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One of the most significant environmental problems facing the entire planet today is water contamination, which is caused by the increasing industry and urbanization. The present study involves the synthesis of polymeric ferrite composites Ni-CoFe 2 O 4 /Chitosan, Zn-NiFe 2 O 4 /Starch, Co-NiZnFe 2 O 4 /Polyaniline, Ni doped CrZnFe 2 O 4 /Alginate, and Cr doped ZnCoFe 2 O 4 /PVA for the removal of Golden Yellow-160 dye. The polymeric ferrite composites were characterized using Scanning electron microscopy (SEM), X-ray Diffraction (XRD), and Fourier transmission infrared spectroscopy (FT-IR) which showed the surface morphology, crystallinity, chemical structure and thermal stability of the composites. To get the optimal removal, different parameters like pH, composite dose, contact time, temperature and initial dye concentration were optimized. Different equilibrium and kinetic models were used to check the nature of process and reaction rate of sorption. Thermodynamic were studied to check the feasibility of reaction. The effect of presence of various electrolytes NaCl, CaCl 2.2 H 2 O and AlCl 3.6 H 2 O was also studied. Effect of presence of different metals and surfactants was also studied which cause reduction in adsorption of dyes. For large scale, the effects of bed height, flow rate, and initial dye concentration were examined in column study. Different eluents were used for the desorption study of reactive dyes to check the reusability of process. [Display omitted] • Langmuir adsorption isotherm displayed chemisorption nature of adsorption. • Both pseudo-first-order and pseudo-second-order showed the satisfactorily fitness. • Zn-NiFe 2 O 4 /Starch showed the highest removal among all the composites. • The dye exclusion showed the endothermic nature of reaction. • The current study applied for the removal of dye at large scale using a column. [ABSTRACT FROM AUTHOR]

This paper reviews the latest research advancements in cathodic membrane (CM)–based electrochemical redox processes (CMERs) for water treatment. The water purification mechanisms by CMERs, including CMER reduction, CMER Fenton, and CMER coupling other oxidant processes (CMEOs), are explained. Especially, the pathways of formation of reactive species (e.g. •OH, 1O 2 , and O 2 • ) are presented in detail. Besides, the effects of different CMs and operating conditions are considered. The applications extending to refractory pollutants removal, disinfection, membrane fouling alleviation, and resource recovery are well presented and analyzed. CMER reactors are also discussed for their potentials of scale up for water treatment. Finally, the trends in the field encompassing current knowledge gaps are highlighted, and the recommendations for future research are proposed. [Display omitted] • CMERs shown corrosion resistance, enhanced mass transfer and antifouling. • The trend in CM materials development is the single-atomic modification. • Operating parameters should be optimized according to the specific water quality. • CMERs effectively remove pollutants, reduce membrane fouling and recover resources. • Tubular CMER reactors are a feasible choice for the large-scale water treatment. [ABSTRACT FROM AUTHOR]

This review provides a brief overview of the electrocatalytic reduction of refractory organic contaminants in water. The electrocatalytic reduction mechanism and principle are thoroughly discussed. The role of various oxidants such as ozone, persulfate, permanganate, peracetic acid, and mixed oxidants on the electrocatalytic reduction of refractory organic contaminants was deeply explored. The impact of various operational parameters such as current density, initial concentration of oxidants, solution pH, and water matrices on the electrocatalytic degradation of refractory organic compounds has been investigated in detail. Moreover, the role of electrode materials and electrocatalytic reactor design in the electrocatalytic reduction of refractory organic contaminants in water was also discussed. Finally, the challenges and future perspectives were highlighted for the practical implementation of electrocatalytic reduction processes for water treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

The underlying pathways leading to stillbirth in low- and middle-income countries are not well understood. Context-specific understanding of how and why stillbirths occur is needed to prioritise interventions and identify barriers to their effective implementation and uptake. To explore the contribution of contextual, individual, household-level and health system factors to stillbirth in Afghanistan. Using a qualitative approach, we conducted semi-structured in-depth interviews with women and men that experienced stillbirth, female elders, community health workers, healthcare providers, and government officials in Kabul province, Afghanistan between October-November 2017. We used thematic analysis to identify contributing factors and developed a conceptual map describing possible pathways to stillbirth. We found that low utilisation and access to healthcare was a key contributing factor, as were unmanaged conditions in pregnancy that increased women's risk of complications and stillbirth. Sociocultural factors related to the treatment of women and perceptions about medical interventions deprived women of interventions that could potentially prevent stillbirth. The quality of care from public and private providers during pregnancy and childbirth was a recurring concern exacerbated by health system constraints that led to unnecessary delays; while environmental factors linked to the ongoing conflict were also perceived to contribute to stillbirth. These pathways were underscored by social, cultural, economic factors and individual perceptions that contributed to the three-delays. Efforts are needed at the community-level to facilitate care-seeking and raise awareness of stillbirth risk factors and the facility-level to strengthen antenatal and childbirth care quality, ensure culturally appropriate and respectful care, and reduce treatment delays. [ABSTRACT FROM AUTHOR]

Nitrogen-doped titanium dioxide (N-TiO 2) nanoparticles were prepared using a modified sol-gel method. The as-prepared nanoparticles were characterized by state-of-the-art techniques for their optical, structural and morphological properties. The crystallite size, surface area and bandgap energy of reference TiO 2 and N-TiO 2 nanoparticles were found to be 16.1 and 10.9 nm, 83.6 and 131.8 m2 g−1 and 3.23 and 2.89 eV, respectively. The photocatalytic activities, in terms of 2,4-dichlorophenol (2,4-DCP) degradation, of reference TiO 2 and N-TiO 2 were found to be 46.9% and 65.4% at 120 min of treatments under UV light irradiation and 21.5% and 77.6% at 240 min of treatment under visible light irradiation, employing 153.4 µM 2,4-DCP, 1 g/L photocatalyst dosage, and pH 5.6. Interestingly, considerable H 2 production rate (i.e., 386 μmol h−1 g−1) was observed for visible/N-TiO 2 system in presence of 0.2 wt% Pt. The study revealed that visible/N-TiO 2 photocatalytic system can be used as an economically viable technology for environmental sustainability. [Display omitted] • Kinetic and mechanistic studies of 2,4-dichlorophenol were performed by visible/N-TiO 2 system. • 82.4% reduction in toxicity of 2,4-dichlorophenol solution was achieved by visible/N-TiO 2. • The rate of H 2 production was 386 μmol h−1 g−1 by using visible/0.2 wt% Pt/N-TiO 2 system. • Visible/N-TiO 2 is an economic and promising technology for environmental sustainability. • A waste to energy concept towards circular economy [ABSTRACT FROM AUTHOR]

Abstract In the present study the synthesis of an inexpensive solar light responsive Co2+ and Fe3+ co-doped TiO 2 (Co Fe TiO 2) for efficient photocatalytic degradation of ofloxacin (OFL) in addition to its excellent activity as peroxidase mimics has been reported. The as-synthesized material was fully investigated morphologically and structurally by X-ray diffraction (XRD) analysis, field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) and UV diffuse reflectance spectroscopy (UV-DRS). The morphology of the as-synthesized Co Fe TiO 2 appeared to be more dispersed, porous and uniform. The UV-DRS analysis showed that the band gap of the as-synthesized TiO 2 , Fe TiO 2 , Co TiO 2 , Co Fe TiO 2 was measured as 3.31, 3.22, 3.15 and 3.04 eV, respectively. The pilot scale experiments were conducted in a simple non-concentrating solar photoreactor by using the as-synthesized Co Fe TiO 2 having total volume of 5 L. To synergize the photocatalytic process the photocatalytic reactor was added with peroxymonosulfate (HSO 5 −). The effect of various process parameters like [HSO 5 −] 0 , flow rate and [Co Fe TiO 2 ] 0 were optimized. The assessment of degradation products (DPs) of OFL and then their toxicity analysis suggested the as-synthesized Co Fe TiO 2 provides a safe route for the solar light induced photocatalytic degradation of OFL. The as-synthesized Co-Fe TiO 2 was also applied as novel peroxidase mimetic that can catalyze 3,3′,5,5′-tetramethylbenzidine (TMB) when H 2 O 2 serves as oxidant. The results showed that the color response and the peroxidase like response of Co Fe TiO 2 highly rely on the concentration of H 2 O 2 and thus the as-synthesized material can successfully be applied for the calorimetric sensing of H 2 O 2. Graphical abstract Unlabelled Image Highlights • Solar light driven photocatalysis of ofloxacin at pilot scale level. • Lowering the band gap of TiO 2 by co-doping with Co2+ and Fe3+. • Fifteen (15) new photocatalytic degradation byproducts of OFL were found. • Toxicity assessment revealed that some of the DPs are more toxic than OFL. • In situ peroxidase like behavior of Co Fe TiO 2 was found. [ABSTRACT FROM AUTHOR]

Bronchobiliary fistula (BBF) is an abnormal connection between the bronchial system and biliary tree. It is a rare condition that often manifests as bilioptysis. BBF has several causes; however infectious disease of the liver and lungs, mostly hydatid cysts, is the leading cause of BBF. For a conclusive diagnosis, imaging studies are useful and able to show the fistula tract, as we did by CT scan. The treatment of BBF is still a challenge for surgeons. In children, in the acute fulminating phase, an aggressive and rapid approach is essential to prevent respiratory tract damage. We present a case of a 17-year-old girl, who complained of bilioptysis, chest pain and loss of appetite for about nine months. Her past history revealed that she developed bilioptysis after laparotomy for excision of liver hydatid cyst 10 months ago. For which she underwent conservative and surgical treatment of bilioptysis, which all failed. After investigations, a bronchobiliary fistula was identified. A right thoracotomy was performed. After the release of adhesions and debridement of damaged tissues, the fistula tract was excised. The connection was sealed by a diaphragmatic muscle flap, which was successful in the outcome after 12 months of follow-up. BBF is a condition that requires strong presumptive evidence for diagnosis and a well-planned approach for management. Hence, each surgeon must carefully consider the optimal method for open surgery or conservative therapy after thoroughly evaluating the patient's profile and imaging. In children, a thoracic approach with a diaphragmatic flap is safe, easily available, and can easily divide the lung from the liver since that is its normal function. [ABSTRACT FROM AUTHOR]

Previous studies conducted on the pyrolysis of used rubber were either directed towards the yield and properties of liquid fuel or focused towards the generation of carbon black as end product and, hence, little attention was paid to the quantitative determination of gaseous, liquid, tar and char fractions obtained from the pyrolysis of used tire rubber. Therefore, the aim of this study was to re-utilize waste tire rubber as raw material for production of these valuable products which has substantial benefits for domestic and commercial use. Pyrolysis experiments were performed for thermal degradation of used tire rubber (UTR). The pyrolysates from the pyrolyzer were collected in separate traps on the basis of volatility into fractions like tar, liquid and gas. Influence of temperature was determined. The gaseous fraction was monitored using gas chromatography and the major hydrocarbons detected were C 1 –C 5 . The liquid fraction was analyzed by gas chromatography/mass spectrometry and the compounds detected in the range of C 16 to C 19 . As the different fractions (gas, liquid, tar and char) were collected independently of each other, therefore, they may be used separately for useful purposes. [ABSTRACT FROM AUTHOR]

Multiresponsive tercopolymer microgel poly( N -isopropyl acrylamide- co -methacrylic acid- co -2-hydroxyethyl methacrylate) was synthesized by free radical emulsion polymerization. The silver and gold nanoparticles were homogeneously dispersed in polymer network by in-situ chemical reduction method at 10 and 40 °C using sodium borohydride as reducing agent. FT-IR spectroscopy confirms the microgel synthesis and existing of metal nanoparticles inside the polymer network. Temperature and pH sensitivity on particle size of the microgel particles was investigated by dynamic light scattering. Transmission electron microscopy analysis showed that the size of Ag and Au nanoparticles is 13 and 7 nm, respectively. The catalytic activity of hybrid microgels was studied for the reduction of aqueous solutions of 4-nitrophenol, congo red and methylene blue as model reactions. [ABSTRACT FROM AUTHOR]

Degradation of the anti-inflammatory drug diclofenac from aqueous media by means of gamma irradiation has been investigated. The results showed that concentration of diclofenac gradually decreased with increasing absorbed dose. When 4.5 mg L −1 aqueous solution of diclofenac was irradiated for an absorbed dose of 1015 Gy, nearly 97% degradation of diclofenac was achieved. The kinetic studies containing 4.5, 10.5, 14.0 and 18 mg L −1 of diclofenac showed that degradation of diclofenac decreased with increase in initial concentration of diclofenac and follows pseudo – first order kinetics. The initial pH value of the solution also affected the degradation efficiency of diclofenac. The degradation efficiency was higher in N 2 O – saturated solution compared to aerated and N 2 – saturated solutions. The radical scavengers like tert -butanol, iso -propanol as additives showed negative effect on the deagrdation of diclofenac. The quantitative role of reactive radical towards degradation of diclofenac was found to be in the order of OH > e aq − > H. The second order rate constant of OH radical with diclofenac was calculated to be 2.5 × 10 9 M −1 s −1 . The addition of various water parameters as additives like nitrite, nitrate, carbonate and bicarbonate restrained the degradation efficiency of diclofenac. The removal of total organic carbon (TOC) was higher in case of N 2 O-saturated media than aerated and N 2 -saturated media. The organic and inorganic byproducts like 2,6-dicholorophenol, 4-chlorcatechol, hydroquinone, Cl − , NH 4 + , CH 3 COO − were qualitative and quantitavely determined. [ABSTRACT FROM AUTHOR]

A type of crystalline porous material known as zirconium metal-organic frameworks (UiO-66) is made up of organic carboxylate ligands and inorganic zirconium clusters. The UiO-66 has consistent pore sizes, large porosities, exceptional adsorption capabilities, and particular functional groups for increasing dye adsorption. This study reports the synthesis of Zirconium metal-organic framework (UiO-66) and chitosan composite of zirconium metal−organic framework (CS/UiO-66) for potential adsorption of methyl orange (MO) and methylene blue (MB) dyes from the aqueous media and additional, excellent photodegradation capability of the synthesized material towards selected dyes. The synthesized materials were successfully characterized for structural, morphological, surface and thermogravimetrical analysis. The exclusion of dyes onto the CS/UiO-66 followed the trend MB (2321 mg/g) > MO (900 mg/g) respectively. The maximum sorption and degradation capacity of the CS/UiO-66 were increased by 5–10 times after its composite with chitosan (CS) and the affinity of the dyes towards the different adsorbents followed the sequence CS/UiO-66 > UiO-66 > CS which is parallel to their surface properties. The negative values of the entropy i.e., − 382 for MB and − 249 for MO affirmed the controlled versatility of the MO, and MB onto CS/UiO-66 whereas the isosteric heat of adsorption i.e., − 201 kJ/mol for MB and − 153 kJ/mol for MO illustrated the exothermicity of the adsorption process. The intraparticle diffusion and Richenberge kinetic models demonstrated that pore diffusion dominates in the adsorption of MB while film diffusion has a greater involvement in the MO adsorption of CS/UiO-66. Moreover, the photocatalytic degradation study indicated that the pH and H 2 O 2 play a significant part in the deprivation of dyes. While GC-MS analysis revealed that the photocatalytic degradation of MB resulted in the formation of six TPs. The toxicity of these TPs of MB was evaluated by ECOSAR program and the results showed that the TPs were less toxic than the parent MB molecule. [Display omitted] • Synthesized CS/UiO-66 showed exceptional adsorptive and photocatalytic properties. • The adsorption capacity of CS/UiO-66 was 2321 mg/g for MB and 900 mg/g for MO. • л-л, pore-filling, chemical and hydrogen bonding were involved in dyes adsorption. • Degradation of MB by CS/UiO-66/H 2 O 2 /UV resulted in the formation of six TPs. • Based on ECOSAR analysis, the TPs were less toxic than the parent MB molecule. [ABSTRACT FROM AUTHOR]

• Highly stable and solar light responsive Bi-TiO 2 was synthesized. • The doping of Bi3+ induced Ti3+ and oxygen vacancy in the TiO 2 lattice. • The photocatalytic efficiency of TBi5 was enhanced by coupling with HSO 5 −. • SO 4 − and OH were dominant species involved in the degradation of FLU. • The contribution rate of SO 4 − was calculated to be 89% in the degradation of FLU. The present study is focused on the synthesis of a novel solar light responsive bismuth doped titania (Bi-TiO 2) through a facile so-gel technique by applying various wt% of Bi. The as-synthesized Bi-TiO 2 showed superior photocatalytic performance than un-doped TiO 2 towards degradation of flumequine (FLU) under solar light irradiation. The as-synthesized material was thoroughly characterized to examine its structure, morphology and chemical states. The EPR analysis revealed the existence of Ti3+ ion and oxygen vacancy, which is created due to Bi-doping. The as-synthesized Bi-TiO 2 with 5 wt% Bi (TBi5) showed excellent photocatalytic performance as compared to their counterparts. The photocatalytic activity of TBi5 was further improved when added with peroxymonosulfate (HSO 5 −) and increased with increasing [HSO 5 −] 0. The mechanistic investigation and radical scavenging studies revealed that OH and SO 4 − are involved in the degradation of FLU by the as-synthesized material. The bimolecular rate constants of OH and SO 4 − were calculated to be 9.1 × 109 M−1s−1 and 8.5 × 109 M−1s−1, respectively. The photocatalytic performance of the as-synthesized TBi5 coupled with HSO 5 − under solar light irradiation towards degradation of FLU in Milli-Q water (MW), tape water (TW) and synthetic wastewater (SWW) was 92, 82 and 70% with k app values of 0.093, 0.085 and 0.066 min−1, respectively. Furthermore, the degradation pathways of FLU were predicted on the basis of its degradation products (DPs). The high mineralization of FLU as well as the evaluation of non-toxic DPs suggests that solar light/TBi5/HSO 5 − is a promising advanced oxidation process for the future wastewater treatment applications. [ABSTRACT FROM AUTHOR]

This study demonstrates the synthesis of highly hydrophilic poly(vinylidene fluoride) composite membranes incorporated with Titania (TiO 2) nanotubes (PVDF/TNT) and then its photocatalytic applications were explored for effective degradation of brilliant green (BG) dye. The membranes were fabricated through phase inversion method using poly(vinylidene fluoride) (PVDF) as matrix, Titania nanotubes (TNT) with different concentrations (0–2 wt%) as filler and poly(vinylpyrrolidone) as pore former. Successful fabrication of composite membranes (PVDF/TNT) was confirmed by using X-ray diffraction analysis, Fourier transform infra-red spectroscopy, differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Membrane properties were studied using contact angle, tensile strength, solvent content, pure water flux, bovine serum albumin (BSA) rejection, antifouling properties, porosity and shrinkage ratio. The degradation results suggested that the fabricated membrane can effectively be applied as a heterogenous photocatalyst for the degradation of BG. The results confirm that the dispersion of TNTs increases the antifouling properties of membranes to a maximum value. A minimum pore volume 0.34 cc g−1, pore size 28.4 nm and maximum surface area 142 m2 g−1 were obtained with loading 1.5 wt% TNTs in PVDF membranes, which can degrade BG up to 42% compared to 13% in the absence of fabricated membrane after 90 min of reaction time. The photocatalytic degradation mechanism of BG by PVDF/TNT ultrafiltration membranes showed that OH is mainly involved in the degradation process. The degradation byproducts of BG were determined using LC–MS/MS and accordingly degradation pathways were proposed. [ABSTRACT FROM AUTHOR]

In this study, activated carbon (AC) and nano-zerovalent copper (nZVCu) functionalized hydroxyapatite (HA) and alginate beads were synthesized and used for the removal of As3+ from aqueous solution. The characterization by X-ray diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, high resolution transmission electron microscopy, BET surface area analysis, thermogravimetric analysis, and Fourier transform infrared spectroscopy revealed successful formation of the AC/nZVCu/HA-alginate, nZVCu/HA-alginate, AC/HA-alginate, and HA-alginate beads. The scanning electron microscopy and surface analysis revealed the prepared beads to be highly mesoporous which led to the maximum adsorption of As3+, i.e., 13.97, 29.33, 30.96, and 39.06 mg/g by HA-alginate, AC/HA-alginate, nZVCu/HA-alginate, and AC/nZVCu/HA-alginate beads, respectively. The thermogravimteric analysis showed the nZVCu/HA-alginate beads to be highly stable while the AC composite beads as the least stable to heat treatment. The HA-alginate beads achieved 39% removal of As3+, however, removal efficiency was promoted to 95% by coupling AC and nZVCu with HA-alginate beads at a reaction time of 120 min. The removal of As3+ by the prepared AC & nZVCu coupled HA-alginate beads was promoted with increasing [As3+] 0 and [AC/nZVCu/HA-alginate] 0. The pH of aqueous solution significantly influenced the removal of As3+ by AC/nZVCu/HA-alginate beads and maximum removal was achieved at pH 5.8. Freundlich adsorption isotherm and pseudo-second-order kinetic models were found to best fit the removal of As3+ by the synthesized beads. The high performance of AC/nZVCu/HA-alginate beads in the removal of As3+ even after seven cyclic treatment as well as least leaching of Cu ions into aqueous solution suggest enhanced reusability and stability of HA-alginate beads by coupling with AC and nZVCu. The results suggest that the synthesized beads have good potential for the removal of As3+ from aqueous solutions. Image 1 • Characterization techniques proved nZVCu and AC coupled HA-Alginate beads formation. • Coupling AC and nZVCu enhanced performance and reusability of HA-Alginate beads. • Removal of As3+ best fitted Freundlich isotherm and pseudo-second-order models. • Removal of As3+ was significantly affected by the pH of aqueous solution. [ABSTRACT FROM AUTHOR]

Abstract Removal of cadmium (Cd2+), a highly toxic heavy metal, from aqueous solutions was investigated using nano zerovalent iron (Fe0). Cadmium was efficiently removed by Fe0, although reactivity and reusability of Fe0 was significantly promoted by coupling with bismuth (Bi). At a reaction time of 20 min, 85% and 96% Cd2+ was removed by Fe0 and Bi/Fe0, respectively, at first cycle using [Cd2+] 0 = 10 mg/L and [Fe0] 0 = [Bi/Fe0] 0 = 1.0 g/L. However, Cd2+ removal efficiency was reduced to 12% and 80% at sixth cycle by Fe0 and Bi/Fe0, respectively. The X-Ray diffraction and energy dispersive X-Ray spectroscopy analysis proved successful formation of Fe0 by the chemical reduction method and also confirmed coupling of Bi with Fe0 to form bimetallic Bi/Fe0. The oxidation of Fe0 and Bi/Fe0 yielded electron that played significant role in the conversion of toxic Cd2+ into non-toxic Cd0. The reactivity of electron with Cd2+ was calculated to be 4.3 × 109 M−1 s−1. The pH of solution showed pronounced effects on the reactivity of both Fe0 and Bi/Fe0. Removal of Cd2+ by both Fe0 and Bi/Fe0 followed pseudo-first-order kinetic model. The conversion of Cd2+ into non-toxic Cd0 proved Fe0 and Bi/Fe0 to be highly efficient and rewarding in detoxification of Cd2+ and other toxic metals in aqueous environments. Graphical abstract Unlabelled Image Highlights • Bi was successfully coupled with Fe0 using chemical reduction method. • The Bi coupled Fe0 displayed greater reactivity, stability, and reusability. • Second-order rate constant of hydrated electron with Cd2+ was estimated. • pH of aqueous solution significantly influenced efficiency of Fe0 and Bi/Fe0. [ABSTRACT FROM AUTHOR]

Photocatalytic materials and additional components, especially promoters, play a pivotal role in the success of photocatalysed environmental remediation processes. To understand the influence of acid promoters in the absence and presence of surfactants, photocatalytic degradation of a model dye rhodamine B (RhB) was studied by UV-photocatalysis (254 nm UV source) with the subsequent addition of each of 0.01 mol dm − 3 of nitric acid (HNO 3 ), sulphuric acid (H 2 SO 4 ), hydrochloric (HCl), citric acid and acetic acid. Furthermore, the effect of 0.01 mol dm − 3 of sodium hydroxide (NaOH) and sodium carbonate (Na 2 CO 3 ), as well as surfactants, including the cationic cetrimonium bromide (CTAB), anionic sodium dodecylsulphate (SDS) and non-ionic surfactant tween 80, were analyzed using a UV–Visible spectrophotometer. The k obs. values for photodegradation of RhB under UV-irradiation was heavily dependent on type of acid and base. Pre-micellar, micellar and post-micellar concentrations of surfactants were also analyzed for their effects on the photodegradation of RhB. Concentrations at and above the critical micelle concentration (CMC) were found to suppress the photocatalytic degradation of RhB in the presence of a promoter (HNO 3 ). Micellar solubilization is responsible for the changes in the photocatalytic activity. Nonionic micelles are unable to protect the dye over longer times due to autooxidation process. The resulting degradation products of RhB by OH were identified by LC-MS and GC–MS analysis and accordingly a schematic degradation pathway was proposed. [ABSTRACT FROM AUTHOR]

Norfloxacin (NOR), an important antibiotic used for the treatment of different infections which is reportedly causing huge quantity of water pollution and severe environmental issues. In this study, biochar prepared from Phoenix dactylifera roots biomass (PB) and composited with mesoporous nano-zerovalent cerium (nZVCe) was used for treatment of NOR solutions. The various characterization and treatment studies showed successful formation of the nZVCe and PB composite. The nZVCe was found to improve physiological characteristics and catalytic efficiency of PB. The nZVCe/PB composite caused 52% removal of NOR as compared to 23% by the individual PB. The use of peroxydisulfate (PDS) with PB and nZVCe/PB showed further improvement in the removal of NOR and caused 58 and 84% removal efficiencies of NOR by PB/PDS and nZVCe/PB/PDS, respectively. The use of PDS with PB and nZVCe/PB was found to yield ●OH and SO 4 ●– which improved degradation of NOR, however, addition of ●OH and SO 4 ●– scavengers impeded NOR degradation. The PB was found to have several oxygen functional groups which decomposed PDS into ●OH and SO 4 ●–. The nZVCe/PB showed high recovery, reusability, and stability and caused high removal of NOR even at fifth cycle of treatment both in the absence and presence of PDS. The treatment of NOR by nZVCe/PB-catalyzed PDS showed encouraging results under different pH, and varying concentrations of PDS, nZVCe/PB, and NOR as well as in real water samples which suggest potential practical applications of NOR contaminated water. Degradation of NOR resulted into several products and the resulting final product proved to be non-toxic. [Display omitted] • nZVCe and biochar composite was prepared and nZVCe improved properties of biochar. • Biochar and nZVCe/PB effectively decomposed PDS into.●OH and SO 4 ●–. • Radical scavengers inhibited role of.●OH and SO 4 ●– in degradation of norfloxacin. • The PB and nZVCe/PB effectively degraded norfloxacin in real water also. • The composite of biochar and nZVCe showed enhanced stability and reusability. [ABSTRACT FROM AUTHOR]

Highlights: [•] Chlorpyrifos was efficiently degraded at a low dose (energy). [•] Hydroxyl radical was shown to be the most reactive species. [•] Organo-chlorine and -sulfur were quantitatively converted to inorganic species. [•] Mass balance of hetero-compounds suggested near mineralization. [ABSTRACT FROM AUTHOR]

This study reported Fe doped zinc oxide (Fe-ZnO) synthesis to degrade chlorpyrifos (CPY), a highly toxic organophosphate pesticide and important sources of agricultural wastes. Fourier transform infrared, X-ray diffraction, scanning electron microscope, and energy-dispersive X-ray spectroscopic analyses showed successful formation of the Fe-ZnO with highly crystalline and amorphous nature. Water collected from agricultural wastes were treated with Fe-ZnO and the results showed 67% degradation of CPY by Fe-ZnO versus 39% by ZnO at 140 min treatment time. Detail mechanism involving reactive oxygen species production from solar light activated Fe-ZnO and their role in degradation of CPY was assessed. Use of H 2 O 2 , peroxydisulfate (S 2 O 8 2−) and peroxymonosulfate (HSO 5 −) with Fe-ZnO under solar irradiation promoted removal of CPY. The peroxides yielded hydroxyl (OH) and sulfate radical (▪) under solar irradiation mediated by Fe-ZnO. Effects of several parameters including concentration of pollutant and oxidants, pH, co-existing ions, and presence of natural organic matter on CPY degradation were studied. Among peroxides, HSO 5 − revealed to provide better performance. The prepared Fe-ZnO showed high reusability and greater mineralization of CPY. The GC-MS analysis showed degradation of CPY resulted into several transformation products (TPs). Toxicity analysis of CPY as well as its TPs was performed and the formation of non-toxic acetate imply greater capability of the treatment technology. [Display omitted] • Fe doped ZnO was successfully synthesized by sol-gel method. • Fe doping and use of peroxides synergistically promoted performance of ZnO. • Degradation of chlorpyrifos was inhibited by h vb + and OH scavengers. • Second-order rate constants of chlorpyrifos with OH and ▪ were calculated. • Toxicities of chlorpyrifos and its transformation products were estimated. [ABSTRACT FROM AUTHOR]

• The nZVMn/PBC showed high activity in adsorptive and oxidative removal of Congo-red. • The physical properties of biochar were improved with the coupling of nZVMn. • The nZVMn/PBC-catalyzed H2O2 into ●OH that caused oxidative removal of Congo-red. • Congo-red removal was promoted with the high dose of adsorbent and H2O2. • Degradation pathways of Congo-red in ●OH-mediated oxidative system were proposed. Congo-red (CR), a precursor of textile products and a contaminant of great concern, has contaminated aquatic environments. Here, we explored the synthesis of mesoporous nano-zerovalent manganese (nZVMn) and Phoenix dactylifera leaves biochar (PBC) composite for the removal of CR from water. The nZVMn/PBC adsorbed 117.647 mg/g of CR versus 25.316 mg/g by PBC at [CR] 0 = 20 mg/L and [PBC] 0 = [nZVMn/PBC] 0 = 500 mg/L. Variation of [nZVMn/PBC] 0 , [CR] 0 and pH influenced the adsorption of CR. Freundlich adsorption isotherm and pseudo-first-order kinetic models best fitted CR adsorption. The H 2 O 2 coupling with nZVMn/PBC promoted removal of CR possibly due to the formation of hydroxyl radical (●OH) and caused 95 % removal of CR versus 77 % by nZVMn/PBC alone. The ●OH scavengers inhibited the removal of CR. The nZVMn/PBC showed a good reusability and efficient removal of CR up to the seventh cycle of treatment. Results reveal that nZVMn improved performance, thermal stability and reusability of biochar. Degradation products from ●OH-mediated degradation of CR were studied by ultraperformance liquid chromatography with mass spectrometric detector to establish degradation pathways. The ion-chromatographic analysis showed the formation of non-toxic inorganic acetate product, which suggests high potential of the newly fabricated adsorbent in the removal of CR. [ABSTRACT FROM AUTHOR]

• Congo-red dye and its DPs were found highly toxic. • Gamma-ray with the added H 2 O 2 and S 2 O 8 2− efficiently degraded CR. • Reactivity of congo-red dye with OH and SO 4 − were calculated. • Proposed degradation pathways of CR were developed from the DPs evolved. Gamma radiation has received increasing attention due to their high potential in degradation of recalcitrant pollutants. Thus in the present study, gamma radiation was used for degradation of congo-red (CR) dye, a highly toxic and carcinogenic pollutant, in the presence of H 2 O 2 and S 2 O 8 2−. The CR was significantly degraded by gamma radiation (i.e., 53%), however, presence of H 2 O 2 and S 2 O 8 2− promoted degradation of CR to 98 and 87%, respectively, at 1184 Gy absorbed dose. The radical scavengers and electron spin resonance studies revealed that gamma radiation decompose H 2 O 2 and S 2 O 8 2− into OH and SO 4 − and both OH and SO 4 − caused degradation of CR. The CR showed high reactivity, i.e., 3.25 × 109 and 8.50 × 108 M−1 s−1 with OH and SO 4 −, respectively, and removal of CR was inhibited in the presence of OH and SO 4 − scavengers. The removal of CR was promoted with elevating initial concentrations of H 2 O 2 and S 2 O 8 2− and decreasing initial concentrations of CR. pH of aqueous solution also significantly influenced removal of the dye. The proposed degradation pathways of CR were established from the OH mediated degradation of CR and nature of identified degradation products. The greater mineralization of CR, formation of small molecular mass degradation product, and decline in concentration of acetate after extended treatment suggest the gamma-ray mediated peroxide based process to be a promising alternative for potential degradation of CR. [ABSTRACT FROM AUTHOR]

Chlorpyrifos (CPY), an organophosphate pesticide is largely used throughout the world on different crops for the control of pests and causes severe health and environmental issues. In this study, highly efficient, crystalline, and nm-rang sized zerovalent zinc (nZVZn) catalyst was synthesized and used for removal of chlorpyrifos at semi-pilot scale. The nZVZn showed high activity and caused 55% removal of CPY at 90 min time under the conditions of [CPY] 0 = 10 mg/L, [nZVZn] 0 = 1.0 g/L, and flow rate of the reactor = 0.2 L/min. Using identical conditions of [CPY] 0 , [nZVZn] 0 and flow rate, the use of peroxymonosulfate (PMS) promoted the performance of nZVZn and caused 99.5% removal of CPY at [PMS] 0 = 40 mg/L. The electron spin resonance (ESR) spectroscopy studies revealed that nZVZn catalyzed PMS reactions yield hydroxyl and sulfate radicals that degraded CPY and removal of CPY was suppressed by applying radical scavengers. The nZVZn catalyzed PMS based removal of CPY was optimum at high [PMS] 0 , [nZVZn] 0 and low pH of solution. The flow rate of the pilot plant reactor also influenced the degradation efficiency of CPY. High pH of solution, high [CPY] 0 as well as use of alcohols, NOM, and some inorganic ions inhibited removal of CPY by nZVZn catalyzed PMS. The analysis of degradation products (DPs) of CPY were used to propose degradation pathways of CPY. The high TOC removal of CPY, low leaching of Zn2+ from Zn0 into aqueous solution, and toxicity reduction of CPY suggest the nZVZn catalyzed PMS process to be highly effective and environmental benign for treatment of CPY. Image 1 • Nano zerovalent zinc was used for removal of chlorpyrifos at semi-pilot scale. • Removal of chlorpyrifos by zerovalent zinc was promoted by peroxymonosulfate. • Hydroxyl and sulfate radical rate constants with chlorpyrifos were calculated. • Proposed degradation pathways of chlorpyrifos were suggested. • Toxicities of treated chlorpyrifos solutions and zinc ion leaching were evaluated. [ABSTRACT FROM AUTHOR]

Quality concerns exist with stillbirth data from low- and middle-income countries including under-reporting and misclassification which affect the reliability of burden estimates. This is particularly problematic for household survey data. Disclosure and reporting of stillbirths are affected by the socio-cultural context in which they occur and societal perceptions around pregnancy loss. In this qualitative study, we aimed to understand how community and healthcare providers' perceptions and practices around stillbirth influence stillbirth data quality in Afghanistan. We collected data through 55 in-depth interviews with women and men that recently experienced a stillbirth, female elders, community health workers, healthcare providers, and government officials in Kabul province, Afghanistan between October-November 2017. The results showed that at the community-level, there was variation in local terminology and interpretation of stillbirth which did not align with the biomedical categories of stillbirth and miscarriage and could lead to misclassification. Specific birth attendant practices such as avoiding showing mothers their stillborn baby had implications for women's ability to recall skin appearance and determine stillbirth timing; however, parents who did see their baby, had a detailed recollection of these characteristics. Birth attendants also unintentionally misclassified birth outcomes. We found several practices that could potentially reduce under-reporting and misclassification of stillbirth; these included the cultural significance of ascertaining signs of life after birth (which meant families distinguished between stillbirths and early neonatal deaths); the perceived value and social recognition of a stillborn; and openness of families to disclose and discuss stillbirths. At the facility-level, we identified that healthcare provider's practices driven by institutional culture and demands, family pressure, and socio-cultural influences, could contribute to under-reporting or misclassification of stillbirths. Data collection methodologies need to take into consideration the socio-cultural context and investigate thoroughly how perceptions and practices might facilitate or impede stillbirth reporting in order to make progress on data quality improvements for stillbirth. • Sociocultural factors and perceptions of pregnancy loss affect stillbirth reporting. • Community frequently interchanged terms for stillbirth with other pregnancy losses. • Distinguishing between stillbirth and early neonatal death had cultural significance. • Institutional values and provider practices may affect stillbirth data in facilities. • Stillbirth data quality improvement efforts need to consider contextual factors. [ABSTRACT FROM AUTHOR]

Abstract This article reports an efficient removal of selected heavy metal ions using a low-cost superabsorbent polymer hydrogel (SPH) composed of acrylic acid and acrylamide in different compositions which were prepared by single step free radical polymerization technique using ammonium persulphate and N, N-methylene bis-acrylamide as an initiator and cross-linker respectively. The morphological, thermal and mechanical properties were assessed for superabsorbent polymer hydrogels. The effect of pH and monomer content on the swelling behaviour of SPH was studied in detail and a maximum swelling capacity of 1841% was found for composition having maximum acrylic acid (AA) content. All the samples were highly effective in the removal of Cd2+, Ni2+, Cu2+ and Co2+ from aqueous medium at pH range of 2–10 following pseudo second order kinetics and Freundlisch adsorption model. Also, the removal capacity was greater at pH 7 and materials showed high selectivity towards Co2+ and Cu2+ in competitive removal process. The high removal ability >75% for each metal ion, make these materials as an efficient, easily obtainable, and environmental friendly product. Graphical abstract Image 1 Highlights • Synthesis of superabsorbent polymer hydrogels in different ratio. • Swelling property is considered for removal of heavy metal ions. • Replacement of classical adsorbents with superabsorbent polymer hydrogels for removal of metal ions. • Optimum pH 7 was found for enhanced removal of metal ions. [ABSTRACT FROM AUTHOR]

The removal of brilliant green (BG), a toxic organic and cationic dye, has been examined by UV/S 2 O 8 2− (PS), UV/HSO 5 − (PMS) and UV/H 2 O 2 processes. BG showed insignificant direct photolysis at 254 nm (i.e., 8.6% after 30 min). However, enhanced BG degradation was observed in UV/PS, UV/PMS and UV/H 2 O 2 systems as revealed from 63.1, 47.0 and 34.8% BG degradation, respectively, at 30 min of reaction time, using 0.05 mM BG and 1.0 mM oxidant initial concentration. The bimolecular rate constants of OH and SO 4 − with BG were determined to be 2.35 × 10 9 and 2.21 × 10 9 M −1 s −1 , respectively. Electrical energy per order (EE/O) values for UV/PS, UV/PMS and UV/H 2 O 2 processes were calculated to be 5.4, 6.8, and 7.8 KWh/m 3 /order, respectively. The addition of humic acid (HA) and inorganic anions inhibited the degradation of BG by UV/PS in the order of NO 2 −  > HA > HCO 3 −  > Cl −   > NO 3 −  ≈ SO 4 2− . The results of frontier electron densities (FEDs) showed that C-atom holding the three rings (C7), and C-atoms at para positions to N-alkyl groups of the two rings (C4 and C14) are the predominant sites for radical addition. Furthermore, nine degradation products (DPs) of BG were detected experimentally using LC/MS/MS. [ABSTRACT FROM AUTHOR]

Ciprofloxacin (CIP) is a widespread emerging water pollutant and thus its removal from aquatic environment is vital. The use of Fe3+/H2O2 and Fe2+/H2O2 resulted in 38 and 64% removal of CIP (8.0 ppm), respectively, within 80 min reaction time (pH 5.8, [H2O2]0 = 80 ppm, and [iron]0 = 20 ppm). Low pH, high temperature, high dose of H2O2 and Fe2+, and low CIP concentration facilitated removal of CIP. The radical scavenger studies proved in situ generated OH to be involved primarily in the removal of CIP. The effect of temperature was used to estimate enthalpy and activation energies of the removal of CIP. At 800 min reaction time, the Fe2+/H2O2 resulted in 54% mineralization of CIP using 16.0 ppm [CIP]0, 320.0 ppm [H2O2]0, and 40.0 ppm [Fe2+]0. The potential degradation pathways of CIP established from the degradation of CIP by OH and products evolved was found to be initiated at C6 through the loss of fluoride ion. The acute and chronic toxicities of CIP and its degradation products were estimated with the final product found to be non-toxic. The results suggest that Fe2+/H2O2-mediated AOPs have high potential for degradation as well as toxicity elimination of CIP and its degradation products. [ABSTRACT FROM AUTHOR]

Carbamazepine (CBZ), a widely used antiepileptic drug, was removed by UV–254 nm based advanced oxidation processes. CBZ was found to be stable under sole UV, however, removal of CBZ was promoted using Fe3+ and Fe2+ with UV. Further, removal efficiency of CBZ was significantly enhanced by coupling H2O2 with UV and Fe3+/Fe2+. At 3600 mJ cm−2, 7.5, 60.2, 74.3 and 90.6% CBZ degradation was achieved in UV, UV/H2O2, UV/H2O2/Fe3+ and UV/H2O2/Fe2+, using CBZ, H2O2, Fe2+ and Fe3+ at 21.16, 1060.00, 17.91 and 17.91 μM, respectively. Higher CBZ degradation in the presence of H2O2 was attributed to HO whose second-order rate constant with CBZ was calculated to be (8.83 ± 0.27) × 109 M−1 s−1. Removal of CBZ by UV/H2O2/Fe2+ system was optimum at pH 3.0, as 80.8, 90.6 and 70.4% CBZ degradation was observed at pH 2.0, 3.0 and 6.5, respectively. The removal of CBZ by UV/H2O2/Fe2+ was retarded in the presence of Cl− and humic acid as revealed from 84.5 and 56.7% CBZ degradation in the presence of Cl− and humic acid, respectively, compared to 90.6% in their absence at 3600 mJ cm−2. The CBZ degradation products were found to be less toxic than the parent compound, suggesting important role of UV-assisted AOPs in efficient removal and toxicity reduction of CBZ and their degradation products. [ABSTRACT FROM AUTHOR]

• The presence of H 2 O 2 with iron promoted the removal of CIP. • The presence of OH scavengers inhibited removal of CIP by Fe2+/H 2 O 2. • Mineralization of CIP by Fe2+/H 2 O 2 -mediated AOPs was explored. • Potential pathways for conversion of CIP into degradation products were developed. • Acute and chronic toxicities of CIP and its degradation products were estimated. Ciprofloxacin (CIP) is a widespread emerging water pollutant and thus its removal from aquatic environment is vital. The use of Fe3+/H 2 O 2 and Fe2+/H 2 O 2 resulted in 38 and 64% removal of CIP (8.0 ppm), respectively, within 80 min reaction time (pH 5.8, [H 2 O 2 ] 0 = 80 ppm, and [iron] 0 = 20 ppm). Low pH, high temperature, high dose of H 2 O 2 and Fe2+, and low CIP concentration facilitated removal of CIP. The radical scavenger studies proved in situ generated OH to be involved primarily in the removal of CIP. The effect of temperature was used to estimate enthalpy and activation energies of the removal of CIP. At 800 min reaction time, the Fe2+/H 2 O 2 resulted in 54% mineralization of CIP using 16.0 ppm [CIP] 0 , 320.0 ppm [H 2 O 2 ] 0 , and 40.0 ppm [Fe2+] 0. The potential degradation pathways of CIP established from the degradation of CIP by OH and products evolved was found to be initiated at C 6 through the loss of fluoride ion. The acute and chronic toxicities of CIP and its degradation products were estimated with the final product found to be non-toxic. The results suggest that Fe2+/H 2 O 2 -mediated AOPs have high potential for degradation as well as toxicity elimination of CIP and its degradation products. [ABSTRACT FROM AUTHOR]

• Degradation of carbamazepine was investigated in UV-assisted AOPs. • Carbamazepine was recalcitrant to sole UV but susceptible to UV/H 2 O 2 /Fe2+ oxidation. • Second order rate constant of carbamazepine with OH was (8.83 ± 0.27) × 109 M−1 s−1. • The UV/H 2 O 2 /Fe2+ treatment was efficient in toxicity reduction of CBZ. • Degradation mechanism was proposed from identified degradation products. Carbamazepine (CBZ), a widely used antiepileptic drug, was removed by UV–254 nm based advanced oxidation processes. CBZ was found to be stable under sole UV, however, removal of CBZ was promoted using Fe3+ and Fe2+ with UV. Further, removal efficiency of CBZ was significantly enhanced by coupling H 2 O 2 with UV and Fe3+/Fe2+. At 3600 mJ cm−2, 7.5, 60.2, 74.3 and 90.6% CBZ degradation was achieved in UV, UV/H 2 O 2 , UV/H 2 O 2 /Fe3+ and UV/H 2 O 2 /Fe2+, using CBZ, H 2 O 2 , Fe2+ and Fe3+ at 21.16, 1060.00, 17.91 and 17.91 μM, respectively. Higher CBZ degradation in the presence of H 2 O 2 was attributed to HO whose second-order rate constant with CBZ was calculated to be (8.83 ± 0.27) × 109 M−1 s−1. Removal of CBZ by UV/H 2 O 2 /Fe2+ system was optimum at pH 3.0, as 80.8, 90.6 and 70.4% CBZ degradation was observed at pH 2.0, 3.0 and 6.5, respectively. The removal of CBZ by UV/H 2 O 2 /Fe2+ was retarded in the presence of Cl− and humic acid as revealed from 84.5 and 56.7% CBZ degradation in the presence of Cl− and humic acid, respectively, compared to 90.6% in their absence at 3600 mJ cm−2. The CBZ degradation products were found to be less toxic than the parent compound, suggesting important role of UV-assisted AOPs in efficient removal and toxicity reduction of CBZ and their degradation products. [ABSTRACT FROM AUTHOR]

Desethyl-atrazine (DEA) and desisopropyl-atrazine (DIA) are the two major degradation by-products of atrazine (a suspected human carcinogen and endocrine disrupting herbicide), and show an equal toxicity to their parent compound. This study investigated the degradation of DEA and DIA with OH and SO 4 − generated from the activation of peroxides, i.e., persulfate (S 2 O 8 2− ), peroxymonosulfate (HSO 5 − ) and hydrogen peroxide (H 2 O 2 ), by UV-254 nm radiation in the presence or absence of Fe 2+ . Quantum yields of DEA and DIA were independent of pH (3.0–11.0). The higher quantum yield of reactive radicals from UV/S 2 O 8 2− , i.e., 1.8 compared to 1.04 for UV/HSO 5 − and 1.0 for UV/H 2 O 2 , resulted in greater efficiency of UV/S 2 O 8 2− for both DEA and DIA degradation. The second-order rate constants of DEA and DIA with SO 4 − were calculated to be (6.42 ± 0.12) × 10 8 and (1.70 ± 0.30) × 10 9 M −1 s −1 , and that with OH were (1.14 ± 0.09) × 10 9 and (2.22 ± 0.44) × 10 9 M −1 s −1 , respectively, suggesting a strong impact of side chains toward radical reactions. Fe 2+ promoted slightly the activation of the examined peroxides at pH 7.4. Presence of organic matter and alkalinity in field water samples negatively influenced the efficiency of UV/S 2 O 8 2− . Based on the identified degradation by-products by GC–MS, potential degradation pathways were proposed for both compounds. The results obtained suggested that DEA and DIA can be efficiently removed from the contaminated water by OH and SO 4 − based-AOPs. [ABSTRACT FROM AUTHOR]