High Concentrations Of Heavy Metals Research Articles

Potensi Tanaman Sangitan (Sambucus javanica) sebagai Fitoremediator Tanah Tercemar Logam Berat Zn dari Air Limbah Industri Pelapisan Logam

Phytoremediation is an alternative biological treatment that can be used to reduce soil or water pollutants. Phytoremediation has the advantage of environmentally friendly waste products and a lower budget compared to physical and chemical processes. In addition, phytoremediation has the weakness of long contaminant absorption times, and quite a few plants that are used as phytoremediation agents die because they are unable to survive the high concentrations of heavy metals contained in polluted media. This study aims to determine the ability of the S. javanica (S. javanica) plant as a phytoremediator for soil contaminated with the heavy metal Zn from industrial wastewater. Phytoremediation lasted for 10 days by contacting artificial Zn wastewater with a concentration of 5 mg/L and as much as 50 ml/day on the test plants. The planting medium used was 100% soil (A1) and 50% homogenized soil with 50% manure (A2). Tests were carried out on each part of the plant and growing medium with contact times of 0, 5, and 10 days of phytoremediation. The plant used as a phytoremediator is Sangitan (S. javanica). The optimum contact time in this study occurred on the 10th day of phytoremediation, and the addition of a 50% dose of organic matter in manure had an effect on the concentration of the heavy metal Zn. The accumulation of heavy metal Zn in plant leaves was greater than in roots, with an average BCF of 0.694 for leaves and 0.308 for roots. While the TF value > 1 represents that the Sangitan plant (S. javanica) has the potential to be a phytoremediator and has a high ability to translocate the heavy metal Zn.

Arsenic contamination of groundwater: Review on arsenic contamination of Assam

Groundwater contamination is a global problem. Although groundwater is considered as safe, high concentrations of heavy metals in groundwater like arsenic (As) can pose potential human health concerns and hazards. Arsenic is a natural chemical element of the earth’s crust and is commonly distributed all over the environment. High concentrations of arsenic (As) in drinking water have been found in several parts of the world. World Health Organization’s provisional guideline value for arsenic in drinking water - 0.01 mg/l (10 μg/l). In Assam, many districts have been reported to be most affected by arsenic contamination of groundwater which is above the permissible level. People in Assam have directly or indirectly consumed the groundwater. This paper emphasizes the overview of the present scenario of intensity of arsenic contamination in groundwater in different districts of Assam. The paper also critically reviews the sources of arsenic contamination and arsenic led human effects.

Characterizing low-grade refractory gold ores using automated mineralogy coupled with LA ICP-MS

Researchers have made notable progress in quantifying refractory components causing gold losses in traditional extraction methods. The potential for improving gold recoveries lies in targeted re-treatment of the 'invisible' gold fraction hosted within various ore minerals, even at low concentrations. This study presents a methodology for analysing the refractory components that cause gold losses in traditional extraction methods. The approach utilizes automated mineralogical techniques in conjunction with in-situ laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) to characterize low-grade refractory ores and assess gold deportment. The methodology combines pre-concentration gravity separation, traditional chemical and mineral techniques, and LA ICP-MS to generate comprehensive datasets. To demonstrate the practical application of the methodology, a case study was conducted on historical tailings material from Witwatersrand's Evander Goldfield in South Africa. The case study aimed to determine the mineralogical distribution of gold that cannot be extracted through cyanidation. The results indicated that invisible gold is primarily hosted in pyrite (with an average concentration of 10.21 ppm representing 32 % of total gold), other sulphides (with an average concentration of 1.29 ppm representing 0.42 % of total gold), and oxides (with an average concentration of 0.50 ppm representing 1 % of total gold). The remaining gold is present in discrete fine cyanide amenable phases (with 28 % deportment) and silicate-hosted phases (with 39 % deportment). Environmental monitoring of the Witwatersrand tailings material revealed a net “acid-producing” nature, with high concentrations of heavy metals (such as As, Cu, Pb, Mn, Hg, and Ni) associated with sulphides (with over 78 % deportment). The deportment information obtained through this approach can optimize ore processing strategies and provide valuable insights for future remediation plans. By characterizing the refractory components causing gold losses and understanding the distribution of gold within the ore, this methodology offers the potential to enhance gold recovery and improve the efficiency of ore processing operations.

Sublethal Concentrations of Cadmium and Lead: Effects on Hemato-Biochemical Parameters and Tissue Accumulation in Wallagu attu.

The exposure of fish to heavy metals can significantly impact physiological processes and potentially lead to adverse health effects. This study assesses the effects of exposure to Cd and Pb sublethal concentrations in water on Wallagu attu. A total of 48 fish with an average body weight of 145.5 ± 26g were distributed among three groups (control, Cd-treated, and Pb-treated) within 60L fiberglass tanks. They were exposed to30% sublethal concentrations of Cd and Pb for durations of 1, 15, and 30 days. Following this exposure, an assessment was conducted on metal bioaccumulation and hemato-biochemical responses. Results revealed a significantly (P < 0.05) higher concentration of heavy metals in the fish tissues of metals exposed groups than in the control. The concentration of Cd and Pb increases in fish tissues (kidney > gills > intestine) with exposure time. In most cases, the Pb-exposed group exhibited significantly (P < 0.05) higher concentrations of Pb in different tissues than the Cd-treated group. With extended exposure time, the activities of CAT and SOD show a significant decrease in both Cd and Pb-treated groups. However, the reduction in activities was more pronounced in the Cd-exposed group. On 15 and 30 days, the levels of red blood cells (RBC), hemoglobin (HB), hematocrit (HCT), and total protein (TP) decrease in groups exposed to Cd and Pb. The cortisol and glucose levels exhibit a more noticeable (P < 0.05) increase with prolonged exposure to Cd and Pb than the control group. On day 30, the survival rate decreased more in the Pb-exposed group. The findings of this study indicate that exposure to sublethal doses of Cd and Pb induces stress in Wallagu attu, resulting in rapid changes in specific hemato-biochemical parameters.

Screening and performance optimization of fungi for heavy metal adsorption in electrolytes.

The resource recovery and reuse of precious metal-laden wastewater is widely recognized as crucial for sustainable development. Superalloy electrolytes, produced through the electrolysis of superalloy scrap, contain significant quantities of precious metal ions, thereby possessing substantial potential for recovery value. This study first explores the feasibility of utilizing fungi to treat Superalloy electrolytes. Five fungi resistant to high concentrations of heavy metals in electrolytes (mainly containing Co, Cr, Mo, Re, and Ni) were screened from the soil of a mining area to evaluate their adsorption characteristics. All five fungi were identified by ITS sequencing, and among them, Paecilomyces lilacinus showed the best adsorption performance for the five heavy metals; therefore, we conducted further research on its adsorption characteristics. The best adsorption effect of Co, Cr, Mo, Re, and Ni was 37.09, 64.41, 47.87, 41.59, and 25.38%, respectively, under the conditions of pH 5, time 1 h, dosage 26.67 g/L, temperature 25-30°C, and an initial metal concentration that was diluted fivefold in the electrolyte. The biosorption of Co, Mo, Re, and Ni was better matched by the Langmuir model than by the Freundlich model, while Cr displayed the opposite pattern, showing that the adsorption process of P. lilacinus for the five heavy metals is not a single adsorption mechanism, but may involve a multi-step adsorption process. The kinetics study showed that the quasi-second-order model fitted better than the quasi-first-order model, indicating that chemical adsorption was the main adsorption process of the five heavy metals in P. lilacinus. Fourier transform infrared spectroscopy revealed that the relevant active groups, i.e., hydroxyl (-OH), amino (-NH2), amide (- CONH2), carbonyl (-C = O), carboxyl (-COOH), and phosphate (PO43-), participated in the adsorption process. This study emphasized the potential application of P. lilacinus in the treatment of industrial wastewater with extremely complex background values.

The Potential of Bentonite as a Low-cost Adsorbent for the Removal of Heavy Metal Ions from Multicomponent Aqueous Systems of the Galvanic Industry

Waste water in the galvanic process contains high concentrations of heavy metals that pose a direct danger to humans and the environment. Conventional methods for their removal are quite expensive and generate a large amount of waste. The development of new and improvement of existing methods for the removal of heavy metals from galvanic wastewater are the subject of many studies. Compared to other purification methods, the adsorption is becoming an increasingly popular method of wastewater purification, especially if the adsorbent is cheap, easily available and does not require any other treatment before use. Therefore, the aim of the work was to investigate the possibility of using natural bentonite for the removal of heavy metal ions from multi-component water systems of the galvanic industry. For this purpose, the physico-chemical characterization of natural bentonite was performed, and then the influence of pH value, time and temperature on the adsorption efficiency was examined. The results of adsorption showed that natural bentonite can be used as an adsorbent for the removal of heavy metal ions from waste galvanic waters, and that at pH 5 it achieves the maximum removal efficiency for Cu(II):Cr(III):Ni(II) ions in the percentage ratio 100 : 99.990 : 99.998. The results showed that the highest removal efficiency for Cu (II) ions was achieved in the first 10 minutes, and 20 minutes for Cr (III) and Ni (II) ions. The maximum efficiency of Cu (II) removal was achieved at all temperatures, while for Cr (III) 99.99% and Ni (II) 100% maximum efficiency was achieved at 35°C, which indicates that the adsorption process is endothermic. The experimental results of the adsorption of Cu (II) metal ions are in good agreement with the Langmuir and Freundlich theoretical models, while for Cr (III) and Ni (II) ions they are in better agreement with the Langmuir adsorption model.

Phytoremediation capacity of hybrid aspen at sites affected by industry and agriculture.

Fast-growing Populus spp. are well-acknowledged to restore contaminated soils from heavy metals in industrial areas. Thus far, there is no knowledge about the phytoremediation capacity of Populus spp. plantations in hemiboreal Estonia conditions to restore industrially polluted areas. The objective of this study was to assess the soil contamination rate of heavy metals (As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn) and their uptake by mature hybrid aspen (Populus tremula × Populus tremuloides Michx.) in plantations in different industrial pollution areas (e.g. cement factory, oil shale mining). For the reference, industrially polluted plantations were compared with the low pollution area hybrid aspen plantation on former agricultural soil, which was influenced by fertilization and liming before afforestation. Twenty-one years after afforestation, soil samples were collected from the 0-10cm topsoil layer. Aboveground biomass sampling was performed for bark and stem wood by ingrowth cores to separate wood formed during early (1-10years) and late (11-21years) stand development. Two decades after the afforestation of industrially polluted areas, the heavy metal concentrations in the soil were higher than the reference plantation and the standard reference for unpolluted soils in most cases. The highest concentrations of heavy metals in woody biomass were in the oil shale quarry spoil; because of poor growth, the accumulated pools in aboveground biomass were low. Cd differed from other metals and accumulated less in wood and more in bark. The concentration of heavy metals (Cd, Cr, Cu, Fe, Mn, Ni and Zn) was higher in the first decade of stand formation (1-10years) than in the last 10years (11-21years). High pools of heavy metals were accumulated in aboveground biomass in the reference plantation, indicating the considerable removal of heavy metal residues from the previous fertilization and liming source with harvest. Two decades of afforestation with hybrid aspen is too short for complete ecosystem restoration from heavy metals in industrially polluted areas.

Turning harmful Mn2+ to treasure: In-situ formed ε-MnO2 for removing heavy metals from acid mine drainage

Acid mine drainage (AMD) contains high concentrations of heavy metals, causing serious environmental pollution. Current neutralization techniques fail to recover and utilize valuable heavy metals, and generate large quantities of hazardous sludge. Manganese (Mn) is generally present at high levels in AMD. Therefore, this paper proposed a technology to recover Mn from AMD, by adding KMnO4 to converting Mn into ε-MnO2. Ultra-Violet C (UVC) was used to photolyze the residual KMnO4. The study then evaluated the processes and mechanisms involved in the technology. The photolysis of KMnO4 in strong acidic conditions was determined, and new mechanisms were proposed. MnO2 produced by the photolysis process was formed through the reaction between Mn(III) and KMnO4. In the absence of KMnO4, Mn(III) underwent further photolysis and was reduced to Mn2+. The maximum adsorption capacities of in-situ formed ε-MnO2 for Pb2+, Cd2+, and Fe3+ were 449.80, 122.05, and 779.88 mg/g, respectively. Higher Mn-OH levels and MnO2 regeneration were crucial in improving adsorption performance. Proton exchange and inner-circle complexation were the main pathways for Pb2+ and Cd2+ adsorption by in-situ formed ε-MnO2. A phase transformation occurred when a substantial amount of Fe3+ was adsorbed, leading to the gradual transformation to MnFe binary oxides. When applying in-situ formed ε-MnO2 technology for actual AMD treatment, 98.62 % of Mn in AMD was recovered within 24 h in the presence of ε-MnO2 for possible further reuse in industries, with a final recovery of 0.76 kg/m3. Further, this technique removed other heavy metals and reduced the sludge volume by 20.99 % when used as a pre-treatment step for neutralization. These results demonstrated the broad potential of this treatment technology.

Remediation of Leachate-Metal-Contaminated Soil Using Selected Bacterial Consortia

Approximately 95% of urban solid waste worldwide is disposed of in landfills. About 14 million metric tonnes of this municipal solid waste are disposed of in landfills every year in Malaysia, illustrating the importance of landfills. Landfill leachate is a liquid that is generated when precipitation percolates through waste disposed of in a landfill. High concentrations of heavy metal(loid)s, organic matter that has been dissolved and/or suspended, and inorganic substances, including phosphorus, ammonium, and sulphate, are present in landfill leachate. Globally, there is an urgent need for efficient remediation strategies for leachate-metal-contaminated soils. The present study expatiates on the physicochemical conditions and heavy metal(loid)s’ concentrations present in leachate samples obtained from four landfills in Malaysia, namely, Air Hitam Sanitary Landfill, Jeram Sanitary landfill, Bukit Beruntung landfill, and Taman Beringin Landfill, and explores bioaugmentation for the remediation of leachate-metal-contaminated soil. Leachate samples (replicates) were taken from all four landfills. Heavy metal(loids) in the collected leachate samples were quantified using inductively coupled plasma mass spectrometry. The microbial strains used for bioaugmentation were isolated from the soil sample collected from Taman Beringin Landfill. X-ray fluorescence spectrometry was used to analyze heavy metal(loid)s in the soil, prior to the isolation of microbes. The results of the present study show that the treatments inoculated with the isolated bacteria had greater potential for bioremediation than the control experiment. Of the nine isolated microbial strains, the treatment regimen involving only three strains (all Gram-positive bacteria) exhibited the highest removal efficiency for heavy metal(loid)s, as observed from most of the results. With regard to new findings, a significant outcome from the present study is that selectively blended microbial species are more effective in the remediation of leachate-metal-contaminated soil, in comparison to a treatment containing a higher number of microbial species and therefore increased diversity. Although the leachate and soil samples were collected from Malaysia, there is a global appeal for the bioremediation strategy applied in this study.

Comparative study of chemical speciation and leaching feature of typical heavy metals in coarse and fine slags from the entrained-flow coal gasification

ABSTRACT The dissimilarity in chemical speciation and release properties of heavy metals will result in varying levels of environmental hazards and potential applications of coal gasification coarse and fine slags. The distribution, chemical speciation, leaching features, and potential environmental risks of heavy metals (Cr, Cu, Cd, Zn, Pb, and Mn) in coarse and fine slags from different coal gasification processes were revealed and compared by the sequential chemical extraction method, Horizontal vibration method, and pH-dependent leaching experiments. The results show that Cr (516.78 mg/kg) in coarse slag, Zn (348.50 mg/kg) and Pb (214.78 mg/kg) in fine slag are highly enriched and the content exceeds the screening value, indicating the need for better management during stockpiling and landfilling. The distribution of Cr, Cu, Pb, and Mn in residual state, Zn in Fe-Mn oxide bound state, and Cd in unstable bound state is the highest in both coarse slag and fine slag. The leaching toxicity of heavy metals (HMs) does not exceed the standard, but the leachate is classified as Level V surface water or groundwater quality due to the leaching concentration of Pb exceeding 0.1 mg/L. Furthermore, leaching of Cr, Zn, Cd, and Pb in fine slag is much more dependent on pH compared to coarse slag, and the concentrations of Zn and Pb exceed emission standards at pH < 3.0. The high concentration of heavy metals caught on the surface of fine slag is more harmful to the environment. The properties of HMs in the slags and pH of the application environment must be comprehensively considered before coal gasification slag disposal, especially fine slag.

The biotoxic effects of heavy metals exposure in miners and non-miners

Since little is known about the comparison of the biotoxic effects of heavy metals exposure on biochemical and hematological parameters in miners and non-miners, the current study aimed to compare the effects of arsenic (As), lead (Pb), and copper (Cu) in both groups. Demographic information and blood samples were collected from all participants and measures of As, Pb and Cu were obtained using Atomic Absorption Spectrophotometry. As and Pb mean concentrations in miners and Cu concentration were greater in non-miners. Miners also showed significantly higher level of RBC, HBG and HCT. In the adjusted model, cholesterol showed a positively association with Pb and Cu levels. Triglycerides, GGT, ALP, WBC and PLT positively and HDL-cholesterol negatively were associated with Cu. Creatinine was negatively associated with group variable. In conclusion, miners' high blood heavy metals concentrations can impact biochemical and hematological indices. These observations make monitoring of heavy metals necessary in miners.

Heavy metal air pollution in an Indonesian landfill site: Characterization, sources, and health risk assessment for informal workers

A landfill is an area for disposing of final-stage waste, from source to transportation and disposal. This study assesses characterization, sources, and health risks assessment exposure to heavy metals (HMs) in ambient air and personal sampler via inhalation by informal workers in the Piyungan landfill site area. The sample was carried out using a high-volume air sampler (HAVS) and a personal dust sampler that measures HMs and analyzes them using inductively coupled plasma mass spectrometry (ICP-MS). The interviews were conducted with the informal workers, with 45 respondents with health complaints. The analysis found a high concentration of HMs and exceeded the concentration limits set by the threshold limit values (TLV) in ambient air and personal sampler. The average concentrations of the elements (mg/m3) in ambient air PM2.5 are shown Fe 54.2, Cu 5.91, Mn 3.02, Zn 1.33, As 0.108, Pb 0.102, Co 0.027, Cd 0.004, and Se 0.0037 and in the personal sampler are shown Fe 480.90, Cu 8.42, Mn 12.26, Zn 12.76, As 0.24, Pb 1.45, Co 0.12, Cd 0.06, and Se 0.02. The Hazard Index (HI) values for the target metals, which indicate non-carcinogenic risk, were found to exceed the stated safety in PM2.5 had an HI value of 6.2 and the personal sampler showed HI values of 25. Analysis of carcinogenic risk of HMs As, Cd, Pb showed that there were high-risk levels of cancer-causing HMs in PM2.5 and in a personal sampler with a risk level ranging from (10−3 ≤ CR <10−1). The primary sources of HMs from are the vehicle emissions of operation landfills and waste components in landfills are electronic, construction, industrial, market, and domestic waste. These findings show that exposure to HMs can impact informal workers' non-carcinogenic and carcinogenic health risks in landfills and need control risk management to protect workplace occupational health effectively.

Prospects of forward osmosis-based membranes for seawater mining: Economic analysis, limitations and opportunities

Processes for separating solutes from water, including desalination, are based on synthetic membranes using the forward osmosis (FO) technique. The industrial-level success of these membrane techniques has been astounding. Modern desalination membranes, however, cannot extract a single metal ion with precision from a commingled ion solution. Lithium, cobalt, uranium, and other energy-critical elements will soon be in greater demand than they can meet, thus elevating their importance as geopolitical resources. Critical metals can be found in seawater, an essential yet unconventional supply. Gold mining and ore processing are activities of great economic importance. However, they are related to generating extremely polluted effluents containing high concentrations of heavy metals and low pH. The review highlights the most recent design and deployment of FO desalination technologies, their application in sea mining, and the remaining challenges and prospects. This work also highlights the enormous potential of FO sea mining and how it is crucial to optimize the operating parameters, including draw solutions and energy consumption, and raise attention toward the economic aspect and market diffusion of FO sea mining.

A metallurgical approach for separation and recovery of Cu, Cr, and Ni from electroplating sludge

Electroplating sludge is extensively produced in chemical precipitation–based treatment of electroplating wastewater. It poses a huge threat to environmental safety if not properly disposed, ascribed to its high contents of heavy metals. An innovative metallurgical approach was proposed a to recycle Cu, Cr, and Ni from it. Ammonia leaching was firstly performed to selectively leach Cu from Cr, in which the Cu oxide and sulfide were leached into the leachate while the Cr oxide and Ni carbide (NiCx) retained in the residue. (NH4)2SO4 increased the Cu leaching rate via increasing the dissolved oxygen amount in the ammonia leachate and converting CuS to Cu2+. Under the optimal conditions, the leaching efficiency of Cu achieved 96.5 % while that of Cr was only 0.1 %. In the followed aluminothermic reduction, C in the leaching residue could be effectively removed via a thermal oxidation, which in turn decreased the formation of a C-containing compound of high melting point and benefited the Cr and Ni recovery. Cr and Ni from the residue were reduced and recovered in a Cr-Ni alloy, and the reductant of Al first changed to a refractory Al2O3 and then transformed to a low melting point 12CaO·7Al2O3 with the additive of CaO. This transformation increased the molten slag fluidity and promoted the separation of Cr-Ni alloy from slag. Moreover, the excessive Al increased the Cr and Ni yields and concentrated all of them to be together. Partial Al was used as reductant, and the other Al transferred into Cr-Ni alloy to decrease its melting point. Cr and Ni contents in the smelting slag could be decreased to 0.11 wt% and 0.12 wt% respectively, showing an efficient recovery. This work provided a high efficiency method to recover Cu, Cr, and Ni from waste electroplating sludge.

Arsenic biomineralization and selenium nanoparticles biosynthesis by Halomonas boliviensis strain H-10 isolated from the high-altitude Salar de Huasco salt flat (Chile)

High-altitude Andean wetlands of the Atacama Desert (Chile), including the Salar de Huasco salt flat, are unusual environments characterized by a great variability of physical-chemical conditions, often combined with a high concentration of heavy metals, including arsenic (As) and semimetals, such as selenium (Se). Microorganisms present in these environments evolved adaptative strategies to cope with environmental stresses, with biotechnological potentials. The present work investigated the natural bacterial community composition in sediments collected from the Salar de Huasco salt flat, by high-throughput Illumina sequencing, and to isolate bacterial strains able to remove As and biosynthesize Se nanoparticles (SeNPs). Dominant taxonomic groups (abundance ≥1%) were affiliated to Proteobacteria (mainly consisting in Delta- and Alfa- Gamma-proteobacteria) Bacteriodetes, Firmicutes, Acidobacteria, Spirochaetes, Deinococcus-Thermus, Gemmatimonadetes and Verrucomicrobia. Halomonas boliviensis strain H-10 was able to both biomineralize As and biosynthesise SeNPs; therefore, the characteristics of H. boliviensis strain H-10 could be used for biotechnological purposes, including As bioremediation from water and bioproduction of SeNPs.

Heavy metal contamination through wastewater irrigation on the soil and vegetables: Impact on the nutrient content and health risks ​

The use of wastewater irrigation may contribute to the metal accumulation, and reduction of nutrient level of vegetables, which would then have an adverse effect on human health. Therefore, in the present study we investigated heavy metals contamination and its impact on nutrient quality of vegetables and health risk. The study was conducted from the agricultural fields of Varanasi distinct during the period from March 2022 to June 2023 and all the laboratory work was carried in the department of Botany, Banaras Hindu University. Heavy metal concentrations in water, soil, and vegetable samples were measured using an atomic absorption spectrophotometer. The physiochemical property (pH), daily intake of metal, metal pollution index and health quotient were also calculated according to the published protocols. All heavy metal were found in higher concentrations in the wastewater irrigated soil that control site. The Lohta site had the highest concentration of heavy metals in the vegetables, followed by Dinapur, and least at control site (BHU). The highest concentration of metals (Cu, Zn, and Pb) were found in the leafy vegetables (S. oleracea and A. esculentus) whereas lowest in fruity vegetables (P. vulgaris). The rise in the Metal Pollution Index (MPI) also provided evidence for the greater metal content of these vegetables. The S. oleracea was found to have the highest DIM (0.061 g/g) while P. vulgaris had the lowest (0.007 g/g). HQ values of these metals were found greater than one ( greater than 1) for both children and adults on the ingestion of the vegetables of wastewater irrigated sites. Further, nutrient contents (Na, Mg, Ca) were also declined in the vegetables of wastewater irrigated site when compared to control site. These findings suggest that the consumption of such vegetables leads to compromised health and might be associated with severe health risk in the human.

Integrated water quality dynamics in Wadi Hanifah: Physical, chemical, and biological perspectives.

The Wadi Hanifah, a crucial aquatic ecosystem, has unfavorable consequences from natural occurrences and human activities. Recognizing the critical need for sustainable water management, this study provides an in-depth evaluation of wadi water quality. A comprehensive assessment was conducted, analyzing physical properties (temperature, pH, electrical conductivity, turbidity, color, and odor), chemical constituents (nitrogen compounds, ion concentrations, heavy metals), and bacterial diversity. The study found significant temperature fluctuations, particularly in sun-exposed or stagnant water areas. The water exhibited slight alkalinity and variable electrical conductivity and turbidity, indicating differing pollution levels. High ammonia and heavy metal concentrations suggested organic and industrial contamination, respectively. In addition, the prevalent fecal-indicator bacteria pointed to possible sewage or agricultural runoff. The research highlights the complex interplay of natural and anthropogenic factors affecting Wadi Hanifah's water quality. It emphasizes the need for location-specific environmental management strategies focusing on pollution control and conservation to safeguard the wadi's ecological health. This study provides vital insights for effective water resource management in Wadi Hanifah, serving as a model for similar ecosystems.

Isolation and identification of metallotolerant bacteria with a potential biotechnological application

Mining has led to severe environmental pollution in countries with exhaustive mining production and inadequate industrial waste regulation. Microorganisms in contaminated sites, like mine tailings, have adapted to high concentrations of heavy metals, developing the capacity of reducing or removing them from these environments. Therefore, it is essential to thoroughly characterize bacteria present in these sites to find different ways of bioremediation. In this regard, in this study, an enrichment and isolation procedure were performed to isolate bacteria with lower nutritional requirements and high tolerance to Cu(II) and Fe(II) from two Sonoran River basin mining tails. Two Staphylococcus species and a Microbacterium ginsengisoli strain were isolated and identified from the San Felipe de Jesús mining tail. Also, three strains were isolated from the Nacozari de García mining tail: Burkholderia cenocepacia, Sphingomonas sp. and Staphylococcus warneri. Significant microbiological differences were found between the two sites. All these species exhibited tolerance up to 300 mg/L for Cu (II)–Fe (II) solutions, indicating their capacity to grow in these conditions. Moreover, a consortium of isolated bacteria was immobilized in two different biocomposites and the biocomposite with larger pore size achieved greater bacterial immobilization showcasing the potential of these bacteria in biotechnological applications.

The Hypersaline Soils of the Odiel Saltmarshes Natural Area as a Source for Uncovering a New Taxon: Pseudidiomarina terrestris sp. nov.

The hypersaline soils of the Odiel Saltmarshes Natural Area are an extreme environment with high levels of some heavy metals; however, it is a relevant source of prokaryotic diversity that we aim to explore. In this study, six strains related to the halophilic genus Pseudidiomarina were isolated from this habitat. The phylogenetic study based on the 16S rRNA gene sequence and the fingerprinting analysis suggested that they constituted a single new species within the genus Pseudidiomarina. Comparative genomic analysis based on the OGRIs indices and the phylogeny inferred from the core genome were performed considering all the members of the family Idiomarinaceae. Additionally, a completed phenotypic characterization, as well as the fatty acid profile, were also carried out. Due to the characteristics of the habitat, genomic functions related to salinity and high heavy metal concentrations were studied, along with the global metabolism of the six isolates. Last, the ecological distribution of the isolates was studied in different hypersaline environments by genome recruitment. To sum up, the six strains constitute a new species within the genus Pseudidiomarina, for which the name Pseudidiomarina terrestris sp. nov. is proposed. The low abundance in all the studied hypersaline habitats indicates that it belongs to the rare biosphere in these habitats. In silico genome functional analysis suggests the presence of heavy metal transporters and pathways for nitrate reduction and nitrogen assimilation in low availability, among other metabolic traits.

Environmental surveillances of River Ogio in Edo State, Nigeria

AbstractThe study assessed the quality of water obtained from River Ogio in Etsako West Local Government Area of Edo State, Nigeria. Using standard procedures, the water samples obtained from three points of the river were analyzed for physicochemical parameters, Total heterotrophic bacteria count and Total coliform count. With exception of upstream samples, the temperature of midstream and downstream samples was lower than the range specified by the World Health Organization (WHO). The Cadmium and Arsenic levels, Total heterotrophic bacteria count and Total coliform count were above the WHO recommended limits. A total of four genera of bacteria were isolated from the water samples. Correlational analysis revealed no significant (p &gt; 0.05) relationship between the physicochemical parameters and bacteriological properties of water obtained from River Ogio. The water obtained from River Ogio is considered unsafe for domestic consumption due to its high heavy metal content and bacteria load.