Insight into the co-hydrothermal humification of corn stalk and sewage sludge for enhanced nitrogen-rich humic acid production

Highlights

● Two mixing modes of hydrothermal humification of corn stalk and sludge were set.

● N-rich hydrothermal humic acid (HHA) from corn stalk and sludge was produced.

● Behavior of hydrothermal humification of corn stalk and sludge was revealed.

● Humification of corn stalk and sludge enhanced N content in HHA.

● HHA derived from corn stalk and sludge has no heavy metal risk.

Abstract

The high organic carbon content in corn stalks (CS) and the rich nitrogen resources in sewage sludge (SS) render them ideal for the hydrothermal production of nitrogen-enriched hydrothermal humic acid (HHA). This study conducted co-hydrothermal humification experiments using varying ratios of CS to SS under two distinct mixing modes: 1) co-hydrothermal carbonization of CS and SS, followed by alkaline hydrothermal humification to yield HHA, and 2) mixing CS-derived hydrochar with SS, followed by alkaline hydrothermal humification to yield HHA. The results indicated no significant difference in HHA yield between the modes when using equivalent raw material ratios. Importantly, the HHA produced did not pose a heavy metal risk. However, HHA from mode (1) had nearly double the nitrogen content compared to mode (2) and contained more valuable metal elements. The study confirmed that while co-hydrothermal humification of CS and SS did not significantly enhance HHA yield, it did markedly increase nitrogen content. Furthermore, HHA yield decreased with increasing SS content in the raw materials, likely due to SS's high ash content (52.4 wt%). In contrast, the nitrogen content in HHA increased with higher SS content, rising from 2.0 wt% to 3.8 wt% in mode (1) and from 1.1 wt% to 2.3 wt% in mode (2). Upon comprehensive analysis of both modes, the study suggests that mode (1) is more promising for engineering applications, as it facilitates the efficient disposal of a larger amount of SS.

Graphical abstract

Keywords

Corn stalk / Sewage sludge / Hydrothermal humification / Hydrochar / Humic acid / Nitrogen content

References

[1] Anas M, Liao F, Verma K K, Sarwar M A, Mahmood A, Chen Z L, Li Q, Zeng X P, Liu Y, Li Y R. (2020). Fate of nitrogen in agriculture and environment: agronomic, eco-physiological and molecular approaches to improve nitrogen use efficiency. Biological Research, 53(1): 47

[2] Chen P F, Yang R J, Pei Y H, Yang Y, Cheng J, He D P, Huang Q, Zhong H, Jin F M. (2022). Hydrothermal synthesis of similar mineral-sourced humic acid from food waste and the role of protein. Science of the Total Environment, 828: 154440

[3] Fatima N, Jamal A, Huang Z X, Liaquat R, Ahmad B, Haider R, Ali M I, Shoukat T, Alothman Z A, Ouladsmane M. . (2021). Extraction and chemical characterization of humic acid from nitric acid treated lignite and bituminous coal samples. Sustainability, 13(16): 8969

[4] Fong S S, Seng L, Chong W N, Asing J, Nor M, Pauzan A. (2006). Characterization of the coal derived humic acids from Mukah, Sarawak as soil conditioner. Journal of the Brazilian Chemical Society, 17(3): 582–587

[5] Heidari M, Dutta A, Acharya B, Mahmud S. (2019). A review of the current knowledge and challenges of hydrothermal carbonization for biomass conversion. Journal of the Energy Institute, 92(6): 1779–1799

[6] Huculak-Mączka M, Hoffmann J, Hoffmann K. (2018). Evaluation of the possibilities of using humic acids obtained from lignite in the production of commercial fertilizers. Journal of Soils and Sediments, 18(8): 2868–2880

[7] Jia P, Wang X, Liu S, Hua Y, Zhou S, Jiang Z. (2023a). Combined use of biochar and microbial agent can promote lignocellulose degradation and humic acid formation during sewage sludge-reed straw composting. Bioresource Technology, 370: 128525

[8] JiaW, GuoA, ZhangR, Shi L (2023b). Mechanism of natural antioxidants regulating advanced glycosylation end products of Maillard reaction. Food Chemistry, 404(Pt A): 134541

[9] Jiang P W, Ma Z J, Han Y X. (2010). Experimental study on extracting humic acid from lignite. Advanced Materials Research, 158: 56–63

[10] Lachos-Perez D, Torres-Mayanga P C, Abaide E R, Zabot G L, De Castilhos F. (2022). Hydrothermal carbonization and liquefaction: differences, progress, challenges, and opportunities. Bioresource Technology, 343: 126084

[11] Lipczynska-Kochany E. (2018). Humic substances, their microbial interactions and effects on biological transformations of organic pollutants in water and soil: a review. Chemosphere, 202: 420–437

[12] Lu W J, Huo W Z, Gulina H, Pan C. (2022). Development of machine learning multi-city model for municipal solid waste generation prediction. Frontiers of Environmental Science & Engineering, 16(9): 119

[13] Lukyanov N V, Syroezhko A M, Slavoshevskaya N V, Strakhov V M. (2015). Humic acids from Belorussian lignite of Brinev and Zhitkovichi deposits. Coke and Chemistry, 58(12): 476–481

[14] Ramya A V, Balachandran M. (2022). Valorization of agro-industrial fruit peel waste to fluorescent nanocarbon sensor: ultrasensitive detection of potentially hazardous tropane alkaloid. Frontiers of Environmental Science & Engineering, 16(3): 27

[15] ShaoY, Bao M, HuoW, YeR, AjmalM, LuW (2023a). From biomass to humic acid: Is there an accelerated way to go? Chemical Engineering Journal, 452: 139172

[16] Shao Y, Geng Y, Li Z, Long Y, Ajmal M, Lu W, Zhao J. (2023b). Unlocking the potential of humic acid production through oxygen-assisted hydrothermal humification of hydrochar. Chemical Engineering Journal, 472: 145098

[17] Shao Y, Li Z, Long Y, Zhao J, Huo W, Luo Z, Lu W. (2024). Direct humification of biowaste with hydrothermal technology: a review. Science of the Total Environment, 908: 168232

[18] Shao Y, Luo Z, Bao M, Huo W, Ye R, Ajmal M, Lu W. (2023c). Enhanced production of hydrothermal humic acid in a two-step hydrothermal process with acid hydrothermal solution recycling. Chemical Engineering Journal, 474: 145634

[19] Shao Y C, Bao M G, Huo W Z, Ye R, Liu Y Q, Lu W J. (2022). Production of artificial humic acid from biomass residues by a non-catalytic hydrothermal process. Journal of Cleaner Production, 335: 130302

[20] ShaoY C, Huo W Z, YeR, LiuY Q, AjmalM, LuW J (2023d). Hydrothermal humification of lignocellulosic components: Who is doing what? Chemical Engineering Journal, 457: 141180

[21] Shao Y C, Zhao J, Long Y Y, Lu W J. (2023e). Two-step hydrothermal conversion of biomass waste to humic acid using hydrochar as intermediate. Frontiers of Environmental Science & Engineering, 17(10): 119

[22] Sharma H B, Sarmah A K, Dubey B. (2020). Hydrothermal carbonization of renewable waste biomass for solid biofuel production: a discussion on process mechanism, the influence of process parameters, environmental performance and fuel properties of hydrochar. Renewable & Sustainable Energy Reviews, 123: 109761

[23] Sriramoju S K, Babu V, Dash P S, Majumdar S, Shee D. (2022). Effective utilization of coal processing waste: separation of low ash clean coal from washery rejects by hydrothermal treatment. Mineral Processing and Extractive Metallurgy Review, 43(2): 165–181

[24] Wang J, Shi A, Yue D, Zhang L, Wang H, Jiang H, Huan X, Zhang Y. (2024). Elucidating the conformation effects within adsorption of natural organic matter on mesoporous graphitic carbon. Chemical Engineering Journal, 480: 148171

[25] Wang J, Wang C, Cheng Z, Wang C, Yue D, Wang H, Jiang H, Jiang B, Zhang L. (2023a). Exploring flotation separation of polycarbonate from multi-microplastic mixtures via experiment and numerical simulation. Chemical Engineering Journal, 474: 145854

[26] Wang J, Wang C, Shi A, Shi Y, Yue D, Zhang L, Wang J, Wang H, Wang C, Cui D. (2023b). An innovative approach for landfill leachate treatment based on selective adsorption of humic acids with carbon nitride. Chemical Engineering Journal, 461: 142090

[27] Wang J, Yue D, Li M, Wang H, Wang J, Wang C, Wang H. (2023c). Application of carbon nitride nanosheets for adsorption of various humic substances from aqueous solutions. Chemical Engineering Journal, 454: 140296

[28] Wei S X, Li Z C, Sun Y, Zhang J M, Ge Y Y, Li Z L. (2022). A comprehensive review on biomass humification: recent advances in pathways, challenges, new applications, and perspectives. Renewable & Sustainable Energy Reviews, 170: 112984

[29] Yang F, Antonietti M. (2020). Artificial humic acids: sustainable materials against climate change. Advanced Science, 7(5): 1902992

[30] Yang F, Zhang S, Cheng K, Antonietti M. (2019). A hydrothermal process to turn waste biomass into artificial fulvic and humic acids for soil remediation. Science of the Total Environment, 686: 1140–1151

[31] Zang X, Van Heemst J D H, Dria K J, Hatcher P G. (2000). Encapsulation of protein in humic acid from a histosol as an explanation for the occurrence of organic nitrogen in soil and sediment. Organic Geochemistry, 31(7−8): 679–695

[32] Zara M, Ahmad Z, Akhtar J, Shahzad K, Sheikh N, Munir S. (2017). Extraction and characterization of humic acid from Pakistani lignite coals. Energy Sources Part A: Recovery Utilization and Environmental Effects, 39(11): 1159–1166

[33] Zhang X, Zhang L, Li A. (2017). Hydrothermal co-carbonization of sewage sludge and pinewood sawdust for nutrient-rich hydrochar production: synergistic effects and products characterization. Journal of Environmental Management, 201: 52–62

[34] Zhang Y C, Zhang H Q, Dong X W, Yue D B, Zhou L. (2022). Effects of oxidizing environment on digestate humification and identification of substances governing the dissolved organic matter (DOM) transformation process. Frontiers of Environmental Science & Engineering, 16(8): 99

[35] Zheng W, Shao Y, Qin S, Wang Z. (2024). Future directions of sustainable resource utilization of residual sewage sludge: a review. Sustainability, 16(16): 6710

[36] Zherebtsov S I, Votolin K S, Malyshenko N V, Smotrina O V, Dugarjav J, Ismagilov Z R. (2019). Optimal parameters for the production of humic acids from brown coals with specific structural-group composition. Solid Fuel Chemistry, 53(5): 253–261

[37] Zhou S, Zhang C, Xu H, Jiang Z. (2022). Co-applying biochar and manganese ore can improve the formation and stability of humic acid during co-composting of sewage sludge and corn straw. Bioresource Technology, 358: 127297

[38] Zhu J, Li M, Whelan M. (2018). Phosphorus activators contribute to legacy phosphorus availability in agricultural soils: a review. Science of the Total Environment, 612: 522–537

Acknowledgements

This work was financially supported by the Major Program of National Natural Science Foundation of China (No. 52091543).

Conflict of Interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Electronic Supplementary Material

Supplementary material is available in the online version of this article at https://doi.org/10.1007/s11783-024-1913-3 and is accessible for authorized users.

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