Precipitable Substances Research Articles

New genetic type of lithium mineralization

In the southern part of the Siberian platform, a new genetic type of lithium mineralization was discovered in the Lower Cambrian halogen-carbonate formation of the Angara-Lena marginal trough, which arose as a result of the introduction of a fluid-saturated solution into the sedimentary cover of the platform. Focal hydrothermal development of halogen-carbonate deposits along deep faults led to the formation of lithium-bearing mineralization. A gradual reduction in tectonic activity within the Angara-Lena marginal trough was accompanied by the subsidence of hydrothermal-sedimentary deposits. In this case, the precipitated substance was dispersed and later transformed into layers. It has been established that the main lithium minerals are hectorite and lithiophorite. The results of a study of lithological and geochemical associations of rare earth elements in sections of Early Cambrian deposits of the studied lithium mineralization are presented.

Evaluation of The Performance of Enzyme-Induced Calcite Precipitations (EICP) Solutions Based on pH and Electrical Conductivity

Abstract EICP is an innovative, sustainable technology that utilizes specific chemicals, particularly urea and calcium chloride, in conjunction with the urease enzyme to induce the precipitation of calcium carbonate. The abovementioned technology is widely acknowledged as contemporary and environmentally responsible, aligning with established sustainability principles and green construction criteria. The quantity of precipitated calcium carbonate is contingent upon the composition of the materials employed in the precipitation process and their respective proportions. The investigation focused on determining the best percentage of calcium carbonate precipitation by conducting experiments on different concentrations of urea, calcium chloride, and the urease enzyme and examining the specific characteristics of the chemical solution that facilitate the precipitation process. The augmentation of urea and calcium chloride to a certain proportion resulted in a corresponding augmentation in the quantity of precipitated substances such as calcium carbonate. In the course of furthering the increase process, it was observed that the value of the precipitated materials remained constant and did not exhibit any further augmentation for some mixing ratios. According to the results of current study, the best ratio to precipitated calcium carbonate can be attributed to using an optimal ratio of 1 mol/L of urea and 0.5 mol/L of calcium chloride. Due to the notable efficacy of urease, the concentration increment of urease did not exhibit significant variation beyond 1 g/l. However, the alteration in the rate of reaction velocity will influence the outcome of EICP process. The experimental results and integration of several methodologies demonstrated a positive correlation between temperature elevation and reaction rate augmentation, resulting in a rapid reaction termination.

Electrocoagulation for the decolorization of textile wastewater in single-channel reactor: Response surface methodology for optimization and a novel model exploitation

This work focuses on the multi-objective optimization of the electrocoagulation process. The goal is to decolorize synthetic Reactive Black 5 wastewater using a single-channel reactor operating in a closed-circuit. Response Surface Methodology (RSM) is employed for the optimization. The Central Composite Design (CCD) is used to study the empirical relationship between two responses (decolorization efficiency (η) and energy consumption (WC)) and four independent variables (recirculation flow rate (Qv), current intensity (I), electrolysis time (τe) and active electrode area (Sa)), while the desirability function (D) is applied to determine optimal conditions. In addition, a novel approach for the exploitation of the RSM model is developed to set correlations between the limit of η (ηLim) and corresponding independent variables’ limit values (below of which η < ηLim). The developed correlations showed a good agreement between the graphical data and the estimated values (R2 > 0.99). The CCD model fits well the experimental data with a R2 of 0.94 and 0.95, for η and WC, respectively. The analysis of variance allowed to build quadratic models for both responses. For a maximal overall desirability D of 0.88, optimal conditions are Qv = 70 L h−1, I = 100 mA, τe = 34.6 min and Sa = 621 cm2. Under these conditions, η = 70.9% and WC = 4.6 Wh.m−3 were achieved. The sludge characterization using X-ray diffraction, Scanning Electron Microscopy, and Fourier Transform InfraRed reveals the formation of the amorphous Al(OH)3 without other precipitated substances and authenticates the successful sorption of RB5 onto the Aluminum hydroxide flocs.

Marine barite morphology as an indicator of biogeochemical conditions within organic matter aggregates

Marine barite is commonly used as a proxy to reconstruct past ocean productivity. Its distribution in the water column mirrors organic carbon fluxes since it precipitates within microenvironments in decomposing organic matter aggregates. Barite and barium proxies are therefore used to study various aspects of organic matter remineralization and the marine carbon cycle. Barite naturally occurs in a wide variety of crystal sizes and morphologies, but barite crystals that form in the ocean water column are dominantly 1–2 μm in length and have barrel-shaped morphologies. Here, we conducted a series of laboratory experiments to determine the physical and chemical conditions that yield barite crystals similar to marine barite. We found that barite saturation index, the presence and identity of organic compounds, and experiment duration all exert a strong influence on barite crystal size and morphology. Barrel-shaped, 1 μm length crystals resembling marine barite were produced in experiments with a barite saturation index of 2.5, soy phospholipid concentrations of ≥50 mg L−1, and experiment durations of ≤10 min. These findings help constrain the plausible biogeochemical conditions within the aggregate microenvironments in which marine barite precipitates. Relatively high experimental concentrations of phospholipids are consistent with the hypothesized involvement of extracellular polymeric substances in marine barite precipitation. Short experiment durations suggest that a favorable saturation state may be short-lived in marine organic matter aggregates. We present detailed mineralogical and crystallographic analyses of the crystals we synthesized to gain insight into barite crystal growth. This work deepens our understanding of the mechanisms behind marine barite precipitation and sheds light on microscale spatial and temporal dynamics within organic matter aggregates.

The current ecological and ichthyotoxicological state of the shlis-selburg bay lake Ladoga

The article presents the materials of biological and chemical-analytical studies of the Shlisselburg Bay of Ladoga lake, that plays an important fishery and sanitary-hygienic role as a source of water supply of St. Petersburg. The dominant role of ichthyo-fauna in the assay of the ecological and toxicological state of the studied water area is shown. The purpose of the conducted research is to assess the ecological and ichthyo - toxicological state of the Shlisselburg Bay of Ladoga lake, as one of the main fishery water areal and the only source of water supply of St. Petersburg (the source of the Neva River). Biological and chemical analytical studies of the water area of the Shlisselburg Bay in laboratory conditions were carried out in the summer-autumn period in 2022 in three water areas. A feature of the Shlisselburg Bay is the presence of a runoff flow, that initiates the removal of pollutants and the nature of bottom sediments, which makes the Bay less vulnerable to anthropogenic impact. Currently, the methods used to assess water quality for the fisheries perspective are biological – bioindication and biotesting, as well as the results of chemical analysis in comparison with the standards for the content of harmful substances in water, sediments, precipitation and fish. Preference is given to “express’ methods: biotesting and bioindication of fish research results. Analysis of materials from previous studies have given reason to consider a gradual decrease in anthropogenic load (exposure to pollutants) on fish, as generally recognized indicators of water quality, given from fisheries positions. The results of the research showed that the ecological and toxicological condition of the Shlisselburg Bay has now improved, but cannot be considered satisfactory. Taking into acount the state of the ichthyo fauna and the level of its pollution, it can be characterized as weakly expressed sublethal with a possible transition to medium-expressed, conditionally sublethal in the spring period.

Emitter Clogging and Hydraulic Performance of Drip System under Different Water Qualities and Placement Techniques

The present study was conducted at the Indian Agricultural Research Institute, New Delhi, India, to evaluate the effect of sand-disc filters, pressure compensating (bioline) and non-pressure compensating (inline) emitters, and surface and subsurface placement of laterals on emitter clogging using wastewater and groundwater for irrigation. Results of this study revealed that besides water quality, the type of emitter, placement of laterals, and emitter position on laterals affected emitter's clogging. The major cause of clogging was associated with the precipitated substance accumulated at the emitter inlet concurrently close the micro-pore channels of the emitter, consequently reduce the emitter discharge. The major substances that took part in the clogging of emitter were EC, pH, HCO3, Turbidity, total solid, Escherichia coli (E. coli), and total coliform. It was observed that these substances (HCO3, Turbidity, total solid, E. coli, and total coliform) of groundwater and wastewater were categorized with a medium risk of clogging except for magnesium (low risk of clogging). Pressure compensating drip emitter showed better performance against clogging as compared to non-pressure compensating drip emitter. Sub-surface placement of drip emitter was more prone to clogging under both wastewater and groundwater. It was observed a significant (p ≤ 0.05) effect of lateral placement, emitter types, and the interaction between these factors on emitter's clogging under both types of water. Emitter flow rate decreased with the increasing time of operation of the drip systems at normal operating pressure, because of clogging of emitters. By flushing operation, it was observed a 3 to 5% higher flow rate in inline drip emitter than bioline (1-2%). The R2 value, which precisely describes the head-discharge relationship, was high (0.99) in most of the bioline treatments. This study also observed and recommended that pressure compensating emitter would be the most appropriate technique to reduce the clogging while using wastewater for irrigation. Flushing effectively controlled the emitter's clogging thus improved the emitter's water discharge rate.

Perfluoroalkyl substances in precipitation from the Tibetan Plateau during monsoon season: Concentrations, source regions and mass fluxes

Atmospheric wet deposition is an important process for the occurrence of perfluoroalkyl substances (PFASs) in polar/remote mountain regions; however, there are limited data on PFASs in precipitation from the Tibetan Plateau (TP). Precipitation (rain from May to October 2017) was therefore collected across the TP to investigate the concentrations, composition profiles, sources, and fluxes of perfluoroalkyl acids (PFAAs). The average ∑PFAA concentrations ranged from 212.3 pg L−1 to 547.7 pg L−1, and perfluoroalkyl carboxylic acids (PFCAs) accounted for 87% of the measured PFAAs (mean value). Significant positive associations (p < 0.05) were found for most PFCAs in the southeast TP, indicating that they may come from similar sources. The monthly PFAA deposition flux ranged from 12.6 to 68.9 ng m−2 month−1, decreasing from east to west. As climate of the eastern TP is controlled mainly by the Indian monsoon, indicating that the Indian monsoon plays an important role in delivering PFAAs to the TP. PCA (principal component analysis) combined with back-trajectory analysis was used to estimate the atmospheric transport pathways, and the PSCF (potential source contribution function) model was applied to define the potential source regions of individual PFAAs. The results suggested that northeast India, Bangladesh, and southern Nepal are the potential sources of C4–C7 PFCAs; C8–C10 PFCAs are more influenced by emissions from southern Nepal and Bhutan; while the source regions of long-chain PFCAs (C11–C12) can be attributed to northern India and Pakistan. Specifically, PFOS (perfluorooctane sulfonic acid) has a local contribution from the central TP.

Study on the Sulfuration Mechanism of Concrete: Microstructure and Product Analysis.

This paper presents an experimental investigation of the sulfuration mechanism of concrete. The microstructure, mineral phase composition, substance content, and pH of the concrete were determined using scanning electron microscopy, X-ray diffraction, comprehensive thermal analysis, and pore-solution pH test. It was observed that light-grey spots appeared on the surface of the specimen, and a large amount of powdery precipitated substances appeared. At the initial stage of sulfuration reaction, the formation of ettringite blocked the concrete pores and densified its cracks and voids. Subsequently, ettringite reacted with H+ to form gypsum, and the continuous increase in gypsum in the pores increased the number of cracks and broadened their width. Gypsum was the final product of the sulfuration reaction, and the mass percentage of gypsum in the powdery precipitated substances at different water–cement ratios was more than 50%. When the water–cement ratios was 0.37, 0.47, and 0.57, the highest Ca(OH)2 content was found for the lowest water–cement ratio. As the water–cement ratios increased, the amount of powdery precipitated substances decreased and the CaCO3 content and pH increased.

Organic, mineral and nutrient substances in the atmospheric precipitation of Barnaul

The objective of this work was to study the annual dynamics and seasonal changes in the concentration of organic (determined by the content of organic carbon) and mineral (Cl-, SO42-, Na+, +, Mg2+, Ca2+) substances and nutrients (NO3-, NH4+, NO2-, PO43-) in atmospheric precipitation of Barnaul. This paper presents the results of a study of precipitation (rain and snow) for the period from October 2013 to March 2020. The seasonal and annual dynamics of changes in the concentration of the studied components were considered. It was found that seasonal variability of NO3-, Cl-, SO42-, Na+, +, PO43- concentrations was the highest in the cold period. The annual increase of the total amount of the studied ions, as well as organic carbon, was proportional to the number of pollutants entering the atmosphere of Barnaul from industrial enterprises and automobile transport.

Ozonation process intensification of p-nitrophenol by in situ separation of hydroxyl radical scavengers and microbubbles.

The ozonation efficiency for removal of recalcitrant organic pollutants in alkaline wastewater is always low because of the presence of some hydroxyl radical scavengers. To solve this problem, the O3/Ca(OH)2 system was put forward, and p-nitrophenol (PNP) was chosen to explore the mechanism of this system. The effects of key operational parameters were studied respectively; the Ca(OH)2 dosage 3 g/L, ozone inlet flow rate 3.5 L/min, ozone concentration 65 mg/L, reactor pressure 0.25 MPa, and temperature 25 °C were obtained as the optimal operating conditions. After 60 min treatment, the organic matter mineralized completely, which was higher than the sum of the ozonation-alone process (55.63%) and the Ca(OH)2 process (3.53%). It suggests that the calcium hydroxide in the O3/Ca(OH)2 process possessed a paramount role in the removal of PNP. The liquid samples and the precipitated substances were analyzed by gas chromatography mass spectrometry, X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy; it was demonstrated that Ca(OH)2 could accelerate the generation of hydroxyl radical and simultaneously in situ separate partial intermediate products and CO3 2- ions through some precipitation reactions.

Per- and polyfluoroalkyl substances (PFASs) in precipitation from mainland China: Contributions of unknown precursors and short-chain (C2[sbnd]C3) perfluoroalkyl carboxylic acids

A nationwide survey was conducted on per- and polyfluoroalkyl substances (PFASs) in precipitation across mainland China. Twenty-two PFASs, including precursors to perfluoroalkyl acids (pre-PFAAs), were investigated in thirty-nine precipitation samples collected from twenty-eight cities. Trifluoroacetate (TFA), perfluorooctanoic acid, and perfluorooctane sulfonic acid (PFOS) were ubiquitous in precipitation. TFA displayed the highest concentrations (8.8–1.8 × 103 ng/L), which were particularly elevated in coastal cities. 6:2 chlorinated polyfluorinated ether sulfonic acid, an alternative to PFOS, was detected for the first time in precipitation at a frequency of 43%. Polyfluoroalkyl phosphoric acid diesters and 6:2 fluorotelomer sulfonic acid were also occasionally detected. PFAS fluxes in the northeastern area (C4C12; 2.0 × 102–3.4 × 103 ng/m2/d) with major PFAS manufacturing facilities were higher than those in the southwestern area (63–1.7 × 103 ng/m2/d). Using total oxidizable precursor (TOP) assay, the occurrence of unknown pre-PFAAs was for the first time uncovered in precipitation with maximum estimated fluxes of C6 and C8 pre-PFAAs at 3.1 × 103 and 4.3 × 103 ng/m2/d, respectively. The relative contribution of ultrashort-chain PFCAs (C2C3) ranged from 22% to 91% of ∑PFASs, while unknown pre-PFAAs accounted for 6%–56% of the total molar concentrations of PFASs. This bears critical concerns on underestimation of PFAS mass load from precipitation to surface environment ascribed to monitoring data solely on known PFASs. Unknown precursors of PFAAs in the atmosphere are yet to be identified for their chemical structures and relevant environmental risks as well.

Ozonation of Phenol-Containing Wastewater Using O3/Ca(OH)2 System in a Micro Bubble Gas-Liquid Reactor

ABSTRACTThe degradation of phenol in aqueous solution was investigated in an integrated process consisting of O3/Ca(OH)2 system and a newly developed micro bubble gas-liquid reactor. The effects of operating parameters such as Ca(OH)2 dosage, reactor pressure, liquid phase temperature, initial phenol concentration and inlet ozone concentration on degradation and mineralization (TOC removal) were studied in order to know the ozonation performance of this new integrated process. It is demonstrated that the degradation and TOC removal efficiency increased with increasing inlet ozone concentration and increasing Ca(OH)2 dosage before 2 g/L, as well as decreasing initial phenol concentration. The optimum Ca(OH)2 dosage should exceed Ca(OH)2 solubility in liquid phase. The reactor pressure and liquid phase temperature have little effects on the removal and TOC removal efficiency. When Ca(OH)2 dosage exceeded 3 g/L, the degradation and TOC removal of phenol almost reached 100% at 30 and 55 min, respectively. The intensification mechanism of Ca(OH)2 assisted ozonation was explored through analysis of the precipitated substances. The mechanism for Ca(OH)2 intensified mineralization of phenol solution is the simultaneous removal of CO32- ions, as hydroxyl radical scavengers, due to the presence of Ca2+ ions. Results indicated that the proposed new integrated process is a highly efficient ozonation process for persistent organic wastewater treatment.

Ozonation of acid red 18 wastewater using O3/Ca(OH)2 system in a micro bubble gas-liquid reactor

The ozonation of acid red 18 (AR18) wastewater was investigated in an integrated process consisting of O3/Ca(OH)2 system and a newly-developed micro bubble gas-liquid reactor. The effects of operating parameters such as Ca(OH)2 dosage, reactor pressure, liquid phase temperature, initial dye concentration and inlet ozone concentration on decolorization and mineralization (TOC removal) were studied in order to know the ozonation performance of this new integrated process. The decolorization and TOC removal efficiency increased with increasing inlet ozone concentration and increasing Ca(OH)2 dosage before 2g/L, as well as decreasing initial dye concentration. The optimum Ca(OH)2 dosage should exceed Ca(OH)2 solubility in liquid phase. The reactor pressure and liquid phase temperature have little effects on the decolorization and TOC removal efficiency. When Ca(OH)2 dosage exceeded 3g/L, the decolorization and TOC removal of AR 18 almost reached 100% at 6 and 25min, respectively. The intensification mechanism of Ca(OH)2 assisted ozonation was explored through the determination of CO32− and SO42− ions formed in the liquid phase and analysis of the precipitated substances. The mechanism for Ca(OH)2 intensified mineralization of dye solution is the simultaneous removal of CO32− ions, as hydroxyl radical scavengers, due to the presence of Ca2+ ions. Results indicated that the proposed new integrated process is a high efficient ozonation process for persistent organic wastewater treatment.

Bio-grout based on microbially induced sand solidification by means of asparaginase activity.

Bio-grout, a new ground improvement method, has been recently developed to improve the mechanical properties, decrease the permeability of porous materials, reinforce or repair cementitious materials and modify the properties of soil or sand. Bio-grout production depends on microbially induced calcite precipitation (MICP), which is driven mainly by an enzyme, urease. However, urease-based MICP process produces excessive ammonia, in addition to secondary pollution generated by urea that is used as substrate in it. In the present study, we reported asparaginase-based MICP process for sand bio-grout development using Bacillus megaterium, and results were also compared with urease-based bio-grouts. The asparaginase activity led to significantly less ammonia production compared to urease without compromising with desired properties of a novel grout. The UCS of bio-grout was obtained at 980 kPa, while the permeability was decreased substantially. The mineralogical composition of precipitated substance was identified as calcite using XRD and the crystal morphology was observed under SEM. The mass percentage of calcite in bio-grout was calculated by thermogravimetric analysis and XCT verified calcite precipitation in it. The results confirmed that biocalcification by means of bacterial asparaginase is a potential solution for geotechnical problems. The asparaginase-based MICP process could be of wider acceptance in future.

MICROSTRUCTURE AND NONOHMIC PROPERTIES OF SnO2–Ta2O5–ZnO BASED CERAMIC VARISTORS DOPED WITH TiO2

The microstructure and nonohmic properties of SnO 2– Ta 2 O 5– ZnO based ceramics sintered at 1450°C for 2 h were investigated in accordance with TiO 2 content (0–8 mol%). Without TiO 2 the prepared sample is nonstoichiometric SnO 2 semiconductor with excessive oxygen; but for the samples doped with TiO 2, Sn 0.9 Ti 0.1 O 2 phase can be identified, and the incorporation of TiO 2 into the ternary system SnO 2– Ta 2 O 5– ZnO ceramics can compensate the defects of Sn 4+ ions loss, promote the sample densification, and facilitate the growth of SnO 2 grains. After 4.0 mol% of TiO 2 is doped, the samples present no precipitated substances residing in the grain juncture, resulting in varistors with maximum nonlinear exponent of 21, varistor voltage of about 1000 V/mm, and minimum leakage current of 100 μA/cm2, which are promising in high-voltage applications. The improvement in nonohmic performance of the varistors after the doping of TiO 2 is mainly attributed to the increase in effective barrier height in grain boundary, which can be supported by the decrease in band gap caused by defects and impurities from periodic density function theory calculation.

Adsorption of cysteine on hematite, magnetite and ferrihydrite: FT-IR, Mössbauer, EPR spectroscopy and X-ray diffractometry studies

In the present paper, the adsorption of cysteine on hematite, magnetite and ferrihydrite was studied using FT-IR, electron paramagnetic resonance (EPR), Mössbauer spectroscopy and X-ray diffractometry. Cysteine was dissolved in artificial seawater (two different pHs) which contains the major constituents. There were two main findings described in this paper. First, after the cysteine adsorption, the FT-IR spectroscopy and X-ray diffractometry data showed the formation of cystine. Second, the Mössbauer spectroscopy did not show any increase in the amount of Fe(2+) as expected due the oxidation of cysteine to cystine. An explanation could be that Fe(2+) was oxidized by the oxygen present in the seawater or there occurred a reduction of cystine by Fe(2+) generating cysteine and Fe(3+). The specific surface area and pH at point of zero charge of the iron oxides were influenced by adsorption of cysteine. When compared to other iron oxides, ferrihydrite adsorbed significantly (p < 0.05) more cysteine. The pH has a significant (p < 0.05) effect only on cysteine adsorption on hematite. The FT-IR spectroscopy results showed that cystine remains adsorbed on the surface of the iron oxides even after being mixed with KCl and the amine and carboxylic groups are involved in this interaction. X-ray diffractometry showed no changes on iron oxides mineralogy and the following precipitated substances were found along with the iron oxides after drying the samples: cysteine, cystine and seawater salts. The EPR spectroscopy showed that cysteine interacts with iron oxides, changing the relative amounts of iron oxides and hydroxide.

Properties of the planar ADH-dry-layer structures based on electrically controlled coupling between enzyme molecules and metal surfaces

Planar structures metal/alcohol dehydrogenase/metal (Me/ADH/Me), constructed of two technologically symmetrical junctions enzyme/metal and capable to detect ethanol vapour in air after special activation, are investigated. The study is based on original technology of the structures according to which the self-assemblage of the junctions between the metal and enzyme's molecule is affected by controllable electrical current flowing in the colloidal solution and wet precipitated substance until the enzyme layers are completely dried. Surface properties of these Me/ADH/Me structures and their electrical response to ethanol vapour were investigated.

Particle formation by turbulent mixing with supercritical antisolvent

A supercritical antisolvent precipitation process is investigated. The objective of the study is related to production of high purity powders with controlled particle size for pharmaceutical and industrial purposes. The model of antisolvent precipitation in turbulent flows is proposed and applied to interpret experimental data. The method combines the non-equilibrium model for scalar dissipation with the conditional moment closure based on probability density function Beta (the Beta PDF). The method is based on expressing the local concentration of the precipitated substance as a function of dimensionless concentration of the solvent (interpreted as a passive scalar) and application of the single precipitation progress variable. The proposed method has been implemented into the CFD code to constitute the complete procedure for prediction of the course of particle formation processes.

The Precipitation Chemistry over Central Bohemia: Attempt to Estimate the Sources and Pathways

An attempt to indicate the sources and pathways of selected chemical substances in precipitation over central Bohemia was accomplished with help of bulk samples, collected in a forested rural landscape approx. 30 km SE from Prague, capital of the Czech Republic. Samples have been collected monthly throughout the 1990s. They were analyzed to determine the concentration of selected major cations and anions (Na+, K+, Ca2+, Mg2+, NH4+, SO42-, NO3-, Cl-), as well as several minor and trace elements (Al, As, Be, Cd, Cu, Fe, Mn, Pb, Sr, Zn, F-).

Surface Active Substances (SAS) and Dissolved Organic Matter (DOC) in Atmospheric Precipitation of Urban Area of Croatia (ZAGREB)

We report measurements of surface active substances (SAS) in atmospheric bulk precipitation on the basis of adsorption characteristics on the mercury electrode by using phase sensitive alternating current voltammetry (out-of-phase measurement). Samples collected during the 1998–1999 at an urban area of Croatia. The obtained surfactant activity values were within the range of 0.09–0.37 mg dm−3 eq. Triton X-100. Concentrations of dissolved organic carbon (DOC) in the same samples were in the range of 0.78–4.39 mg dm−3. In this paper, we also used Pb2+ ion as an electrochemical probe for additional characterization of the properties of the organic matter in precipitation, which may be important in various atmospheric processes.