Flame retardants (FRs) are additives used in consumer products to reduce flammability, even though they can easily contaminate the indoor environment. Since it is common for people in modern cities to spend up to 85% of time indoors, the quality of the indoor environment is critical for human health. In this study, polybrominated diphenyl ethers (PBDEs), organophosphorus flame retardants (OPFRs), emerging brominated flame retardants (EBFRs), and dechlorane-related compounds (DRCs) were measured in household dust samples (n = 34) from Latvia, followed by human exposure assessment. Among all studied compounds, OPFRs showed the highest concentrations (1380–133,000 ng g⁻¹). Despite the phase-out of PBDEs, they were the second most significant flame retardants in the studied dust samples (468–25,500 ng g⁻¹) and the predominant compound was BDE-209. The concentrations of EBFRs were in the range of 120–7295 ng g⁻¹, with the most abundant contaminant being DBDPE, which is widely used as a substitute for the deca-BDE formulation. DRCs were the least common flame retardants in the Latvian indoor environments, with concentrations ranging 22.4–192 ng g⁻¹. Although the concentrations of specific FRs are known to vary between different countries, the levels and patterns observed in dust samples from Latvia were similar to those reported from Central Europe. Human exposure was evaluated as the estimated daily intake (EDI). The calculated exposure to most of the FRs was several orders of magnitude lower than the available reference dose (RfD) values.

This article presents a study on the degradation of a residual textile mixture composed of cationic surfactant cetyltrimethylammonium bromide (CTAB) and the remazol yellow gold RNL-150% and reactive blue BF-5G textile dyes. This was carried out by employing the photo-peroxidation and photo-Fenton processes in LED and UV-C photoreactors. The photo-Fenton process was the most efficient as regards the degradation of the CTAB and dye mixture, for both types of radiation. In the kinetic study, degradations of 99% were obtained in 180 min for the chromophore groups using both types of radiation. The degradation of the CTAB and aromatic groups was, meanwhile, an average of 25% when employing LED radiation. The behavior of the degradation reaction was pseudo-first-order. Toxicity tests indicated that the solutions were better able to grow seeds and bacteria after treatment with the photo-Fenton process, using both types of radiation. The photo-Fenton processes carried out by employing LED and UV-C photoreactors were able to degrade the CTAB and dye mixture, thus highlighting the efficiency of LED radiation when its power (three times smaller) is compared to that of UV-C radiation. This process, therefore, represents an alternative for use in textile wastewater treatment systems.

Fine particulate matter (PM2.5) is of widespread concern, as it poses a serious impact on economic development and human health. Although the influence of socioeconomic factors on PM2.5 has been studied, the constitution and the effect analysis of social vulnerability to PM2.5 remain unclear. In this study, a comprehensive theoretical framework with appropriate indicators for social vulnerability to PM2.5 was constructed. Using spatial autocorrelation analysis, a positive global spatial autocorrelation and notable local spatial cluster relationships were identified. Spatial econometric modeling and geographically weighted regression modeling were performed to explore the cause-effect relationship of social vulnerability to PM2.5. The spatial error model indicated that population and education inequality in the sensitivity dimension caused a significant positive impact on PM2.5, and biocapacity and social governance in the capacity dimension strongly contributed to the decrease of PM2.5 globally. The geographically weighted regression model revealed spatial heterogeneity in the effects of the social vulnerability variables on PM2.5 among countries. These empirical results can provide policymakers with a new perspective on social vulnerability as it relates to PM2.5 governance and targeted environmental pollution management.

Meaningful assessment of pesticide fate in soils and plants is based on fate models that represent all relevant processes. With mechanistic models, these processes can be simulated based on soil, substance, and plant properties. We present a mechanistic model that simulates pesticide uptake from soil and investigate how it is influenced, depending on the governing uptake process, by root and substance properties and by distributions of the substance and water in the soil profile. A new root solute uptake model based on a lumped version of the Trapp model (Trapp, 2000) was implemented in a coupled version of R-SWMS-ParTrace models for 3-D water flow and solute transport in soil and root systems. Solute uptake was modeled as two individual processes: advection with the transpiration stream and diffusion through the root membrane. We set up the model for a FOCUS scenario used in the European Union (EU) for pesticide registration. Considering a single vertical root and advective uptake only, the root hydraulic properties could be defined so that water and substance uptake and substance fate in soil showed a good agreement with the results of the 1D PEARL model, one of the reference models used in the EU for pesticide registration. Simulations with a complex root system and using root hydraulic parameters reported in the literature predicted larger water uptake from the upper root zone, leading to larger pesticide uptake when pesticides are concentrated in the upper root zone. Dilution of root water concentrations at the top root zone with water with low pesticide concentration taken up from the bottom of the root zone leads to larger uptake of solute when uptake was simulated as a diffusive process. This illustrates the importance of modeling uptake mechanistically and considering root and solute physical and chemical properties, especially when root-zone pesticide concentrations are non-uniform.

The behavior of Hg release from iron ores during temperature-programmed heat treatment (TPHT) in air is studied, primarily using an online monitoring method. The Hg release behavior during TPHT depends significantly on the type of ore being processed, involving the evolved forms, Hg⁰ and Hg²⁺, and those that remain thermally stable up to 950 °C. Furthermore, TPHT experiments for model Hg compounds suggest the presence of several types of Hg forms (HgCl₂, Hg₂Cl₂, HgS, HgO, HgSO₄, and associated mineral Hg) in the considered iron ores. The findings of this study provide insights for designing an efficient method for the removal of Hg from iron ore and gaseous Hg.

Improving the chemical and physical properties of saline soils is crucial for the sustainable production of sugar beet and efficient processing of beet sugar. Here, the impacts of the application of treated filter cake on sugar beet biofortification under saline soil and sugar losses into molasses during beet sugar processing were evaluated for the first time. The application of treated filter cake significantly reduced K%, Na%, and α-amino-N while enhanced sucrose content and quality index of beet root juice. Consequently, sugar loss percentage, sugar loss yield, and relative sugar loss yield were reduced, whereas recoverable sugar yield was enhanced. Linear regression analysis revealed that quality index and sugar loss yield were increased, whereas sugar loss percentage and relative sugar loss yield were reduced in response to the reduction of soil Na⁺ content accompanied with increasing Ca²⁺ content in the soil increased. The results provide treated filter cake as a promising amendment for saline soil remediation for improving biofortification of sugar beet and reducing sugar losses during beet sugar processing.

Ladle furnace (LF) slag is a type of steel slag, which has limited applications due to its high S content. Aqueous carbonation is a prospective method for desulfurization of the LF slag. However, the Al-rich LF raw slag has very low desulfurization efficiency with carbonation method. This study investigated the improvement of desulfurization efficiency of the Al-rich LF slag with carbonation method by hydrothermal (HP) or ultrasound pretreatment (UP). The results showed that C₃AHX was formed in pretreated slags because of C₁₂A₇ hydration, which could remove part of S. After carbonation, most of the C₃AHX in pretreated slags produced crystalline CaCO₃ bonded by amorphous Al(OH)₃ (the other reaction product) in 10 min. In the carbonation process, S removal was mainly determined by carbonation efficiency. The S content was reduced to about 0.40% for the pretreated slags from 1.04% in the raw slag. By contrast, the S content was reduced to only 0.93% for slag without pretreatment under the same carbonation conditions. The possible reason of the improvement of desulfurization efficiency by HP or UP was the formation of thin plate–like C₃AHₓ, which increased the surface area available for carbonation reaction. The UP slag presented slightly lower S content than the HP slag because high ultrasound energy increased the reactivity of Ca₂SiO₄.

During the recent past, electronic waste (E-waste) has emerged as a major category of toxic waste in both global North and global South. Particularly, the emerging economies such as India are a major contributor to the E-waste volume in the world today. Accordingly, we attempted to carry out this study to evaluate the journey of equipment from ‘electronic products’ to ‘electronic waste’ in the city of New Delhi in India. The purpose was to carry out an exclusive pilot study with the potential to replicate the same at a larger scale in major Indian metropolis which are mostly the hubs of intense E-waste generation. The case of mobile phones (both smartphones and feature phones) was considered as the key representative. A structured questionnaire survey was carried out with 334 purposively selected respondents in the city of New Delhi. Among several other noteworthy findings, we observed that there exists a gap among purchase behaviour of mobile phones, awareness on E-waste and disposal behaviour of these phones. For instance, the relatively high knowledge/awareness about E-waste is yet to be reflected in consumers’ responsible purchase and disposal behaviour. We argue that creating awareness among citizens is central to a sustainable E-waste management system and effective policy instruments.

Appropriate management systems for the protection of fishes are mostly relying on the information of size at sexual maturity and optimum catchable length. The purpose of this research was to estimate the size at sexual maturity (Lₘ) and optimum catchable length (Lₒₚₜ) of 10 marine fish species from the Bay of Bengal (Bangladesh) through multi-models using commercial catches from October 2019 to September 2020. Also, we calculated the Lₘ and Lₒₚₜ of these species from worldwide water bodies based on maximum length (Lₘₐₓ). A total of 2967 specimens of 10 fish species were evaluated in the current study and total length (TL) was noted up to 0.1 cm using a measuring board, while body weight (BW) and gonad weight (GW) are weighed by digital electronic balance with 0.01 g accuracy. To assess the Lₘ, three different models such as (i) empirical model based on Lₘₐₓ, (ii) the relationship between TL (total length in cm) vs. GSI (gonadosomatic index in %), and (iii) logistic model were considered and Lₒₚₜ was assessed based on L∞. The estimated lowest Lₘ was 11.8 cm (Lₘₐₓ-based), 12.8 cm (TL vs. GSI), and 13.7 cm (logistic model) for Thryssa setirostris and highest Lₘ was 23.3, 20.5, and 22.0 cm for Priacanthus macracanthus through Lₘₐₓ, TL vs. GSI, and logistic-based models, respectively. From these three models, the lowest mean value of Lₘ was obtained for T. setirostris (12.7 cm) and highest was recorded for P. macracanthus (21.9 cm). Fifty percent of mature marine species was in 14.9 cm TL and 90% species was in 19.5 cm TL. The smallest Lₒₚₜ was obtained as 13.4 cm TL for T. setirostris and largest was 28.2 cm TL for P. macracanthus. This study was generated data on Lₘ and Lₒₚₜ for 10 newly marine species, which are globally absent. Therefore, this study will be helpful for developing sustainable management strategies and conservation of marine fishes through the implementation of mesh size based on the size at sexual maturity (Lₘ) and optimum catchable length (Lₒₚₜ).

Golinga reservoir provides water for drinking and domestic and agricultural activities for its surrounding communities. However, competitive demand and multiple-use necessitated a study into the influence of the multipurpose use on the water quality and subsequent health risks. The 6-month research employed observations and water sampling to assess the impact. Empirical orthogonal function, analysis of variance, and variance–covariance were run to interpret the obtained data. The study recorded ranges for pH (6.65–7.11 pH units), turbidity (3.33–80.66 NTU), conductivity (67.73–191.93), nitrate-nitrogen (0.13–6.17 mg/L), PO₄-P (0.01–0.08 mg/L), sulphate (0.05–0.09 mg/L), fluoride (0.12–0.32 mg/L), sodium (4.67–15.46 mg/L), potassium (2.20–3.75 mg/L), faecal coliform (log₁₀ 1.30–log₁₀ 2.56 cfu/100 mL), E. coli (log₁₀ 0.77–log₁₀ 1.23 cfu/100 mL), and Salmonella spp. (log₁₀ 1.51–log₁₀ 1.62 cfu/100 mL). All except turbidity fell within acceptable levels. Pairing the physical and chemical parameters showed a significant relationship (p < 0.05) except for pH and Na⁺, SO₄²⁻, K⁺ and F⁻, Na⁺ and K⁺, and F⁻, and K⁺ and F⁻, and SO₄²⁻ and F⁻ and SO₄²⁻ which revealed no significance (p > 0.05). Pairing the bacteria loads was presented a significant association (p < 0.05) except for faecal coliform and Salmonella spp. which were not significant (p > 0.05). Frequent activities were noted to support the revelation of high faecal contamination. The research suggests community by-laws enforcement curtail cattle movement as well as adequate disinfection methods to render the water suitable for potable use. The presence of pathogenic bacteria was attributed to open defaecation which poses negative health effects such as gastroenteritis, especially when water is orally consumed without prior treatment. Open defaecation was noted and supports the detection of high faecal contamination. The research suggests the promotion of simpler disinfection methods to render the water potable, enforcement of community by-laws, and in-depth environmental quality monitoring.