MnSO4 Research Articles

Highly improved aqueous Zn‖LiMn2O4 hybrid-ion batteries using poly(ethylene glycol) and manganese sulfate as electrolyte additives

Using a low dosage of poly(ethylene glycol) and MnSO4 for co-filling a bisalt electrolyte efficiently enhances the charging/discharging cycling performance of aqueous Zn‖LiMn2O4 batteries at relatively low current densities.

Evaluation of Chili Germplasm against Leaf Spot and its Management by Nutrients and Fungicides

Chili (Capsicum annum L.) is a widely grown vegetable in tropical and subtropical areas that is attacked by a diverse range of bacterial and fungal pathogens, causing severe yield and quality losses. Alternaria leaf spot, caused by Alternaria alternata, is the major fungal disease of chili that deteriorates the vitality of the crop. The objective of the current research is to identify the most effective nutrient combination and fungicide against Alternaria leaf spot disease and to evaluate resistant sources. The current research was conducted using six varieties (CH-121, Chilli-900 F1, Red Wing, SAYBAN, AAHP-1, and Diamond CH-121) collected from Ayub Agricultural Research Institute, Faisalabad, Pakistan. Seeds were sown in the Plant Pathology field area, University of Agriculture, Faisalabad, to screen against leaf spot disease. The effect of different fungicides and nutrients to overcome chili leaf spot was studied, and three treatment combinations were prepared: (ZnSO4 (ZS) + MnSO4 (MS) + boric acid (BA) + Topsin M), (ZS + MS + BA + Mancozeb), and (ZS + MS + BA + Vitavax). Among these, the combination of (ZS + MS + BA + Vitavax) was the most effective against leaf spot disease. Minimum disease severity was observed with ZS + MS + BA + Vitavax in CH-121 (15.00), while maximum disease severity was observed with the control in Red Wing (93.67). Environmental data were collected and statistically analyzed. There was a significant (p 0.05) but positive correlation between maximum temperature, minimum temperature, wind speed, rainfall, and disease severity. There was a negative correlation between relative humidity and disease severity. In conclusion, micronutrients were found to enhance Alternaria leaf spot tolerance in chili plants, providing a cost-effective and easily obtainable solution. The combined use of nutrients and fungicide is effective in preventing the development of resistance in pathogens against fungicides.

Optimizing the Zn, Mn, and Fe mineral dose as tank mix foliar application for improvement of fruit yield, quality, and uptake of nutrients in the kinnow mandarin

Kinnow production is hampered due to the lack of micronutrient applications such as zinc (Zn), iron (Fe), and manganese (Mn), which play a significant role in the metabolic activities of the plant, affecting yield and quality. The farmers of the region use mineral micronutrient fertilizers, but it leads to phytotoxicity due to unoptimized fertilizer application dose. In the present investigation, an attempt has been made to optimize the Zn, Mn, and Fe minerals dose as tank mix foliar application for improvement of fruit yield, quality, and uptake of nutrients. The twelve combinations of different doses of zinc sulphate, manganese sulphate, and ferrous sulphate fertilizers replicated three times were tested at kinnow orchards established at Krishi Vigyan Kendra, Bathinda, Punjab, India. The data revealed that the fruit drop was significantly low in the treatment F12 (43.4%) (tank mix spray of 0.3% ZnSO4 + 0.2% MnSO4 + 0.1% FeSO4 ) compared to control treatment. The fruit yield per tree was significantly higher in the treatment F12 compared to untreated control. The juice percentage was also recorded higher in treatment F12 as compared to control, and the juice percentage improved by 2.6%. The leaf nutrient analysis also revealed translocation of higher amount of nutrient from leaf to fruit under optimized supply of micronutrient. Thus, the application of tank mix spray of 0.3% ZnSO4 + 0.2% MnSO4 + 0.1% FeSO4 may be used for better fruit yield and quality.

A Study Of Growth And Characteristics Of Metal Salt Like Manganese Sulphate [MnSO4] Doped In L Threonine Amino Acid Single Crystal For NLO Application

L threonine is one of the amino acids exhibiting NLO properties. Study of Manganese sulfate doped in L threonine has been investigated. Pure L threonine and doped with MnSO4 were grown by slow evaporation method at room temperature. Good quality & transparent crystals were obtained in a month. . The Powder XRD study shows the tetragonal structure with lattice parameter a = b = 7.506 Å and c = 7.555 Å. Doping of MnSO4 in L-threonine crystal was confirmed by FT–IR spectroscopy. NLO properties & hardness testing was executed for grown crystal. Poor SHG efficiency of grown crystal was observed as compared to KDP

Synthesis of manganese oxide from manganese ore of bajaur agency khyber Pakhtunkhwa (KPK), Pakistan

In the present work manganese sulphate developed from the Bajaur (KPK, Pakistan) manganese ore was utilized successfully for the synthesized Manganese Oxide chemically by an alkali-oxidation of manganese sulphate using the co-precipitation method. The advantages of this eco-friendly co-precipitation method include quick and easy preparation, simple control of particle size, and cost-effective composition using local ore. Because of the readily available raw materials and the controlled reaction conditions, this method is widely used in industry. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the synthetic manganese oxide. Fourier transforms infrared spectroscopy (FTIR) Infrared reveals that the O-Mn-O vibrational mode occurs in pure manganese oxide at wavelengths between 600 and 500 cm-1. The chemical composition was obtained by EDX analysis and confirmed the presence of Mn and O in the sample. Experimental optimization was done for the manganese oxide precipitation conditions. The findings show that a variety of parameters have an impact on the product yield; the precursor ratio and reaction temperature are the most important variables, and the reaction time and pH value have the greatest impact on the quality of crystallization. Bangladesh J. Sci. Ind. Res. 58(4), 221-230, 2023

Cathode Active Material Synthesis and Battery Performance Tests for Li-Ion Batteries Obtained from Domestic Raw Materials: A Special Case Study from Ore to Battery

The energy requirement brought by technological developments from the past to the present evolves depending on the society's desire to be mobile, which is increasing day by day. Many technological devices such as electrical vehicles, smart phones, computers, drones, cameras meet the required energy from rechargeable lithium-ion batteries. However, the increasing world population and the increasing specifications of the technological devices developed in parallel with the per capita energy consumption by making the raw material resources needed for the production of these technological devices even more important. Nickel, cobalt and manganese compounds, which are the main raw materials used in the cathode production of NMC type lithium-ion batteries, are among these elements of strategic and critical importance, and the production of these chemicals in appropriate quality is of great importance for the industrial development of lithium-ion-based domestic battery technologies in each country. Meta Nikel Kobalt A.Ş., is the first and the only industrially scaled nickel-cobalt plant using HPAL technology in northern hemisphere at . In Gördes plant, nickel-cobalt-manganese hydroxide intermediate product concentrate (MHP) is produced from low grade Gördes lateritic ore following the unit operations of ore preparation, mineral processing, high pressure acid leaching, neutralization and precipitation and is currently completely exported to overseas. However, due to the responsibility of transforming domestic resources to high value-added technological products and obtaining value-added products, research in this field has been regarded and the necessary technological infrastructure and specific knowledge have been created. Within the scope of this project, precious metals in the MHP intermediate product obtained from Gördes lateritic ore were leached and valuable elements are taken to the liquid phase and crystallized after further purification processes such as solvent extraction and ion exchange. As a result, metal salts with purity up to 99.99% were obtained. The obtained nickel, cobalt and manganese sulphate salts were precipitated together with the developed co-precipitation process to obtain precursor in the form of NMC 622. After that, the precursor is treated with lithium and the cathode active material (CAM) is obtained by going through various heat treatments by systematically designed test campaign. The coin cell made with the CAM obtained from domestic raw materials showed a capacity of 184.55 mAh/g at 0.1C. It showed a capacity of 170.58 mAh/g in the first cycle and 157.45 mAh/g in the 50th cycle at 0.5 C, and the capacity conservation was calculated as 92.3% after 50 cycles at 0.5 C. The CAM obtained in the pilot-scale studies carried out according to the lab-scale developed process and sent to for making pouch type battery. In the 10 Ah capacity cells of the produced pouch type, 82% capacity conversation has been achieved as a result of 1000 cycles at a charge/discharge rate of 0.5 C at 100% CoC(Dept of Discharge) in the voltage range of 3-4.15V. Figure 1

Effect of pH by Manganese Salts and Natural Organic Matter on Nanofiltration Membrane Fouling

This research aimed to determine the removal performance of manganese affected from solution pH of combined manganese salts with natural organic matter (NOM) using commercial nanofiltration (NF) membrane. The filtration experiments were tested under a dead-end filtration test cell. Variational factors used in this study were the types of manganese salts (i.e. manganese chloride (MnCl2), manganese sulfate (MnSO4), and manganese nitrate (Mn(NO3)2)) with the solution pH of 3, 5, and 7, and ionic strength of 0.01 mol/L. Water samples were prepared with NOM concentration of 10 mg/L, while the operating pressure was operated constant at 60 psig. Experimental results found that the MnSO4 salt provided the highest manganese removal efficiency of 95%, while the removal efficiencies of MnCl2 and Mn(NO3)2 were about 84.86% and 70.7%, respectively. Solution fluxes were not significantly different. In the presence of NOM concentration of 10 mg/L, solution pH of 3–7, it was found that low solution pHs for all conditions provided the highest manganese removal. The removals of NOM were relatively high more than 97%. The mathematical fouling model was done with cake filtration model (CFM) due to NOM accumulation on NF membrane surface.

Effect of Micronutrients on Growth and Yield of Chrysanthemum (Dendrathemum grandiflorum Tzeuleu) cv.CO 1

Micronutrient is considered as one of the constraints in the optimum production of crops. A field experiment entitled “Effect of micronutrients on growth, yield and quality of chrysanthemum (Dendrathemum grandiflorum Tzeuleu) cv.CO 1” was carried out at Faculty of Agriculture, Annamalai University, during 2008-2010 in Randomized Block Design with seventeen treatments and three replications. The treatment comprised of various combination of micronutrients viz., Zinc sulphate 0.5 %, Ferrous sulphate 0.5 %, Borax 0.5 %, Manganese sulphate 0.5 %, Copper sulphate 0.5 %, Mixture of all micronutrients 0.5 % and micronutrients mixture at 12.5 kg ha-1, different concentrations with recommended 25 t FYM ha-1 + Recommended Dose of Fertilizer (RDF) and a control at 5 different interval. The results of present investigation indicated that, the vegetative growth in term of plant height (54.62 cm), number of branches (10.23), number of leaves (52.15), stem girth (3.33 cm) and flower yield per plant (201.74 g) were found superior under, soil application of micronutrients mixture @ 12.5 kg ha-1 in split as basal, 25, 50 and 75 DAT days after transplanting (T17).

THE INFLUENCE OF THE SYNHTETIC WAY OF LAYERED-TYPE MANGANSESE DIOXIDE ON THE PROPERTIES OF CATHODE MATERIALS FOR AQUEOUS ZINC-ION BATTERIES

This research presents an analysis of physico-chemical, structural and electrochemical properties of cathode materials for aqueous zinc-ion batteries based on manganese dioxide with birnessite-type structure in dependence on the conditions of hydrothermal synthesis. The manganese oxides obtained are capable to the reversible zin ions intercalation into the crystal lattice because of large interlayer distances. They were considered two approaches of synthesis: a reaction between manganese sulfate and potassium permanganate at 160 °С (MnO2-I) and a hydrothermal treatment of potassium permanganate solution at 220 °С (MnO2-II). From the structural analysis it was shown that both methods allow obtaining the birnessite-type manganese dioxide. At the same time, electrochemical properties of cathodes obtained differ in the models of aqueous zinc-ion batteries. MnO2-II material demonstrate higher initial specific capacity (180 mAh∙g-1 at current density 0.3 A∙g-1) while its cyclic stability is on 40% lower than for MnO2-I material. This can be explained with higher surface area of the active material and lower crystallinity.

Assesment of Foliar Micronutrient Fertilization on Leaf and Crop Growth Attributes in Sweet Corn (Zea Mays L. saccharata)

ABSTRACT Micronutrients are critical for the development of plants and play major role in enhancing both quantitative and qualitative crop yield. To examine the impact of foliar fertilization with micronutrients on various crop growth attributes, an experiment was conducted during kharif season of 2020 and 2021. Foliar spray with different combinations of zinc sulfate, ferrous sulfate, and manganese sulfate was done at 20 and 40 days after sowing. Increased plant height, leaf area index, leaf weight ratio, leaf area ratio, specific leaf weight, specific leaf area, crop growth rate, relative growth rate, and net assimilation rate were observed. Positive effect of foliar spray was observed in all parameters through all treatments. But, the overall maximum effect was observed in the treatment of foliar spray with T9 (0.2% FeSO4 +0.5% ZnSO4) followed by T7 (0.2% FeSO4 +0.2% ZnSO4) and T8 (0.5% FeSO4 and 0.2% ZnSO4). Given the positive effect of zinc, iron and manganese micronutrients on leaf and crop growth attributes, these treatments are suggested to be applied for the development of sweet corn.

Lithium and Cesium Doping on the Properties of ZTS Crystals (Tris (Thiourea) Zinc (II) Sulphate)

The influence of alkali metals (Cs and Li) doping on the properties and crystal growth of tris(thiourea)zinc(II)sulphate crystals by slow evaporation solution growth technique at 30ºC has been investigated. Each metals as dopant incorporate into the crystal lattice even at its low concentrations is well confirmed by energy dispersive X – ray spectroscopy (EDS). In the powder X –ray diffraction (XRD), high intense peaks are observed for all doped specimens due to stress developed in the crystal because of doping when compared to pure one. Single crystal XRD reveals a nominal increase in the cell parameter values of the doped samples compared to pure. Presence of each alkali metal (Li, Cs) quantitatively is confirmed by inductively coupled plasma (ICP) technique. It is interesting to observe the enhancement of fluorescence intensity of pure ZTS by the dopant in the photoluminescence (PL) spectra. The grown crystals are also characterized by FT-IR, UV-Visible and TG/DSC methods. The second harmonic generation (SHG) efficiency, an essential character required for the single crystals to identify the non-linear optical (NLO) property, was performed by kurtz powder technique. 2.The characterization results of influence of various concentration of Mn (II) ion on the properties and crystalline perfection of ammoniumdihydrogenphosphate (ADP) crystal are presented. Using water as a solvent pure, 1 and 20 mol % of Mn (II) ion in the form manganese (II) sulphate added ADP crystals are prepared by slow evaporation solution growth technique (SEST). Well faceted grown crystals are characterised by different experimental techniques. The presence of Mn (II) in the doped specimens is confirmed by energy dispersive X-ray spectroscopy (EDS) and inductively coupled plasma (ICP) technique. High resolution X- ray diffraction (HRXRD) study of the doped samples when compared with the pure ADP crystal reveals interesting features. In the single crystal XRD studies, the dopants have not altered the lattice parameter values and the crystal system of pure ADP. Reduction in the intensity of peaks is observed in the powder XRD of all the doped samples. It is interesting to enhancement of fluorescence intensity of pure ADP by the dopants in the photoluminescence (PL) spectra. The surface morphology of the crystals is studied by scanning electron microscopy (SEM). The grown crystals are also characterized by FT-IR, UV-Vis and TG/DTA methods. The second harmonic generation (SHG) efficiency, which is an essential character required for the single crystals to identify the nonlinear optical (NLO) property, is performed by Kurtz powder technique. Increasing in concentrations of dopant enhance the SHG efficiency of ADP crystal.

Kinetics of the antisolvent crystallization of manganese sulfate monohydrate from a pregnant leach solution

Kinetics of the antisolvent crystallization of manganese sulfate monohydrate from a pregnant leach solution

Efficient leaching of manganese from electrolytic manganese residue and recovery of the leaching solution: Reuse and purification

Electrolytic manganese residue (EMR) is a hazardous solid waste, while it also contains resources of Mn over 7 %. In this study, sulfuric acid with high concentration was used to leach Mn from EMR, and the leaching solution was reused and purified to produce battery-grade manganese sulfate. The optimal leaching conditions for EMR were determined through single-factor experiments and response surface methodology. Under the conditions of H2SO4 concentration at 5.4 mol/L, liquid–solid ratio at 4.8 mL/g, and temperature at 80 °C, the highest Mn leaching efficiency of 99.12 % was achieved. The kinetics of leaching Mn from EMR follows the Avrami model. The leaching characteristics were described according to the basic hypothesis made by the Avrami equation and the fitted Avrami index. The kinetic process is macroscopically regarded as the inverse process of non-equilibrium crystallization. According to the Arrhenius equation, the leaching of Mn is controlled by the mixture of diffusion and reaction with an apparent activation energy of 19.8 kJ/mol. The EMR leaching solution was then reused for the leaching step of rhodochrosite ore to simulate actual production. The secondary leaching solution was purified using neutralization, sulfide precipitation, and fluoride precipitation, and manganese sulfate with high purity was produced from it by evaporative crystallization. This study provides a low-cost and high-efficiency process for leaching and recovering Mn from EMR, which can also reduce the environmental risk.

Scaled-up aqueous redox flow battery using anthraquinone negalyte and vanadium posilyte with inorganic additive

In this study, one kilowatt aqueous redox flow battery (ARFB) using anthraquinone-2,7-disulfonic acid (2,7-AQDS) and vanadium oxide sulfate (VOSO4) as active materials for negalyte (negative electrolyte) and posilyte (positive electrolyte) is successfully accomplished. Then, manganese sulfate (MnSO4) is further included in negalyte to increase reactivity of active materials and to suppress their crossover by controlling their osmotic pressure. This binary effects of MnSO4 are predicted by density functional theory and reduction in concentration gap. The decrease in energy band gap of 2,7-AQDS with MnSO4 facilitated electron transfer rate. Anodic and cathodic diffusion coefficient and reaction rate constant are also improved. More specifically, with adoption of MnSO4 additive, energy efficiency and capacity retention rate of ARFB single cells operated with MnSO4 additive are improved from 79.1 to 83.9% at the current density of 40 mA cm−2 and from 82 to 88% at the current density of 80 mA cm−2 after 100 cycles. Based on that, ARFB stack using 2,7-AQDS and VOSO4 with MnSO4 additive is prepared and this ARFB stack exhibits a high power of 1.15 kW.

Manganese sulfate application promotes berry flavonoid accumulation in Vitis vinifera cv. 'Cabernet Sauvignon' by regulating flavonoid metabolome and transcriptome profiles.

Flavonoids are vital for developing grapes and wine quality, and manganese deficiency decreases grape berry coloration. However, the effects and underlying mechanisms of action of manganese sulfate on grape metabolic profiles have not been well studied. In this study, three concentrations of manganese sulfate solutions: 0.5 μmol·L-1 (low, L), 5 μmol·L-1 (middle, M, the standard manganese concentration of Hoagland nutrient solution, control), and 1000 μmol·L-1 (high, H) were applied to "Cabernet Sauvignon" grapevine (Vitis vinifera L.) to explore the effect on berry composition. Manganese application effectively improved manganese concentration in grape organs. Furthermore, the concentrations of malvidin 3-O-(6-O-acetyl)-glucoside, malvidin 3-O-glucoside, malvidin-trans-3-O-(6-O-p-coumaryl)-glucoside, and peonidin 3-O-(6-O-acetyl)-glucoside were significantly increased under H treatment. More importantly, weighted gene co-expression network analysis (WGCNA) revealed that the structural genes (VvDFR, VvUFGT, and VvOMT) of flavonoid biosynthesis in brown module were upregulated under H treatment, and positively correlated with malvidin- and peonidin-derived anthocyanin concentrations. This study suggested that manganese application regulates berry transcriptional and flavonoid metabolic profiles, providing a theoretical basis for improving the color of red grapes and wines. This article is protected by copyright. All rights reserved.

An environmentally friendly approach for the extraction and recovery of Mn from pyrolusite by ammonium sulfate roasting‐water leaching and ammonium carbonate precipitation

AbstractWith the growth of the new energy industry, the requirements for manganese have increased significantly. In this paper, the method of manganese extraction from pyrolusite using ammonium sulfate roasting and water leaching was presented. At the optimal process parameters: mass ratio of (NH4)2SO4 to pyrolusite of 2:1, the roasting temperature of 420°,C and duration of 120 min, the leaching efficiency of Mn and Fe was 94.55% and 54.38%, respectively. The mechanism analysis shows that MnO2 and Fe2O3 in pyrolusite were converted to (NH4)2Mn2(SO4)3, (NH4)3Fe(SO4)3, and NH4Fe(SO4)2 by roasting with ammonium sulfate. Iron was removed from the leaching solution with the addition of ammonia. Afterward, manganese carbonate products were prepared from iron‐free manganese sulfate solution by adding ammonium carbonate at a stirring duration of 60 min, a reaction temperature of 40°C, a pH of 7, and a molar ratio of ammonium carbonate to the manganese of 1.1:1, the precipitation efficiency of manganese could reach 99.8%, and the obtained manganese carbonate products were compliant with the industry standards. The ammonia released during the roasting process could be absorbed to regenerate (NH4)2SO4 and the final filtrate after evaporation and crystallization could be used to recycle (NH4)2SO4, both of which were used again into roasting process to reduce the consumption of raw material. In this process, the roasting temperature was only 420°C, which was significantly lower than the pyrometallurgical process suggested in earlier studies.

Study on the efficiency of manganese oxide-bearing manganese sand for removing Mn2+ from aqueous solution

To obtain efficient and rapid manganese removal performance of NMS (natural manganese sand), MOBMs (manganese oxide-bearing manganese sand) were prepared and loaded with manganese oxide formed by forced oxidation of manganese sulfate with sodium hypochlorite onto the surface of NMS. The results of SEM, EDS, BET, XPS, XRD and Zeta potential analyses showed that manganese oxides were successfully loaded on the surface of NMS, with the main components being MnO2 and Mn2O3. The surface of MOBMs is covered by needle-shaped flocculent manganese oxides, with a large number of mesopores. The isothermal adsorption and kinetic adsorption model indicated that the adsorption of Mn2+ by MOBMs occurred through monolayer adsorption and chemical adsorption. The intraparticle diffusion model showed that the adsorption process is dominated by mesoporous and microporous diffusion, which is controlled by adsorption, membrane diffusion, particle diffusion and catalytic oxidation. Under the conditions of the static test, the best adsorption conditions were determined as follows: Df = 2 g/100 ml (q = 0.149 mg/g), pH = 7.5–8.5. Under these conditions, the removal rate of Mn2+ by MOBMs was 84.47%. The presence of competing cations NH4+ and Fe2+ had a negative effect on the removal of Mn2+. The dynamic test shows that the MOBM maturation cycle takes only 7 days. MOBMs can realize the efficient utilization of low-quality NMS, shorten the maturity period of manganese removal filter material, improve the adsorption performance, and ensure the efficient removal of Mn2+.

Biological synthesis of manganese oxide nanoparticles from aerial parts of Prunus dulcis and their in vitro investigation of medical properties

The field of functional nanohybrid material is an emerging research area in material science due to its vast range of applications. The use of novel technology and innovative therapeutics has led to potent applications, including controlling the size of nanoparticles (NPs). This has resulted in a novel report on the synthesis of manganese oxide NPs using aerial parts of queen of roses Prunus dulcis (almond) leaves, seed, and seed oil (using Clevenger apparatus), which functions as a reducing agent. Manganese sulfate was used as a precursor in the synthesis process. The synthesized nanohybrid Mn3O4 NPs were studied using different characteristics techniques such as X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy‐dispersive X‐ray spectroscopy (EDX). The photoluminescence spectra display the blue emission ranging from 483.2 to 486.5 nm. The biosynthesized Mn3O4 NPs were tested for bactericidal activity and showed tremendous inhibition against gram‐positive and gram‐negative bacteria. The antioxidant activity of Mn3O4 NPs was enhanced using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) assay, which revealed the higher activity of Mn3O4 NPs from P. dulcis leaf extract. In vitro cytotoxicity of hybrid Mn3O4 NPs was examined using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay against cervical cancer (HeLa cell line) with different concentrations. The results showed an IC50 value of 61.97 μg mL−1 for Mn3O4 NPs from P. dulcis leaf extract. In general, the phytosynthetic route with synergistic effect of nanohybrid demonstrated an interaction with cancer cells, highlighting a pioneering optimum approach in synthesis of Mn3O4 NPs from aerial parts of P. dulcis.

The effect of nanomaterials in the treatment of medical waste in hospitals

In recent years, there has been a significant increase in the amount of medical waste produced, which poses a serious threat to the environment. Within such waste, the presence of antibiotics, which are now widely used, poses a potential threat to human health. This paper investigates the ability of Fe–Mn-NAM adsorbent material made from water hyacinth extract, iron chloride, and manganese sulfate, to adsorb the antibiotics norfloxacin (NOR) and ofloxacin (OFLX) in medical solid waste. Experimental results indicated that the specific surface area of the Fe–Mn-NAM nanosorbent material was 32.56 m2/g, with an average pore volume of 0.083 cm3/g and an average pore size of 3.21 nm. The amount of antibiotics adsorbed by Fe–Mn-NAM peaked under weakly alkaline conditions, and the capacity of the material to adsorb NOR significantly exceeded that for OFLX. There was a negative correlation between the amount of Fe–Mn-NAM adsorbent material added and the adsorption of NOR and OFLX, and a positive correlation with the antibiotic removal rate. At the same adsorbent dosage, the amount of adsorption and the removal rate of NOR by the Fe–Mn-NAM adsorbent material were significantly higher than for OFLX. Through electrostatic attraction, hydrogen bonding, surface complexation, and surface hydrophobicity, the Fe–Mn-NAM adsorbent material demonstrated a certain capacity to treat and eliminate NOR and OFLX in medical solid waste.

A near-zero waste process for the full-component utilization of deep-sea polymetallic nodules based on reductive leaching with SO2 followed by separation and recovery

Recovery of critical metals from marine minerals is a promising option to ensure the sustainable supply of critical metals, but existing recovery processes suffer from technical bottlenecks in terms of low resource utilization and large waste discharge. This paper presents a complete hydrometallurgical route for the full-component utilization of deep-sea polymetallic nodules (DPN). Leaching experiments were first carried out in the presence of SO2 because cheap SO2 can destroy the original mineral structure based on a reductive mechanism. The leaching efficiencies of Ni, Co, Mn, Cu, La, Ce, and Fe were reached 99.2%, 99.3%, 98.7%, 95.9%, 95.3%, 95.4%, and 91.4%, respectively, under the optimal conditions of 30 °C, L/S ratio of 6:1 mL/g, H2SO4 dosage of 37.5 wt%. The downstream process aimed at the sequential recycling of metal ions from the pregnant leach solution (PLS) consists of Fe recovery by the hematite process, selective solvent extraction of Cu and rare earth elements (REEs), co-extraction of Ni/Co/Mn, and Mn electrowinning. As a result, high-grade hematite (60 wt% of Fe), industrial-grade CuSO4, mixed rare earth oxides, battery-grade (Ni, Co, Mn)SO4 solution, and electrolytic manganese were obtained. During the whole process, the recovery efficiency of Ni, Co, Mn, Cu, La, Ce, and Fe reached 97.1%, 97.1%, 96.9%, 91.5%, 91.1%, 91.1%, and 91.3%, respectively. Since the hydrometallurgical process achieves the resource utilization of all the DPN constituents, it has the advantages of near-zero waste and low energy consumption.