S1 Site Research Articles

Assessing the Efficiency of Phragmites australis in Wastewater Treatment as a Natural Approach to Water Quality Improvement

The Oued Zénati, a vital waterway in Algeria, faces severe pollution from urban discharges, hospital wastewater, and agricultural activities, threatening both the ecosystem and public health. This pollution is characterized by high nutrient levels, suspended solids, and fecal contamination indicators, jeopardizing biodiversity and human well-being. To explore natural restoration solutions, this study assessed the purification potential of reeds (Phragmites australis) found in the Oued Zénati riverbed. Water quality was analyzed at three sites: a non-polluted control site (S1), a wastewater discharge area (S2), and a reed-dense area (S3). Results revealed a significant deterioration in water quality at site S2, with high concentrations of nutrients, suspended solids (SS), and fecal contamination indicators. However, a notable improvement in water quality was observed at site S3, downstream of the reed-dense area, with reductions in fecal coliforms (68.5%), fecal streptococci (92.3%), and phosphates (40.3%), and increased levels of dissolved oxygen (DO). These findings suggest that phytoremediation using P. australis could offer a cost-effective, sustainable, and eco-friendly solution for restoring the Oued Zénati. This study recommends establishing phragmifiltration stations, developing artificial wetlands, and enhancing sanitation systems, including hospital wastewater treatment. Public awareness campaigns promoting water and environmental protection are crucial for long-term success. This phytoremediation approach offers economic, ecological, and aesthetic advantages over conventional wastewater treatment techniques.

Spatio-temporal pollution assessment of Kulfo River using CCME-WQI and pollution tolerance index by benthic macroinvertebrates, Arba Minch, Ethiopia.

In developing nations, the biggest threat to public health is the quality of the water. The Kulfo River provides the majority demand of the domestic water and irrigation along its course; however, it is observed that wastes from anthropogenic and natural activities enter the river. Therefore, this study aimed to examine the pollution status by integrating conventional methods with benthic macroinvertebrates. One hundred twenty samples were collected for 15 water quality parameters from five sampling sites during dry and rainy events. The mean concentration of DO, TSS, BOD5, COD, ortho-phosphate, and turbidity did not meet the standard limits in five sampling sites during the rainy season. Benthic macroinvertebrates were collected from the left, middle, and right sides of the river for each sampling site and examined using the Benthos Biomonitoring Protocol Network Manual. CCME index and PTI index of benthic macroinvertebrates were used to examine the pollution status of the river. According to CCME index result, S2 (39.79), S3 (38.90), and S4 (37.71) are classified under poor pollution status during the rainy season and S1 (92.13) and S5 (95.70) are categorized as good and excellent pollution status in the dry season, respectively. On the contrary, based on the PTI index result, S2 (7.0), S3 (9.0), S4 (9.0), and S5 (9.0) are classified under poor pollution status during the rainy season, whereas S2 (14.0), S3 (10.0), and S4 (15.0) are categorized under fair, and sampling sites S1 (21.0) and S5 (20.0) have good pollution status in the dry season. Based on study findings, the Kulfo River is contaminated by pollutant intrusion, resulting in a decrease in its quality. Therefore, management of solid, liquid, runoff, and domestic activities is critical in upstream tributaries and Arba Minch town to prevent river water quality deterioration.

River health assessment based on set pair analysis model in typical Northern Chinese City

Rivers are critical to ecological and societal sustainability, yet human activities like urbanization, industrialization, and agricultural runoff increasingly threaten their ecological health. This study investigates the ecological health of six major rivers in Dalian City, China, focusing on the relationships between aquatic biological communities and environmental factors. A total of 168 phytoplankton species, 110 zooplankton species, and 102 macrozoobenthos species were identified. The key environmental factors influencing these communities included pH, dissolved oxygen, ammonium nitrogen, total phosphorus, and altitude. Using an entropy-weighted set pair analysis model, spatial variations in river ecosystem health were evaluated. Monitoring sites S12 and S15 exhibited good health conditions, while sites S4, S8, and S17 were rated as poor (Grade IV), and S7 was severely polluted (Grade V). Other sites showed borderline health (Grade III). This research provides valuable insights for improving river ecosystem management and biodiversity conservation in Dalian City, offering a scientific basis for addressing water quality and ecological challenges.

Holistic analysis of Ganga basin water quality: a statistical approach with WQI, HMCI, HMQI and HRI indices.

The Ganga river, one of the largest and most culturally significant rivers in India, supports millions of people living along its banks. However, extensive use and untreated wastewater discharge have led to significant contamination. This study utilizes land use and land cover (LULC) analysis, along with regular water sampling from 2021 to 2222, to assess variations in physical, chemical, and biological characteristics and evaluate health risks posed by heavy metals across eight monitoring sites in the Ganga and Yamuna rivers, Prayagraj, India. Results were compared with drinking water standards established by the Bureau of Indian Standards (BIS) and the World Health Organization (WHO). The Water Quality Index (WQI) indicated substantial water quality degradation at sites S2 (Ganga) and S8 (Yamuna). Although heavy metal levels (Cu, Fe, Cd, Pb, Mn, Cr) fluctuated across sites, Pb and Cd frequently exceeded permissible limits. Health Risk Assessment (HRI) findings pointed to potential health risks at sites S4 (Ganga) and S8 (Yamuna) due to elevated Pb and Cd levels. The Heavy Metal Contamination Index (HMCI) ranged from 733.78 to 981.33, classifying all samples as highly polluted, with Heavy Metal Quality Index (HMQI) values also indicating high risk, especially at sites S4 and S8. Further analysis using principal component analysis (PCA) and cluster analysis highlighted correlations among water quality parameters, while Pearson's correlation matrix and heat maps indicated positive relationships for DO, pH, alkalinity, and SO4, with most heavy metals (except Zn and Mg) showing strong inter-correlations. These findings underline the urgent need for pollution control measures to safeguard public health in the region.

Nutrient cycling characteristics along a chronosequence of forest primary succession in the Hailuogou Glacier retreat area, eastern Tibetan Plateau.

The Hailuogou Glacier has been continuously retreating since the end of the Little Ice Age, resulting in a 125-year soil chronosequence and a complete primary forest succession sequence. Nutrient cycling and utilization are the foundation to forest succession processes and dynamic changes, directly influencing the structure and stability of ecosystems. However, our understandings on the characteristics of ecosystem nutrient accumulation and recycling during succession, especially in the context of primary succession within glacier retreat areas, remain limited. To address this, we investigated nutrient characteristics across six forest primary succession sites in the Hailuogou Glacier retreat area. Six sites representing three forest stages: the pioneer plant stage (S1), the broad-leaved forest stage (S2-S4), and the coniferous forest stage (S5-S6). Three quadrats were established at each site, and measurements of biomass as well as soil characteristics were documented within each quadrat. Subsequently, we collected samples of vegetation, soil and litter. By measuring the concentrations of N, P, K, Ca, and Mg in vegetation and soil and combining with the data of the quadrat survey, the pools and nutrient characteristics of N, P, K, Ca, and Mg in various components of the ecosystem were calculated at each site. Our findings indicated that: (1) Nutrient pools, excluding the soil C layer, increased with forest primary succession, reaching 5,995.71 kg hm-2 N, 461.83 kg hm-2 P, 3,798.09 kg hm-2 K, 7,559.81 kg hm-2 Ca and 1,948.13 kg hm-2 Mg at site S6; however, the pools of P, K, and Mg in the Oa layer, and Ca and Mg in the tree layer, attained their peak levels at sites S3 to S4. (2) The pools of N, Ca, and Mg in the organic soil were significantly greater than vegetation. Although over 60% of the P and K were stored in the organic soil at site S1, these proportions shifted, with vegetation holding 60.71% of P and 56.86% of K at site S5. (3) Broad-leaved forests exhibited higher nutrient return, cycling, and absorption, thereby accelerating nutrient circulation and depleting soil nutrients to maintain growth. In contrast, coniferous forests were more efficient at nutrient utilization and storage, retaining nutrients and maintaining high biomass and productivity in nutrient-poor environments. Overall, these findings highlighted that the nutrients in each component of the ecosystem continue to accumulate with forest primary succession. Coniferous forests' nutrient cycling mechanisms offer a competitive edge in nutrient-poor environments, enhancing ecosystem stability.

Microbiological and physicochemical water quality assessments of the Upper Basin Litany River, Lebanon.

The Litany River has encountered severe environmental pollution. This study focused on assessing the pollution level in the upper basin of the Litany River by monitoring seasonal variation of water quality and testing physicochemical parameters and microbial qualities. A total of 72 freshwater samples were taken from six sites for 1 year during the four seasons. The microbiological parameters included total coliform, fecal coliform, and Escherichia coli counts. The physicochemical parameters comprised pH, total dissolved solids, nitrate, sodium, potassium, biochemical oxygen demand, chemical oxygen demand, total nitrogen, and total phosphorus. The microbiological quality of samples was evaluated by comparing the fecal pollution indicators loads to the SEQ-EAUX2003 standard for irrigation, and the physicochemical analyses were assessed according to Lebanese Standards Institution (LIBNOR) NL161: 2016 and the World Health Organization (WHO) Guidelines for Water Quality. The results revealed that most physicochemical parameters are not within the permitted limit of LIBNOR and WHO, especially in sites S2, S3, and S6 during the dry seasons. The pH ranged between 6 and 8.16. The total dissolved solids reached 1948 mg/L. The nitrate, sodium, and potassium ranged between 0 and 253 mg/L. The total nitrogen and total phosphorous reached 103 and 5.16 mg/L, respectively. The chemical oxygen demand reached 2210 mg/L, and the biochemical oxygen demand reached 732 mg/L. Concerning the microbiological analysis, fecal pollution was detected in all sites during all seasons, with detectable higher values during the dry seasons, and all samples were considered to be non-conforming, with significant spatiotemporal variation of most parameters. Our results highlight the need to take measures to prevent the high level of pollution. This could be achieved by monthly water quality monitoring of the upper basin and introducing appropriate guidelines to detect pathogens and toxic chemicals that affect the entire ecosystem and lead to severe public health issues.

Discovery of orally bioavailable SARS-CoV-2 papain-like protease inhibitor as a potential treatment for COVID-19

The RNA-dependent RNA polymerase (RdRp), 3C-like protease (3CLpro), and papain-like protease (PLpro) are pivotal components in the viral life cycle of SARS-CoV-2, presenting as promising therapeutic targets. Currently, all FDA-approved antiviral drugs against SARS-CoV-2 are RdRp or 3CLpro inhibitors. However, the mutations causing drug resistance have been observed in RdRp and 3CLpro from SARS-CoV-2, which makes it necessary to develop antivirals with novel mechanisms. Through the application of a structure-based drug design (SBDD) approach, we discover a series of novel potent non-covalent PLpro inhibitors with remarkable in vitro potency and in vivo PK properties. The co-crystal structures of PLpro with lead compounds reveal that the residues D164 and Q269 around the S2 site are critical for improving the inhibitor’s potency. The lead compound GZNL-P36 not only inhibits SARS-CoV-2 and its variants at the cellular level with EC50 ranging from 58.2 nM to 306.2 nM, but also inhibits HCoV-NL63 and HCoV-229E with EC50 of 81.6 nM and 2.66 μM, respectively. Oral administration of the GZNL-P36 results in significantly improved survival and notable reductions in lung viral loads and lesions in SARS-CoV-2 infection mouse model, consistent with RNA-seq data analysis. Our results indicate that PLpro inhibitors represent a promising SARS-CoV-2 therapy.

Atomic catalysis meets heterostructure synergy: Unveiling the trifunctional efficacy of transition Metal@WS2/ReSe2

Integrating and advancing renewable energy storage and conversion technologies such as water splitting and rechargeable air-based batteries face significant challenges in finding appropriate catalysts that offer both high activity and low cost. This paper successfully designed efficient, cost-effective, and eco-friendly catalysts that meet the requirements for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) catalytic activity by employing two-dimensional (2D) transition metal dichalcogenides (TMDs) interface engineering combined with a single-atom doping strategy. First, the heterostructure was constructed, and its optimal layer spacing (3.13 Å) was determined by calculating the most negative binding energy. These materials were theoretically evaluated using density functional theory (DFT), demonstrating that transition metal (TM) can all be firmly attached to the S1 site of the WS2/ReSe2 Z-scheme heterostructure with favorable binding energies and excellent electronic properties. By comparing the catalysts doped with different metals (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn), the three functional catalysts with the best performance were finally selected: Mn@WS2/ReSe2, Ni@WS2/ReSe2, and Cu@WS2/ReSe2. In particular, Mn@WS2/ReSe2 exhibited exceptional promise as multifunctional catalysts, with overpotentials for the HER/OER/ORR of 0.05/0.29/0.35 V, respectively. The superior catalytic performance of this WS2/ReSe2 Z-scheme heterostructure was attributed to the introduction of TM atoms and the synergistic interaction between rhenium and the TM atoms. This interaction facilitated more efficient electron transfer between the catalyst and the reactants, enhancing the overall catalytic activity. This research is a successful attempt to combine interface engineering with single-atom catalysis (SACs). It provided valuable insights into the design of next-generation multifunctional electrocatalysts, offering a novel approach to address the growing energy demands in an environmentally benign and economically viable way.

Li10GeP2S12-xSex solid solution as a new Li+ solid-state electrolyte

A new type electrolyte Li10GeP2S12-xSex (LGPSS, 0 < x ≤ 7) was designed and synthesized by solid-state reaction method. The cell parameters a and c of Li10GeP2S12-xSex (0 ≤ x ≤ 7) increase from 8.7295(8) to 8.995(2) Å and 12.675(1) to 13.102(3)Å with x increasing from 0 to 7, respectively. S2 site is mainly occupied by Se, while the secondly occupied is S3 site. Li1 is occupied by Li completely and embedded in framework, while other Li sites are all partially occupied and involved in conducting. The occupancy of Li2, Li3, Li4 site are 0.71, 0.70 and 0.47, respectively, when x = 4. Li2 has lowest energy, and Li2 site are preferred to be the destination of Li+ migration pathway. Substitution of S is proved to be selective and there is a priority for Se to bind with Ge. The maximum conductivity 4.98 mS/cm is obtained by Li10GeP2S8Se4 at 25 °C, which is about three times higher than that of Li10GeP2S12 (LGPS). The activation energy (Ea) and electrochemical window of Li10GeP2S8Se4 are 0.23 eV and 0–3 V. Li+ migration mechanism is calculated using bond valency theory, the migration of Li + presents 1D pathway has maximum barrier of 0.233 eV and 3D pathway barrier is 0.392 eV Li10GeP2S8Se4 has favorable stability that there is no breakdown occurring under 0.72 mA/cm2 current density.

Characterization of AhR-mediated potency in sediments from Kongsfjorden, Svalbard: Application of effect-directed analysis and nontarget screening

In this study, we aimed to identify the major aryl hydrocarbon receptor (AhR) agonists in surface sediments (S1–S10, n = 10) from Kongsfjorden, Arctic Svalbard, using effect-directed analysis. High AhR-mediated potencies were observed in the mid-polar fractions and RP-HPLC subfractions (F2.6–F2.8; log KOW 5–8) in the sediments of sites S2 and S3, which are located near abandoned coal mine areas, as assessed by the H4IIE-luc bioassay. The concentrations of traditional polycyclic aromatic hydrocarbon (t-PAHs), emerging PAHs, alkyl-PAHs, and styrene oligomers ranged from 6.1 to 2100 ng g−1 dry weight (dw), 0.5–1000 ng g−1 dw, 47 to 79,000 ng g−1 dw, and 4.2–130 ng g−1 dw, respectively, with elevated levels in S2 and S3. Principal component analysis coupled with multiple linear regression suggested that t-PAHs in sediments primarily originated from coal, petroleum combustion, and coal combustion. Twenty-four target AhR agonists accounted for 3.2%–100% (mean = 47%) of the total AhR-mediated potencies in S2 and S3. Nontarget screening via GC-QTOFMS in the highly potent fractions identified 48 AhR agonist candidates through four-step selection criteria. Among these, 27 compounds were identified as coal-derived substances. VirtualToxLab in silico modeling predicted that most of the 48 tentative AhR agonist candidates could bind to AhR. Overall, our findings indicate significant contamination of the Kongsfjorden sediments by coal-derived substances, highlighting the need for further studies to assess the ecological risks associated with these contaminants.

Evaluation of stormwater runoff pollutant distributions combined with land-use information in a regional karst aquifer in Texas, USA.

Fast urbanization can result in significant stormwater runoff pollution due to changes in land use. A 3-year study on the distribution and temporal variations of urban water pollutants in stormwater runoff was conducted, with a specific focus on the influence of land-use patterns in the recharge zone of a regional karst aquifer in Texas (Edwards Aquifer). The presence and concentration of various water pollutants including total suspended solids (TSS), total dissolved solids (TDS), nutrients (nitrite, nitrate, ammonia and phosphate), total carbon (TC) and total organic carbon (TOC), oil and grease (O&G), and eight heavy metals (Fe, Mg, Cu, Pb, Zn, Ni, Cr, Cd) were measured in stormwater samples collected from three bioswales. Results show that average TSS in site S1 (598.87mg/L) and S2 (628.69mg/L), COD in site S1 (103.97mg/L), phosphate in sites S1 (1.44mg/L) and S3 (0.65mg/L), and O&G (ranging from 50.63 to 84.32mg/L) in all three sites surpassed the national average (NSQD). While residential areas were identified as the main sources of nutrients, roads and parking lots were associated with heavy metals. Temporal variations indicated the effect of antecedent dry days on the concentrations of TSS and phosphate. Growing seasons as well as pet feces were associated with elevated nitrate concentrations in residential areas. Organic carbon was found overall higher during warmer months, while heavy metals during cooler months. The study also identified specific land-use practices that can be enhanced to mitigate stormwater pollution, such as the implementation of permeable pavements, rain gardens, and stricter waste disposal regulations. The results of this study offer valuable insights for enhancing stormwater management strategies to better mitigate stormwater pollution in urban regions.

Puerarin alleviates symptoms of preeclampsia through the repression of trophoblast ferroptosis via the CREB/HO-1 pathway

IntroductionPreeclampsia (PE) is a pregnancy-associated complication characterised by new-onset hypertension and proteinuria. This study explored the therapeutic potential of puerarin (Pue) in PE and investigated the underlying mechanism, with a focus on placental ferroptosis. MethodsUsing an NG-nitro-L-arginine methyl ester (L-NAME)-induced PE mouse model, we assessed the effects of Pue on PE phenotypes and placental ferroptosis. Antioxidative and anti-ferroptotic effects of Pue were studied in three ferroptotic cell models (hypoxia/reperfusion, cobalt chloride, and erastin). The regulation of Pue on cAMP response element binding protein (CREB) and heme oxygenase-1 (HO-1) was evaluated through gain- and loss-of-function assays. Luciferase assays were used to elucidate the effect of Flag-CREB on Hmox1 promoter fragments. CREB/HO-1 modulation by Pue was validated in mouse placentas with PE. ResultsPue significantly alleviated maternal hypertension, proteinuria, fetal growth restriction, and placental damage in PE mice. This was associated with an upregulation of the anti-ferroptosis system (glutathione peroxidase 4 [GPX4], cys2/glutamate antiporter [SLC7A11], and glutathione [GSH]) and repression of reactive oxygen species (ROS) and malondialdehyde (MDA) in trophoblasts. Pue reduced HO-1 and CREB, and HO-1 deficiency upregulated GPX4 and SLC7A11. Manipulation of CREB expression led to changes in HO-1/GPX4; whereas, the regulation reversed by Pue administration. Flag-CREB enhanced luciferase activity on the full length Hmox1 promoter (−2000/+78), which contains three CREB1 binding sites (S1–S3). In contrast, no increase in luciferase activity was observed with promoter fragments (−850/+78) and (−550/+78), which contain only the CREB1 binding sites S2 and S3, respectively. DiscussionPue ameliorated PE-like symptoms in mice by repressing trophoblast ferroptosis via inhibition of CREB signalling and affecting the Homx1 promoter.

Assessment of Ecological Hazards in the Inaouen Wadi and Its Tributaries Using the Presence of Potentially Toxic Elements in Its Sediments

Inaouen wadi is the second largest tributary of the Sebou river, one of Morocco’s major rivers, which holds significant economic and social importance. Unfortunately, this watercourse is severely impacted by pollution from various human activities, particularly industrial sources. However, available data on the presence of potentially toxic elements (PTEs) that could harm human health in this region remain limited. PTEs pose major environmental risks due to their toxicity, persistence, and bioaccumulation. This study aimed to assess the concentrations of PTEs in the sediments of Inaouen wadi and its main tributaries based on sediment samples collected from 12 locations in 2019. The concentrations of Cd, Pb, Cr, Ag, Al, Cu, Fe, and Zn were measured using inductively coupled plasma atomic emission spectroscopy (ICP–AES), and sediment contamination levels were evaluated using multiple indices: the enrichment factor (EF), the geo-accumulation index (Igeo), the potential ecological hazard index (RI), and the modified ecological risk index (MRI). The results indicate that concentrations of Pb, Cd, Cr, Cu, Fe, and Zn are significantly influenced by urban discharges, particularly at sites S1, S3, and S5 near the cities of Taza and Oued-Amlil. The maximum values recorded were 7.01 g/kg for Pb, 0.9 g/kg for Cd, 0.1 g/kg for Cr, 19.9 g/kg for Fe and 1.9 g/kg for Zn. The enrichment factor (EF) revealed anthropogenic sources of Fe and Pb, confirming the human origin of these elements. The geo-accumulation index (Igeo) showed that the areas around stations S1, S3, and S5 are highly contaminated by Pb, Cd, and Fe, a finding also supported by the MRI. The study identified potential ecological risks at stations S1, S3, and S5, highlighting the urgent need for improved pollution management practices to mitigate environmental risks.

Structural bases for blockade and activation of BK channels by Ba2+ ions.

We studied the impact of Ba2+ ions on the function and structure of large conductance potassium (BK) channels. Ion composition has played a crucial role in the physiological studies of BK channels due to their ability to couple ion composition and membrane voltage signaling. Unlike Ca2+, which activates BK channels through all Regulator of K + Conductance (RCK) domains, Ba2+ has been described as specifically interacting with the RCK2 domain. It has been shown that Ba2+ also blocks potassium permeation by binding to the channel's selectivity filter. The Cryo-EM structure of the Aplysia BK channel in the presence of high concentration Ba2+ here presented (PDBID: 7RJT) revealed that Ba2+ occupies the K+ S3 site in the selectivity filter. Densities attributed to K+ ions were observed at sites S2 and S4. Ba2+ ions were also found bound to the high-affinity Ca2+ binding sites RCK1 and RCK2, which agrees with functional work suggesting that the Ba2+ increases open probability through the Ca2+ bowl site (RCK2). A comparative analysis with a second structure here presented (PDBID: 7RK6), obtained without additional Ba2+, shows localized changes between the RCK1 and RCK2 domains, suggestive of coordinated dynamics between the RCK ion binding sites with possible relevance for the activation/blockade of the channel. The observed densities attributed to Ba2+ at RCK1 and RCK2 sites and the selectivity filter contribute to a deeper understanding of the structural basis for Ba2+'s dual role in BK channel modulation, adding to the existing knowledge in this field.

Distribution Characteristics of Nitrogen-Cycling Microorganisms in Deep-Sea Surface Sediments of Western South China Sea.

Nitrogen-cycling processes in the deep sea remain understudied. This study investigates the distribution of nitrogen-cycling microbial communities in the deep-sea surface sediments of the western South China Sea, using metagenomic sequencing and real-time fluorescent quantitative PCR techniques to analyze their composition and abundance, and the effects of 11 environmental parameters, including NH4+-N, NO3--N, NO2--N, PO43--P, total nitrogen (TN), total organic carbon (TOC), C/N ratio, pH, electrical conductivity (EC), SO42-, and Cl-. The phylum- and species-level microbial community compositions show that five sites can be grouped as a major cluster, with sites S1 and S9 forming a sub-cluster, and sites S13, S19, and S26 forming the other; whereas sites S3 and S5 constitute a separate cluster. This is also evident for nitrogen-cycling functional genes, where their abundance is influenced by distinct environmental conditions, including water depths (shallower at sites S1 and S9 against deeper at sites S13, S19, and S26) and unique geological features (sites S3 and S5), whereas the vertical distribution of nitrogen-cycling gene abundance generally shows a decreasing trend against sediment depth. Redundancy analysis (RDA) exploring the correlation between the 11 environmental parameters and microbial communities revealed that the NO2--N, C/N ratio, and TN significantly affect microbial community composition (p < 0.05). This study assesses the survival strategies of microorganisms within deep-sea surface sediments and their role in the marine nitrogen cycle.

Assessing Heavy Metal Accumulation in Urban Plants: Implications for Environmental Health and Traffic-Related Pollution in Al-Diwaniyah City, Iraq

This study aimed to compare the ability of five plant species, including (Conocarpus erectus, Acacia sensu lato (s.l.), Melaleuca viminalis, Dodonaea viscosa and Lantana camara) to absorb and accumulate heavy elements in their tissues, which were grown in the central islands in the city of Diwaniyah. This included areas of street in front of the medical college, Umm Al Khail First Street, Umm Al-Khail Street, near Abbas Attiwi Bridge, Al-Adly Street in the Euphrates District, and Clock Field Street, respectively. Results showed that soil samples S1 and S3 were contaminated by Pb, and the rest of the sites were contaminated with nickel only. This indicates through the table findings a rise in these heavy metals’ concentrations with a rise in traffic momentum. Thus, the Pb concentrations in the growing plants’ shoot parts with respect to this research had surpassed the allowed critical limit of 5.00 mg.kg-1 dry matter, in which the highest value was recorded at the site with respect to S3 as well as S2. Meanwhile, the findings indicate that Cd concentrations in S3 and S1 had increased and exceeded the allowable limit of 0.20 mg.kg-1 dry matter. In the meantime, the nickel concentrations were within the permissible limits of 67.90 mg.kg-1 dry matter. The Zn concentration exceeded the permitted limits of 60.00 mg.kg-1 dry matter except for plants (Acacia s.l. and Lantana camara) in sites S5 and S2. The results confirmed that the values of Heavy Metals Bioaccumulation Coefficient (BAC) for most of the study elements had recorded the highest value in the Dodonaea plant for Zn, Cd, and Pb, except for Ni. It was more accumulated in the Melaleuca viminalis plant, which indicates the superiority of the Dodonaea plant in accumulating Pb, Cd, and Zn over the rest of the study plants, as they took the following order: Lantana camara &lt; Acacia s.l. &lt; Conocarpus erectus &lt; Melaleuca viminalis &lt; Dodonaea viscosa. The best plants accumulated nickel in the following order: Acacia s.l. &lt; Lantana camara &lt; Conocarpus erectus &lt; Dodonaea viscosa &lt; Melaleuca viminalis.

Elemental Profiling with Reference to Metal Index to Study Pollutant Load in Northern River of India

Present light was to determine elemental load in Sirsa river ecosystem to know the concentration of toxicants in this Sutlej river’s tributary that act as a gutter for industrial effluents of Baddi region. The inductively coupled plasma mass spectroscopy was used to detect concentration of elements in the department of biochemical engineering and biotechnology at IIT Delhi and the collected data was further analyzed statistically using one way ANOVA at (p≤0.05) followed by post hoc Duncan’s test to predict degree of variations and comparative profile in Table 1. The application of metal index was also performed to estimate water quality and co-related it with health hazards. Variations in concentration of elements was reported near common effluent treatment plant on pollutant Nallah (S2) in deceasing order read as Mg&gt;Na&gt;Ca&gt;B&gt;Zn&gt;Cu&gt;Mn&gt;Fe&gt;Mo&gt;Al&gt;Tl&gt;Se in ppb. The concentration of elements reported at S1, S2, S3 were within permissible limit of WHO and Bureau of Indian Standards, except the value of Boron, Magnesium and Thallium were exceeded these guidelines constantly at site S2 of study area.The metal index values at S1, S2 and S3 were 1.55, 5.80 and 2.57 respectively. The site S2 was affected strongly due to presence of elemental dust and un-treated waste water discharged by chemical industrial units of Baddi region. This site (S2) was nearer to common effluent treatment plant on the bank of Sirsa river and found to be unsuitable at all with more value of metal index. It was also viewed to adopt such scale indices to estimate drinking water quality with respect to concentration of elements after equal interval of time; as there may be seasonal change in the load of debris due to rate of pollutants dumping in the riverine ecosystem which is directly proportional to the content of elements. The load of pollutants in water system was underlined to know the impact of inorganic waste discharges on water quality of river in this region of Himachal Pradesh along industrial belt.

Revealing the Protective Dynamics of an Ecologically Engineered Wetland against Acid Mine Drainage: A Case Study in South Africa

This study investigated the Zaalklapspruit valley bottom wetland in South Africa, an ecologically engineered site influenced by acid mine drainage (AMD) from a defunct coal mine upstream. Conducted in 2022, the research aimed to elucidate the dynamics of contaminant dispersal within this wetland, focusing on the sources, pathways, and receptors of metals and sulfur compounds. The analysis revealed that the wetland’s bottom sediment is rich in organic material, with pH values ranging from 6.05 to 6.59 and low oxidation-reduction potentials reaching −219.67 mV at Site S3. The significant findings included the highest adsorption rates of manganese, contrasted with iron, which was primarily absorbed by the roots of Typha capensis and the algae Klebsormidium acidophilum. The macrophyte rhizospheres were found to host diverse microbiota, including families such as Helicobacteraceae and Hydrogenophilaceae, pivotal in metal and sulfur processing. This study highlighted the complex biogeochemical interactions involving sediment, macrophyte root systems, periphyton, and microbial populations. These interactions demonstrate the efficacy of ecologically engineered wetlands in mitigating the impacts of acid mine drainage, underscoring their potential for environmental remediation. Importantly, the sustainability of such interventions highlights the need for community involvement and acceptance, acknowledging that local support is essential for the long-term success of ecological engineering solutions that address environmental challenges like AMD.

Impact assessment of solid waste dumping sites on soil and groundwater quality in Haridwar district, Uttarakhand, India

The present work aimed to evaluate the effects of municipal solid waste (MSW) dumping on the quality of soil and groundwater at six specific sites (S1-S6) located in the Haridwar district of Uttarakhand, India. An analysis of selected physicochemical and heavy metal characteristics (Cu, Zn, Fe, Mn, Cd, and Cr) was conducted on groundwater and soil samples collected between July 2022 and June 2023 using standard techniques. Furthermore, the composition of municipal solid waste (MSW) was also analysed, revealing a significant proportion of biodegradable waste in comparison to non-biodegradable wastes. The areas affected by urban and industrial activity showed markedly higher concentrations of physicochemical and heavy metal parameters in both soil and groundwater samples (p &lt; 0.05). An study of groundwater revealed concentrations from BDL to 0.170 ± 0.008 mg/L (S6) , 0.034 ± 0.004 mg/L (S4) to 1.565 ± 0.048 mg/L (S6), 1.786 ± 0.089 mg/L (S4) to 10.630 ± 0.279 mg/L (S6), 0.096 ± 0.006 mg/L (S4) to 0.321 ± 0.005 mg/L (S6), and 0.110 ± 0.005 mg/L (S6) for Cu, Zn, Fe, Mn, and Cd mg/kg , respectively. Cr was detected at the BDL level in all groundwater samples from all sites. Findings revealed that metals exceeded the BIS range, with Iron over the limit at all sites, Manganese at S1, S2, and S6 sites, and Cadmium at S1, S2, S3, and S6 sites. The examination of the soil samples revealed concentrations ranging from 0.399 ± 0.125 mg/kg (S5) to 2.806 ± 0.083 mg/kg (S6), 1.207 ± 0.044 mg/kg (S5) to 3.813 ± 0.238 mg/kg (S2), 24.972 ± 1.128 mg/kg (S5) to 47.417 ± 1.713 mg/kg (S3), 2.297 ± 0.43 mg/kg (S5) to 14.641 ± 0.229 mg/kg (S2), and BDL (S4, S5, and S6) to 0.194 ± 0.291 mg/kg (S2) for their respective elements. The Cr content was BDL in all soil samples from all sites. Several metals over the BIS range were detected, including Cu at site S6, Zn at sites S1, S2, S3, S4, and S6, Fe at all sites and Mn at site S2. In S1-S6, the total bacterial population in the soil ranged from 397 ± 67 CFU to 459±88 CFU, with values of 442 ± 86 CFU, 404 ± 78 CFU, 459 ± 88 CFU, 397 ± 67 CFU, 405 ± 67 CFU, and 451 ± 77 CFU, respectively. The findings revealed soil and groundwater pollution caused by the elevated levels of heavy metals in the groundwater, rendering the water unfit for drinking. The study underscores the need of adopting effective waste management strategies to reduce the adverse effects of solid waste disposal sites. The results can guide the formulation of development policies and laws aimed at enabling the implementation of suitable solid waste management techniques.

Evaluation of fluoride emissions and pollution from an electrolytic aluminum plant located in Yunnan province

The monitoring and evaluation of fluoride pollution are essentially important to make sure that concentrations do not exceed threshold limit, especially for surrounding atmosphere and soil, which are located close to the emission source. This study aimed to describe the atmospheric HF and edaphic fluoride distribution from an electrolytic aluminum plant located in Yunnan province, on which the effects of meteorological conditions, time, and topography were explored. Meanwhile, six types of solid waste genereted from different electrolytic aluminum process nodes were characterized to analyze the fluoride content and formation characteristics. The results showed that fluoride in solid waste mainly existed in the form of Na3AlF6, AlF3, CaF2, and SiF4. Spent electrolytes, carbon residue, and workshop dust are critical contributors to fluoride emissions in the primary aluminum production process, and the fluorine content is 17.14 %, 33.30 %, and 31.34 %, respectively. Unorganized emissions from electrolytic aluminum plants and solid waste generation are the primary sources of fluoride in the environment, among which the edaphic fluoride content increases most at the sampling sites S1 and S7. In addition, the atmospheric HF concentration showed significant correlations with wind speed, varying wildly from March to September, with daily average and hourly maximum HF concentrations of 4.32 μg/m3 and 9.0 μg/m3, respectively. The results of the study are crucial for mitigating fluorine pollution in the electrolytic aluminum industry.