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南京师范大学杨朕副教授、杨维本教授团队坚持“变废为宝”和“可持续发展”理念，利用自主研发的全尺度机械化高温好氧发酵装置，系统研究了以蓝藻泥与当地典型农业废弃物鸡粪、秸秆等为原料进行的堆肥技术。相关成果发表于Science of the Total Environment（IF=6.551）。
论文第一作者为南师大硕士研究生张泽朋，合作者包括研究生胡敏、边博教授和张利民教授。该项研究获得国家科技重大项目“水专项”(ZX07202-004)、江苏省太湖水环境综合治理科研课题(TH201)、国家自然科学基金(51978341)和江苏省自然科学基金(BK0087)等的资助。
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Highlights
Full-scale mechanized composting of algae with chicken faeces and straw is assessed.
Compost product quality fully meets the requirement of organic fertiliser standard.
Toxic microcystin and volatile fatty acid contents are decreased by >99.5%.
Notable economic benefit with a gross profit margin of 167%–434% is calculated.
Dominant aerobic thermophilic microbial species for composting are identified.
Abstract
A high incidence of harmful algal bloom in eutrophic surface waters causes many environmental problems. Thermophilic aerobic composting enables effective treatment and disposal of algal sludge that remains after the dewatering of algae slurries, and provides a value-added organic fertiliser. Previous studies have either only dealt with the composting of a single waste component or were conducted at a lab-/pilot-scale; however, this work is a comprehensive assessment of full-scale mechanized thermophilic aerobic co-composting of algal sludge and other typical biomass-based wastes, including chicken faeces and rice straw, in a water-rich rural area in the Tai lake basin, China. With the optimised feedstock material mass ratio (6.0:1.8:1.0 for straw:algae:faeces; initial C/N ratio of 20; and initial moisture of 60 wt%), the co-composting process effectively achieved the reduction, harmlessness, and reuse of waste. The moisture content (28.36 wt% of wet weight), organic matter content (57.91 wt% of dried weight), total nutrient content (6.59 wt% for TN + TP + TK of dried weight), and heavy metal contents as well as the pH of the final product fully met the Chinese National Agricultural Organic Fertiliser Standard requirements. The reduction rates of microcystin and toxic volatile fatty acid contents were higher than 99.5%, and the seed germination index of the product was 114.5%. A notable economic benefit with a gross profit margin of 167–434% of the process was highlighted. Investigation of the associated mechanisms, including statistical analysis, spectral characterisation, micro-morphological observation, and microbial community analysis, revealed that a decreased particle sizes with a looser structure and an efficient humification effect, resulting from the work of several identified dominant microbial species, contributed to the high product quality. The current study provided a demonstration of the promising full-scale co-composting technology for comprehensive management of the environment in water-rich rural areas and the construction of a sustainable watershed.
太湖是中国第三大淡水湖，总面积达2250km2。太湖周边城市众多，存在一定的水体富营养化现象，蓝藻水华时有发生。目前，治理蓝藻的方法以打捞为主，每年4月~11月是太湖蓝藻打捞高峰。通过打捞船、吸藻泵等工具打捞蓝藻后，就近运输至藻水分离站，将藻浆体积缩小到十分之一至数十分之一后，产生的团块即为蓝藻藻泥。藻泥用手已挤不出水，但其含水量仍然很高。目前，打捞后的蓝藻除少部分资源化利用外，大部分未得到妥善处置。藻泥产量逐年增加，藻泥堆放已产生一系列问题：若露天堆放，藻泥腐烂后产生藻毒素释放和强烈恶臭，对周边环境影响巨大；如封闭存放，则需消耗大量人力物力及土地，且藻泥腐烂发酵后产生沼气，在封闭环境内存在巨大的安全隐患。
以蓝藻泥的减量化、无害化和资源化为目标，综合考虑太湖流域典型农业地区发展实际现状和地方需求，南京师范大学相关研究团队坚持“变废为宝”和“可持续发展”理念，结合团队前期在中试规模农业有机废弃物高效高温堆肥的研究积累（边博, 胡修韧, 张少鹏, 吕成旭, 杨朕*, 杨维本, 张利民, Bioresour. Technol., 287 (), 121482），利用自主研发的全尺度机械化高温好氧发酵装置，系统研究了以蓝藻泥与当地典型农业废弃物鸡粪、秸秆等为原料进行的共堆肥技术。
本篇论文从堆肥参数优化、堆肥产品质量评估和经济效益、堆肥机理分析三个方面，全面评价了在太湖流域农村地区将蓝藻泥与典型农业废弃物（鸡粪和秸秆）共处理的高温好氧堆肥工艺，为水系丰富的农村地区统筹兼顾地治理环境问题和建设生态清洁小流域提供了有力的技术支撑。
综合评估不同批次条件下堆肥前后物料的含水率、pH、总氮(TN)、总磷(TP)、总碳(TC)、碳氮比(C/N)等的变化趋势，得出了最优堆肥参数：混合物料的质量比（秸秆：蓝藻泥：鸡粪=6.0:1.8:1.0），初始物料碳氮比为20，堆肥温度75℃，堆肥时间18小时。最优批次堆肥产品中，产品含水率（28.36 wt%）、总养分含量(TN + TP + TK：6.59 wt%)、重金属含量、pH值等完全符合中国有机肥料行业标准(NY 525—)。此外，在最优条件下，堆肥后产品中的藻毒素含量也大幅下降（原料：1470μg/kg；产品：5.715μg/kg）。
堆肥产品质量评估和经济效益：最优条件下堆肥产品的种子发芽指数(GI)达到114.5%，表明产品充分腐熟。除环境效益外，该共堆肥工艺还存在显著的经济效益。按当地高品质农业有机肥售价估计，产品毛利率在167%-434%。
堆肥机理分析：通过系统的红外光谱表征、微观形态观察、粒度分析、三维荧光分析和微生物测序等手段，本文还对共堆肥机制进行了充分的讨论。高温好氧堆肥过程中，利用嗜热、好氧型优势物种Bacillus thermolactis、Bacillus aerophilus、 Lactobacillus brevis、Pseudomonas fragi、Pseudomonas azotoformans等发挥的腐殖化作用，得到了粒径更小、结构更疏松，腐殖质含量更高、腐熟化程度更高的高品质有机肥。
责任编辑：宋潇
校对和审核：张阳 王农
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