Metals Manganese Research Articles

Life cycle assessment of ethanol production from broken wheat and rice grains

Ethanol from broken grains will contribute to India’s fuel mix, therefore, the environmental impacts must be systematically quantified. This work performs a detailed life cycle assessment (LCA) of ethanol production from broken wheat and rice in the Indian context. Cradle-to-gate system boundary is considered, and the functional unit is 1 L ethanol. Process inventory is based on literature studies and basic process engineering calculations. Ecoinvent® v3.3 database is also used to get required inventory data. OpenLCA 1.11.0 software and the ReCiPe midpoint (H) model are used for the calculations. A key conclusion is that ethanol from broken grains has substantially lower global warming potential (GWP) (0.536–0.983 kg CO2 eq.) as compared to other fuels. Ethanol from rice has higher GWP and water depletion than that from wheat. The results also show the impacts are dominated by the farming stage. About 98% of water depletion was due to the agricultural stage for both grains. The other import impact factors are fossil depletion, human toxicity, metal depletion, marine eutrophication, and terrestrial acidification. The main driving factors for these are the depletion of coal, natural gas, and crude oil and by the emissions in the form of methane, mercury, manganese, and other metals.

Efficient separation of cerium from rare earth elements and major impurities using low cost manganese ferrites from highly acidic solutions

Sorption of REEs using spinel-ferrite nanoparticles has received great attention in the last decades, because of combining the advantages of iron and manganese metal oxides. Nano-manganese ferrite (MnFe2O4) was successfully synthesized using the co-precipitation method and modified with the addition of zinc to produce (Mn0.8Zn0.2Fe2O4). The synthesized materials were characterized using FTIR, SEM with EDX-mapping, XRD, chemical stability, and surface area. Several process parameters were studied to optimize the efficiency of Ce(III) separation from La(III), Eu(III), Pb(II), and Fe(III) from highly acidic media. The parameters include contact time, solution pH, and metal ion concentration. The sorption process was well fitted to the pseudo-2nd order model, which confirms the chemical nature of the sorption process where equilibrium was achieved after 30 minutes. The pH study's findings demonstrate that Ce(III) was most effectively separated at a very high, acidic pH of 0.5. Both MnFe2O4 and Mn0.8Zn0.2Fe2O4 have high chemical stability in different media where the weight loss was less than 10 %. The correlation coefficient and residual errors analysis confirm that the non-linear extended sips isotherm model more accurately expresses the behavior of the sorption process than the non-linear Freundlich and Langmuir isotherm models. The modified material Mn0.8 Zn0.2Fe2O4 shows higher sorption capacities for all the studied metal ions than MnFe2O4. The maximum sorption capacities of Ce(III), La(III), Eu(III), Pb(II), and Fe(III) in the mixture were 59.2, 6.5, 6.3, 15.4, and 13.7 mg/g, respectively.

An Mn-Enriched Interfacial Layer for Reversible Aqueous Mn Metal Batteries.

Aqueous manganese metal batteries have emerged as promising candidates for stationary storage due to their natural abundance, safety, and high energy density. However, the high chemical reactivity and sluggish migration kinetics of the Mn metal anode induce a severe hydrogen evolution reaction (HER) and dendrite formation, respectively. The situation deteriorates in the low-concentration electrolyte especially. Here, we propose a novel approach to construct an Mn-enriched interfacial layer (Mn@MIL) on the Mn metal anode surface to address these challenges simultaneously. The Mn@MIL acts as a physical barrier to not only suppress HER but also accelerate the Mn2+ diffusion kinetics through the Mn2+ saturated interfacial layer to inhibit dendrite growth. Therefore, in the low-concentration electrolyte (1 M MnCl2), the Mn||Mn symmetric cells and Mn||V2O5 full cells with high mass loading demonstrate promising cycling stability with minimal polarization and parasitic reactions, making them more suitable for practical applications in a smart grid.

Highly efficient CO2 mineralization: Mechanisms and feasibility of utilizing electrolytic manganese residue as a feedstock and implementing ammonia recycling

Electrolytic manganese residue (EMR) and CO2 emissions from the electrolytic manganese metal (EMM) production process present significant challenges to achieving cleaner production within the industry. Given the high capacity for CO2 sequestration and the stability of the sequestered forms, CO2 mineralization methods utilizing minerals or industrial residues have garnered considerable research interest. The efficacy of such methods is fundamentally dependent on the properties of the materials employed. EMR, due to its calcium sulfate dihydrate (CaSO4·2H2O) content, possesses an intrinsic potential for CO2 solidification. In this study, we propose a novel method for CO2 mineralization utilizing EMR, coupled with NH3·H2O recycling. Experimental results indicated that under conditions of a reaction temperature of 55 °C and a pH of approximately 8, each ton of EMR can sequester 0.16 t of CO2, with equilibrium achieved within 10 min. The mineralization mechanism was elucidated using SEM, TG curves, and XRD analyses, which revealed that Ca2+ ions are initially leached from CaSO4·2H2O in the EMR, subsequently precipitating with CO32− ions to form CaCO3. This CaCO3 layer effectively covers the surface of CaSO4·2H2O, inhibiting further Ca2+ release and stabilizing the reaction equilibrium. Furthermore, the ammonia in the solution is regenerated into NH3·H2O, facilitating its reuse and preventing secondary pollution. The utilization of EMR for CO2 mineralization not only mitigates carbon emissions in the EMM production process but also promotes environmentally sustainable practices in the industry. This study highlights a promising pathway towards achieving carbon neutrality and cleaner production in electrolytic manganese production.

Sr, Mn, and Zn extraction and separation from zinc electrolyte crystallization sediment with Ca and Sr sulfate cocrystallization structure: Reduction roasting reconstruction mechanism

Zinc electrolyte crystallization sediment (ZECS) generated in the zinc hydrometallugy industry contains valuable metals of strontium (Sr), manganese (Mn), and zinc (Zn), which has economical value but poses potential detrimental to the environment. However, the extraction and recovery of Sr is extremely difficult due to the thermodynamically stable Ca and Sr sulfate cocrystallization structure in ZECS. The destruction of refractory sulfate cocrystallization structure is a prerequisite for Sr extraction, and the carbothermal reduction roasting method is demonstrated to be efficient for the phase reconstruction. In this study, a stepwise Sr, Mn, and Zn recovery process from ZECS via carbothermal reduction roasting-acid leaching-selective precipitation-multistage extraction was proposed. In the reduction roasting procedure, all the sulfates including CaSO4, SrSO4, and Ca0.7Sr0.3SO4 are reduced to soluble sulfides. Meanwhile, most MnO2 is converted to a low-valence Mn product (MnO) that is soluble in acid, and the reduced Zn(g) is volatilized which can be collected from the flue dust. In the acid leaching procedure, the leaching efficiencies of Sr, Ca, and Mn are as high as 97.34 %, 97.44 %, and 95.49 % respectively, while 99.50 % Si in the form of silica is enriched in the leaching residue. After that, high-purity Sr solution was obtained after selective precipitation for Mn removal and D2EHPA multistage extraction for Ca removal. 97.41 % Mn in the leaching solution is precipitated by adjusting the pH value to 9.5 with NaOH solution. After four-stage extraction, 79.60 % Sr and only 0.35 % Ca are retained in the aqueous phase. The purified solution contains 2.88 g/L Sr, 0.052 g/L Ca, and 0.014 g/L Mn, which can be used to prepare industrial SrCO3 product via the carbonation operation. Thermodynamic behavior and reduction roasting reconstruction mechanism of Ca and Sr sulfate cocrystallization structure in ZECS were discussed in this work. The distributions of main metal elements (Sr, Ca, Mn, and Zn) in ZECS during the carbothermal reduction roasting-acid leaching-selective precipitation-multistage extraction process were also systematically studied.

Investigation of the Effects of Heavy Metals (Copper, Cobalt, Manganese, Selenium, and Zinc) on Fish Immune Systems – An Overview

Abstract Aquaculture, as a strategic and developmental industry, plays an important role in ensuring food security and economic stability within countries. This crucial sector faces various influences, including infectious and nutritional diseases. Certain minerals function as essential nutrients, playing a main role in processes across all aquatic animals when present in appropriate dietary proportions. Studies showed that some heavy metals serve as a catalyst for various biological functions, including the maintenance of colloidal systems, acid-base balance, bone formation, and the regulation of fundamental natural elements such as vitamins, hormones, and minerals. Fish acquire essential elements crucial for their well-being through both diet and water sources. Adequate levels of essential elements, such as iron, zinc, copper, cobalt, manganese, and selenium, in the diet contribute to enhanced growth, increased survival rates, improved disease resistance, and heightened specific immunity in fish. When incorporated in appropriate quantities, these elements play a pivotal role in disease prevention, fostering the production of high-quality fish, minimizing economic losses, and solidifying aquaculture as a robust and profitable industry. This article aims to delve into the immunological effects induced by metal elements, specifically copper (Cu), cobalt (Co), manganese (Mn), zinc (Zn), and selenium (Se), in diverse fish species. The objective is to underscore the significance of this exploration, paving the way for the development of more potent immune supplements in the future. These supplements have the potential to improve growth, fortify immune responses, and enhance resilience against diseases in various fish species.

Optimation of Adsorpsi and Desorpsi of Mn2+ Ions on Gel-GPTMS Silica (Glycidoxypropyltrimethoxysilane) Modified with Sulfonates

Silica gel is an adsorbent often used in chromatography columns as a resin or stationary phase. Silica gel has active groups on its surface in the form of silanol (-SiOH) and siloxane (-Si-O-Si-). The effectiveness of silica gel in absorbing heavy metal ions is very low, so modification is needed to increase the absorption capacity of silica gel to metal ions. The addition of sulfonate with the GPTMS linkage compound dose modification. Adsorption and desorption are two methods that can be used to separate manganese metal. This research aims to obtain the optimum desorption agent (NaCl and CaCl2) and the concentration of the AAS-characterised desorption agent. This study used the column method for the adsorption and desorption process. This study used the column method for the adsorption and desorption process. The column method is a technique used to separate certain substances from a mixture by utilizing the interaction between adsorbent and adsorbate. The results obtained optimum desorption agent CaCl2 where the weight desorbed 0.1168002 mg with a percent desorption of 92.3%, the optimum concentration of CaCl2 0.05 M where the weight desorbed 0.132264 mg with a percent desorption of 95% Adsorbent characterization was conducted with FTIR and XRF.

Characteristics of Host Rocks Manganese of The Anabanua Village Barru District South Sulawesi Province, Indonesia

One of the prospects for a wealth of geological resources that can be utilized for the benefit of mankind is manganese metal mineral resources. In Anabanua Village, especially at the research location, there is an indication of manganese mineralization that the type of rock carrying the mineralization is not yet known. The purpose of this study was to determine the chemical elements of metallic minerals, mineralogy, and types of mineralization-carrying rocks, as many as three samples in the form of chunks, which were analyzed using megascopic analysis methods identifying the texture and structure of carrier rocks, XRD (X-Ray Diffraction) analysis minerals, and XRF (X-Ray Fluorescence). The characteristics of manganese mineralization carrier rocks consist of metallic elements Mn (0.046%-20.455%), Fe (1.555%-3.673%), and nonmetallic elements SiO2 (11.403%-48.165%), K2O (0.398%-4.177%). Mineralogy of manganese mineralization carrier rocks are roeblingite (Pb2Ca6Mn2+(Si3O9)2(SO4)2(OH)2·4H2O), rhodonite (CaMn3Mn[Si5O15]), diopside (CaMgSi2O6), calcite (CaCO3), kieserite (Al, Ga)2(GeO4)(OH)2), zeolite (Mn2O.Al2O3.xSiO .yH2O), and palygorskite ((Mg, Al)2 Si4O 10(OH)·4H2O). Manganese mineralization host rocks are determined by referring to the SiO2 (%weight) and K2O(%weight) diagrams to produce basalt igneous rock types.

Biotic homogenization in multisystem cascade reservoirs: insights from sedimentary photopigment analysis.

The existing literature provides limited insights into the dynamics of phytoplankton communities and the spatial heterogeneity of physicochemical parameters in multisystem cascade reservoirs (interconnected reservoirs derived from different rivers). The existing studies are concentrated on cascade reservoirs (interconnected reservoirs derived from the same river). To address this knowledge gap, the aims of the present study were as follows: (1) investigate the spatial heterogeneity, within and between reservoirs, of geochemical parameters associated with the eutrophication process, considering total phosphorus, chlorophyll-a, pheophytin, and metals (chromium, copper, nickel, lead, zinc, iron, and manganese); (2) evaluate sediment quality at the designated locations; (3) assess differences in the richness and concentration of sedimentary photopigments between the reservoirs. Application of principal component analysis revealed discernible gradients for the abiotic variables, although the differences were not statistically significant (one-way PERMANOVA test, p > 0.05). The observations suggested a tendency towards spatial homogeneity within and between the reservoirs. The metal concentrations were consistent with regional reference values, while phosphorus levels in the sediment approached the threshold for classification as pollution (~ 2000mg/kg). Analysis of pigments indicated low dissimilarity among the reservoirs, which could be mainly attributed to the eutrophication process and high connectivity of the sampled areas. To counteract ongoing biotic homogenization, it is essential to reduce nutrient inputs and invest in ecological protection and restoration programs. The analysis of sedimentary photopigments provides an efficient and cost-effective alternative way to assess phytoplankton communities.

An integrated novel approach to the environmental health assessment of Bangladesh's coastal ecosystems

The coastal expanse of Bangladesh, situated along the Bay of Bengal, is a susceptible and low-lying area grappling with multiple environmental challenges. Various physicochemical parameters were employed in the assessment of water quality. The CCME Water Quality Index indicated the western coast as 70.13 (Fair), the Central coast as 42.2 (Poor), and the Eastern Coast as 64.6 (Marginal). This outcome was corroborated by the Environmental Quality Index, with the Western Coast ranked as (Good), the Eastern Coast as (Fair), and the Central Coast as (Poor). The analyzed parameters provided insights into pollution levels, water clarity, nutrient dynamics, and the overall health of the coastal ecosystems. Additionally, the study delved into heavy metal concentrations, encompassing arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), lead (Pb), and zinc (Zn). The eastern coast exhibited higher contamination compared to the other two regions, emphasizing potential risks to both the environment and human health. This study aimed to evaluate the environmental health risks and water quality in this region, introducing a novel Environmental Health Risk Index (EHRI) to gauge the overall environmental health conditions. According to the EHRI, the Western Coast exhibited good conditions (2.25), while the Central (3.625) and Eastern (3.5) Coasts were classified as not bad, with the Eastern Coast experiencing comparatively lesser impact. Based on these findings, several recommendations emerge, including the implementation of climate change adaptation strategies such as coastal protection measures, the advocacy of sustainable land use practices, and the enhancement of monitoring and management protocols for water quality.

Cinchona alkaloids-derived chiral ligands for Mn-catalyzed ATH of ketones: Improvement of enantioselectivity through π-π stacking-induced hydrogen bond

Inexpensive and readily available manganese metals combined with novel chiral ligands derived from cinchona alkaloids catalyzed the asymmetric transfer hydrogenation of aromatic ketones. All tested aromatic ketones were highly enantioselectively converted to the corresponding chiral alcohols, obtaining up to 99.4% ee. Based on control experiments and density functional theory (DFT) calculations, a plausible mechanism was discussed. During catalysis, π-π stacking in the catalyst promoted the formation of hydrogen bonds between the substrate and the catalyst, and the stronger the stacking, the stronger the hydrogen bonds, while stronger hydrogen bonds were more favourable for achieving high enantioselectivity in manganese-catalyzed asymmetric transfer hydrogenation.

Nickel‐Catalyzed Reductive Amidation of Aryl Sulfonium Salts with Isocyanates for Amide Synthesis via C−S Bond Activation

AbstractA nickel‐catalyzed reductive amidation of aryl sulfonium salts with isocyanates for amide synthesis via C−S bond cleavage was developed. The reactions proceeded smoothly at ambient temperature in the presence of nickel catalyst and manganese metal in DMF to give a variety of amides in moderate to good yields with wide functional group tolerance.

Techno-economic-environmental analysis based on life cycle carbon accounting and pollutants audit for cleaner production of electrolytic manganese

The electrolytic manganese metal (EMM) industry faces significant environmental challenges, including substantial resource and energy consumption, severe pollution, and high CO2 emissions. This study introduced a novel approach for developing collaborative strategies aimed at mitigating pollutants and CO2 emissions. Through the implementation of life cycle carbon accounting and critical pollutant audits, a process enhancement program incorporating 17 advanced technologies was developed. Aligned with the principles of cleaner production, this project effectively mitigates the environmental burden at the source and offers viable solutions for addressing prominent emissions, such as manganese residue and acid fog. Furthermore, the marginal abatement cost curves demonstrate the economic practicality and applicability of these measures. This study provides a strategic blueprint for achieving sustainable green development in China’s EMM industry and offers valuable guidelines for formulating relevant environmental policies.

Development of a Hydrometallurgical Process for the Extraction of Cobalt, Manganese, and Nickel from Acid Mine Drainage Treatment By-Product

Critical minerals (CMs) are pivotal in modern industries, such as telecommunications, defense, medicine, and aerospace, contributing significantly to regional and global economic growth. However, the reliance on external sources for 26 out of 50 identified CMs raises concerns about supply chain vulnerabilities. To address this, the research focused on developing a hydrometallurgical process for extracting cobalt, manganese, and nickel from acid mine drainage (AMD) treatment by-products, emphasizing the need to diversify CM supply chains within the United States (US). A solution composed of an REE solvent extraction raffinate loaded with cobalt, manganese, nickel, and various impurity metals was utilized as a feedstock in this study. The developed hydrometallurgical process involved initial sodium hydroxide precipitation to remove impurities like aluminum and iron from an SX raffinate solution generated during the extraction of rare earth elements (REEs). Precipitation stages were performed in a pH region ranging from 2 to 12 to identify the optimum pH values, achieving a tradeoff between recovery and impurity removal. A subsequent precipitation process at pH 5–10 yielded a product rich in CMs, such as manganese, cobalt, and nickel. Further separation steps involved nitric acid washing, resulting in a Mn product with a purity of 47.9% by weight and a solution with extractable concentrations of cobalt and nickel. Stagewise precipitation with sodium sulfide subsequently produced three solid products: cobalt and nickel product at pH 1–5, manganese product at pH 5–10, and magnesium at pH 10–12. The study also explored other separation approaches, including solvent extraction, to enhance the separation of nickel from cobalt. Overall, the developed hydrometallurgical process generated the following products with varying degrees of purities: cobalt (9.92 wt.%), nickel (14 wt.%), manganese (47.9 wt.%), and magnesium (27.49 wt.%). This research aimed to contribute to the sustainable extraction of CMs from secondary sources, reducing the US’ reliance on imports and promoting a more resilient supply chain for these crucial elements.

Comparative assessment of phytoremediation potential of four Ficus spp. under Semi-arid environmental conditions.

Heavy metals have been recognized as a prominent hazard in today's world, causing pollution in the air environment. Woody tree species can play a significant role in the extraction and remediation of metal pollutants from the air, therefore promoting the air quality index. This study investigated the potential of four species of the Ficus genus (F. benjamina, F. microcarpa, F. religiosa, and F. virens) to remediate varying levels of heavy metal contamination in industrial, residential, and highway areas of Faisalabad City, Pakistan. For this purpose, six heavy metals (cadmium, chromium, copper, lead, zinc, and manganese) were assessed in young leaves (YL) as well as old leaves (OL) of subjected tree species at selected study sites. Eight fully expanded leaves were selected from each tree species: two from each cardinal direction from the shoot of the current year (young leaves, YL), as well as from the shoot of the previous year (old leaves, OL). The results showed that the same genus has different capabilities to accumulate different heavy metals, and the overall trend was in the following order: F. virens > F. religiosa > F. benjamina > F. microcarpa at all study sites. The heavy metal contents in both YL and OL of selected tree species decreased in the order of Manganese (Mn)> Zinc (Zn)> Copper (Cu) > Chromium (Cr) > Lead (Pb) > Cadmium (Cd) at all study sites. The metal accumulation index (MAI) values ranged between 2.14-5.42 for F. benjamina, 2.09-3.89 for F. microcarpa, 3.61-7.01 for F. religiosa and 4.77-6.48 for F. virens across all study sites. Among the studied tree species, it has been determined that F. virens and F. religiosa are well-suited for urban areas with significant heavy metal contamination and can be strategically planted in barrier areas to effectively combat atmospheric pollution.

Design, Synthesis and Characterization of Mn(II)Cysteine-Tyrosine Dithiocarbamate Complex for against the Cancer on MCF-7 Breast Cancer Cell Line.

Breast cancer is the most frequently diagnosed cancer and the second cause of death worldwide. The drug often used for chemotherapy is cisplatin. However, the drug cisplatin has a number of problems, including lack of selectivity, undesirable side effects, resistance, and toxicity in the body. So research is carried out on new drug compounds with low toxicity by designing in silico with molecular docking. Mn(II) Cysteine-Tyrosine dithiocarbamate is a new complex molecule whose research involves several steps, such as in-silico molecular docking testing with target proteins, ADMET then synthesis, characterization and in-vitro MCF-7 cells for anticancer drugs. The synthesis process involves the reaction of manganese metal with tyrosine, cysteine, CS2 and KOH. Characterization tests have been carried out including FT-IR spectroscopy, SEM-EDS, UV Vis, conductivity, melting point and XRD. Confirm the structure of the compound using UV Vis, obtained orbitals π to π* and n to π* in the group N = C = S is represented by the absorption at 400 nm and 600 nm, FT-IR with the results obtained by the functional groups O-H, N-H, C =N and C=S. In vitro test results showed morphological changes (apoptosis) in MCF-7 cancer cells starting from 250 μg/mL and an IC50 value of 416.90 µg/mL. Molecular docking studies of the Mn(II)Cysteine-Tyrosine dithiocarbamate complex were identified with 4,4',4''-[(2R)-butane-1,1,2-triyl]triphenol - Estrogen α which showed an active site with amino acid residues GLU323, GLU385, VAL446, ILE514, TRP360, LYS449, MET388, MET357, PHE445, VAL392 and ILE389. Hydrophobic and hydrophobic bonds are seen in Mn(II)Cysteine-Tyrosine dithiocarbamate - Estrogen α has a bond energy of -77.5372 kJ/mol. Despite having a high H-bond interaction intensity, the chemical does not have a powerful enough anticancer impact. Despite the produced compound's low bioactivity, this study should offer important new understandings into how molecular structure affects anticancer activity.

Halogen makes manganese metal batteries rechargeable

Halogen makes manganese metal batteries rechargeable

Early postnatal and concurrent exposure to metals and neurobehavioral outcomes at 5 years: Associations with individual environmental exposures and mixtures

BackgroundLittle is known about the effect of postnatal exposure to heavy metals on children’s behavior problems. This study aimed to investigate the association between metal exposure during different stages of postnatal life and neurobehavioral outcomes in preschool children. MethodsUrinary concentrations of six metals (arsenic, cadmium, chromium, lead, manganese, and vanadium) were measured using inductively coupled plasma mass spectrometry in 220 participants at two time points: before 1 year and at 5 years of age. Mothers completed the Child Behavior Checklist when the children were 5 years old. Multivariable linear and logistic regression analyses were used to evaluate the association between metal concentrations and behavioral outcomes. We employed Bayesian kernel machine regression (BKMR) to assess possible joint effects and potential interactions between metal mixtures and behavioral outcomes. ResultsConcentrations of urinary arsenic (As) in infants were associated with higher scores for anxious/shy behavior problems (β ranging from 0.03 to 0.23). Further analyses showed that As exposure increased the odds of scores falling into the borderline or clinical range on anxious/depressed, affective, and pervasive developmental problems (ORs: 2.45–3.40). Stratification by sex indicated significance in girls but not in boys. BKMR analysis showed that, among the metal mixtures, As displayed a major effect on behavior scores. Concentrations of urinary cadmium in infants were also associated with higher behavioral scores but did not increase the risk of clinical problems. A cross-sectional survey in 5-year-olds did not show a significant association between concurrent metal exposure and behavioral outcome. ConclusionOur results showed that exposure to As and Cd during infancy was associated with emotional problems in children. The effect of arsenic exposure was more pronounced among female infants. We suggest reducing exposure to toxic metals during early postnatal life to prevent behavioral problems in children."

Manganese metal ion removal from aqueous solution using industrial wastes derived geopolymer

Heavy metal pollutants, highly toxic and invisible, have garnered attention due to bioaccumulation. Increased manganese production from steel industries is expected to lead to harmful concentrations in water, adversely affecting the environment and public health. The sustainable approach of utilizing industrial by-products to synthesize geopolymers for the immobilization of heavy metal ions has gained research interest. The current study aims to verify the feasibility of Paper sludge ash (PSA) in conventional geopolymer (CGP) to immobilize manganese (Mn) heavy metal ions from aqueous solutions. CGP was prepared using Fly ash (FA) as resource material, which was replaced by PSA at a level of 30 %, by weight. The precursors were treated with alkali solutions, namely sodium hydroxide and sodium silicate, incorporating ambient curing. The characterization studies of precursors and CGP were investigated using XRD, XRF, SEM, EDS, FTIR, and Brunauer-Emmett-Teller surface area (BET) analysis techniques to outline the crystal structure, morphology, and pore parameters. Additionally, the experimental investigation comprehensively examined the impact of various pH levels, dosages, contact times, and initial concentrations on the removal efficiency of Mn heavy metal ions. The difference in concentration of Mn heavy metal ions quantified by atomic absorption spectrometry. The Langmuir models effectively explained the removal of Mn ions by CGP due to high fitting coefficients. The highest value of uptake capacity was found to be 28 mg/g at 30 °C with pH value of 4. Therefore, blending industrial wastes improves the potential of decontamination agents in removing heavy metals from wastewater, promoting environmental sustainability.

Some Physicochemical Parameters and Heavy Metals Concentration in Water and Organs of Oreochromis niloticus (Linnaeus, 1758) in Ajiwa Reservoir, Katsina State

Ajiwa Reservoir serves as a vital drinking water source and protein source to the nearby communities and Katsina metropolitan. Fishes are a great dependable source of protein and assessment to determine their safety or otherwise is very crucial. In this work, four vital organs (gills, gonads, liver and muscles) collected from Ajiwa reservoir in Katsina state were analyzed for some heavy metals (Cobalt, Copper, Manganese, Nickel, and Lead). This preliminary investigation was carried out between September to December (2023) to expose additional information on the concentration of heavy metals in both water and tissues of Oreochromis niloticus, four sampling stations were randomly chosen for the survey along the bank of the reservoir. Samples were collected fortnightly throughout the research. The mean physicochemical parameters of the Ajiwa reservoir were pH (7.10±0.48), Temperature (22.93±4.02), Transparency (12.61±2.46), Conductivity (113.97±10.63), DO (6.78±1.09), and BOD (3.52±0.88). Atomic Absorption Spectrometry (AAS) instrument was used to determine the heavy metal concentrations in the samples and their levels compared with the World Health Organization (WHO, 2020) specified maximum levels. The results showed the concentration of heavy metals in the water to be (mg/L) Co (0.45±0.23), Cu (0.05±0.03), Mn (0.06±0.09), Ni (0.10±0.07), and Pb (0.40±0.18). Co, Mn, Ni and Pb were higher than the set standards limits of WHO (2023). The results indicate that the concentration of heavy metals in the analyzed fish tissues are in (mg/L) Co (1.03±0.16), Cu (0.13±0.05), Mn (0.10±0.19), Ni (0.18±0.22) and Pb (0.21±0.66). The concentration of Co, Ni and Pb were above the set standards of WHO (2020). Co, Mn and Pb concentrations mostly in the liver and gills were higher than the maximum permissible limit recommended by standard bodies.