Chloride Type Research Articles

Structural basis and molecular mechanisms of Cl- transmembrane transport in cardiomyocytes

The intracellular concentration of chlorine anions ([Cl-]i), the equilibrium potential for chlorine anions (ECl) and transmembrane chloride currents (ICl) are the factors that significantly influence the electrophysiological properties of excitable tissue, including the myocardium. Several types of chloride (anion) conductance have been identified in the heart. In recent years, a number of transmembrane proteins demonstrating chloride conductance have been identified (CFTR, ClC, TMEM16, LRRC8), and the expression of these macromolecules in cardiac tissue has been confirmed. Accumulated data allow for establishing a molecular substrate for some chloride anion currents (ICl,PKA, ICl,ir, ICl,vol, ICl,swell, ICl,Ca, Ito2) detected in the heart. Furthermore, the molecular mechanisms regulating [Cl-]i and ECl through chloride cotransporters (KCC, NKCC1) and chloride-bicarbonate exchangers have been established. The variety of structures determining chloride transmembrane conductivity and the complexity of molecular mechanisms regulating chloride homeostasis underlie the complex effects of activation of chloride transporters in the pacemaker, conduction system and working myocardium of the heart. This review discusses the structural, biophysical properties and molecular regulation of chloride transporter protein complexes identified in the myocardium. The review also covers the mechanisms by which chloride transmembrane transport influences the bioelectrical activity of cardiomyocytes.

The effect of geology and agricultural development on the groundwater, West Minia, Egypt

Fifty groundwater samples were collected from the Oligocene sand and Middle Eocene limestone aquifers and analyzed for major ions and stable isotopes. Aquifer sediment samples were examined to determine hydraulic properties, and sixty-six well logs were investigated to understand the subsurface geology. The study reveals that lithofacies, mineral composition, and geologic structures significantly influence groundwater quality and behavior. Karst features in the Middle Eocene limestone aquifer create subsurface caves, leading to challenges such as abrupt salinization and well failure. In the Oligocene aquifer, groundwater is predominantly of the sodium chloride type. In the Middle Eocene aquifer, 80 % of samples are sodium chloride, with variations of sodium bicarbonate (10 %) and sodium sulfate (10 %) types. Remote sensing from 2013 to 2021 shows significant agricultural expansion, with vegetation increasing by over 227 km². This growth, driven by large agricultural projects, has led to substantial groundwater consumption, resulting in a 5-meter decline in water levels within just one year (from 2020 to 2021). The over-extraction poses a risk to the aquifers, threatening long-term sustainability. Understanding the region's geology is crucial for mitigating these issues and ensuring sustainable groundwater management.

Experimental study on surface optimization of dosage in magnetic coagulation process for enhancing primary treatment of urban sewage

This work aims to investigate the minimum dosage required to achieve optimal removal of carbon, nitrogen, and phosphorus in the Chemical Enhanced Primary Treatment (CEPT) process using magnetic coagulation technology. A response surface methodology was adopted to generate multiple regression models to optimize the dosages of three types of coagulation, i.e., polyaluminum chloride (PAC), polyacrylamide (PAM), and magnetic medium Fe3O4 particles (MP), based on the removal rates of chemical oxygen demand (COD), ammonia nitrogen (NH3-N), and total phosphorus (TP). The results showed that the regression models could predict results well with actual engineering results. Compared to the traditional coagulation process, the synergistic enhancement of PAC+PAM+MP in the CEPT process significantly improved the treatment effects. Based on the COD removal rates, PAC performed better than MP, followed by PAM; likewise, for the NH3-N and TP removal rates, PAC outperformed PAM, followed by MP. The optimized PAC, PAM, and MP dosages were 135.87, 1.51, and 108.36 mg/L, respectively, reaching 92.27 % COD, 71.98 % NH3-N, and 91.33 % TP removal rates with less than 5 % errors compared to the experimental verification results. These optimization models offer a practical and cost-saving reference for enhancing the primary treatment effect on carbon, nitrogen, and phosphorus removal using PAC+PAM+MP.

Molecular modeling to elucidate the dynamic interaction process and aggregation mechanism between natural organic matters and nanoplastics

The interactions of nanoplastics (NPs) with natural organic materials (NOMs) dominate the environmental fate of both substances and the organic carbon cycle. Their binding and aggregation mechanisms at the molecular level remain elusive due to the high structural complexity of NOMs and aged NPs. Molecular modeling was used to understand the detailed dynamic interaction mechanism between NOMs and NPs. Advanced humic acid models were used, and three types of NPs, i.e., polyethylene (PE), polyvinyl chloride (PVC), and polystyrene (PS), were investigated. Molecular dynamics (MD) simulations revealed the geometrical change of the spontaneous formation of NOMs-NPs supramolecular assemblies. The results showed that pristine NPs initially tend to aggregate homogeneously due to their hydrophobic nature, and then NOM fragments are bound to the formed NP aggregates mainly by vdW interaction. Homo- and hetero-aggregation between NOMs and aged NPs occur simultaneously through various mechanisms, including intermolecular forces and Ca2+ bridging effect, eventually resulting in a mixture of supramolecular structures. Density functional theory calculations were employed to characterize the surface properties and reactivity of the NP monomers. The molecular polarity indices for unaged PE, PS, and PVC were 3.1, 8.5, and 22.2 ​kcal/mol, respectively, which increased to 43.2, 51.6, and 42.2 ​kcal/mol for aged NPs, respectively, indicating the increase in polarity after aging. The vdW and electrostatic potentials of NP monomers were visualized. These results clarified the fundamental aggregation processes, and mechanisms between NPs and NOMs, providing a complete molecular picture of the interactions of nanoparticles in the natural aquatic environment.

Multivariate approach to assess groundwater resources in the multilayer system of Iullemmeden basin in Dosso Region, Southwestern Niger

The Iullemmeden basin groundwater resources were assessed in the Dosso Region for the groundwater management. Classical and multivariate tools of hydrogeochemistry were thus used to stand out main factors impacting the groundwater mineralization. The multilayer system indicates the occurrence of acidic to basic fresh groundwaters but with an excessive content in some places. Good to excellent drinking groundwaters are largely represented in the system. The categorization of groundwater patterns evolves from (i) mixed types namely Ca/Mg-HCO3, Ca/Mg-Cl, Na-Cl/SO4, Ca-Cl/SO4 and Ca/Mg-Cl/SO4 for the Ct3 particularly; (ii) to chloride types such as NaCl, CaCl and MgCl mostly for Ct1 and Ct2; (iii) and the bicarbonate types precisely Na-HCO3, Ca-HCO3, Mg-HCO3 for Ch. The weathering of silicate minerals and dissolution (carbonate and salts) are the major processes in the multilayer system. The increase of EC and salts (halite and gypsum) in Ct2 could come from the relics of ancient seawater during the last regression. In a lesser extent, fertilizers from agricultural and livestock farming also contribute to the mineralization in the study area. The groundwater assessment of the Iullemmeden sedimentary basin in the Dosso Region stands out the main factors and processes characterizing each aquifer of this system, able to useful for a better groundwater resource management.

Configuring a structure self-curable lithium aluminum layered double hydroxide chloride type lithium adsorbents via a facile one-pot synergistical modification way

Taking the application merits and difficulty into consideration, a synergistical synchronous doping strategy was firstly proposed for configuring a structure stable high-performance lithium aluminum layered double hydroxide chloride type lithium adsorbents by a simple one-pot precipitation method to resist the performance attenuation of aluminum-based adsorbents during sorption. As-proposed designing strategy not only grants the LDHs-type adsorbents high adsorption capacity up to 10.4 mg/g in 400 ppm LiCl solution, but also ensures the adsorbents excellent Li+/Na+, Li+/Mg2+, Li+/K+ separation coefficients up to 236.7, 187.2 and 282.6, respectively. The initial and retained adsorption capacities after 70 desorption/adsorption cycles of as-prepared adsorbents after granulation are 12.08 and 5.09 mg/g, respectively in real sulfate-type West Taijinar Salt Lake brines with 400 ppm Li+, which is mainly attributed to the largely accelerated structure self-curability at sorption. Generally, this study can actually achieve efficient, selective and stable collection of Li+ from low-grade brines with high Mg2+/Li+ ratio.

Sustainability and durability performance evaluation of geopolymer concrete with industrial effluent as alternative to conventional river sand

Due to infrastructural development activities, the need for the construction materials increases, because of which most of the naturally available natural resources are over exploited and the cost of construction materials are increased. Therefore, the present study focuses on the use of industrial by-products for the development of concrete and examines the physical, mechanical, durability and sustainable performances. Fly ash (FA) and ground granulated blast furnace slag (GGBS) were employed as binder medium and the industrial effluent sodium silicate waste was used to replace the conventional river sand in the geopolymer concrete (GPC). GGBS was employed as source material for the production of concrete to increase the polymerization reaction process and further, the developed concrete was cured in the ambient condition of temperature range 27 ± 2 °C, in the laboratory. The concentration of the sodium hydroxide (NaOH) in the present study was 12M, and the alkaline solution ratio was 1:1.5. During the production process of sodium silicate solution in the factory, the residue left at the bottom of the boiling hopper were dumped as waste in the open land. GPC gains its strength based on the alumina and silica in the source material and alkaline activator solution, therefore, this industrial waste residue was identified as potential alternative to conventional river sand. The concrete with and without effluent was subjected to two types of acid (Sulfuric acid (H2SO4) and Hydrochloric acid (HCl)) and further to examine the performance of concrete under marine condition, two types of salt solutions, namely, magnesium sulfate (MgSO4) and Sodium Chloride (NaCl) were used, the concentration of acids employed in the present study is 2% and the marine solution is 3.5%. Increase in the proportion of effluent from 0% to 100% decreases the slump value of the concrete. Contrastingly, increasing the proportion of effluent increases the strength of GPC after 28-d of room temperature curing. To examine the performance of the concrete under acidic and marine conditions, average of three concrete specimens were employed and the duration of exposure was considered in the present study starts from 28-d and continues till 360-d. After exposing to acidic environment, mass loss, strength loss and surface modification were examined; the loss in mass was found to be 1.5–3% and the strength loss was found to be 35%–45%. In the case of salt solution exposure, the loss in mass was seen to be 1–2% and whereas in the case of strength, the loss was found to be 30%–42%, respectively. Further, the sustainability aspects of the concrete with industrial effluents were examined in detail; focusing on economic value of the concrete, carbon emission and energy demand during the production of concrete.

Effect of pumping in a coastal aquifer of limited thickness, Buenos Aires, Argentina

In the northern sector of the Partido de La Costa, Argentina, the chemical quality of the groundwater was analyzed in the water supply area of the water utility cooperative. This resource is the only water source for consumption and is extremely vulnerable to contamination, both from the surface and from salinization processes. The impact of pumping was assessed to ensure the sustainable management of the water resources. Deep exploration wells were drilled, a monitoring network was implemented and water samples were obtained for chemical analysis. Continuously recording sensors were installed in the wells and geoelectrical methods were applied (vertical electrical soundings, electrical tomography). A chemical zonation was found at depth with a transition at 6 m. Calcium bicarbonate type water was identified above such a limit (Zone A) and sodium chloride type water below (Zone B), whose anion and cation concentrations exceed the limits set for drinking quality. In the sector where water extraction is most intensive, a deterioration of the chemical quality has been observed as a result of the salinization of the wells by water originating from Zone B. This phenomenon was identified by every method used. Electrical tomography allowed the measurement of the surface area defined by data of the individual wells. A reversal of the conductivity values occurred after the redistribution of the wells, which has been verified by the methods applied. A series of recommendations are offered to service providers for a more efficient management of the resources. The monitoring of the extraction areas is an essential tool to avoid processes of deterioration of the water resource.

Identification of Shallow Groundwater Facies and Flow Patterns in Batang Regency, Central Java, Indonesia

Abstract Population growth as a result of a subsequent increase in the economic center and industrial complex construction has also proven to influence the shallow groundwater occurrence in Batang Regency, Central Java, Indonesia. The region per se, had a minimum amount of observation and literature, especially regarding the issue namely groundwater flow pattern and facies distribution. This research discussed hydrogeological assessment through systematic mapping to investigate shallow groundwater occurrence, including 90 observation & measurement points consisting of 89 dug well and one water spring. Based on purposive random sampling with upstream-downstream consideration, 73 of 90 samples were analyzed in the laboratory to determine groundwater hydrochemistry. The results indicated that the shallow groundwater pattern in Batang Regency generally flows from south to north with a dominant southwest-northeast pattern. Based on the trilinear piper diagram, shallow groundwater facies in the study area are characterized by calcium bicarbonate, alkaline chloride, alkaline bicarbonate, and mixed types. The distribution of calcium bicarbonate facies is widely spread in the southern part of the study area. In contrast, alkaline bicarbonate is mainly found between the coastline and hilly in the south. On the other hand, alkaline chloride is distributed evenly along the coastal area. Intermixing of different groundwater facies is expected due to its positive correlation between TDI and major ions plot in the composition diagram.

Elucidating the role of rice straw biochar in modulating Helianthus annuus L. antioxidants, secondary metabolites and soil post-harvest characteristics in different types of microplastics

The emergence of microplastics (MPs) as pollutants in agricultural soils is increasingly alarming, presenting significant threats to soil ecosystems. Given the widespread contamination of ecosystems by various types of MPs, including polystyrene (PS), polyvinyl chloride (PVC), and polyethylene (PE), it is crucial to understand their effects on agricultural productivity. The present study was conducted to investigate the effects of different types of MPs (PS, PVC, and PE) on various aspects of sunflower (Helianthus annuus L.) growth with the addition of rice straw biochar (RSB). This study aimed to examine plant growth and biomass, photosynthetic pigments and gas exchange characteristics, oxidative stress indicators, and the response of various antioxidants (enzymatic and non-enzymatic) and their specific gene expression, proline metabolism, the AsA–GSH cycle, cellular fractionation in the plants and post-harvest soil properties. The research outcomes indicated that elevated levels of different types of MPs in the soil notably reduced plant growth and biomass, photosynthetic pigments, and gas exchange attributes. Different types of MPs also induced oxidative stress, which caused an increase in various enzymatic and non-enzymatic antioxidant compounds, gene expression and sugar content; notably, a significant increase in proline metabolism, AsA–GSH cycle, and pigmentation of cellular components was also observed. Favorably, the addition of RSB significantly increased plant growth and biomass, gas exchange characteristics, enzymatic and non-enzymatic compounds, and relevant gene expression while decreasing oxidative stress. In addition, RSB amendment decreased proline metabolism and AsA-GSH cycle in H. annuus plants, thereby enhancing cellular fractionation and improving post-harvest soil properties. These results open new avenues for sustainable agriculture practices and show great potential for resolving the urgent issues caused by microplastic contamination in agricultural soils.

Bisphenol A sorption on commercial polyvinyl chloride microplastics: Effects of UV-aging, biofilm colonization and additives on plastic behaviour in the environment.

Chemical additives are important components in commercial microplastics and their leaching behaviour has been widely studied. However, little is known about the potential effect of additives on the adsorption/desorption behaviour of pollutants on microplastics and their subsequent role as vectors for pollutant transport in the environment. In this study, two types of commercial polyvinyl chloride (PVC1 and PVC2) microplastics were aged by UV irradiation and biotic modification via biofilm colonization to investigate the adsorption and desorption behaviour of bisphenol A (BPA). Surface cracks and new functional groups (e.g., O–H) were found on PVC1 after UV irradiation, which increased available adsorption sites and enhanced H‒bonding interaction, resulting in an adsorption capacity increase from 1.28 μg/L to 1.85 μg/L. However, the adsorption and desorption capacity not showed significant changes for PVC2, which might be related to the few characteristic changes after UV aging with the protection of light stabilizers and antioxidants. The adsorption capacity ranged from 1.28 μg/L to 2.06 μg/L for PVC1 and PVC2 microplastics, and increased to 1.62 μg/L—2.95 μg/L after colonization by biofilms. The increased adsorption ability might be related to the N–H functional group, amide groups generated by microorganisms enhancing the affinity for BPA. The opposite effect was observed for desorption. Plasticizers can be metabolized during biofilm formation processes and might play an important role in microorganism colonization. In addition, antioxidants and UV stabilizers might also indirectly influence the colonization of microorganisms’ on microplastics by controlling the degree to which PVC microplastics age under UV. The amount of biomass loading on the microplastics would further alter the adsorption/desorption behaviour of contaminants. This study provides important new insights into the evaluation of the fate of plastic particles in natural environments.

Synthesis of a novel tertiary amine chloride type cationic covalent organic framework at room temperature for rapid removal of Cr(Ⅵ)

Persistent toxic heavy metal Cr(Ⅵ) oxyanions is increasingly damaging to the environment and human life safety. In this study, a novel tertiary amine chloride type cationic covalent organic framework with high yield (>95%) was synthesized using a one-step Schiff base reaction by room temperature standing two functional monomers. The adsorbent was characterized by SEM, EDS, FTIR, NMR, PXRD, BET, TGA and pHPZC. And a series of adsorption experiments were conducted to verify the removal effect for Cr(Ⅵ). It exhibited excellent adsorption performance and the adsorption equilibrium time was within 10 min, superior to most adsorbents. The adsorption conformed to the pseudo-second-order kinetics and the Langmuir adsorption isothermal models based on the values of R2 and RMSE in the corresponding four models. The impact of pH was significant, and the maximum adsorption capacity was 161.4 mg/g at a pH of 2. The adsorbent had good adsorption selectivity for Cr(Ⅵ) oxyanions in the presence of coexisting ions (Cl−, SO42−, NO3−, and PO43−), and good recyclability with only decrease of removal rate from 98.3% to 91.5% after five cycles. The mechanism for Cr(Ⅵ) adsorption was mainly attributed to ion exchange, and hydrogen bonding also played a subordinate role. In the Cr(Ⅵ)-MO binary system, the increase for Cr(VI) adsorption results from the new active sites in methyl orange. This work highlights the mild synthetic conditions, fast adsorption rate, and good adsorption of Cr(Ⅵ), which make it a promising prospect.

Assessment of Groundwater in Erbil Central Basin, N Iraq

The present effort is expected to consider the groundwater quality of the Erbil Central Basin. In this study, we compared the physiochemical properties and distribution of major cations and anions in groundwater to evaluate the quality assessment as a special usage (drinking and irrigation) and identify the sources and types of water quality variation and pollution. The mean richness of major cations are Ca2+ > Mg2+ > Na+ > K+, whereas the major anions are HCO3- > SO42- > NO3- > Cl-. The quality of water was evaluated using SAR, sodium (%), PI, TH, MH, PS, and WQI. When the chemical and physical characteristics were compared to Iraqi and public health standards (IQS) for drinking water, it was discovered that the majority of the wells' groundwater during both periods was within the acceptable range, and suitable for all human drinking and domestic purposes except for three wells exceed the maximum permissible limit of NO3-, which are Newroz, Rizgari, and Birayaty, while HCO3ˉ is showed a maximum in Newroz, and in Rizgari well the total hardness (TH) doesn’t lie within recommended standards. The Ca and Mg- Bicarbonate type was the predominant form for the groundwater classified for both seasons, with only one well (Zanko) being Ca- Chloride type for the dry season. The majority of ionic species originated from alkaline earth metals that originate from interactions between weak acidic anions in groundwater and soil or rock. All samples were suitable for drinking water according to the WQI, only the Zanko well had poor water during the dry season.

Multimodal detection and analysis of microplastics in human thrombi from multiple anatomically distinct sites

Microplastic (MP) pollution has emerged as a significant environmental concern worldwide. While extensive research has focused on their presence in marine organisms and ecosystems, their potential impact on human health, particularly on the circulatory system, remains understudied. This project aimed to identify and quantify the mass concentrations, polymer types, and physical properties of MPs in human thrombi surgically retrieved from both arterial and venous systems at three anatomically distinct sites, namely, cerebral arteries in the brain, coronary arteries in the heart, and deep veins in the lower extremities. Furthermore, this study aimed to investigate the potential association between the levels of MPs and disease severity. Thrombus samples were collected from 30 patients who underwent thrombectomy procedures due to ischaemic stroke (IS), myocardial infarction (MI), or deep vein thrombosis (DVT). Pyrolysis-gas chromatography mass spectrometry (Py-GC/MS) was employed to identify and quantify the mass concentrations of the MPs. Laser direct infrared (LDIR) spectroscopy and scanning electron microscopy (SEM) were used to analyse the physical properties of the MPs. Demographic and clinical information were also examined. A rigorous quality control system was used to eliminate potential environmental contamination. MPs were detected by Py-GC/MS in 80% (24/30) of the thrombi obtained from patients with IS, MI, or DVT, with median concentrations of 61.75μg/g, 141.80μg/g, and 69.62μg/g, respectively. Among the 10 target types of MP polymers, polyamide 66 (PA66), polyvinyl chloride (PVC), and polyethylene (PE) were identified. Further analyses suggested that higher concentrations of MPs may be associated with greater disease severity (adjusted β=7.72, 95% CI: 2.01-13.43, p<0.05). The level of D-dimer in the MP-detected group was significantly higher than that in the MP-undetected group (8.3±1.5μg/L vs 6.6±0.5μg/L, p<0.001). Additionally, LDIR analysis showed that PE was dominant among the 15 types of identified MPs, accounting for 53.6% of all MPs, with a mean diameter of 35.6μm. The shapes of the polymers detected using LDIR and SEM were found to be heterogeneous. This study presents both qualitative and quantitative evidence of the presence of MPs, and their mass concentrations, polymer types, and physical properties in thrombotic diseases through the use of multimodal detection methods. Higher concentrations of MPs may be associated with increased disease severity. Future research with a larger sample size is urgently needed to identify the sources of exposure and validate the observed trends in the study. This study was funded by the SUMC Scientific Research Initiation Grant (SRIG, No. 009-510858038), Postdoctoral Research Initiation Grant (No. 202205230031-3), and the 2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant (No. 2020LKSFG02C).

Chemical properties and single-particle mixing state of soot aerosol in Houston during the TRACER campaign

Abstract. A high-resolution soot particle aerosol mass spectrometer (SP-AMS) was used to selectively measure refractory black carbon (rBC) and its associated coating material using both the ensemble size-resolved mass spectral mode and the event trigger single particle (ETSP) mode in Houston, Texas, in summer 2022. This study was conducted as part of the Department of Energy Atmospheric Radiation Measurement (ARM) program's TRacking Aerosol Convection interactions ExpeRiment (TRACER) field campaign. The study revealed an average (±1σ) rBC concentration of 103 ± 176 ng m−3. Additionally, the coatings on the BC particles were primarily composed of organics (59 %; 219 ± 260 ng m−3) and sulfate (26 %; 94 ± 55 ng m−3). Positive matrix factorization (PMF) analysis of the ensemble mass spectra of BC-containing particles resolved four distinct types of soot aerosol, including an oxidized organic aerosol (OOABC,PMF) factor associated with processed primary organic aerosol, an inorganic sulfate factor (SO4,BC,PMF), an oxidized rBC factor (O-BCPMF), and a mixed mineral dust–biomass burning aerosol factor with significant contribution from potassium (K-BBBC,PMF). Additionally, K-means clustering analysis of the single-particle mass spectra identified eight different clusters, including soot particles enriched in hydrocarbon-like organic aerosol (HOABC,ETSP), sulfate (SO4,BC,ETSP), two types of rBC, OOA (OOABC,ETSP), chloride (ClBC,ETSP), and nitrate (NO3,BC,ETSP). The single-particle measurements demonstrate substantial variation in BC coating thickness with coating-to-rBC mass ratios ranging from 0.1 to 100. The mixing state index (χ), which denotes the degree of homogeneity of the soot aerosol, varied from 4 % to 94 % with a median of 40 %, indicating that the aerosol population lies in between internal and external mixing but has large temporal and source type variability. In addition, a significant fraction of BC-containing particles, a majority enriched with oxidized organics and sulfate, exhibit sufficiently high κ values and diameters conducive to activation as cloud nuclei under atmospherically relevant supersaturation conditions. This finding bears significance in comprehending the aging processes of rBC-containing particles and their activation into cloud droplets. Our analysis highlights the complex nature of soot aerosol and underscores the need to comprehend its variability across different environments for accurate assessment of climate change.

Utilisation of Waste Sludge from Drinking Water Treatment as a Filler Material in Hot Mix Asphalt.

This research investigated the suitability of using sludge from the treatment of drinking water in hot mix asphalt (HMA) as a filler material. The storage and environmental impact of sludge is an enormous problem, especially for countries with large populations. Two different types of sludges, ferric chloride (FC) and aluminium sulphate (AS), were used as a filler material in HMA. The Hamburg Wheel Tracking (HWT) test, which correlates with rutting, and the Indirect Tensile Strength (ITS) test, which indicates the moisture sensitivity of HMA, were carried out at the optimum bitumen content of the mixes to investigate the usability of sludge in HMA. The test results indicate the usability of FC and AS in HMA compared to the reference mixes. However, the AS type of sludge has better rutting resistance than the FC type. Although the results support the usability of both sludges in HMA, it should be noted that the increased cost of the mix containing sludges due to the combustion process and the increased bitumen content during application should be considered.

Influence of microplastics on the availability of antibiotics in soils

Microplastics (MPs) and antibiotics, as two major types of emerging pollutants, inevitably coexist in the soil environment due to agricultural film residue, sewage irrigation and sludge application. However, the impact of MPs on antibiotic availability in soils with varying characteristics has not been extensively studied. Therefore, in this study, an interference experiment was conducted using three types of MPs (polyethylene (PE), polyvinyl chloride (PVC) and polypropylene (PP)) in red soil, paddy soil and cinnamon soil. The available antibiotics in soils were evaluated using diffusive gradients in thin-films (DGT). Results showed that MPs had a significant impact on the amount of antibiotics adsorbed on soil solid (Cs) by providing additional binding sites or altering soil characteristics (e.g., pH and dissolved organic carbon). The most significant effects on Cs were observed in cinnamon soil, and the Cs values were dependent on concentration of MPs. The available antibiotics, as measured by DGT significantly decreased after the addition of MPs. This decrease was influenced by the soil characteristics. However, the concentration of antibiotics in soil solutions (Cd) was only slightly impacted by MPs. Therefore, the influence of MPs on the migration of antibiotics was reflected by their impact on the soil/water partition coefficient (Kd), while the resupply ability (R) from the soil solid phase was less influential. Moreover, the dosage of MPs had a significant effect on the availability of antibiotics in CS by promoting the adsorption of antibiotics on the solid phase, while in RS and PS, the soil properties played a dominate role in the changes in antibiotic availability after MP addition. These results indicate that the impact of MPs on available antibiotics mainly depends on soil properties. In addition, DGT measurement is more sensitive than soil solution to investigate the effects of coexisting pollutants on the behavior of antibiotics in soil.

Groundwater quality assessment using water quality index and principal component analysis in the Achnera block, Agra district, Uttar Pradesh, Northern India

The qualitative and quantitative assessment of groundwater is one of the important aspects for determining the suitability of potable water. Therefore, the present study has been performed to evaluate the groundwater quality for Achhnera block in the city of Taj, Agra, India, where groundwater is an important water resource. The groundwater samples, 50 in number were collected and analyzed for major ions along with some important trace element. This study has further investigated for the applicability of groundwater quality index (GWQI), and the principal component analysis (PCA) to mark out the major geochemical solutes responsible for origin and release of geochemical solutes into the groundwater. The results confirm that, majority of the collected groundwater samples were alkaline in nature. The variation of concentration of anions in collected groundwater samples were varied in the sequence as, HCO3− > Cl− > SO42− > F− while in contrast the sequence of cations in the groundwater as Na > Ca > Mg > K. The Piper diagram demonstrated the major hydro chemical facies which were found in groundwater (sodium bicarbonate or calcium chloride type). The plot of Schoellar diagram reconfirmed that the major cations were Na+ and Ca2+ ions, while in contrast; major anions were bicarbonates and chloride. The results showed water quality index mostly ranged between 105 and 185, hence, the study area fell in the category of unsuitable for drinking purpose category. The PCA showed pH, Na+, Ca2+, HCO3− and fluoride with strong loading, which pointed out geogenic source of fluoride contamination. Therefore, it was inferred that the groundwater of the contaminated areas must be treated and made potable before consumption. The outcomes of the present study will be helpful for the regulatory boards and policymaker for defining the actual impact and remediation goal.

Investigating the serve life of common earthed materials based on evaluations of the soil corrosion in offshore areas of East China

The serve life of common earthed materials in power systems is essentially affected by the soil environment, especially the potential corrosion problem of sodium chloride contaminated soil in offshore areas. This study measured the corrosion rates of three common earthed metal materials, Q235 carbon steel, pure Al, and H62 brass, in typical chloride saline soil using accelerated and field corrosion tests. The acceleration ratio and kinetic correlation coefficient under different acceleration conditions were calculated, and the laboratory and field corrosion time correlation models of common earthed metal materials were obtained. The results show a good correlation between soil accelerated and field corrosion tests. Under the same temperature and salinity, the correlation degree of Q235 carbon steel is larger when the water content is 30%. In comparison, the correlation degree of pure Al and H62 brass is larger when the water content is 20%. The laboratory and field corrosion time correlation models of Q235 carbon steel, pure Al, and H62 brass in chloride type saline soil environment are T1=18.32T0, T1=95.56T0, T1=15.78T0, which can effectively evaluate the serve life of common earthed metal materials in typical chloride type saline soil in the offshore area of East China.

Experimental study on combustion characteristics of billboard materials

Billboards are permanent facilities in large commercial buildings, indoor and outdoor public places, and in fire accidents, billboards will become the main cause of the expansion and spread of fires. To reduce the fire accidents caused by the burning of billboards, this paper conducted experimental tests on 12 commonly used billboard material types of Polyethylene glycol terephthalate (PET) and Polyvinyl chloride (PVC). Among the 12 materials, only PVC4 belongs to the range of flame-retardant materials. PVC6 has the lowest calorific value, less heat release, and a stronger fire effect than other materials. The flammability experiment shows that the ignition time of the material is positively correlated with the combustion height under the same ignition method, and the ignition time is also positively correlated with the combustion width. Under the same ignition time conditions, the flame aspect ratio using edge ignition is greater than or equal to the flame aspect ratio using surface ignition, and the fire hazard is greater. It is necessary to avoid the presence of combustibles around 250 mm to cause fire spread. The monomer combustion experiment shows that the flame spread area of PVC material is much larger than that of PET material. Among all materials, the most dangerous is PVC6, which releases the largest CO concentration and the fastest rate after combustion, produces the most flue gas within 100 after combustion and has poor flame-retardant performance. The combustion of all advertising materials releases less CO and CO2 concentration, which can cause physiological adverse reactions in the human body but will not cause death.