics of sunflowers treated with NCTS. Characterization of NCTS by FTIR, Raman spectroscopy, and scanning electron microscopy testified to the structural alignment and good adhesion of NCTS components. The viability of NCTS was 100% after 72 h of storage at 4 °C. Overall, the present study attempted to validate the efficacy of the formulation of Streptomyces sp. UTMC 3136 in nanoclay for growth improvement of sunflower. It was the first study to show the administration of PGPA in combination with nanomaterials as a growth enhancing biofertilization agent for sunflower.

Comparative localization of cystathionine beta synthases and cystathionine gamma lyase in canine, non-human primate and human retina.

Chronic exposure of the retina to light and high concentrations of polyunsaturated fatty acid in photoreceptor cells make this tissue susceptible to oxidative damage. As retinal degenerative diseases are associated with photoreceptor degeneration, the antioxidant activity of both hydrogen sulfide (H2S) and glutathione (GSH) may play an important role in ameliorating disease progression. H2S production is driven by cystathionine-γ-lyase (CSE) and cystathionine-ß-synthase (CBS), the key enzymes that also drive transsulfuration pathway (TSP) necessary for GSH production. As it is currently unclear whether localized production of either H2S or GSH contributes to retinal homeostasis, we undertook a comparative analysis of CBS and CSE expression in canine, non-human primate (NHP) and human retinas to determine if these antioxidants could play a regulatory role in age-related or disease-associated retinal degeneration. Retinas from normal dogs, NHPs and humans were used for the study. Laser capture microdissection (LCM) was performed to isolate individual layers of the canine retina and analyze CBS and CSE gene expression by qRT-PCR. Immunohistochemistry and western blotting were performed for CBS and CSE labeling and protein expression in dog, NHP, and human retina, respectively. Using qRT-PCR, western blot, and immunohistochemistry (IHC), we showed that CBS and CSE are expressed in the canine, NHP, and human retina. IHC results from canine retina demonstrated increased expression levels of CBS but not CSE with post-developmental aging. IHC results also showed non-overlapping localization of both proteins with CBS presenting in rods, amacrine, horizontal, and nerve fiber cell layers while CSE was expressed by RPE, cones and Mϋller cells. Finally, we demonstrated that these enzymes localized to all three layers of canine, NHP and human retina: photoreceptors, outer plexiform layer (OPL) and notably in the ganglion cells layer/nerve fiber layer (GCL/NFL). QRT-PCR performed using RNA extracted from tissues isolated from these cell layers using laser capture microdissection (LCM) confirmed that each of CBS and CSE are expressed equally in these three layers. Together, these findings reveal that CSE and CBS are expressed in the retina, thereby supporting further studies to determine the role of H2S and these proteins in oxidative stress and apoptosis in retinal degenerative diseases.

An ultrasensitive fluorescence sensor for determination of trace levels of copper in blood samples.

A novel SBA-15-based fluorescent sensor, SBA-PI: mesoporous SBA-15 structure modified with iminostilbene groups, was designed, synthesized, and characterized by Fourier transform-infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), low-angle X-ray diffraction techniques (low-angle XRD), and N2 adsorption-desorption techniques. The SBA-PI as a sensor with a selective behavior for detection of Cu2+ comprises iminostilbene carbonyl as the fluorophore group. The SBA-PI sensor displays an excellent fluorescence response in aqueous solutions and the fluorescence intensity quenches remarkably upon addition of Cu2+. Other common interfering ions even at high concentration ratio showed either no or very small changes in the fluorescence intensity of SBA-PI in the absence of Cu2+. A limit of detection of 8.7 × 10-9 M for Cu2+ indicated that this fluorescence sensor has a high sensitivity and selectivity toward the target copper (II) ion. The fabricated Cu2+ sensor was successfully applied for the determination of the Cu2+ in human blood samples without any significant interference. With the selective analysis of Cu2+ ions down to 0.9 nM in blood, the sensor is a promising and a novel detection candidate for Cu2+ and can be applied in the clinical laboratory. A reversibility and accuracy in the fluorescence behavior of the sensor was found in the presence of I¯ that was described as a masking agent for Cu2+. Graphical abstract.

Response surface methodology modeling to improve degradation of Chlorpyrifos in agriculture runoff using TiO2 solar photocatalytic in a raceway pond reactor.

This paper deals with the use of a raceway pond reactor (RPR) as an alternative photoreactor for solar photocatalytic applications. Raceway pond reactors are common low-cost reactors which can treat large volumes of water. The experiments were carried out with TiO2 in the agriculture effluent spiked with Chlorpyrifos (CPF) at circumneutral pH. The Response Surface Methodology (RSM) was used to find the optimum process parameters to maximize CPF oxidation from the mathematical model equations developed in this study using R software. By ANOVA, p-value of lack of fit > 0.05 indicated that, the equation was well-fitted. The theoretical efficiency of CPF removal, under the optimum oxidation conditions with UV solar energy of around 697 ± 5.33 lux, was 84.01%, which is in close agreement with the mean experimental value (80 ± 1.42%) confirming that the response model was suitable for the optimization. As far as the authors know, this is the first study of CPF removal using RPR in agriculture runoff at circumneutral pH.