Retention properties and mechanism of agricultural waste maize whisker on atmospheric mercury

Abstract

Mercury (Hg) is a global pollutant transmitted mainly through the atmosphere, posing a serious threat to biological survival and human health. Porous materials, with high specific surface area, high porosity, and high adsorption, are particularly suitable for the purification of atmospheric Hg mixtures. However, plant porous materials are rarely directly used for atmospheric Hg purification. In this study, the properties and mechanism of maize whisker in removing atmospheric Hg were analyzed. The results show that the Hg content in the whiskers increases significantly as the initial Hg concentration increases, and 79.38% Hg can be removed by 0.2 g maize whiskers after 1 h exposure when the initial Hg concentration is 0.1 μg m⁻³, indicating that maize whiskers can accumulate atmospheric Hg rapidly and effectively. The hole diameter of the maize whisker is between 0.83 and 3.06 μm, which is suitable for the adsorption of small substances. Correlation analysis shows that maize whiskers have a significant correlation between atmospheric Hg retention and its specific surface area, pore size, medium pore ratio, and micropore ratio, suggesting that the maize whisker hole feature has a significant influence on its ability to retain atmospheric Hg. Compared with the energy profiles before and after Hg treatment, the peak of Mg decreased after Hg adsorption. Fourier infrared spectrometer analysis suggests that functional groups such as -OH, -COOH, and -O- are involved in the adsorption process. The change in pH value shows an obvious effect on the overall change in zeta potential in the adsorption process. Therefore, a variety of mechanisms, including physical adsorption, electrostatic adsorption, complexation, chelation, and ion exchange, are involved in Hg retention with the maize whisker. This study reveals the important potential value of agricultural waste maize whiskers in the purification of atmospheric heavy metal Hg.

Keywords

Air pollution / Biosorption / Heavy metal / Porous material

References

[1] Asadpour R, Sapari NB, Isa MH, Kakooei S, Orji KU. Acetylation of corn silk and its application for oil sorption. Fiber Polym, 2015, 16(9): 1830-1835.

[2] Bondada BR, Tu S, Ma LQ. Absorption of foliar-applied arsenic by the arsenic hyperaccumulating fern (Pterisvittata L). Sci Total Environ, 2004, 332(1–3): 61-70.

[3] Chai Y, Bai M, Chen A, . Thermochemical conversion of heavy metal contaminated biomass: Fate of the metals and their impact on products. Sci Total Environ, 2022, 822.

[4] Chojnacki A, Chojnacka K, Hoffmann J, . The application of natural zeolites for mercury removal: from laboratory tests to industrial scale. Miner Eng, 2004, 17(7–8): 933-937.

[5] Davis TA, Llanes F, Volesky B, . Metal selectivity of Sargassum spp and their alginates in relation to their alpha-L-guluronic acid content and conformation. Environ Sci Technol, 2003, 37(2): 261-267.

[6] Duan T, Mu J, Tang Q, Rong T, Wang P. Sexual incompatibility between maize and its wild relatives Tripsacum L and Coix L. Acta Agron Sin, 2008, 34(9): 172-177.

[7] Ericksen JA, Gustin MS, Schorran DE, Johnson DW, Lindberg SE, Coleman JS. Accumulation of atmospheric mercury in forest foliage. Atmos Environ, 2003, 37: 1613-1622.

[8] Fang L, Li L, Qu Z, . A novel method for the sequential removal and separation of multiple heavy metals from wastewater. J Hazard Mater, 2018, 342: 617-624.

[9] Fomina M, Gadd GM. Biosorption: current perspectives on concept, definition and application. Bioresour Technol, 2014, 160: 3-14.

[10] Hasanudin K, Hashim P, Mustafa S. Corn silk (stigma maydis) in healthcare: A phytochemical and pharmacological review. Molecules, 2012, 17: 9697-9715.

[11] Kogut K, Gorecki J, Burmistrz P. Opportunities for reducing Hg emissions in the cement industry. J Clean Prod, 2021, 293.

[12] Lakshmi S, Baker S, Shivamallu C, . Biosorption of oxybenzene using biosorbent prepared by raw wastes of Zea mays and comparative study by using commercially available activated carbon. Saudi J Bio Sci, 2021, 28(6): 3469-3476.

[13] Liu Y, Liu G, Wang Z, Guo Y, Yin Y, Zhang X, Cai Y, Jiang G. Understanding foliar accumulation of atmospheric Hg in terrestrial vegetation: progress and challenges. Crit Rev Environ Sci Technol, 2021, 52(24): 4331-4352.

[14] Ma S, Zhang M, Yang B, Song S, Nie J, Lu P. Preparation of cellulosic air filters with controllable pore structures via organic solvent–based freeze casting: the key role of fiber dispersion and pore size. BioResources, 2018, 13(3): 5894-5908.

[15] Meng B, Li Y, Cui W, Jiang P, Liu G, Wang Y, Richards J, Feng X, Cai Y. Tracing the uptake, transport, and fate of mercury in sawgrass (Cladium jamaicense) in the Florida everglades using a multi-isotope technique. Environ Sci Technol, 2018, 52: 3384-3391.

[16] Mo H, Li L, Lai W, Zhao M, Pu J, Zhao Y, Deng S. Characterization of summer PM25 aerosols from four forest areas in Sichuan. SW China. Particuology, 2015, 20(3): 94-103.

[17] Natasha SM, Khalid S, Bibi I, Bundschuh J, Niazi NK, Dumat C. A critical review of mercury speciation, bioavailability, toxicity and detoxification in soil-plant environment: Ecotoxicology and health risk assessment. Sci Total Environ, 2020, 711: 134749.

[18] Ngah WSW, Hanafiah MAKM. Removal of heavy metal ions from wastewater by chemically modified plant wastes as adsorbents: a review. Bioresour Technol, 2008, 99(10): 3935-3948.

[19] Obrist D, Agnan Y, Jiskra M, Olson CL, Colegrove DP, Hueber J, Moore CW, Sonke JE, Helmig D. Tundra uptake of atmospheric elemental mercury drives arctic mercury pollution. Nature, 2017, 547(7662): 201-204.

[20] Pavithra KG, SundarRajan P, SundarRajan PS, Rangasamy G. Hg sources, contaminations, Hg cycle, detection and treatment techniques: a review. Chemosphere, 2023, 312.

[21] Pavlish JH, Sondreal EA, Mann MD, . Status review of mercury control option for coal fired power plants. Fuel Processing Technol, 2003, 82(23): 89-165.

[22] Petrović M, Šoštarić T, Stojanović M, Milojković J, Mihajlović M, Stanojević M, Stanković S. Removal of Pb²⁺ ions by raw corn silk (Zea mays L.) as a novel biosorbent. J Taiwan Inst Chem Eng, 2016, 58: 407-416.

[23] Petrović M, Šoštarić T, Stojanović M, Petrović J, Mihajlović M, Cosović A, Stanković S. Mechanism of adsorption of Cu²⁺ and Zn²⁺ on the corn silk (Zea mays L). Ecol Eng, 2017, 99: 83-90.

[24] Rea AW, Lindberg SE, Keeler GJ. Dry deposition and foliar leaching of mercury and selected trace elements in deciduous forest throughfall. Atmos Environ, 2001, 35: 3453-3462.

[25] Sabri MA, Ibrahim TH, Sayed Y. Synthesis and characterization of activated carbon fibers derived from corn silk and its application in p-cresol removal. Desalin Water Treat, 2019, 168: 77-87.

[26] Tsui TK, Blum JD, Kwon SY. Review of stable mercury isotopes in ecology and biogeochemistry. Sci Total Environ, 2020, 716.

[27] Wang Z, Zhang Y, Ma XYD, Ang J, Zeng Z, Ng BF, Wan MP, Wong SC, Lu X. Polymer/MOF-derived multilayer fibrous membranes for moisture-wicking and efficient capturing both fine and ultrafine airborne particles. Sep Purif Technol, 2020, 235.

[28] Wang X, Yuan W, Lin CJ, Feng X. Mercury cycling and isotopic fractionation in global forests. Crit Rev Env Sci Technol, 2021, 52(21): 3763-3786.

[29] Wegst UGK, Bai H, Saiz E, Tomsia AP, Ritchie RO. Bioinspired structural materials. Nat Mater, 2015, 14(1): 23-26.

[30] Yadav S, Rajamani V. Air quality and trace metal chemistry of different size fractions of aerosols in N-NW India: implications for source diversity. Atmos Environ, 2006, 40(4): 698-712.

[31] Yu H, Pang J, Ai T, Liu L. Biosorption of Cu²⁺, Co²⁺ and Ni²⁺ from aqueous solution by modified corn silk: equilibrium, kinetics, and thermodynamic studies. J Taiwan Inst Chem Eng, 2016, 62: 21-30.

[32] Zanoletti A, Bilo F, Federici S, Borgese L, Depero LE, Ponti J, Valsesia A, Spina RL, Segata M, Montini T, Bontempi E. The first material made for air pollution control able to sequestrate fine and ultrafine air particulate matter. Sustain Cities Soc, 2020, 53: 10961.

[33] Zheng G, Qian J, Li P. Potential use of corn leaf and silk to monitor atmospheric particulate matter. Ecol Indic, 2019, 106.

[34] Zhou J, Obrist D. Global mercury assimilation by vegetation. Environ Sci Technol, 2021, 55: 14245-14257.

[35] Zhu X, Yu H, Jia H, Wu Q, Liu J, Li X. Solid phase extraction of trace copper in water samples via modified corn silk as a novel biosorbent with detection by flame atomic absorption spectrometry. Anal Methods, 2013, 5(17): 4460-4466.