{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,29]],"date-time":"2026-10-29T12:26:55Z","timestamp":1793276815484,"version":"4.5.0"},"reference-count":50,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2025,5,7]],"date-time":"2025-05-07T00:00:00Z","timestamp":1746576000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China","award":["42177051"],"award-info":[{"award-number":["42177051"]}]},{"name":"National Natural Science Foundation of China","award":["Y09E24009"],"award-info":[{"award-number":["Y09E24009"]}]},{"name":"Science Foundation of China Urban Construction Design &amp; Research Institute Co., Ltd.","award":["42177051"],"award-info":[{"award-number":["42177051"]}]},{"name":"Science Foundation of China Urban Construction Design &amp; Research Institute Co., Ltd.","award":["Y09E24009"],"award-info":[{"award-number":["Y09E24009"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biology"],"abstract":"<jats:p>The pyrolysis of sewage sludge into biochar, enhanced by incorporating agriculture waste rich in inorganic minerals and lignocellulosic compounds, provides an effective approach for achieving sludge-harmless treatment and resourceful utilization. In this study, sewage sludge and maize straw-based biochar (SMB) was prepared using the co-pyrolysis method, and the effects of different application ratios (0%, 1%, 3%, and 5%, w\/w) of SMB on soil properties, ryegrass growth, microbial community structure, and Pb content and speciation in the contaminated soil of constructed wetlands were investigated. The results showed that SMB had a high carbon content (28.58%) and was rich in functional groups (e.g., -C-O, -C-N). The results indicated that increasing SMB dosage (0\u20135% w\/w) in Pb-contaminated soil elevated soil pH from 6.40 to 7.93, cation-exchange capacity (CEC) from 30.59 to 79.03 cmol\/kg (+158%), and organic carbon content by 65% (from 176.79 mg\/kg to 107.3 mg\/kg), while reducing available phosphorus and potassium by 20% and 30%, respectively, resulting in a 6% decline in ryegrass leaf length. SMB application enriched Pb-resistant bacteria (e.g., Sphingomonas abundance increased from 10.3% to 11.2%) and enhanced Pb immobilization. After 55 days, the total soil Pb increased by 33%, and the residual fraction Pb significantly increased by 7.3% to 21.7%, driven by functional group complexation, ion exchange, pH, and CEC improvements.<\/jats:p>","DOI":"10.3390\/biology14050515","type":"journal-article","created":{"date-parts":[[2025,5,7]],"date-time":"2025-05-07T08:20:53Z","timestamp":1746606053000},"page":"515","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Application of Biochar on Soil Improvement and Speciation Transformation of Heavy Metal in Constructed Wetland"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-2824-2589","authenticated-orcid":false,"given":"Yuan","family":"Zhou","sequence":"first","affiliation":[{"name":"Innovation Center for Ecology and Landscape Architecture Engineering Technology, Ministry of Housing and Urban-Rural Development, Beijing 100120, China"},{"name":"China Urban Construction Design & Research Institute Co., Ltd., Beijing 100120, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaoqin","family":"Nie","sequence":"additional","affiliation":[{"name":"Innovation Center for Ecology and Landscape Architecture Engineering Technology, Ministry of Housing and Urban-Rural Development, Beijing 100120, China"},{"name":"China Urban Construction Design & Research Institute Co., Ltd., Beijing 100120, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yao","family":"Zhao","sequence":"additional","affiliation":[{"name":"School of Marxism, Beijing Forestry University, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liqiu","family":"Zhang","sequence":"additional","affiliation":[{"name":"Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China"},{"name":"Engineering Research Center for Water Pollution Source Control & Eco-Remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yatian","family":"Cheng","sequence":"additional","affiliation":[{"name":"Innovation Center for Ecology and Landscape Architecture Engineering Technology, Ministry of Housing and Urban-Rural Development, Beijing 100120, China"},{"name":"China Urban Construction Design & Research Institute Co., Ltd., Beijing 100120, China"},{"name":"School of Architecture, Tsinghua University, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9064-5990","authenticated-orcid":false,"given":"Cancan","family":"Jiang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenbin","family":"Zhao","sequence":"additional","affiliation":[{"name":"Innovation Center for Ecology and Landscape Architecture Engineering Technology, Ministry of Housing and Urban-Rural Development, Beijing 100120, China"},{"name":"China Urban Construction Design & Research Institute Co., Ltd., Beijing 100120, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiangchun","family":"Wang","sequence":"additional","affiliation":[{"name":"Innovation Center for Ecology and Landscape Architecture Engineering Technology, Ministry of Housing and Urban-Rural Development, Beijing 100120, China"},{"name":"China Urban Construction Design & Research Institute Co., Ltd., Beijing 100120, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chao","family":"Yang","sequence":"additional","affiliation":[{"name":"Innovation Center for Ecology and Landscape Architecture Engineering Technology, Ministry of Housing and Urban-Rural Development, Beijing 100120, China"},{"name":"China Urban Construction Design & Research Institute Co., Ltd., Beijing 100120, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"627","DOI":"10.1016\/j.chemosphere.2017.09.102","article-title":"Effect of sewage sludge hydrochar on soil properties and Cd immobilization in a contaminated soil","volume":"189","author":"Ren","year":"2017","journal-title":"Chemosphere"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1016\/j.jaap.2015.01.010","article-title":"Influence of pyrolysis temperature on physical and chemical properties of biochar made from sewage sludge","volume":"112","author":"Yuan","year":"2015","journal-title":"J. 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