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Bisphenols (BPs) are pervasive environmental contaminants extensively found in indoor environments worldwide. Despite their ubiquitous presence and potential health risks, there remains a notable gap in the comprehensive reviews focusing on BPs in indoor dust. Existing literature often addresses specific aspects such as exposure pathways, transformation products, or biomonitoring techniques, but lacks a consolidated, in-depth review encompassing all these facets. This review provides a comprehensive overview of the global distribution of BPs, emphasizing their prevalence in diverse indoor settings ranging from households and workplaces to public areas. Variations in BP concentrations across these environments are explored, influenced by factors such as industrial activities, consumer product usage patterns, and geographical location. Exposure assessments highlight ingestion, inhalation, and dermal contact as primary pathways for BP exposure, with ingestion being particularly significant for vulnerable groups such as infants and young children. Studies consistently reveal higher concentrations of BPs in urban indoor dust compared to rural settings, reflecting the impact of urbanization and intensive consumer practices. Moreover, BPs from mobile sources like vehicles contribute significantly to overall human exposure, further complicating exposure assessments. The review also delves into the transformation of BPs within indoor environments, emphasizing the diverse roles of physical, chemical, and biological processes in generating various transformation products (TPs). These TPs can exhibit heightened toxicity compared to their parent compounds, necessitating deeper investigations into their environmental fate and potential health implications. Critical examination of biomonitoring techniques for BPs and their metabolites underscores the importance of non-invasive sampling methods, offering ethical advantages and practicality in assessing human exposure levels. The emerging use of bioindicators, encompassing plants, animals, and innovative approaches like spider webs, presents promising avenues for effectively monitoring environmental contamination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

In India, Ceramic Water Filters (CWF) named G-filters are becoming a point-of-use household water treatment solution. The filter's reliability may be primarily characterized by the filtrate turbidity and microbial removal efficiency. The temperature and moisture gradients of the location affect its performance. This paper describes a 19-week laboratory investigation of G-filters simulating field conditions. The basic objective during the study was to ascertain the effective useable life of the filter. The discharge rate and turbidity reduction ability of the filters are studied in depth. The G-filters were prepared using locally available salty clay and sawdust taken in equal volume fractions. A total of 30 filters with a 9-liter capacity each were used for the experiments. The results showed that CWFs can reduce turbidity effectively. The influent water used for the study had a mean turbidity of 7.65 NTU, which reduced in the range of 0.03 NTU to 1.03 NTU. Over the course of four months, the average flow rate decreased from 1.94 Lh -1 to 0.93 Lh -1 . Although a soft brushing of filters improved the filtration rate but that too failed in the long run. Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption measurements were used to determine the variation in pore size of filters with time. An average pore radius of 2.91 nm was found in the original filter that has not been used for filtration experiments. Moreover, an average pore radius of 1.77 nm, 1.21 nm, and 1.22 nm were reported in G-filters through which 427.5 L, 807.5 L, and 1035.5 L, respectively, of water were passed. This reduction in pore size is attributed to the clogging of pores over a period of time. This study aims to collect performance data to establish a scientific model using statistical analysis for implementing CWF technology in developing nations., Competing Interests: Declaration of competing interest There is not conflict of interest among the authors which penning down the paper titled “Assessment of the physiochemical properties and sustainability of locally produced ceramic G-filter in a long term experiment”., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The natural phototransformation of organic pollutants in the environment depends on several water constituents, including inorganic ions, humic substances, and pH. However, the literature information concerning the influence of various water components on the amount of phototransformation and their impact on the development of various transformation products (TPs) is minimal. This study investigated the phototransformation of ofloxacin (OFL), a fluoroquinolone antibiotic, in the presence of various water components such as cations (K + , Na + , Ca 2+ , NH 4 + , Mg 2+ ), anions (NO 3 - , SO 4 2- , HCO 3 - , CO 3 2- , PO 4 3- ), pH, and humic substances when exposed to natural sunlight. The study reveals that neutral pH levels (0.39374 min⁻ 1 ) enhance the phototransformation of OFL in aquatic environments. Carbonate, among anions, shows the highest rate constant (2.89966 min⁻ 1 ), significantly influencing OFL phototransformation, while all anions exhibit a notable impact. In aquatic environments, indirect phototransformation of OFL, driven by increased reactive oxygen species, expedites light-induced reactions, potentially enhancing OFL phototransformation. A clear difference was visible in the type of transformation products (TPs) formed during direct and indirect photolysis. The impact of indirect photolysis in the product profile was evaluated by examining the unique properties of TPs in direct and indirect photolysis. The primary transformation products were generated by oxidation and cleavage processes directed towards the ofloxacin piperazinyl, oxazine, and carboxyl groups. The toxicity assessment of TPs derived from OFL revealed that among the 26 identified TPs, TP3 (demethylated product), TP7 and TP8 (decarboxylated products), and TP15 (piperazine ring cleaved product) could potentially have some toxicological effects. These findings suggest that the phototransformation of OFL in the presence of various water components is necessary when assessing this antibiotic's environmental fate., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Meeting societal demand for potable water supply remains one of the prioritized challenges faced in the modern era. The anthropogenic intervention has led to a dire situation threatening ecological balance and human health. There is an inevitable need for the development of new technologies and innovations in existing technologies for water treatment. Photocatalytic Membrane technology, encompassing the merits of membrane filtration and photocatalytic degradation has evolved as a potential and reliable technology for sustainable water treatment. Innovations in photocatalytic materials and membrane fabrication techniques can lead to the goal of commercialization of membrane water treatment technology. Herein, we demonstrate the potential of graphitic carbon nitride (g-C 3 N 4 ) and its functionalized analog as photocatalytic membranes for sustainable water treatment. g-C 3 N 4 and Tetracarboxyphenylporphyrin sensitized g-C 3 N 4 (g-C 3 N 4 /TCPP) was introduced onto commercial nylon membrane surface via a layer-by-layer (LBL) assembly method using chitosan and sodium salt of polystyrene sulphonic acid as polyelectrolytes. The fabricated membranes were characterized to ensure the integration of the photocatalysts. The performance of the membranes for water treatment was assessed by selecting some common dyes as model pollutants. The modified membranes exhibited excellent flux recovery and could afford high rejection rates upon irradiation indicating the prospects for sustainable filtration., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Steroid hormones (SHs) are among the important classes of Contaminants of Emerging Concern (CECs) whose detection in aquatic environments is vital due to their potential adverse health impacts. Their detection is challenging because of their lower stability in natural conditions and low concentrations. This study reports the presence of steroid hormones in a major river system, the Periyar River, in Kerala (India). Water samples were collected from thirty different river locations in the case of SHs and five locations within these in the case of other CECs. These were subjected to LC-MS/MS and LC-Q-ToF/MS analyses. Five SHs, estriol, estrone, 17 β estradiol, progesterone, and hydroxy progesterone, were separated and targeted using MS techniques. The studies of the water samples confirmed the presence of the first three estrogens in different sampling sites, with estrone present in all the sampling sites. The concentration of estrone was detected in the range from 2 to 15 ng/L. Estriol and estradiol concentrations ranged from 1.0 to 5 ng/L and 1-6 ng/L, respectively. The hormones at some selected sites were continuously monitored for seven months. The chosen areas include the feed water sites for the drinking water treatment plants across the river. The monthly data revealed that estrone is the only SHs detected in all the samples in the selected months. The highest concentration of SH was found in August. Twelve CECs belonging to pharmaceuticals and personal care products were identified and quantified. In addition, 31 other CECs were also identified using non-target analysis. A detailed study of the hormone mapping reported here is the first from any South Indian River., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Polyelectrolyte multilayer (PEM) deposition conditions can favorably or adversely affect the membrane filtration performance of various pollutants. Although pH and ionic strength have been proven to alter the characteristics of PEM, their role in determining the buildup interactions that control filtration efficacy has not yet been conclusively proved. A PEM constructed using electrostatic or non-electrostatic interactions from controlled deposition of a weak polyelectrolyte could retain both charged and uncharged pollutants from water. The fundamental relationship between polyelectrolyte charge density, PEM buildup interaction, and filtration performance was explored using a weak-strong electrolyte pair consisting of branching poly (ethyleneimine) and poly (styrene sulfonate) (PSS) across pH ranges of 4-10 and NaCl concentrations of 0 M-0.5 M. PEI/PSS multilayers at acidic pH were dominated by electrostatic interactions, which favored the selective removal of a charged solute, phosphate over chloride, while at alkaline pH, non-electrostatic interactions dominated, which favored the removal of oxybenzone (OXY), a neutral hydrophobic solute. The key factor determining these interactions was the charge density of PEI, which is controlled by pH and ionic strength of the deposition solutions. These findings indicate that the control of buildup interactions can largely influence the physico-chemical and transport characteristics of PEM membranes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The degradation of pollutants by a non-radical pathway involving singlet oxygen ( 1 O 2 ) is highly relevant in advanced oxidation processes. Photosensitizers, modified photocatalysts, and activated persulfates can generate highly selective 1 O 2 in the medium. The selective reaction of 1 O 2 with organic pollutants results in the evolution of different intermediate products. While these products can be identified using mass spectrometry (MS) techniques, predicting a proper degradation mechanism in a 1 O 2 -based process is still challenging. Earlier studies utilized MS techniques in the identification of intermediate products and the mechanism was proposed with the support of theoretical calculations. Although some reviews have been reported on the generation of 1 O 2 and its environmental applications, a proper review of the degradation mechanism by 1 O 2 is not yet available. Hence, we reviewed the possible degradation pathways of organic contaminants in 1 O 2 -mediated oxidation with the support of density functional theory (DFT). The Fukui function (FF, f - , f + , and f 0 ), HOMO-LUMO energies, and Gibbs free energies obtained using DFT were used to identify the active site in the molecule and the degradation mechanism, respectively. Electrophilic addition, outer sphere type single electron transfer (SET), and addition to the hetero atoms are the key mechanisms involved in the degradation of organic contaminants by 1 O 2 . Since environmental matrices contain several contaminants, it is difficult to experiment with all contaminants to identify their intermediate products. Therefore, the DFT studies are useful for predicting the intermediate compounds during the oxidative removal of the contaminants, especially for complex composition wastewater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Degradation of benzenesulfonic acid (BSA), the simplest aromatic sulfonic acid with extreme industrial importantance, by sonochemically generated hydroxyl radical (OH) have been thoroughly investigated. A reasonable reduction (∼50%) in the total organic carbon (TOC) was achieved only after prolonged irradiation (∼275 min, 350 kHz) of ultrasound, although a short irradiation of less than an hour is enough to degrade significant amount of BSA. The degradation efficiency of ultrasound has been reduced in lower and extremely higher frequencies, and upon increasing the pH. An irregular, but continuous, release of sulfate ions was also observed. Further, the release of protons upon the oxidation of BSA consistently reduces the experimental pH to nearly 2. High resolution mass spectrometric (HRMS) analyses reveals the formation of a number of aromatic intermediates, including three mono (I a-c ) and two di (II a&b ) hydroxylated BSA derivatives as the key products in the initial stages of the reaction. Pulse radiolysis studies revealed the generation of hydroxycyclohexadienyl-type radicals, characterized by absorption bands at 320 nm (k 2  = (7.16 ± 0.04) × 10 9  M -1  s -1 ) and 380 nm, as the immediate intermediates of the reaction. The mechanism(s) leading to the degradation of BSA under sonolytic irradiation conditions along with the effect of various factors, such as the ultrasound frequency and reaction pH, have been explained in detail. The valuable mechanistic aspects obtained from our pulse radiolysis and HRMS studies are essential for the proper implementation of sonochemical techniques into real water purification process and, thus, receives extreme environmental relevance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The emergence of issues related to environment from ECs is a topic under serious discussions worldwide in recent years. Indian scenario is not an exception as it is tremendously growing in its rate of production and consumption of compounds belongs to ECs categories. However, a comprehensive documentation on the occurrence of ECs and consequent ARGs as well as their toxic effects on vertebrates on Indian context is still lacking. In the present study, an extensive literature survey was carried out to get an idea on the geographical distribution of ECs in various environmental matrices (water, air, soil, sediment and sludge) and biological samples by dividing the entire subcontinent into six zones based on climatic, geographical and cultural features. A comprehensive assessment of the toxicological effects of ECs and the consequent antibiotic resistant genes has been included. It is found that studies on the screening of ECs are scarce and concentrated in certain geological locations. A total of 166 individual compounds belonging to 36 categories have been reported so far. Pharmaceuticals and drugs occupy the major share in these compounds followed by PFASs, EDCs, PCPs, ASWs and flame retardants. This review throws light on the alarming situation in India where the highest ever reported values of concentrations of some of these compounds are from India. This necessitates a national level monitoring system for ECs in order to assess the magnitude of environmental risks posed by these compounds., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Coomassie Brilliant Blue (CBB), discharged mainly from textile industries, is an identified water pollutant. Ultrasound initiated degradation of organic pollutants is one among the promising techniques and forms part of the Advanced Oxidation Processes (AOPs). Ultrasonic degradation of CBB under different experimental conditions has been investigated in the present work. The effect of frequency (200 kHz, 350 kHz, 620 kHz and 1 MHz) and power density (3.5 W mL(-1), 9.8 W mL(-1) and 19.6 W mL(-1)) on the degradation profile was evaluated. The optimum performance was obtained at 350 kHz and 19.6 W mL(-1). Similar to other sonolytic degradation of organic pollutants, maximum degradation of CBB was observed under acidic pH. The degradation profile indicated a pseudo-first order kinetics. The addition of ferrous ion (1×10(-4) M), hydrogen peroxide (1×10(-4) M), and peroxodisulphate (1×10(-4) M) had a positive effect on the degradation efficiency. The influence of certain important NOM like SDS and humic acid on the sonolytic degradation of CBB was also investigated. Both the compounds suppress the degradation efficiency. LC-Q-TOF-MS was used to identify the stable intermediate products. Nearly 13 transformed products were identified during 10min of sonication using the optimized operational parameters. This product profile demonstrated that most of the products are formed mainly by the OH radical attack. On the basis of these results, a degradation mechanism is proposed., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Oxidative degradation of fensulfothion, a model organophosphorus compound, has been investigated by pulse radiolysis and H2O2/UV photolysis. A nearly complete transformation of fensulfothion was observed within 4min of irradiation. Very little Total Organic Carbon (TOC) reduction was obtained at this time scale. When the product studies at this stage were conducted using LC-MS/MS analyses, nearly 20 transformation products were obtained. The entire products were identified as from the reaction of OH with fensulfothion or with some of its initially transformed products. Nearly 80% reduction in TOC was observed when photolysis was conducted using higher concentrations of H2O2 at longer time scale. A reaction rate constant (bimolecular) of 1.10×10(10)dm(3)mol(-1)s(-1) was obtained for the reaction of OH with fensulfothion using pulse radiolysis technique. The transient absorption spectrum obtained from the reaction of OH has a maximum at 280nm and a weak, broad maximum around 500nm along with a small shoulder around 340nm. The intermediate spectrum is assigned to the radical cation of fensulfothion (3) and the hydroxyl radical adducts (1 and 2). This assignment is supported by the intermediate spectrum (λmax at 280nm) from the reaction of sulfate radical anion (SO4(-)) (k2=3.20×10(9)dm(3)mol(-1)s(-1)) which is a one electron oxidant. It is thus demonstrated that the combination of both pulse radiolysis and the product estimation using LC-MS/MS is ideal in probing the complete mechanism which is very important in the mineralization reactions using Advanced Oxidation Processes., (Copyright © 2012 Elsevier Ltd. All rights reserved.)