Lingju Dai , Jie Xue , Rui Lu , Zheng Wang , Zhongxing Chen , Qiangyi Yu , Zhou Shi , Songchao Chen
{"title":"In-situ prediction of soil organic carbon contents in wheat-rice rotation fields via visible near-infrared spectroscopy","authors":"Lingju Dai , Jie Xue , Rui Lu , Zheng Wang , Zhongxing Chen , Qiangyi Yu , Zhou Shi , Songchao Chen","doi":"10.1016/j.seh.2024.100113","DOIUrl":"10.1016/j.seh.2024.100113","url":null,"abstract":"<div><div>Visible near-infrared (VNIR) spectroscopy is a reliable method for estimating soil properties. However, its effectiveness in accurately predicting soil organic carbon (SOC) contents, particularly in wheat-rice rotation fields, remains uncertain. In this study, we collected 202 samples from wheat-rice fields (0–20 cm) in southeastern China and measured <em>in-situ</em> spectra of the vertical surface of the soil cores and the laboratory spectra of the dried and sieved soil samples. Our study focused on evaluating three algorithms - external parameter orthogonalization (EPO), direct standardization (DS), and piecewise direct standardization (PDS) - to address the influence of external factors, particularly soil moisture. To carry out our analysis, the dataset was divided into calibration (141 samples) and validation (61 samples) sets via the Kennard-Stone algorithm. A subset of the corresponding <em>in-situ</em> and laboratory spectra in the calibration set (transfer set) was used to derive the transfer matrix for EPO, DS, and PDS, enabling the conversion of <em>in-situ</em> spectra to laboratory spectra by characterizing their differences. Four machine learning models, including cubist, partial least squares regression (PLSR), random forest (RF), and memory-based learning (MBL), were used to predict the SOC, particulate organic carbon (POC), and mineral-associated organic carbon (MAOC) contents based on the laboratory, <em>in-situ</em>, and corrected <em>in-situ</em> spectra. The results revealed that the laboratory spectra outperformed the non-corrected <em>in-situ</em> spectra, with coefficients of determination (R<sup>2</sup>) of 0.91, 0.75, and 0.80 for SOC, POC, and MAOC, respectively. Among the models, MBL and PLSR exhibited the highest average R<sup>2</sup> at 0.85–0.86. EPO marginally improved the prediction accuracy (R<sup>2</sup> increased from 0.85 to 0.87 for SOC, 0.64 to 0.69 for POC, and 0.75 to 0.82 for MAOC). These promising prediction accuracies underscore the potential of VNIR spectra for <em>in-situ</em> predictions in wheat-rice fields in Southeast China, offering insights for predicting SOC contents via <em>in-situ</em> spectroscopy.</div></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"2 4","pages":"Article 100113"},"PeriodicalIF":0.0,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Salla H. Venäläinen , Aura Nousiainen , Sanna Kanerva
{"title":"The potential of phosphate mine tailings in the remediation of acidic Pb-contaminated soil","authors":"Salla H. Venäläinen , Aura Nousiainen , Sanna Kanerva","doi":"10.1016/j.seh.2024.100112","DOIUrl":"10.1016/j.seh.2024.100112","url":null,"abstract":"<div><p>We investigated the potential of tailings from phosphate mining, consisting of phlogopite, carbonate minerals calcite and dolomite, and residues of apatite, to serve as a stabilizing agent in the remediation of Pb-contaminated soil <em>in situ</em> or on-site. In a 2.5-year field trial, test plots located in a former shooting range area were surface-treated with the tailings and analyzed for tailings-induced changes in Pb solubility and thus potential mobility within the soil profile. The factors and mechanisms controlling tailings-induced changes in Pb solubility in various soil types, and the susceptibility of Pb to leaching down the soil profile following the treatment, were investigated in supplementary laboratory-scale experiments carried out with horizon-specific soil samples collected from the field site. In the tailings-treated soil, the dissolution of the carbonate fraction of the tailings and the subsequent increase in soil pH contributed to the displacement of shot-derived Pb<sup>2+</sup> ions by the carbonate-derived calcium ions (Ca<sup>2+</sup>) and the adsorption of Pb<sup>2+</sup> by soil organic matter and Al, Fe, and Mn (hydr)oxide surfaces. Moreover, the apatite fraction of the tailings formed poorly-soluble compounds with Pb, particularly in soils high in exchangeable Pb<sup>2+</sup> with respect to their cation exchange capacity. Consequently, the Pb solubility in tailings-treated soils substantially decreased. The reduction in Pb solubility was most evident in the organic topsoil high in Pb. Despite the liming effect of the tailings, and the susceptibility of Pb to form organic complexes conducive to solubilization upon an increase in pH, we found no evidence of tailings-induced leaching of Pb down the soil profile.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"2 4","pages":"Article 100112"},"PeriodicalIF":0.0,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949919424000554/pdfft?md5=2d0368c5657cabf7a34b8cb7260b96a6&pid=1-s2.0-S2949919424000554-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142099166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sheng-Zhi Chen , Xin-Ying Lin , Rong-Yue Xue , Xu Duan , Dong-Mei Zhou , Lena Q. Ma , Hong-Bo Li
{"title":"Fortifying casein phosphopeptides and Ca in wheat reduces the As, Cd, and Pb bioavailability based on a mouse model: Calcium and phosphate transporters and gut microbiota","authors":"Sheng-Zhi Chen , Xin-Ying Lin , Rong-Yue Xue , Xu Duan , Dong-Mei Zhou , Lena Q. Ma , Hong-Bo Li","doi":"10.1016/j.seh.2024.100111","DOIUrl":"10.1016/j.seh.2024.100111","url":null,"abstract":"<div><p>Reducing the oral bioavailability of metal contaminants including As, Cd, , and Pb in foods can protect human health. Studies showed reduced metal bioavailability with elevated Ca and Fe intake; however, the effectiveness of enhancing food Ca and Fe bioavailability remains unknown. Based on a mouse bioassay and using metal accumulation in mouse tissues (kidneys and liver) as the bioavailability endpoint, this study investigated the roles of casein phosphopeptides (CPP, food nutrition fortifier) in lowering the As, Cd, and Pb bioavailability from consuming a metal-contaminated wheat. The CPP amendment at 0.10–0.50% in wheat promoted its Ca bioavailability, causing 33–62% and 59–80% decreases in the gene expression encoding for duodenal Ca and phosphate transporters in mice. This limited transcellular transport of Cd<sup>2+</sup> and inorganic arsenate via Ca and phosphate transporters respectively, thus leading to 27% and 34% decreases in Cd and As contents in mouse kidneys fed with wheat at 0.50% CPP amendment. In addition, CPP promoted the colonization of <em>Feacalibaculum</em> and <em>Bifidobacterium</em> in mouse gut, likely promoting As excretion in feces by 81–112%. In contrast to As, and Cd, CPP failed to reduce Pb contents in mouse tissue after consuming CPP-amended wheat, probably by elevating wheat-Pb solubility in the intestinal fluid by 48–136%. However, co-amendment of 0.30% CPP and 500 μg g<sup>−1</sup> Ca as Ca gluconate lowered the As, Cd, and Pb contents in mouse kidneys by 38–71%. The data indicate that fortifying Ca together with CPP in wheat can reduce human exposure to multi-metals via dietary intake.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"2 4","pages":"Article 100111"},"PeriodicalIF":0.0,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949919424000542/pdfft?md5=ca34c08264b1ae06deaa156e09a31b74&pid=1-s2.0-S2949919424000542-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142148523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mingxuan Qi , Songchao Chen , Yuchen Wei , Hangxin Zhou , Shuai Zhang , Mingming Wang , Jinyang Zheng , Raphael A. Viscarra Rossel , Jinfeng Chang , Zhou Shi , Zhongkui Luo
{"title":"Using visible-near infrared spectroscopy to estimate whole-profile soil organic carbon and its fractions","authors":"Mingxuan Qi , Songchao Chen , Yuchen Wei , Hangxin Zhou , Shuai Zhang , Mingming Wang , Jinyang Zheng , Raphael A. Viscarra Rossel , Jinfeng Chang , Zhou Shi , Zhongkui Luo","doi":"10.1016/j.seh.2024.100100","DOIUrl":"10.1016/j.seh.2024.100100","url":null,"abstract":"<div><p>Soil organic carbon (SOC) is crucial for soil health and quality, and its sequestration has been suggested as a natural solution to climate change. Accurate and cost-efficient determination of SOC and its functional fractions is essential for effective SOC management. Visible near-infrared spectroscopy (vis-NIR) has emerged as a cost-efficient approach. However, its ability to predict whole-profile SOC content and its fractions has rarely been assessed. Here, we measured SOC and its two functional fractions, particulate (POC) and mineral-associated organic carbon (MAOC), down to a depth of 200 cm in seven sequential layers across 183 dryland cropping fields in northwest, southwest, and south China. Then, vis-NIR spectra of the soil samples were collected to train a machine learning model (partial least squares regression) to predict SOC, POC, MAOC, and the ratio of MAOC to SOC (MAOC/SOC – an index of carbon vulnerability). We found that the accuracy of the model indicated by the determination coefficient of validation (R<sub>val</sub><sup>2</sup>) is 0.39, 0.30, 0.49, and 0.48 for SOC, POC, MAOC, and MAOC/SOC, respectively. Incorporating mean annual temperature improved model performance, and R<sub>val</sub><sup>2</sup> was increased to 0.64, 0.31, 0.63, and 0.51 for the four carbon variables, respectively. Further incorporating SOC into the model increased R<sub>val</sub><sup>2</sup> to 0.82, 0.64, and 0.59, respectively. These results suggest that combining vis-NIR spectroscopy with readily-available climate data and total SOC measurements enables fast and accurate estimation of whole-profile POC and MAOC across diverse environmental conditions, facilitating reliable prediction of whole-profile SOC dynamics over large spatial extents.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"2 3","pages":"Article 100100"},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949919424000438/pdfft?md5=aaab9f30a0ddc715bf07d6633cc27f8d&pid=1-s2.0-S2949919424000438-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141849142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zihan Li , Dana M. Miles , Leah Hammons , Frances A. Podrebarac , John P. Brooks , Ardeshir Adeli , Renotta Smith , Joby M. Prince Czarnecki , Robert J. Moorhead , Jing Hu
{"title":"Nitrous oxide fluxes during a winter cover crop season in a Mississippi corn cropping system","authors":"Zihan Li , Dana M. Miles , Leah Hammons , Frances A. Podrebarac , John P. Brooks , Ardeshir Adeli , Renotta Smith , Joby M. Prince Czarnecki , Robert J. Moorhead , Jing Hu","doi":"10.1016/j.seh.2024.100103","DOIUrl":"10.1016/j.seh.2024.100103","url":null,"abstract":"<div><p>Agroecosystems are the largest source of anthropogenic N<sub>2</sub>O fluxes. While cover crops (CC) offer benefits for soil health, their impacts on greenhouse gas fluxes are inconsistent. In the southeastern US, where intensive agriculture and low CC adoption are prevalent, few studies have investigated CC impact on soil N<sub>2</sub>O fluxes. Our study explored the effects of CC species and management practices on soil N<sub>2</sub>O fluxes during the winter CC growing season in Mississippi, which was conducted in a non-tilled corn cropping system with seven CC treatments. We measured <em>in situ</em> soil N<sub>2</sub>O fluxes, along with soil moisture and temperature, throughout the CC growing season from 2022 to 2023. Surface soil samples were also collected to analyze soil mineral nitrogen (N) content and enzyme activity. Over the study period (a total of 188 days), cumulative N<sub>2</sub>O fluxes were 0.50–1.03 kg N<sub>2</sub>O–N ha<sup>−1</sup>, with the lowest values from the annually-rotated Elbon rye treatment and the highest from the annually-rotated Austrian winter pea. Our results show that both CC treatments and sampling time significantly affected soil N<sub>2</sub>O fluxes. There was a strong positive correlation (r = 0.34, <em>p</em> < 0.05) between N<sub>2</sub>O fluxes and NO<sub>3</sub>–N content, which was lowest under continuous rye and rotated-rye treatments (0.31 and 0.34 mg kg<sup>−1</sup> ). The results suggest that Elbon rye effectively reduced soil N<sub>2</sub>O fluxes during this period by lowering the soil NO<sub>3</sub>–N content, the primary substrate for denitrification. This study is one of the few studies to examine the impacts of cover crops on soil N<sub>2</sub>O fluxes in cropping systems in the southeastern US, offering insights into the cover crop effects on soil N<sub>2</sub>O fluxes during their growing season.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"2 4","pages":"Article 100103"},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949919424000463/pdfft?md5=7211933d4ac9ea8b08cef2cc85482307&pid=1-s2.0-S2949919424000463-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141854013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shutao Wang , Wanqing Wang , Sashuang Rong , Guiming Liu , Yuxin Li , Xinxin Wang , Wei Liu
{"title":"Key factors and mechanisms of microplastics’ effects on soil nitrogen transformation: A review","authors":"Shutao Wang , Wanqing Wang , Sashuang Rong , Guiming Liu , Yuxin Li , Xinxin Wang , Wei Liu","doi":"10.1016/j.seh.2024.100101","DOIUrl":"10.1016/j.seh.2024.100101","url":null,"abstract":"<div><p>It is indisputable that microplastics (MPs) can profoundly alter nitrogen transformation in soil. However, it remains poorly understood how MPs impact soil nitrogen processes. This review systematically analyzed literature published in recent years related to the impact of MPs on nitrogen transformation. After reviewing the environmental behavior of MPs in soil media, the mechanisms of action and key factors of MPs’ effects on soil nitrogen transformation are elucidated. The size, shape, concentration, and type of MPs significantly alter nitrogen transformation. When MPs enter the soil, they can significantly affect the habitat and diversity of soil microorganisms and the transformation of soil nitrogen by adsorbing pollutants, releasing additives, and altering the physicochemical characteristics of the soil. As organic substrates, MPs can directly affect microbial community structure by promoting microbial colonization. Besides, MPs can also be toxic to soil microorganisms by coming into direct contact with cell surfaces. Microorganisms, key enzymes, and functional genes associated with nitrogen transformation respond to the presence of MPs, thereby affecting the nitrogen conversion process. At the last, measures to mitigate soil MPs contamination are suggested. The article highlights the effects of MPs on soil nitrogen transformation factors, leading to valuable insights into microbially-mediated nitrogen transformation processes in MP-contaminated soils. It offers useful information for determining nitrogen regulation and assessing ecological risks in soils contaminated by MPs.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"2 4","pages":"Article 100101"},"PeriodicalIF":0.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S294991942400044X/pdfft?md5=757c0b443a9ac2a439dfa69b5f90211a&pid=1-s2.0-S294991942400044X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141845702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Loryssa M. Lake , Sarah B. Scott , Darryl B. Hood , Meagan Kellis , Mary M. Gardiner , Nicholas T. Basta
{"title":"Risk management approach using ash-based amendment blends for remediation of lead-contaminated urban soils and protection of public health","authors":"Loryssa M. Lake , Sarah B. Scott , Darryl B. Hood , Meagan Kellis , Mary M. Gardiner , Nicholas T. Basta","doi":"10.1016/j.seh.2024.100102","DOIUrl":"10.1016/j.seh.2024.100102","url":null,"abstract":"<div><p>Anthropogenic activities have left a legacy of contaminated vacant land, which disproportionately affects lower income communities and can have detrimental impacts on human health, particularly children. A management solution is needed to address this widespread lead contamination in urban soils of vacant lots. In this study, high-Fe biosolids incinerator ash (BIA) was evaluated for its ability to sequester soil Pb. Five blends were created using BIA and different amount of other products (dredge, biosolids compost, and yard waste compost) to determine the most effective treatment to reduce Pb bioaccessibility in the soil. The sorption capacity of the BIA for Pb was evaluated by mixing the BIA with Pb(NO<sub>3</sub>)<sub>2</sub> at 1000 to 100,000 mg Pb/kg BIA. The contaminated soil from Cleveland, OH was treated with five BIA-based blends at a 1:1 (w/w) ratio, and Pb bioaccessibility was evaluated using USEPA Method 1340 at pH 2.5 and the Physiologically Based Extraction Test (PBET) at pH 2.5. BIA was a strong sorbent for Pb, sorbing ∼100% of the Pb from solution at 10,000 mg/L with only 41% bioaccessibility based on Method 1340 at pH 2.5. The blend containing 4.5%, 10%, or 19% BIA reduced the Pb bioaccessibility by 48% from the control based on both bioaccessibility methods. The bioaccessible Pb determined by PBET was less than that by USEPA Method 1340 at pH 2.5. However, similar reductions in bioaccessible Pb between blend-treated soils and the unamended soil were observed for all bioaccessibility methods. Plant growth assays showed the blends to have little to no significant impact on clover growth, mortality, or flower production, with the blend containing 10% BIA showing greater biomass yield. Results showed BIA-based blends were able to reduce bioaccessible Pb in the soil. This remediation approach may improve the urban living environment and protects public health.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"2 4","pages":"Article 100102"},"PeriodicalIF":0.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949919424000451/pdfft?md5=7ec034de4e270e42931f968e0ce2c935&pid=1-s2.0-S2949919424000451-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141851342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Pseudo-persistence of organic fertilizer-derived antimicrobials and estrogens in soil profiles and their potential ecological risks","authors":"Hui Zhi, Hefa Cheng","doi":"10.1016/j.seh.2024.100099","DOIUrl":"10.1016/j.seh.2024.100099","url":null,"abstract":"<div><p>Organic fertilizer-derived emerging contaminants, such as antimicrobials and estrogens, could migrate vertically into subsoil and potentially reach shallow groundwater aquifers. This study investigated the vertical distribution of these antimicrobials and estrogens in soil profiles, as well as their potential ecological risks, in the Yellow River Delta of China, a major agricultural zone. A total of 47 emerging contaminants, including 42 antimicrobials, 2 antimicrobial degradation products, and 3 estrogens, along with reference contaminant atrazine, were detected within 7 soil layers that were down to 1 m below the surface at 10 farmland sites. The concentrations of individual contaminants varied greatly in these soil layers, ranging from 0.0095 to 1680 ng/g. Antimicrobials were ubiquitous (detection frequency up to 85%), while estrogens were only detected occasionally (detection frequency up to 27%). The concentrations of antimicrobials and estrogens in subsoil were generally lower than those in topsoil, e.g., the total concentrations of antimicrobials and estrogens in Level 1 (0–5 cm) and Level 7 (70–100 cm) at all sampling sites were up to 99.3 and 29.2 ng/g, respectively. Nineteen out of the 26 emerging contaminants with relevant toxicity data could pose medium to high ecological risk to potential aquatic organisms, soil microbes, and/or crop plants. The ecological risks posed by the organic fertilizer-derived emerging contaminants were comparable in different soil layers in the soil profiles. These findings demonstrate the pseudo-persistence of these emerging contaminants in soil profiles and their substantial potential ecological risks. The data also indicate the need of controlling the residues of antimicrobials and estrogens in organic fertilizers to protect the quality and health of farmland soils.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"2 3","pages":"Article 100099"},"PeriodicalIF":0.0,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949919424000426/pdfft?md5=f15a90650aa2a636f5c7a417420b0a27&pid=1-s2.0-S2949919424000426-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141715395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Applications of ionic liquids in soil remediation: Mechanisms, efficiency and life cycle assessment","authors":"Shams Razzak Rothee, Hamed Heidari, Marie-Odile Fortier, Eakalak Khan","doi":"10.1016/j.seh.2024.100097","DOIUrl":"10.1016/j.seh.2024.100097","url":null,"abstract":"<div><p>Ionic liquids (ILs) are eco-friendly substitutes for volatile organic solvents due to their unique properties, fostering widespread adoption across academic fields and industries. This review critically evaluates their application in soil remediation, comparing their performance and environmental footprint against conventional soil remediating agents. The review provides insights into the interplay of IL characteristics, optimal environmental conditions, and contaminant removal mechanisms, while also exploring strategies for modifying and regenerating ILs. Optimal conditions for contaminant removal involve acidic pH for organic compounds and metals, with high temperatures proving beneficial for metal extraction. ILs remove organic contaminants from soil via electrostatic attraction and π–π interactions. In contrast, heavy metal extraction is facilitated by forming complexes through hydrogen bonding, coordination bonding, and electrostatic interactions. The incorporation of acetone and calcium chloride reduces the viscosity while sodium azide effectively prevents microbial degradation of ILs. Using magnetic ILs, acid elution, ultrasonication, and supercritical CO<sub>2</sub> extraction techniques enhances IL regeneration efficiency and facilitates their reuse, thereby minimizing secondary pollution and reducing cost. Life cycle assessment of common ILs for remediation, such as 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF<sub>4</sub>]) and 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF<sub>6</sub>]) showed that producing 1 kg of [Bmim][BF<sub>4</sub>] emits 6.75 kg CO<sub>2</sub>, whereas manufacturing 1 kg of [Bmim][PF<sub>6</sub>] releases 5.70 kg CO<sub>2</sub>, indicating [Bmim][PF<sub>6</sub>] has a lower global warming potential due to its environmentally-friendly precursors. The review advocates for continuous improvements in production processes and the development of ILs synthesized from renewable sources to mitigate environmental impacts and enhance their suitability for soil remediation.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"2 3","pages":"Article 100097"},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949919424000402/pdfft?md5=8da5857f0a0500e21dc1847a738a0296&pid=1-s2.0-S2949919424000402-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141405092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}