Seed germination of the weed Rumex obtusifolius after on-farm conventional, biodynamic and vermicomposting of cattle manure

This study investigated whether composting methods differ in their impact on seed germination of Rumex obtusifolius (broad‐leaved dock). Weed seeds were buried in windrows of cattle farmyard manure, removed at monthly intervals and germinated during the course of 7 months. Composting methods differed in the maximum temperatures reached (63°C for conventional and biodynamic composting and 35°C for vermicomposting), the addition of 1000 m^?2 earthworms (Eisenia fetida) for vermicomposting and the inoculation of biodynamic preparations for biodynamic composting. After 1 month in windrows, germination rate of Rumex seeds was significantly higher in vermicompost (48%) than in conventional (28%) or biodynamic compost (18%). After 2 months in windrows, 26% of the seeds germinated in vermicomposting windrows, while those inserted in conventional and biodynamic windrows showed a negligible germination (0% and 2%, respectively). After 3 and 4 months, only seeds under vermicomposting germinated (22% and 3%, respectively). No germination was determined when seeds were inserted for longer than 4 months in any of the treatments. Seeds stored at room temperature germinated at 89% over the course of the experiment. Results suggest that the maximum temperature reached in windrows is not the single main factor reducing weed seed germination during composting.     

Bacterial community and decomposition rate in long term fed-batch composting using woodchip and Polyethylene terephthalate (PET) as bulking agents

Long term fed-batch composting experiments were conducted for 200 days using two types of bulking agents; woodchip and PET flake, with periodic compost withdrawal through a washing process. The bacterial communities of composting materials in the two different bulking agents were also investigated by 16S rRNA gene clone analysis. The decomposition rate in both composting reactors was 86.1% and 88.2% of the total organic load, respectively. The control experiment of dead-end operation without compost withdrawal by washing process could not be maintained for more than 102 days because of its low performance. The reactor with compost withdrawal, however, improved the decomposition rate in the composting process, and could be applied in the long run. There was a significant difference in the bacterial community between the FBC reactor with woodchip and another with PET flake as the bulking agent though the decomposition rates were similar. The reactor with woodchip as the bulking agent consisted of 95% Bacillales while the PET flake reactor contained 54% of total bacteria count. In addition, Lactobacillales was dominant at 38% in the PET flake reactor and the bacterial community in general significantly differed from the woodchip reactor. Furthermore, there was a difference in the species composition in the Bacillales and the bacterial community showed a significant difference at the species level between the two reactors. Although bacterial community differed, the decomposition rates between the two reactors were similar and PET flake showed greater viability than woodchip as a bulking agent due to its high abrasion resistance and non-biodegradability.     

城市污泥好氧堆肥过程中积温规律的探讨

对城市污泥好氧堆肥稳定化过程的温热条件进行了探讨 ,将物候学中的积温概念应用于堆肥稳定化 (腐熟 )过程。它同时兼顾到堆肥过程中的温度强度和持续时间两个参数。对于采用的强制通风静态垛堆肥工艺 ( CTB自动控制堆肥工艺 ) ,建议以 1 5℃作为生物学零度 ,积温指标为 1 0 0 0 0℃· h左右。堆肥原料的性质、堆肥工艺、微生物种群、生物学零度、外界环境等因素可能会对积温产生一定影响     

蘑菇培养料堆制过程中微生物的演替及作用

蘑菇培养料堆制的完成依赖于微生物群落共同作用来实现。综述了堆制阶段培养料中细菌、放线菌、真菌三大类型菌群出现、发展的规律 ,各自作用特点以及它们之间的相关性、拮抗性 ,同时从呼吸途径、酶学角度阐述了嗜热真菌对料选择性的形成和蘑菇菌丝生长的积极意义。     

沼渣与污泥混合高温堆肥效果及氮素控制

以锯木屑为调理剂,以Mg(OH)2与H3PO4的混合液为高温堆肥过程中的氮素抑制剂,研究沼渣与啤酒厂污泥混合堆肥效果。结果表明:混合物经好氧发酵处理后,均达到腐熟。添加氮素固定剂处理和对照处理的最高温度都可达65℃以上,在堆肥过程中添加氮素固定剂处理可提高堆体中有机物质的转化速率,对氮素的固定率达18%以上,添加固氮剂处理的堆肥结束后P元素增加了51%,堆肥品质得到了大幅度提高。堆肥过程中的物料的种子发芽指数不断提高,达到0.9;添加固氮剂的处理堆肥的种子发芽指数为1.0,明显高于对照。可见采用高温堆肥和氮素固定技术可有效地实现沼渣及啤酒厂污泥的混合资源化,该研究为后期沼渣和啤酒厂污泥堆肥的规模化应用提供了技术参数。     

农业废弃物养分循环利用技术模式评估模型的研究进展

农业废弃物的养分循环利用技术模式是实现农业循环经济的重要手段,其评估模型为优化养分循环利用技术提供了重要支撑。本文总结了农业废弃物养分循环技术模式评估框架、评估模型及评价指标、模型的数据源及其不确定性分析,以及模型应用尺度的研究进展。当前,常用于评估养分流动的模型主要是过程数学模型和产业生态学模型。过程数学模型和产业生态学模型在评估结果的可靠性和模拟尺度上存在较大差异,前者主要集中在实验室或中试规模,精度较高;后者可以实现从微观到宏观的多尺度模拟,数据的获取方式导致其具有较高的不确定性。最后,本文对农业废弃物养分循环利用技术评估模型的研究进行展望,提出为了在区域尺度上实现对农业生产系统废弃物资源化利用技术的准确评估,可以将过程数学模型与工业生态学模型相结合,建立可靠的模型框架和数据库,同时,在工厂、农场、村落、乡镇、区域等地理尺度进行模型拓展研究。     

土霉素对堆肥过程中酶活性和微生物群落代谢的影响

摘 要;以猪粪和秸秆为试验材料,研究了土霉素对堆肥温度、种子发芽指数、C/N、纤维素酶、脲酶、过氧化氢酶以及微生物群落代谢的影响。结果表明, 0 mg/kg (对照处理)的堆肥在第 2 天上升到 50 ℃以上, 维持了 5 d,达到了无害化处理的要求。35 mg/kg 土霉素处理(A1 处理）第 4 天升到 51.0 ℃,其高温期维持了 1 d。70 mg/kg 土霉素处理(A2 处理)第 3 天升到 50 ℃以上,高温期维持了 2 d。105 mg/kg 土霉素处理(A3 处理)和 140 mg/kg 土霉素处理(A4 处理)的温度在整个堆肥期间均未达到 50 ℃。在堆肥结束时各个处理的种子发芽指数均达到 80 % 以上。CK（Control check, 对照处理）、A1、A2、A3 和 A4 处理的 C/N 由 34.50 分别降为 16.64、16.07、19.48、18.45 和 19.83。堆肥的第 1 天,A1、A2、A3 和 A4 处理对纤维素酶活性的抑制率分别为 60.30%、21.30%、48.81% 和 76.05%,第 3 天,土霉素对纤维素酶活性起促进作用,在 4—30 d,A3、A4 处理对纤维素酶活性有抑制作用。在堆肥的前期（1—3 d）,土霉素刺激脲酶活性,随着堆肥时间的延长,土霉素对脲酶活性由刺激变为抑制作用,在第 18—30 天 A3、A4 处理与 CK 相比有着显著的抑制作用。在堆肥第 1 天到第 18 天,土霉素基本上促进过氧化氢酶的活性,堆肥 18 d 之后土霉素对过氧化氢酶起着是抑制作用。用 Biolog (ECO Microplate)方法研究了土霉素对堆肥过程中微生物群落代谢的影响,结果表明,在升温期 CK 处理的 AWCD (Average Well Color Development, 平均颜色变化率)在培养 60 h 之后大于其他处理,高温期 A2 处理的 AWCD 值最高,在降温期 CK 的 AWCD 值一直是最高的。对 Shannon 指数进行分析显示,堆肥的初始阶段土霉素降低微生物群落的功能多样性,随着时间的延长,土霉素增加微生物群落的功能多样性。对微生物利用六大类碳源分析表明, 140 mg/kg 的土霉素浓度能够改变微生物利用碳源的种类。     

Design and application of a pre-composting test step to determine the effect of high fat food wastes on an industrial scale in-vessel composting system

The high fat content in food wastes was suspected to inhibit an industrial in-vessel composting process from reaching the European Union Animal By-Product Regulation (composting temperature >70 °C for 1 h). The aim of this study was to design a test step to guide the mixing ratio of food waste to green waste to meet the regulation. A 15-compartment composting unit was designed to contain the compost mixes. Sausage and cheese wastes were mixed with green waste at 1:1; 1:2; 1:3 and 1:4 ratios by wet weight volume. Only the sausage waste mix ratio of 1:4 gave an average temperature of 70 °C for at least 1 h after 2 days of composting (fat content - 17%; C: N ratio - 8.6). All the cheese waste mixes did not reach 70 °C after 15 days of composting. This study demonstrated that using a simple pre-composting test step could reduce the chances of process failure during industrial composting. Although both sausage and cheese wastes are high in fat, they performed very differently in the composting process. Two linear equations were fitted to model the impact of these wastes on the maximum composting temperature.