Biochar effects on bacterial communities in recycled concrete aggregates

Highlights

	● Biochar application enhanced the nutrients of recycled concrete aggregates.
	● Higher salinity caused by biochar application inhibits urease and phosphatase activities.
	● Biochar addition improves certain bacterial species that promote plant growth.

Abstract

The substantial generation of building waste had precipitated significant environmental issues in China, attributable to urban expansion. Recycled concrete aggregate (RCA) produced from building waste had been used as an alternative material in green roofs as substrates. However, the biological dynamics of RCA are unknown. Thus, the column test was performed to investigate the effects of different biochar types and application ratios on the biochemical properties and bacterial communities of RCA. Results show that the nutrients of RCA have been improved by biochar addition regardless of biochar types and application ratios. This led to the increase in plant weight and height by at least 227% and 38% in biochar amended RCA. However, biochar application reduced bacterial richness and α-diversity, while enhancing plant growth. This indicated that biochar application directly improves certain bacterial species that promote plant growth and productivity. Biochar application reduced the Proteobacteria abundance and enhanced the percentage of Acidobacteriota in RCA, indicating that biochar application shaped the bacterial communities into raw soil composition. The outcome of this research suggests that biochar application improved RCA biochemical performance as a substrate for green roofs, which provides a potential method to consume substantial RCA.

Graphical abstract

Keywords

Recycled concrete aggregates / Biochar / Bacterial communities / Enzyme activities

References

[1] Abujabhah I S, Doyle R B, Bound S A, Bowman J P. (2018). Assessment of bacterial community composition, methanotrophic and nitrogen-cycling bacteria in three soils with different biochar application rates. Journal of Soils and Sediments, 18(1): 148–158

[2] Artiola J F, Rasmussen C, Freitas R. (2012). Effects of a biochar-amended alkaline soil on the growth of romaine lettuce and bermudagrass. Soil Science, 177(9): 561–570

[3] ASTM (20112011. ASTM Standard d2487: Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). West Conshohocken: ASTM International

[4] ASTM (20122012. ASTM Standard d698: Standard Test Method for Laboratory Compaction Characteristics of Soil Using Standard Effort. West Conshohocken: ASTM International

[5] ASTM (20132013. ASTM d4972–13: Standard Test Method for pH of Soils. West Conshohocken: ASTM International

[6] Berndtsson J C. (2010). Green roof performance towards management of runoff water quantity and quality: a review. Ecological Engineering, 36(4): 351–360

[7] Berndtsson J C, Emilsson T, Bengtsson L. (2006). The influence of extensive vegetated roofs on runoff water quality. Science of the Total Environment, 355(1−3): 48–63

[8] Besklubova S, Kravchenko E, Tan B Q, Zhong R Y. (2023). A feasibility analysis of waste concrete powder recycling market establishment: Hong Kong case. Environmental Impact Assessment Review, 103: 107225

[9] Bian Y, Chen Y B, Zhan L T, Guo H W, Ke H, Wang Y Z, Wang Q, Gao Y, Gao Y. (2024a). Effects of enzyme-induced carbonate precipitation technique on multiple heavy metals immobilization and unconfined compressive strength improvement of contaminated sand. Science of the Total Environment, 947: 174409

[10] Bian Y, Chen Y B, Zhan L T, Ke H, Gao Y Q, Wang Q Y, Gao Y F, Gao Y Q. (2024b). An enzyme-induced carbonate precipitation method for Zn²⁺, Ni²⁺, and Cr (Ⅵ) remediation: an experimental and simulation study. Applied Sciences, 14: 6559

[11] Cao C T, Farrell C, Kristiansen P E, Rayner J P. (2014). Biochar makes green roof substrates lighter and improves water supply to plants. Ecological Engineering, 71: 368–374

[12] Casida L Jr, Klein D A, Santoro T. (1964). Soil dehydrogenase activity. Soil Science, 98(6): 371–376

[13] Chen H M, Ma J Y, Wei J X, Gong X, Yu X C, Guo H, Zhao Y. (2018). Biochar increases plant growth and alters microbial communities via regulating the moisture and temperature of green roof substrates. Science of the Total Environment, 635: 333–342

[14] Chen J H, Liu X Y, Li L Q, Zheng J W, Qu J J, Zheng J F, Zhang X, Pan G. (2015). Consistent increase in abundance and diversity but variable change in community composition of bacteria in topsoil of rice paddy under short term biochar treatment across three sites from south china. Applied Soil Ecology, 91: 68–79

[15] Chen J H, Liu X Y, Zheng J W, Zhang B, Lu H F, Chi Z Z, Pan G, Li L, Zheng J, Zhang X. (2013). Biochar soil amendment increased bacterial but decreased fungal gene abundance with shifts in community structure in a slightly acid rice paddy from southwest China. Applied Soil Ecology, 71: 33–44

[16] Chen R, Luo Z Y, Zhang L L, Li Z F, Tan R Q. (2025). A new flexible-wall triaxial permeameter for localized characterizations of soil suffusion. Quarterly Journal of Engineering Geology and Hydrogeology, 58(1): 1–11

[17] Chen R, Wu F, Ng C W W, Tai P, Mei D J. (2024c). Effects of fine aggregate content on the unsaturated hydraulic characteristics of recycled concrete aggregate. Canadian Geotechnical Journal, 61(3): 604–610

[18] Chen Y B, Gao Y F, Guo H W. (2021b). Bio-improved hydraulic properties of sand treated by soybean urease induced carbonate precipitation and its application. Part 2: sand-geotextile capillary barrier effect. Transportation Geotechnics, 27: 100484

[19] Chen Y B, Gao Y F, Ng C W, Guo H W. (2021a). Bio-improved hydraulic properties of sand treated by soybean urease induced carbonate precipitation and its application. Part 1: water retention ability. Transportation Geotechnics, 27: 100489

[20] ChenY B, Liu B, BianY, GaoY F, LiuY, ChengM Y, Wang L Y, Hang L (2024b). Effects of soybean urease induced carbonate precipitation on the seed emergence and seedling growth of caragana korshinskii kom and its application in wind erosion control. Plant and Soil, 39: 1–25

[21] Chen Y B, Wang Q Y, Bian Y, Zhan L T, Gao Y F, Guo H W, Wang Y, Gao Y. (2024a). Effects of enzyme-induced carbonate precipitation (EICP) with different urease sources on the zinc remediation. Journal of Hazardous Materials, 480: 136321

[22] Chen Z K, Kamchoom V, Leung A K, Xue J X, Chen R. (2023). Influence of biochar on the water permeability of compacted clay subjected to freezing-thawing cycles. Acta Geophysica, 72(3): 2071–2081

[23] Chintala R, Mollinedo J, Schumacher T E, Malo D D, Julson J L. (2014). Effect of biochar on chemical properties of acidic soil. Archives of Agronomy and Soil Science, 60(3): 393–404

[24] Cui H, Xu R, Yu Z, Yao Y, Zhang S, Meng F. (2023). Tank-dependence of the functionality and network differentiation of activated sludge community in a full-scale anaerobic/anoxic/aerobic municipal sewage treatment plant. Frontiers of Environmental Science & Engineering, 17(3): 36

[25] Dai M D, Tan X F, Ye Z R, Li B J, Zhang Y, Chen X T, Kong D. (2023). Soil bacterial community composition and diversity respond to soil environment in rooftop agricultural system. Environmental Technology & Innovation, 30: 03042

[26] Dai Z M, Su W Q, Chen H H, Barberán A, Zhao H C, Yu M J, Yu L, Brookes P C, Schadt C W, Chang S X. . (2018). Long-term nitrogen fertilization decreases bacterial diversity and favors the growth of Actinobacteria and Proteobacteria in agro-ecosystems across the globe. Global Change Biology, 24(8): 3452–3461

[27] Elzobair K A, Stromberger M E, Ippolito J A, Lentz R D. (2016). Contrasting effects of biochar versus manure on soil microbial communities and enzyme activities in an aridisol. Chemosphere, 142: 145–152

[28] Fan W, Shen X, Zhu Z, Liu X, Zhang H, Qiu Y, Yin D. (2025). Rsearch progress on biochar materials for new pollutants removal in the aquatic environment: a mini-review. Frontiers of Environmental Science & Engineering, 19(3): 33

[29] Fouladidorhani M, Shayannejad M, Shariatmadari H, Mosaddeghi M R, Arthur E. (2020). Biochar, manure, and super absorbent increased wheat yields and salt redistribution in a saline‐sodic soil. Agronomy Journal, 112(6): 5193–5205

[30] Gao Y, Shao G C, Yang Z, Zhang K, Lu J, Wang Z Y, Wu S, Xu D. (2021). Influences of soil and biochar properties and amount of biochar and fertilizer on the performance of biochar in improving plant photosynthetic rate: a meta-analysis. European Journal of Agronomy, 130: 126345

[31] Gautam R K, Goswami M, Mishra R K, Chaturvedi P, Awashthi M K, Singh R S, Giri B S, Pandey A. (2021). Biochar for remediation of agrochemicals and synthetic organic dyes from environmental samples: a review. Chemosphere, 272: 129917

[32] Gorin G, Chang C C. (1966). Urease. VI: a new method of assay and the specific enzymic activity Analytical Biochemistry, 17: 49–58

[33] Guo H W, Zhang Q, Chen Y B, Lu H. (2023). Effects of biochar on plant growth and hydro-chemical properties of recycled concrete aggregate. Science of the Total Environment, 882: 163557

[34] Hagemann N, Joseph S, Schmidt H P, Kammann C I, Harter J, Borch T, Young R B, Varga K, Taherymoosavi S, Elliott K W. . (2017). Organic coating on biochar explains its nutrient retention and stimulation of soil fertility. Nature Communications, 8(1): 1089

[35] Heng T, He X L, Yang L L, Xu X, Feng Y. (2022). Mechanism of saline–alkali land improvement using subsurface pipe and vertical well drainage measures and its response to agricultural soil ecosystem. Environmental Pollution, 293: 118583

[36] Hoch J M K, Rhodes M E, Shek K L, Dinwiddie D, Hiebert T C, Gill A S, Salazar Estrada A E, Griffin K L, Palmer M I, McGuire K L. (2019). Soil microbial assemblages are linked to plant community composition and contribute to ecosystem services on urban green roofs. Frontiers in Ecology and Evolution, 7: 198

[37] Huang D L, Liu L S, Zeng G M, Xu P, Huang C, Deng L J, Wang R, Wan J. (2017). The effects of rice straw biochar on indigenous microbial community and enzymes activity in heavy metal-contaminated sediment. Chemosphere, 174: 545–553

[38] Jing Z B, Lu Z D, Zhao Z N, Cao W F, Wang W B, Ke Y C, Wang X, Sun W. (2023). Molecular ecological networks reveal the spatial-temporal variation of microbial communities in drinking water distribution systems. Journal of Environmental Sciences, 124: 176–186

[39] José M, Sánchez-Martín Á M, Campos P, Miller A Z. (2019). Effect of pyrolysis conditions on the total contents of polycyclic aromatic hydrocarbons in biochars produced from organic residues: Assessment of their hazard potential. Science of the Total Environment, 667: 578–585

[40] Kalam S, Basu A, Ahmad I, Sayyed R, El-Enshasy H A, Dailin D J, Suriani N L. (2020). Recent understanding of soil acidobacteria and their ecological significance: a critical review. Frontiers in Microbiology, 11: 580024

[41] KerstersK, De Vos P, GillisM, SwingsJ, Vandamme P, StackebrandtE (20062006. Introduction to the proteobacteria. In: The Prokaryotes: A Handbook on the Biology of Bacteria. Berlin:　Springer

[42] Khadem A, Raiesi F. (2017). Influence of biochar on potential enzyme activities in two calcareous soils of contrasting texture. Geoderma, 308: 149–158

[43] Khodadad C L M, Zimmerman A R, Green S J, Uthandi S, Foster J S. (2011). Taxa-specific changes in soil microbial community composition induced by pyrogenic carbon amendments. Soil Biology & Biochemistry, 43(2): 385–392

[44] Kim H Y. (2013). Statistical notes for clinical researchers: assessing normal distribution (2) using skewness and kurtosis. Restorative Dentistry & Endodontics, 38(1): 52–54

[45] Kravchenko E, Besklubova S. (2024a). Value stream assessment of the sustainable concrete recycling process with sequestration of CO₂ from flue gases. Sustainable Production and Consumption, 46: 282–293

[46] Kravchenko E, Sauerwein M, Besklubova S, Ng C W W. (2024b). A comparative life cycle assessment of recycling waste concrete powder into CO₂-capture products. Journal of Environmental Management, 352: 119947

[47] Li L B, Chen M X, Zhou X M, Lu L C, Wang Y, Cheng X. (2018a). Evaluation of the preparation and fertilizer release performance of planting concrete made with recycled-concrete aggregates from demolition. Journal of Cleaner Production, 200: 54–64

[48] Li L Q, Li S, Ma X G, Yan Y Q. (2023). Effects of urban green infrastructure designs on soil bacterial community composition and function. Ecosystems, 26(4): 815–825

[49] Li X N, Wang T, Chang S X, Jiang X, Song Y. (2020). Biochar increases soil microbial biomass but has variable effects on microbial diversity: a meta-analysis. Science of the Total Environment, 749: 141593

[50] Li Z, Wang Y H, Chow J K, Su Z, Li X. (2018b). 3D pore network extraction in granular media by unifying the delaunay tessellation and maximal ball methods. Journal of Petroleum Science Engineering, 167: 692–701

[51] Li Z F, Zhang Y F, Chen R, Tai P, Zhang Z T. (2025). Numerical investigation of morphological effects on crushing characteristics of single calcareous sand particle by finite-discrete element method. Powder Technolgy. ,

[52] Liao J X, So P S, Bordoloi S, Li D N, Yuan H R, Chen Y, Xin L Q. (2024). Plant performance and soil–plant carbon relationship response to different biochar types. Biochar, 6(1): 75

[53] Liao S H, Pan B, Li H, Zhang D, Xing B S. (2014). Detecting free radicals in biochars and determining their ability to inhibit the germination and growth of corn, wheat and rice seedlings. Environmental Science & Technology, 48(15): 8581–8587

[54] Liu K W, Ouyang J Z, Sun D S, Jiang N J, Wang A G, Huang N N, Liang P. (2022). Enhancement mechanism of different recycled fine aggregates by microbial induced carbonate precipitation. Journal of Cleaner Production, 379: 134783

[55] Liu L X, Chen Y B, Gao Y F, Liu B, Zhou Y D, Li C. (2023). Effect of urease enrichment degree of multiple sources of urease on bio-cementation efficacy via enzyme-induced carbonate precipitation. Canadian Geotechnical Journal, 60(12): 1923–1937

[56] Liu T, Xu J W, Tian R Q, Quan X. (2021). Enhanced simultaneous nitrification and denitrification via adding n-acyl-homoserine lactones (AHLS) in integrated floating fixed-film activated sludge process. Biochemical Engineering Journal, 166: 107884

[57] Mulvaney R, Khan S. (2001). Diffusion methods to determine different forms of nitrogen in soil hydrolysates. Soil Science Society of America Journal, 65(4): 1284–1292

[58] Murtaza G, Ahmed Z, Eldin S M M, Ali B, Bawazeer S, Usman M, Iqbal R, Neupane D, Ullah A, Khan A. . (2023). Biochar-soil-plant interactions: a cross talk for sustainable agriculture under changing climate. Frontiers in Environmental Science, 11: 1–31

[59] Ng C W W, Guo H W, Ni J J, Chen R, Xue Q, Zhang Y M, Feng Y, Chen Z, Feng S, Zhang Q. (2022). Long-term field performance of non-vegetated and vegetated three-layer landfill cover systems using construction waste without geomembrane. Geotechnique, 74(2): 155–173

[60] Ng C W W, Liao J X, Lau S Y, So P S, Hau B C H, Peprah-Manu D. (2023). Coupled effects of elevated CO₂ and biochar on microbial communities of vegetated soil. Journal of Environmental Management, 342: 118136

[61] Oberndorfer E, Lundholm J, Bass B, Coffman R R, Doshi H, Dunnett N, Gaffin S, Köhler M, Liu K K Y, Rowe B. (2007). Green roofs as urban ecosystems: ecological structures, functions, and services. Bioscience, 57(10): 823–833

[62] Pardo G, Sarmah A, Orense R. (2019). Mechanism of improvement of biochar on shear strength and liquefaction resistance of sand. Geotechnique, 69(6): 471–480

[63] Qiao H, Qiao Y, Sun C, Ma X, Shang J, Li X, Li F, Zheng H. (2023). Biochars derived from carp residues: characteristics and copper immobilization performance in water environments. Frontiers of Environmental Science & Engineering, 17(6): 72

[64] Ren H, Huang B L, Fernández-García V, Miesel J, Yan L, Lv C Q. (2020). Biochar and rhizobacteria amendments improve several soil properties and bacterial diversity. Microorganisms, 8(4): 502

[65] Safiuddin M, Alengaram U J, Rahman M M, Salam M A, Jumaat M Z. (2013). Use of recycled concrete aggregate in concrete: a review. Journal of Civil Engineering and Management, 19(6): 796–810

[66] Salomon M, Smith J B. (1957). A comparison of methods for determining extractable soil potassium in fertilizer test plots. Soil Science Society of America Journal, 21(2): 222–225

[67] Shi C J, Li Y K, Zhang J K, Li W G, Chong L L, Xie Z B. (2016). Performance enhancement of recycled concrete aggregate: a review. Journal of Cleaner Production, 112: 466–472

[68] Shinogi Y, Kanri Y. (2003). Pyrolysis of plant, animal and human waste: physical and chemical characterization of the pyrolytic products. Bioresource Technology, 90(3): 241–247

[69] Singh H, Northup B K, Rice C W, Prasad P V. (2022). Biochar applications influence soil physical and chemical properties, microbial diversity, and crop productivity: a meta-analysis. Biochar, 4(1): 8

[70] Solaiman Z M, Murphy D V, Abbott L K. (2012). Biochars influence seed germination and early growth of seedlings. Plant and Soil, 353(1−2): 273–287

[71] TabatabaiM (1996). Soil organic matter testing: an overview. Environmental Science, Agricultural and Food Sciences 46: 1–9 doi:10.2136/SSSASPECPUB46.C1

[72] Tabatabai M A, Bremner J M. (1969). Use of p-nitrophenyl phosphate for assay of soil phosphatase activity. Soil Biology & Biochemistry, 1(4): 301–307

[73] Tang J Y, Zhang L H, Zhang J C, Ren L H, Zhou Y Y, Zheng Y Y, Luo L, Yang Y, Huang H, Chen A. (2020). Physicochemical features, metal availability and enzyme activity in heavy metal-polluted soil remediated by biochar and compost. Science of the Total Environment, 701: 134751

[74] Tian R M, Ning D L, He Z L, Zhang P, Spencer S J, Gao S H, Shi W, Wu L, Zhang Y, Yang Y. . (2020). Small and mighty: adaptation of Superphylum patescibacteria to groundwater environment drives their genome simplicity. Microbiome, 8(1): 51

[75] Tzoulas K, Korpela K, Venn S, Yli-Pelkonen V, Kaźmierczak A, Niemela J, James P. (2007). Promoting ecosystem and human health in urban areas using green infrastructure: a literature review. Landscape and Urban Planning, 81(3): 167–178

[76] Vaccari F, Maienza A, Miglietta F, Baronti S, Di Lonardo S, Giagnoni L, Lagomarsino A, Pozzi A, Pusceddu E, Ranieri R. . (2015). Biochar stimulates plant growth but not fruit yield of processing tomato in a fertile soil. Agriculture, Ecosystems & Environment, 207: 163–170

[77] Wang C, Chazallon C, Braymand S, Hornych P. (2023a). Influence of self-cementing properties on the mechanical behaviour of recycled concrete aggregates under monotonic loading. Construction & Building Materials, 367: 130259

[78] Wang H, Garg A, Ping Y, Sreedeep S, Chen R. (2023b). Effects of biochar derived from coconut shell on soil hydraulic properties under salt stress in roadside bioretention. Waste and Biomass Valorization, 14: 1005–1022

[79] Wang M M, Zhu Y, Cheng L R, Andserson B, Zhao X H, Wang D Y, Ding A. (2018). Review on utilization of biochar for metal-contaminated soil and sediment remediation. Journal of Environmental Sciences, 63: 156–173

[80] Wang Y K, Chen H, Chen Y B, Jiao M J, Fan Z Y. (2024). Experimental study on macro-micro effectiveness of yellow river silt solidified by using soybean-induced carbonate precipitation (SICP) technology. Marine Georesources and Geotechnology, 43(1): 112–122

[81] Xiang Y Z, Liu Y, Niazi N K, Bolan N, Zhao L, Zhang S Y, Xue J, Yao B, Li Y. (2023). Biochar addition increased soil bacterial diversity and richness: large-scale evidence of field experiments. Science of the Total Environment, 893: 164961

[82] Xu H J, Wang X H, Li H, Yao H Y, Su J Q, Zhu Y G. (2014). Biochar impacts soil microbial community composition and nitrogen cycling in an acidic soil planted with rape. Environmental Science & Technology, 48(16): 9391–9399

[83] Xu Y, Zheng C, Liang L, Yi Z L, Xue S. (2021). Quantitative assessment of the potential for soil improvement by planting miscanthus on saline-alkaline soil and the underlying microbial mechanism. Global Change Biology. Bioenergy, 13(7): 1191–1205

[84] Xu Y J, Li Q Q, Tang Y Y, Huang H, Ren H Q. (2024). Electrocatalytic denitrification biofilter for advanced purification of chlorophenols via ceramsite-based Ti/SnO₂–Sb particle electrode: performance, microbial community structure and mechanism. Environmental Pollution, 346: 123594

[85] Yang J S, Yang F L, Yang Y, Xing G L, Deng C P, Shen Y T, Luo L Q, Li B Z, Yuan H L. (2016). A proposal of “core enzyme” bioindicator in long-term Pb-Zn ore pollution areas based on topsoil property analysis. Environmental Pollution, 213: 760–769

[86] Yang Y H, Chen T T, Xiao R, Chen X P, Zhang T. (2022). A quantitative evaluation of the biochar’s influence on plant disease suppress: a global meta-analysis. Biochar, 4(1): 43

[87] Yap S P, Chen P Z C, Goh Y, Ibrahim H A, Mo K H, Yuen C W. (2018). Characterization of pervious concrete with blended natural aggregate and recycled concrete aggregates. Journal of Cleaner Production, 181: 155–165

[88] Yu B B. (2021). Ecological effects of new-type urbanization in china. Renewable & Sustainable Energy Reviews, 135: 110239

[89] Yuan G, Lavkulich L. (1995). Colorimetric determination of phosphorus in citrate-bicarbonate-dithionite extracts of soils. Communications in Soil Science and Plant Analysis, 26(11−12): 1979–1988

[90] Yuan P, Wang J Q, Pan Y J, Shen B X, Wu C F. (2019). Review of biochar for the management of contaminated soil: preparation, application and prospect. Science of the Total Environment, 659: 473–490

[91] Zhang Q, Han Y, Chen W, Guo Y, Wu M, Wang Y, Li H. (2022). Soil type and pH mediated arable soil bacterial compositional variation across geographic distance in north china plain. Applied Soil Ecology, 169: 104220

Conflict of Interests

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgements

The first author would like to thank the National Key R&D Program of China (No. 2023YFC3905800). The second author would like to thank Open Foundation of the State Key Laboratory of Subtropical Building and Urban Science in South China University of Technology (No. 2022ZC01).

Electronic Supplementary Material

Supplementary material is available in the online version of this article at https://doi.org/10.1007/s11783-025-1967-x and is accessible for authorized users.

RIGHTS & PERMISSIONS

2025 Higher Education Press 2025