Selenium distillation slag(SDS)is a high-value-added secondary resource with a high recovery value.This paper aims to investigate the leaching behavior and kinetics of selenium,tellurium,and copper in the SDS acid oxi...Selenium distillation slag(SDS)is a high-value-added secondary resource with a high recovery value.This paper aims to investigate the leaching behavior and kinetics of selenium,tellurium,and copper in the SDS acid oxidation leaching process with H_(2)SO_(4) and H_(2)O_(2).The experimental results showed that under the optimum conditions,the contents of selenium,tellurium,and copper in the SDS were reduced from 22.13 wt%,3.58 wt%,and 6.42 wt%to 3.06 wt%,0.27 wt%,and 0.33 wt%,respectively.Correspondingly,the recovery rates are 87.08%,97.15%and 99.7%.The leaching processes of selenium and tellurium were controlled by diffusion and chemical reactions,and the leaching behavior of copper was controlled by chemical reactions.Below 45℃,the activation energies for selenium,tellurium,and copper were found to be 26.47,62.18 and 19.67 kJ/mol,respectively.In addition,the contents of lead,silver and gold in the leaching residue are increased to 46.8 wt%,8.35 wt%and 0.27 wt%,respectively.These substances can be utilized as raw materials for the recovery of these valuable metals.Importantly,the entire process does not generate toxic or harmful waste,making it a green and environmentally friendly method for resource recovery.展开更多
To completely recover valuable elements and reduce the amount of waste,the impact of phosphoric acid on the decomposition of rare earth,fluorine and phosphorus during cyclic leaching was studied based on the character...To completely recover valuable elements and reduce the amount of waste,the impact of phosphoric acid on the decomposition of rare earth,fluorine and phosphorus during cyclic leaching was studied based on the characteristics of low-tempe rature sulfuric acid deco mposition.When a single monazite was leached using 75 wt% H_(2)SO_(4) solution with phosphoric acid,the size and number of monazite particles in the washing slag gradually decrease with the increase in phosphoric acid content in the leaching solution.The monazite phase can hardly be found in the slag when the phosphoric acid content reaches 70 g/L,which indicates that phosphoric acid is favorable for monazite decomposition.The mixed rare earth concentrate was leached by 75 wt% H_(2)SO_(4) containing 70 g/L phosphoric acid,the mineral compositions of the washing slag are only gypsum and unwashed rare earth sulfuric acid.After cyclic leaching of75 wt% H_(2)SO_(4),the mineral compositions of the primary leaching washing slag are mainly undecomposed monazite,rare earth sulfate and calcium sulfate.However,monazite is not found in the mineral phase of the second and third leaching washing slag.The leaching rates of rare earth and phosphorus gradually increase with the increase in cyclic leaching times.In addition,the phosphoric acid content in the leaching solution increases with the increase in the number of cyclic leaching time.However,the rising trend decreases when the phosphoric acid content reaches 50 g/L by adsorption and crystallization of phosphoric acid.A small amount of water can be used to clean the leaching residue before washing to recover the more soluble phosphorus acid according to the difference of dissolution between phosphoric acid and rare earth sulfuric acid.展开更多
Chemical leaching techniques have been proven effective in removing heavymetal contaminants fromsoil using various leaching agents.Previous research has shown that both singleagent and composite leaching systems have ...Chemical leaching techniques have been proven effective in removing heavymetal contaminants fromsoil using various leaching agents.Previous research has shown that both singleagent and composite leaching systems have been applied for the remediation of chromiumcontaminated soils,with varying degrees of success depending on soil type and contaminant form.However,the removal rate of total chromium(Cr)and hexavalent chromium(Cr(Ⅵ))often fluctuates based on the chemical composition of the leaching agents,as well as the soil’s physicochemical properties,such as pH and Cr speciation stability.Therefore,this study investigates the effectiveness of 20 composite leaching systems,including deionized water,lime water,calcium chloride,sodium carbonate,and sodium phosphate,through soil column leaching tests.The aim was to evaluate their impact on soil pH,total Cr,and Cr(Ⅵ)removal,and to examine the transformation of various Cr species during the leaching process.Results reveal that lime water and sodium phosphate were particularly effective in stabilizing Cr(Ⅵ)and neutralizing soil pH,while total Cr removal amount ranged from 197.4 mg/kg to 1671.6 mg/kg and Cr(Ⅵ)removal amount ranged from 113.2mg/kg to 316.8mg/kg.We also find that using 0.2 mol/L citric acid,0.1 mol/L hydrochloric acid,and 1.2 mL/g lime solution adjusted soil pH to 7.37,with average removal efficiencies of 34.6%.for total Cr and 72.7%for Cr(Ⅵ).Overall,our results suggest that the combined use of lime water and sodium phosphate is an effective strategy for remediating chromium-contaminated soil,particularly for stabilizing unleached Cr and adjusting soil pH.展开更多
Neodymium-iron-boron(Nd-Fe-B)sludge is an important secondary resource of rare-earth elements(REEs).However,the state-of-the-art recycling method,i.e.,HCl-preferential dissolution faces challenges such as slow leachin...Neodymium-iron-boron(Nd-Fe-B)sludge is an important secondary resource of rare-earth elements(REEs).However,the state-of-the-art recycling method,i.e.,HCl-preferential dissolution faces challenges such as slow leaching kinetics,excessive chemical consumption and wastewater generation.In this work,the in situ anodic leaching of Nd-Fe-B sludge was developed to selectively recover REEs with high efficiency.The leaching rates of the REEs are 2.4-9.0 times higher using the in situ anodic leaching at the current density from 10 to 40 mA/cm^(2)than using conventional chemical leaching under the maintained pH of 3.7.Mechanism studies reveal that the anode-generated H~+plays the key role during the in situ anodic leaching process that locally increases the H^(+)concentration at the interface of sludge particles,accele rating the leaching kinetics.By achieving a total leaching efficiency of Nd-Fe-B sludge close to 100%and the Fe deposition efficiency in the range of 70.9%-74.3%,selective leaching of REEs is successfully realized and thus largely reduces chemical consumption.Additionally,a two-step recycling route involving electrolysis-selective precipitation was proposed that enables a stable REEs recovery of 92.2%with recyclable electrolyte.This study provides a novel and environmentally-friendly strategy for the efficient recovery of REEs from secondary resources.展开更多
Cyanide is the most widely used reagent in gold production processes. However, cyanide is highly toxic and poses safety haz-ards during transportation and use. Therefore, it is necessary to develop gold leaching reage...Cyanide is the most widely used reagent in gold production processes. However, cyanide is highly toxic and poses safety haz-ards during transportation and use. Therefore, it is necessary to develop gold leaching reagents that can replace cyanide. This paper intro-duces a method for synthesizing a gold leaching reagent. Sodium cyanate is used as the main raw material, with sodium hydroxide and so-dium ferrocyanide used as additives. The gold leaching reagent can be obtained under the conditions of a mass ratio of sodium cyanate,sodium hydroxide, and sodium ferrocyanide of 15:3:1, synthesis temperature of 600℃, and synthesis time of 1 h. This reagent has a goodrecovery effect on gold concentrate and gold-containing electronic waste. The gold leaching rate of roasted desulfurized gold concentratecan reach 87.56%. For the extraction experiments of three types of gold-containing electronic waste, the gold leaching rate can reach over90% after 2 h. Furthermore, the reagent exhibits good selectivity towards gold. Component analysis indicates that the effective compon-ent in the reagent could be sodium isocyanate.展开更多
The rare earth elements(REEs)extraction by chemical leaching from ion-adsorption type rare earth ores(IAREO)has led to serious ecological and environmental risks.Conversely,demand for bioleaching is on the rise with t...The rare earth elements(REEs)extraction by chemical leaching from ion-adsorption type rare earth ores(IAREO)has led to serious ecological and environmental risks.Conversely,demand for bioleaching is on the rise with the advantage of being environmental-friendly.As one of the organic acids produced by biological metabolism,citric acid was used to leach REEs and explore the performance and process.The results demonstrate that citric acid exhibits higher leaching efficiency(96.00%)for REEs at a relatively low concentration of 0.01 mol/L compared with(NH_(4))_(2)SO_(4)(84.29%,0.1 mol/L)and MgSO_(4)(83.99%,0.1 mol/L).Citric acid shows a preference for leaching heavy rare earth elements,with 99%leaching efficiency in IAREO,which shows higher capacity than(NH_(4))_(2)SO_(4)and MgSO_(4)(as inorganic leaching agents).Kinetic analysis indicates that the leaching process of REEs with citric acid is controlled by both the internal diffusion kinetics and chemical reaction kinetics,which is different from inorganic leaching agents.Visual Minteq calculations confirm that RE-Citrate is the main constituent of the extract solution in the leaching process of the IAREO,thereby enhancing the leaching efficiency of REEs from the IAREO.It suggests that citric acid may be used as a promising organic leaching agent for the environmentalfriendly extraction of REEs from IAREO.展开更多
The leaching process of magnesiothermic self-propagating product generated during the multistage deep reduction process was investigated.The influence of magnesiothermic self-propagating product particle size,HCl solu...The leaching process of magnesiothermic self-propagating product generated during the multistage deep reduction process was investigated.The influence of magnesiothermic self-propagating product particle size,HCl solution concentration,and leaching solution temperature on the leaching behavior of elements Al and V was investigated.Results demonstrate that the leaching rate of Al and V is increased with the rise in leaching solution temperature,the increase in HCl solution concentration,and the enlargement of magnesiothermic self-propagating product particle size.The leaching processes of Al and V are consistent with the chemical reaction control model.When the magnesiothermic self-propagation product with D_(50) of 59.4μm is selected as the raw material,the leaching temperature is 40℃,and 1 mol/L HCl solution is employed,after leaching for 180 min,the leaching rates of Al and V are 24.8%and 12.6%,respectively.The acid-leached product exhibits a porous structure with a specific surface area of 3.5633 m^(2)/g.展开更多
As the main component of electronic products,plastics contain complex and diverse metal additives.Recycling process is not conducive to stable existence of metal additives in electronic plastics.Once the e-waste plast...As the main component of electronic products,plastics contain complex and diverse metal additives.Recycling process is not conducive to stable existence of metal additives in electronic plastics.Once the e-waste plastics enter the environment,they will continue to release harmful metals into environment after aging,causing serious hazards.This study delved into the analysis and comparison of metal content of e-waste plastics,elucidating aging process and metal leaching behavior over a 112-day natural light exposure period.The findings underscored that metal content in recycled plastics surpassed that in their new counterparts.Specifically,Ti content in new plastics remained below 100 mg/kg,while recycled plastics exhibited Ti content surpassing 100 mg/kg threshold.Throughout prolonged natural light exposure,metals such as Zn,Ba and Sb demonstrated a heightened likelihood of release from electronic plastics in comparison to other metals.The aging process during light exposure led to fragmentation of electronic plastics,accompanied by a reduction in particle size.Notably,the particle size reduction was more pronounced in poly acrylonitrile butadiene styrene(ABS)and recycled ABS,experiencing reductions of 40µm and 85µm,respectively.This phenomenon was attributed to the presence of polybutadiene structural units,which proved more susceptible to aging.Along with the breaking of plastics,the ABS plastics released metal species such as Pb,Cd,Ni,Al that had not been detected in other plastics solutions.The collective evidence from this study suggested that ABS and recycled ABS electronic plastics might pose a heightened potential environmental risk compared to other electronic plastics.展开更多
针对Leach(low energy adaptive clustering hierarchy)协议在大规模网络中存在着数据传输效率不高和网络生命周期短的问题,提出了一种LEACH-CM-NGO优化算法。该方法通过在簇头选取阶段优化簇头数在所有节点中占比,引进能量密度因子和...针对Leach(low energy adaptive clustering hierarchy)协议在大规模网络中存在着数据传输效率不高和网络生命周期短的问题,提出了一种LEACH-CM-NGO优化算法。该方法通过在簇头选取阶段优化簇头数在所有节点中占比,引进能量密度因子和能耗因子改进阈值公式优化簇头分布,并在数据传输阶段,由原本的单跳传输改为多跳方式传输数据,引入基于立方映射方法,自适应权重策略和柯西变异的北方苍鹰优化算法改进簇头间数据传输路径,以提高网络的能效和数据传输效率。仿真结果表明,所提出的方法在减少能耗的同时,显著延长了网络的生命周期并提高了数据传输的成功率。展开更多
Copper extraction from chalcopyrite is challenging,because acid dissolution is slow,occurring incongruently via a complex three-step reaction mechanism.Silver has been known to catalyse copper extraction from chalcopy...Copper extraction from chalcopyrite is challenging,because acid dissolution is slow,occurring incongruently via a complex three-step reaction mechanism.Silver has been known to catalyse copper extraction from chalcopyrite since the 1970's;yet the mechanism remains controversial.Microcharacterisation of experimental products obtained under optimal leaching conditions(50-150μm chalcopyrite grains in ferric/ferrous-sulfate solution with a redox potential around 500 mV vs.Ag/AgCl,approximately 1ppm Ag;[Ag]6.4×10^(−6)mol/L;70℃;4 days)highlights the heterogeneity of the reaction:µm-thick layers of a porous copper-sulfide with variable composition formed both in cracks within,and on the surface of the chalcopyrite grains.There is no evidence for formation of Ag-rich phases(Ag_(2)S_((s)),Ag_((s)^(0))).The fundamental three-step reaction mechanism remains the same with or without added silver;silver merely accelerates the initial dissolution step.An integrated model for the catalytic effect of silver is proposed that incorporates recent advances in the reactivity of sulfide minerals.The initial reaction follows a‘Fluid-Induced Solid State Diffusion Mechanism’,where diffusion of Fe in the chalcopyrite lattice is driven towards the surface by its rapid removal into solution,resulting in a Fe-deficient surface layer.The large Ag+ion,relative to Cu+/Fe3+,diffuses into this Fe-deficient surface layer and accelerates chalcopyrite dissolution in the subsequent step,whereby chalcopyrite is replaced by copper sulfides via an interface coupled dissolution reprecipitation reaction as a consequence of the sulfide-rich micro-environment at the mineral surface.Effective Ag+recycling is key to the catalytic effect of silver,and occurs as a result of the strong affinity of Ag+for bisulfide ligands accumulating at the surface of dissolving chalcopyrite.展开更多
With the development of vanadium redox flow battery technology,the demand for pure vanadium is rapidly increasing.The separation of vanadium from vanadium-chromium leaching solutions are critical step in the productio...With the development of vanadium redox flow battery technology,the demand for pure vanadium is rapidly increasing.The separation of vanadium from vanadium-chromium leaching solutions are critical step in the production of purity-vanadium.This study presents an innovative adsorption process that utilizes amorphous ZrO_(2)(AZrO) for the selective separation of V(Ⅴ) and Cr(Ⅵ).In this process,a high adsorption capacity for V(V) at 64.5 mg·g^(-1) was achieved,while the capacity for Cr(Ⅵ) is relatively low at 24.1 mg·g^(-1),demonstrating good separation performance.This is mainly caused by the large specific surface area and mesoporous structure,which are favorable for molecular diffusion and mass transfer.The kinetic analysis shows that the adsorption process follows pseudo-second-order kinetic process with chemisorption being the rate-controlling process.AZrO showed excellent separation performance in mixed solutions over a wide range of concentrations.After five cycles,AZrO retained over 73% of its capacity,indicating good stability.In mixed solutions containing up to 40 g·L^(-1) of V(Ⅴ) and 3 g·L^(-1) of Cr(Ⅵ),the innovative adsorption process successfully achieved effective separation and purification.By an adsorption-desorption process using 0.1 mol·L^(-1) NaOH,a 99.02% V(Ⅴ)-rich solution was obtained from a high concentration sodium vanadium slag leaching solution,demonstrating its effectiveness for practical industrial applications.展开更多
Extracting lithium from coal measures can alleviate the shortage of strategic metal resources.However,the lattice substitution characteristics of lithium in carrier minerals and its extremely fine intercalation and en...Extracting lithium from coal measures can alleviate the shortage of strategic metal resources.However,the lattice substitution characteristics of lithium in carrier minerals and its extremely fine intercalation and entrainment behavior are the challenges that constrain the extraction efficiency of lithium from coal series.This study focuses on improving the separation efficiency between lithium-contain-ing minerals and other minerals and the release behavior of lithium in the liquid phase.First,the feasibility of extracting lithium from car-rier minerals is confirmed based on the occurrence state and the process mineralogy characterized by Bgrimm process mineralogy analyz-ing system(BPMA)and time of flight secondary ion mass spectrometry(TOF-SIMS).The optimal selective grinding behavior is achieved within 15 min,allowing Li carrier minerals,including chlorite,kaolinite,and halloysite,to deliver the best dispersion effect with other minerals.Thus,the enriched lithium carrier minerals have been preenriched through screening.The leaching efficiency of Li has reached 97.43%under 1 mol/L hydrochloric acid,15 g/L pulp density,70℃,and 20 min.Leaching kinetics studies indicate that the de-crease in apparent energy validates the impact of grinding on metal leaching,aligning with the rate-controlling step of a chemical reaction.The process proposed in this study achieves the coordinated control of size and components in coal gangue and actualizes the effective se-lective enrichment of lithium through its low energy consumption and environmentally friendly nature.展开更多
Improving cotton fiber quality can increase the economic income of cotton farmers, but achieving high fiber quality without decreasing cotton fiber yield remains a major challenge in saline-alkaline cotton fields. A f...Improving cotton fiber quality can increase the economic income of cotton farmers, but achieving high fiber quality without decreasing cotton fiber yield remains a major challenge in saline-alkaline cotton fields. A field experiment was conducted in 2020 and 2021 on saline-alkaline soil with cotton under drip irrigation to examine how amount and timing of leaching affected soils salinity, cotton fiber yield and quality. There were five leaching amounts(CK: 0 mm, W1: 75 mm, W2: 150 mm, W3: 225 mm and W4: 300 mm) and three leaching timings(T1: once at the seedling stage, T2: twice at the seedling and budding stages, and T3: thrice at the seedling, budding and pollen-setting stages). Soil salinity, soil nitrate nitrogen(NO_(3)-N), cotton nitrogen(N) uptake, irrigation water productivity(IWP), cotton fiber yield, fiber length, fiber uniformity, fiber strength, fiber elongation, micronaire and fiber quality index(FQI) were investigated. The results indicated that soil salinity and NO_(3)-N reduced with increasing leaching amount. The N uptake of cotton bolls was greater than in cotton leaves, stems and roots, and total N accumulation increased with increasing leaching amount. The optimal cotton fiber yield and IWP occurred in treatment W3T2, and were 3,199 and 2,771 kg ha^(-1), and 0.5482 and 0.4912 kg m-3in 2020 and 2021, respectively. Fiber length, strength, elongation, and uniformity increased with increasing leaching amount, while there was a negative relationship between fiber micronaire and leaching amount. Soil salinity, NO_(3)-N and fiber micronaire were negatively correlated with fiber quality(i.e., length, strength, elongation and uniformity) and yield, nitrogen uptake of various organs(i.e., root, stems and leaves) and whole plant nitrogen uptake. Pearson correlation analysis revealed that fiber elongation was most sensitive to soil salinity. The method of Entropy–Order Preference by Similarity to Ideal Solution(EM–TOPSIS) indicated that leaching of 300 mm of water applied equally at the seedling and budding periods was the optimal treatment to maintain soil salinity and nutrient levels and achieve high cotton fiber yield and quality. In conclusion, the optimal level of leaching treatment decreased soil salinity and improved nitrogen uptake and was beneficial to achieve high fiber yield and quality. Our results will be significant for guiding drip irrigation practice of leaching on saline-alkaline soils for sustainable cotton fiber production.展开更多
Contamination of microplastics(MPs)and their associated plastic additives in the marine environment is a global concern due to their widespread distribution and toxicity to aquatic life.Although polyvinyl chloride(PVC...Contamination of microplastics(MPs)and their associated plastic additives in the marine environment is a global concern due to their widespread distribution and toxicity to aquatic life.Although polyvinyl chloride(PVC)materials are commonly used in aquaculture environments,the potential risks of PVC MPs and the release of their additives in aquatic environments and organisms remain largely unknown.In this study,we investigated the leaching behaviors of phthalate esters(PAEs),including the mass and composition of PAEs in PVC MPs and their leaching kinetics,and evaluated the environmental risks of using PVC canvas in aquaculture activities.It was found that diethyl phthalate(DEP)was the most dominant PAE compound leached from PVC MPs(44.70±7.87 ng/g),followed by dimethyl phthalate(DMP,24.40±1.56 ng/g).The Elovich model was applied to simulate the leaching kinetics,and the simulated curves showed similar logarithmic trends that PAEs rapidly migrated from MPs to the water column at first and followed by a gradual increase over time.The different leaching kinetics of PAEs can be explained by their chemical properties,such as water solubility,molecular weight,and octanol-water partition coefficient.Compounds with lower solubility showed higher leaching coefficients,which are the constants of different PAEs in Elovich equation.Considering the potential joint toxicity of PVC leachates and the importance of food security,it is recommended to use PVC products responsibly and manage plastic waste properly.展开更多
Cotton,as one of important economic crops,is widely planted in the saline-alkaline soil of southern Xinjiang,China.Moreover,in order to control the saline-alkaline content for seed germination and seedlings survive of...Cotton,as one of important economic crops,is widely planted in the saline-alkaline soil of southern Xinjiang,China.Moreover,in order to control the saline-alkaline content for seed germination and seedlings survive of cotton,farmers always adopt salt leaching during winter and spring seasons.However,excessive amount of salt leaching might result in the waste of water resources and unsuitable irrigation seasons might further increase soil salinization.In this study,a field experiment was conducted in the saline-alkaline soil in 2020 and 2021 to determine the effects of leaching amount and period on water-salinity dynamics and cotton yield.Five leaching amounts(0.0(W0),75.0(W1),150.0(W2),225.0(W3),and 300.0(W4)mm)and three leaching periods(seedling stage(P1),seedling and squaring stages(P2),and seedling,squaring,flowering,and boll setting stages(P3))were used.In addition,a control treatment(CK)with a leaching amount of 300.0 mm in spring was performed.The soil water-salt dynamics,cotton growth,seed cotton yield,water productivity(WP),and irrigation water productivity(WPI)were analyzed.Results showed that leaching significantly decreased soil electrical conductivity(EC),and W3P2 treatment reduced EC by 11.79%in the 0-100 cm soil depth compared with CK.Plant height,stem diameter,leaf area index,and yield under W3 and W4 treatments were greater than those under W1 and W2 treatments.Compared with W3P1 and W3P3 treatments,seed cotton yield under W3P2 treatment significantly enhanced and reached 6621 kg/hm^(2)in 2020 and 5340 kg/hm^(2)in 2021.Meanwhile,WP and WPI under W3P2 treatment were significantly higher than those under other leaching treatments.In conclusion,the treatment of 225.0 mm leaching amount and seedling and squaring stages-based leaching period was beneficial for the salt control,efficient water utilization,and yield improvement of cotton in southern Xinjiang,China.展开更多
Cropland nitrate leaching is the major nitrogen(N) loss pathway, and it contributes significantly to water pollution. However, cropland nitrate leaching estimates show great uncertainty due to variations in input data...Cropland nitrate leaching is the major nitrogen(N) loss pathway, and it contributes significantly to water pollution. However, cropland nitrate leaching estimates show great uncertainty due to variations in input datasets and estimation methods. Here, we presented a re-evaluation of Chinese cropland nitrate leaching, and identified and quantified the sources of uncertainty by integrating three cropland area datasets, three N input datasets, and three estimation methods. The results revealed that nitrate leaching from Chinese cropland averaged 6.7±0.6 Tg N yr^(-1)in 2010, ranging from 2.9 to 15.8 Tg N yr^(-1)across 27 different estimates. The primary contributor to the uncertainty was the estimation method, accounting for 45.1%, followed by the interaction of N input dataset and estimation method at 24.4%. The results of this study emphasize the need for adopting a robust estimation method and improving the compatibility between the estimation method and N input dataset to effectively reduce uncertainty. This analysis provides valuable insights for accurately estimating cropland nitrate leaching and contributes to ongoing efforts that address water pollution concerns.展开更多
基金Project(2022YFC2904900) supported by the National Key Research and Development Program of ChinaProject(U1902221) supported by the National Natural Science Foundation of China。
文摘Selenium distillation slag(SDS)is a high-value-added secondary resource with a high recovery value.This paper aims to investigate the leaching behavior and kinetics of selenium,tellurium,and copper in the SDS acid oxidation leaching process with H_(2)SO_(4) and H_(2)O_(2).The experimental results showed that under the optimum conditions,the contents of selenium,tellurium,and copper in the SDS were reduced from 22.13 wt%,3.58 wt%,and 6.42 wt%to 3.06 wt%,0.27 wt%,and 0.33 wt%,respectively.Correspondingly,the recovery rates are 87.08%,97.15%and 99.7%.The leaching processes of selenium and tellurium were controlled by diffusion and chemical reactions,and the leaching behavior of copper was controlled by chemical reactions.Below 45℃,the activation energies for selenium,tellurium,and copper were found to be 26.47,62.18 and 19.67 kJ/mol,respectively.In addition,the contents of lead,silver and gold in the leaching residue are increased to 46.8 wt%,8.35 wt%and 0.27 wt%,respectively.These substances can be utilized as raw materials for the recovery of these valuable metals.Importantly,the entire process does not generate toxic or harmful waste,making it a green and environmentally friendly method for resource recovery.
基金support by the National Natural Science Foundation of Inner Mongolia (2022SHZR1885)Natural Science Foundation of Hebei province (E2022402101,E2022402105)。
文摘To completely recover valuable elements and reduce the amount of waste,the impact of phosphoric acid on the decomposition of rare earth,fluorine and phosphorus during cyclic leaching was studied based on the characteristics of low-tempe rature sulfuric acid deco mposition.When a single monazite was leached using 75 wt% H_(2)SO_(4) solution with phosphoric acid,the size and number of monazite particles in the washing slag gradually decrease with the increase in phosphoric acid content in the leaching solution.The monazite phase can hardly be found in the slag when the phosphoric acid content reaches 70 g/L,which indicates that phosphoric acid is favorable for monazite decomposition.The mixed rare earth concentrate was leached by 75 wt% H_(2)SO_(4) containing 70 g/L phosphoric acid,the mineral compositions of the washing slag are only gypsum and unwashed rare earth sulfuric acid.After cyclic leaching of75 wt% H_(2)SO_(4),the mineral compositions of the primary leaching washing slag are mainly undecomposed monazite,rare earth sulfate and calcium sulfate.However,monazite is not found in the mineral phase of the second and third leaching washing slag.The leaching rates of rare earth and phosphorus gradually increase with the increase in cyclic leaching times.In addition,the phosphoric acid content in the leaching solution increases with the increase in the number of cyclic leaching time.However,the rising trend decreases when the phosphoric acid content reaches 50 g/L by adsorption and crystallization of phosphoric acid.A small amount of water can be used to clean the leaching residue before washing to recover the more soluble phosphorus acid according to the difference of dissolution between phosphoric acid and rare earth sulfuric acid.
基金supported by the National Key Research and Development Program of China(No.2023YFC3707902)China Postdoctoral Science Foundation(No.2024M752168)+1 种基金Jiangsu Funding Programfor Excellent Postdoctoral Talent(No.2024ZB393)the National Natural Science Foundation of China(No.42407126).
文摘Chemical leaching techniques have been proven effective in removing heavymetal contaminants fromsoil using various leaching agents.Previous research has shown that both singleagent and composite leaching systems have been applied for the remediation of chromiumcontaminated soils,with varying degrees of success depending on soil type and contaminant form.However,the removal rate of total chromium(Cr)and hexavalent chromium(Cr(Ⅵ))often fluctuates based on the chemical composition of the leaching agents,as well as the soil’s physicochemical properties,such as pH and Cr speciation stability.Therefore,this study investigates the effectiveness of 20 composite leaching systems,including deionized water,lime water,calcium chloride,sodium carbonate,and sodium phosphate,through soil column leaching tests.The aim was to evaluate their impact on soil pH,total Cr,and Cr(Ⅵ)removal,and to examine the transformation of various Cr species during the leaching process.Results reveal that lime water and sodium phosphate were particularly effective in stabilizing Cr(Ⅵ)and neutralizing soil pH,while total Cr removal amount ranged from 197.4 mg/kg to 1671.6 mg/kg and Cr(Ⅵ)removal amount ranged from 113.2mg/kg to 316.8mg/kg.We also find that using 0.2 mol/L citric acid,0.1 mol/L hydrochloric acid,and 1.2 mL/g lime solution adjusted soil pH to 7.37,with average removal efficiencies of 34.6%.for total Cr and 72.7%for Cr(Ⅵ).Overall,our results suggest that the combined use of lime water and sodium phosphate is an effective strategy for remediating chromium-contaminated soil,particularly for stabilizing unleached Cr and adjusting soil pH.
基金Project supported by the Natural Science Foundation of Inner Mongolia Autonomous Region of China(2021BS02007,2022MS02014)the"Science and Technology Project of Ordos"Program(2021 CGI 17-9,2021 ZDI11-14)+2 种基金the National Natural Science Foundation of China(21971129,21961022,51903125,21661023)the"Inner Mongolia Autonomous Region 2022 Leading Talent Team of Science and Technology"Program(2022LJRC0008)China Postdoctoral Science Foundation(2018M640043,2019T120038)。
文摘Neodymium-iron-boron(Nd-Fe-B)sludge is an important secondary resource of rare-earth elements(REEs).However,the state-of-the-art recycling method,i.e.,HCl-preferential dissolution faces challenges such as slow leaching kinetics,excessive chemical consumption and wastewater generation.In this work,the in situ anodic leaching of Nd-Fe-B sludge was developed to selectively recover REEs with high efficiency.The leaching rates of the REEs are 2.4-9.0 times higher using the in situ anodic leaching at the current density from 10 to 40 mA/cm^(2)than using conventional chemical leaching under the maintained pH of 3.7.Mechanism studies reveal that the anode-generated H~+plays the key role during the in situ anodic leaching process that locally increases the H^(+)concentration at the interface of sludge particles,accele rating the leaching kinetics.By achieving a total leaching efficiency of Nd-Fe-B sludge close to 100%and the Fe deposition efficiency in the range of 70.9%-74.3%,selective leaching of REEs is successfully realized and thus largely reduces chemical consumption.Additionally,a two-step recycling route involving electrolysis-selective precipitation was proposed that enables a stable REEs recovery of 92.2%with recyclable electrolyte.This study provides a novel and environmentally-friendly strategy for the efficient recovery of REEs from secondary resources.
基金financially supported by the National Natural Science Foundation of China (No.51974016)。
文摘Cyanide is the most widely used reagent in gold production processes. However, cyanide is highly toxic and poses safety haz-ards during transportation and use. Therefore, it is necessary to develop gold leaching reagents that can replace cyanide. This paper intro-duces a method for synthesizing a gold leaching reagent. Sodium cyanate is used as the main raw material, with sodium hydroxide and so-dium ferrocyanide used as additives. The gold leaching reagent can be obtained under the conditions of a mass ratio of sodium cyanate,sodium hydroxide, and sodium ferrocyanide of 15:3:1, synthesis temperature of 600℃, and synthesis time of 1 h. This reagent has a goodrecovery effect on gold concentrate and gold-containing electronic waste. The gold leaching rate of roasted desulfurized gold concentratecan reach 87.56%. For the extraction experiments of three types of gold-containing electronic waste, the gold leaching rate can reach over90% after 2 h. Furthermore, the reagent exhibits good selectivity towards gold. Component analysis indicates that the effective compon-ent in the reagent could be sodium isocyanate.
基金Project supported by the Thousand Talents Program of Jiangxi Province,China(JXSQ2023201003)National Natural Science Foundation of China(42107254)+4 种基金Science and Technology Major Program of Ordos City(2022EEDSKJZDZX014-2)Technological Innovation Guidance Program of Jiangxi Province(20212BDH81029)Rare Earth Industry Fund(IAGM2020DB06)Selfdeployed Projects of Ganjiang Innovation Academy,Chinese Academy of Sciences(E055A01)the Key Research Program of the Chinese Academy of Sciences(ZDRW-CN-2021-3-3)。
文摘The rare earth elements(REEs)extraction by chemical leaching from ion-adsorption type rare earth ores(IAREO)has led to serious ecological and environmental risks.Conversely,demand for bioleaching is on the rise with the advantage of being environmental-friendly.As one of the organic acids produced by biological metabolism,citric acid was used to leach REEs and explore the performance and process.The results demonstrate that citric acid exhibits higher leaching efficiency(96.00%)for REEs at a relatively low concentration of 0.01 mol/L compared with(NH_(4))_(2)SO_(4)(84.29%,0.1 mol/L)and MgSO_(4)(83.99%,0.1 mol/L).Citric acid shows a preference for leaching heavy rare earth elements,with 99%leaching efficiency in IAREO,which shows higher capacity than(NH_(4))_(2)SO_(4)and MgSO_(4)(as inorganic leaching agents).Kinetic analysis indicates that the leaching process of REEs with citric acid is controlled by both the internal diffusion kinetics and chemical reaction kinetics,which is different from inorganic leaching agents.Visual Minteq calculations confirm that RE-Citrate is the main constituent of the extract solution in the leaching process of the IAREO,thereby enhancing the leaching efficiency of REEs from the IAREO.It suggests that citric acid may be used as a promising organic leaching agent for the environmentalfriendly extraction of REEs from IAREO.
基金Scientific and Technological Project of Nanyang(23KJGG017)Key Specialized Research&Development and Promotion Project(Scientific and Technological Project)of Henan Province(232102221022)+1 种基金College Students and Technology Innovation Fund Project of Nanyang Institute of Technology(2023139)Project of Doctoral Scientific Research Startup Fund of Nanyang Institute of Technology(NGBJ-2023-25)。
文摘The leaching process of magnesiothermic self-propagating product generated during the multistage deep reduction process was investigated.The influence of magnesiothermic self-propagating product particle size,HCl solution concentration,and leaching solution temperature on the leaching behavior of elements Al and V was investigated.Results demonstrate that the leaching rate of Al and V is increased with the rise in leaching solution temperature,the increase in HCl solution concentration,and the enlargement of magnesiothermic self-propagating product particle size.The leaching processes of Al and V are consistent with the chemical reaction control model.When the magnesiothermic self-propagation product with D_(50) of 59.4μm is selected as the raw material,the leaching temperature is 40℃,and 1 mol/L HCl solution is employed,after leaching for 180 min,the leaching rates of Al and V are 24.8%and 12.6%,respectively.The acid-leached product exhibits a porous structure with a specific surface area of 3.5633 m^(2)/g.
基金the Natural Science Foundation of Guangdong Province(No.2021B1515020041)the National Natural Science Foundation of China(No.42277403)+4 种基金the Projects of International Cooperation and Exchange of the National Natural Science Foundation of China(NSFC-UNEP)(No:32261143459)the Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control(No.2023B1212060002)the Guangdong Major Project of Basic and Applied Basic Research(No.2023B0303000024)the High-level University Special Fund(No.G03050K001)the Research Projects of the General Administration of Customs(No.2022HK060)for financial support.
文摘As the main component of electronic products,plastics contain complex and diverse metal additives.Recycling process is not conducive to stable existence of metal additives in electronic plastics.Once the e-waste plastics enter the environment,they will continue to release harmful metals into environment after aging,causing serious hazards.This study delved into the analysis and comparison of metal content of e-waste plastics,elucidating aging process and metal leaching behavior over a 112-day natural light exposure period.The findings underscored that metal content in recycled plastics surpassed that in their new counterparts.Specifically,Ti content in new plastics remained below 100 mg/kg,while recycled plastics exhibited Ti content surpassing 100 mg/kg threshold.Throughout prolonged natural light exposure,metals such as Zn,Ba and Sb demonstrated a heightened likelihood of release from electronic plastics in comparison to other metals.The aging process during light exposure led to fragmentation of electronic plastics,accompanied by a reduction in particle size.Notably,the particle size reduction was more pronounced in poly acrylonitrile butadiene styrene(ABS)and recycled ABS,experiencing reductions of 40µm and 85µm,respectively.This phenomenon was attributed to the presence of polybutadiene structural units,which proved more susceptible to aging.Along with the breaking of plastics,the ABS plastics released metal species such as Pb,Cd,Ni,Al that had not been detected in other plastics solutions.The collective evidence from this study suggested that ABS and recycled ABS electronic plastics might pose a heightened potential environmental risk compared to other electronic plastics.
文摘针对Leach(low energy adaptive clustering hierarchy)协议在大规模网络中存在着数据传输效率不高和网络生命周期短的问题,提出了一种LEACH-CM-NGO优化算法。该方法通过在簇头选取阶段优化簇头数在所有节点中占比,引进能量密度因子和能耗因子改进阈值公式优化簇头分布,并在数据传输阶段,由原本的单跳传输改为多跳方式传输数据,引入基于立方映射方法,自适应权重策略和柯西变异的北方苍鹰优化算法改进簇头间数据传输路径,以提高网络的能效和数据传输效率。仿真结果表明,所提出的方法在减少能耗的同时,显著延长了网络的生命周期并提高了数据传输的成功率。
基金supporting this work through an ARC linkage grant(LP190101230)Part of this work was funded by ARC DP220100500+2 种基金The authors acknowledge the use of the instruments and scientific and technical assistance at the Monash Centre for Electron Microscopy,Monash University,a Microscopy Australia(ROR:042mm0k03)facility supported by NCRISThis research used equipment funded by Australian Research Council grant(s)(LE200100132,LE110100223).
文摘Copper extraction from chalcopyrite is challenging,because acid dissolution is slow,occurring incongruently via a complex three-step reaction mechanism.Silver has been known to catalyse copper extraction from chalcopyrite since the 1970's;yet the mechanism remains controversial.Microcharacterisation of experimental products obtained under optimal leaching conditions(50-150μm chalcopyrite grains in ferric/ferrous-sulfate solution with a redox potential around 500 mV vs.Ag/AgCl,approximately 1ppm Ag;[Ag]6.4×10^(−6)mol/L;70℃;4 days)highlights the heterogeneity of the reaction:µm-thick layers of a porous copper-sulfide with variable composition formed both in cracks within,and on the surface of the chalcopyrite grains.There is no evidence for formation of Ag-rich phases(Ag_(2)S_((s)),Ag_((s)^(0))).The fundamental three-step reaction mechanism remains the same with or without added silver;silver merely accelerates the initial dissolution step.An integrated model for the catalytic effect of silver is proposed that incorporates recent advances in the reactivity of sulfide minerals.The initial reaction follows a‘Fluid-Induced Solid State Diffusion Mechanism’,where diffusion of Fe in the chalcopyrite lattice is driven towards the surface by its rapid removal into solution,resulting in a Fe-deficient surface layer.The large Ag+ion,relative to Cu+/Fe3+,diffuses into this Fe-deficient surface layer and accelerates chalcopyrite dissolution in the subsequent step,whereby chalcopyrite is replaced by copper sulfides via an interface coupled dissolution reprecipitation reaction as a consequence of the sulfide-rich micro-environment at the mineral surface.Effective Ag+recycling is key to the catalytic effect of silver,and occurs as a result of the strong affinity of Ag+for bisulfide ligands accumulating at the surface of dissolving chalcopyrite.
基金supported financially by the National Natural Science Foundation of China(22178229)the Natural Science Foundation of Sichuan Province(2022NSFSC1190)。
文摘With the development of vanadium redox flow battery technology,the demand for pure vanadium is rapidly increasing.The separation of vanadium from vanadium-chromium leaching solutions are critical step in the production of purity-vanadium.This study presents an innovative adsorption process that utilizes amorphous ZrO_(2)(AZrO) for the selective separation of V(Ⅴ) and Cr(Ⅵ).In this process,a high adsorption capacity for V(V) at 64.5 mg·g^(-1) was achieved,while the capacity for Cr(Ⅵ) is relatively low at 24.1 mg·g^(-1),demonstrating good separation performance.This is mainly caused by the large specific surface area and mesoporous structure,which are favorable for molecular diffusion and mass transfer.The kinetic analysis shows that the adsorption process follows pseudo-second-order kinetic process with chemisorption being the rate-controlling process.AZrO showed excellent separation performance in mixed solutions over a wide range of concentrations.After five cycles,AZrO retained over 73% of its capacity,indicating good stability.In mixed solutions containing up to 40 g·L^(-1) of V(Ⅴ) and 3 g·L^(-1) of Cr(Ⅵ),the innovative adsorption process successfully achieved effective separation and purification.By an adsorption-desorption process using 0.1 mol·L^(-1) NaOH,a 99.02% V(Ⅴ)-rich solution was obtained from a high concentration sodium vanadium slag leaching solution,demonstrating its effectiveness for practical industrial applications.
基金supported by the National Key R&D Program of China(No.2023YFC2907701)This work was also supported by the Fundamental Research Program of Shanxi Province,China(No.202103021223045)+4 种基金the Shanxi Scholarship Council of China(No.2022-062)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi,China(No.2021L064)This study was also funded by Open Foundation of State Key Laboratory of Mineral Processing(No.BGRIMM-KJSKL-2025-26)This work was supported by the National Natural Science Foundation of China(No.52104260)This work was supported by Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
文摘Extracting lithium from coal measures can alleviate the shortage of strategic metal resources.However,the lattice substitution characteristics of lithium in carrier minerals and its extremely fine intercalation and entrainment behavior are the challenges that constrain the extraction efficiency of lithium from coal series.This study focuses on improving the separation efficiency between lithium-contain-ing minerals and other minerals and the release behavior of lithium in the liquid phase.First,the feasibility of extracting lithium from car-rier minerals is confirmed based on the occurrence state and the process mineralogy characterized by Bgrimm process mineralogy analyz-ing system(BPMA)and time of flight secondary ion mass spectrometry(TOF-SIMS).The optimal selective grinding behavior is achieved within 15 min,allowing Li carrier minerals,including chlorite,kaolinite,and halloysite,to deliver the best dispersion effect with other minerals.Thus,the enriched lithium carrier minerals have been preenriched through screening.The leaching efficiency of Li has reached 97.43%under 1 mol/L hydrochloric acid,15 g/L pulp density,70℃,and 20 min.Leaching kinetics studies indicate that the de-crease in apparent energy validates the impact of grinding on metal leaching,aligning with the rate-controlling step of a chemical reaction.The process proposed in this study achieves the coordinated control of size and components in coal gangue and actualizes the effective se-lective enrichment of lithium through its low energy consumption and environmentally friendly nature.
基金financially supported by the National Key Research and Development Program of China (2022YFD1900401)the Science and Technology Project of Agriculture, Xinjiang Production and Construction Corps, China (2021AB037)。
文摘Improving cotton fiber quality can increase the economic income of cotton farmers, but achieving high fiber quality without decreasing cotton fiber yield remains a major challenge in saline-alkaline cotton fields. A field experiment was conducted in 2020 and 2021 on saline-alkaline soil with cotton under drip irrigation to examine how amount and timing of leaching affected soils salinity, cotton fiber yield and quality. There were five leaching amounts(CK: 0 mm, W1: 75 mm, W2: 150 mm, W3: 225 mm and W4: 300 mm) and three leaching timings(T1: once at the seedling stage, T2: twice at the seedling and budding stages, and T3: thrice at the seedling, budding and pollen-setting stages). Soil salinity, soil nitrate nitrogen(NO_(3)-N), cotton nitrogen(N) uptake, irrigation water productivity(IWP), cotton fiber yield, fiber length, fiber uniformity, fiber strength, fiber elongation, micronaire and fiber quality index(FQI) were investigated. The results indicated that soil salinity and NO_(3)-N reduced with increasing leaching amount. The N uptake of cotton bolls was greater than in cotton leaves, stems and roots, and total N accumulation increased with increasing leaching amount. The optimal cotton fiber yield and IWP occurred in treatment W3T2, and were 3,199 and 2,771 kg ha^(-1), and 0.5482 and 0.4912 kg m-3in 2020 and 2021, respectively. Fiber length, strength, elongation, and uniformity increased with increasing leaching amount, while there was a negative relationship between fiber micronaire and leaching amount. Soil salinity, NO_(3)-N and fiber micronaire were negatively correlated with fiber quality(i.e., length, strength, elongation and uniformity) and yield, nitrogen uptake of various organs(i.e., root, stems and leaves) and whole plant nitrogen uptake. Pearson correlation analysis revealed that fiber elongation was most sensitive to soil salinity. The method of Entropy–Order Preference by Similarity to Ideal Solution(EM–TOPSIS) indicated that leaching of 300 mm of water applied equally at the seedling and budding periods was the optimal treatment to maintain soil salinity and nutrient levels and achieve high cotton fiber yield and quality. In conclusion, the optimal level of leaching treatment decreased soil salinity and improved nitrogen uptake and was beneficial to achieve high fiber yield and quality. Our results will be significant for guiding drip irrigation practice of leaching on saline-alkaline soils for sustainable cotton fiber production.
基金Supported by the State Key Laboratory of Marine Pollution(SKLMP)in City University of Hong Kong,the Shenzhen Science and Technology Program(No.JCYJ20220530140813030 to Meng YAN)the Innovation and Technology Commission(ITC)of the Hong Kong SAR Government(No.9448002),which provides regular research funding support to SKLMP。
文摘Contamination of microplastics(MPs)and their associated plastic additives in the marine environment is a global concern due to their widespread distribution and toxicity to aquatic life.Although polyvinyl chloride(PVC)materials are commonly used in aquaculture environments,the potential risks of PVC MPs and the release of their additives in aquatic environments and organisms remain largely unknown.In this study,we investigated the leaching behaviors of phthalate esters(PAEs),including the mass and composition of PAEs in PVC MPs and their leaching kinetics,and evaluated the environmental risks of using PVC canvas in aquaculture activities.It was found that diethyl phthalate(DEP)was the most dominant PAE compound leached from PVC MPs(44.70±7.87 ng/g),followed by dimethyl phthalate(DMP,24.40±1.56 ng/g).The Elovich model was applied to simulate the leaching kinetics,and the simulated curves showed similar logarithmic trends that PAEs rapidly migrated from MPs to the water column at first and followed by a gradual increase over time.The different leaching kinetics of PAEs can be explained by their chemical properties,such as water solubility,molecular weight,and octanol-water partition coefficient.Compounds with lower solubility showed higher leaching coefficients,which are the constants of different PAEs in Elovich equation.Considering the potential joint toxicity of PVC leachates and the importance of food security,it is recommended to use PVC products responsibly and manage plastic waste properly.
基金supported by the National Key Research and Development Program of China(2021YFD1900805,2022YFD1900401)the Science and Technology Project,Xinjiang Production and Construction Corps,China(2021AB009,2024AB030).
文摘Cotton,as one of important economic crops,is widely planted in the saline-alkaline soil of southern Xinjiang,China.Moreover,in order to control the saline-alkaline content for seed germination and seedlings survive of cotton,farmers always adopt salt leaching during winter and spring seasons.However,excessive amount of salt leaching might result in the waste of water resources and unsuitable irrigation seasons might further increase soil salinization.In this study,a field experiment was conducted in the saline-alkaline soil in 2020 and 2021 to determine the effects of leaching amount and period on water-salinity dynamics and cotton yield.Five leaching amounts(0.0(W0),75.0(W1),150.0(W2),225.0(W3),and 300.0(W4)mm)and three leaching periods(seedling stage(P1),seedling and squaring stages(P2),and seedling,squaring,flowering,and boll setting stages(P3))were used.In addition,a control treatment(CK)with a leaching amount of 300.0 mm in spring was performed.The soil water-salt dynamics,cotton growth,seed cotton yield,water productivity(WP),and irrigation water productivity(WPI)were analyzed.Results showed that leaching significantly decreased soil electrical conductivity(EC),and W3P2 treatment reduced EC by 11.79%in the 0-100 cm soil depth compared with CK.Plant height,stem diameter,leaf area index,and yield under W3 and W4 treatments were greater than those under W1 and W2 treatments.Compared with W3P1 and W3P3 treatments,seed cotton yield under W3P2 treatment significantly enhanced and reached 6621 kg/hm^(2)in 2020 and 5340 kg/hm^(2)in 2021.Meanwhile,WP and WPI under W3P2 treatment were significantly higher than those under other leaching treatments.In conclusion,the treatment of 225.0 mm leaching amount and seedling and squaring stages-based leaching period was beneficial for the salt control,efficient water utilization,and yield improvement of cotton in southern Xinjiang,China.
基金supported by the National Key Research and Development Program of China (2023YFD1902703)the National Natural Science Foundation of China (Key Program) (U23A20158)。
文摘Cropland nitrate leaching is the major nitrogen(N) loss pathway, and it contributes significantly to water pollution. However, cropland nitrate leaching estimates show great uncertainty due to variations in input datasets and estimation methods. Here, we presented a re-evaluation of Chinese cropland nitrate leaching, and identified and quantified the sources of uncertainty by integrating three cropland area datasets, three N input datasets, and three estimation methods. The results revealed that nitrate leaching from Chinese cropland averaged 6.7±0.6 Tg N yr^(-1)in 2010, ranging from 2.9 to 15.8 Tg N yr^(-1)across 27 different estimates. The primary contributor to the uncertainty was the estimation method, accounting for 45.1%, followed by the interaction of N input dataset and estimation method at 24.4%. The results of this study emphasize the need for adopting a robust estimation method and improving the compatibility between the estimation method and N input dataset to effectively reduce uncertainty. This analysis provides valuable insights for accurately estimating cropland nitrate leaching and contributes to ongoing efforts that address water pollution concerns.
