Chemical Engineering Department, ITQUIMA, University of Castilla-La Mancha, Avenida Camilo José Cela S/N. 13071 Ciudad Real, Spain.
J Environ Manage. 2012 Mar;95 Suppl:S134-8. doi: 10.1016/j.jenvman.2010.10.053. Epub 2010 Nov 12.
An experimental technique for compost stability measurements based on Sapromat electrolytic respirometry was optimised and subsequently applied to a sludge composting process. Anaerobically digested sewage sludge mixed with reed was composted during 90 days in a pilot-scale rotary drum with forced aeration. Periodic solid samples were taken, and a previously optimised respirometric procedure was applied in order to measure the oxygen consumption. The respirometric experiments were made directly with a few grams of solid samples, optimum moisture and 37 °C over a period of 96 h. The results obtained showed how the respiration activity of the sludge decreased during the composting experiment under the specific operating conditions. The specific oxygen uptake rate (SOUR) instant values from the oxygen consumption curves were obtained, and two commonly used respirometric indexes (RI(24) and AT(4)) were calculated for all samples. Both RI(24) (a mean of the SOUR values during the 24 h maximum activity period) and AT(4) (total oxygen consumption after 4 days) were the recommended parameters for the estimation of compost stability by the European Union in the second draft of the Working Document on the Biological Treatment of Biowaste in 2001. Both indexes exponentially decreased with the composting time, and a good linear correlation between them was observed. Final values of RI(24) and AT(4) after 90 days were 600 mg O(2) kg VS(-1) h(-1) and 26 mg O(2) gTS(-1), respectively. We also considered if this technique could be classified as a Dynamic or Static method, the two primary respirometric techniques for measuring compost stability. Supposing that the proposed procedure is considered a dynamic method (no limitations on the amount of oxygen supply), the final RI(24) obtained was compared with the dynamic respiration index (DRI) proposed by the EU (1000 mg O(2) kg VS(-1) h(-1)). Our result indicated that stable compost was obtained after 90 d. However, if a static limit was considered (AT(4) lower than 10 mg O(2) gTS(-1) as proposed by the EU), our result would indicate that more residence composting time would be needed. Taking into account these results, the advantages and disadvantages and the validity of the proposed method are discussed.
基于 Sapromat 电解呼吸测量法的堆肥稳定性实验技术得到了优化，随后应用于污泥堆肥过程中。在带有强制通风的中试规模转鼓中，将厌氧消化的污水污泥与芦苇混合，在 90 天内进行堆肥。定期采集固体样品，并应用先前优化的呼吸测量程序测量耗氧量。呼吸测量实验直接在几克固体样品上进行，在最佳湿度和 37°C 下进行 96 小时。实验结果表明，在特定操作条件下，污泥的呼吸活性在堆肥实验过程中如何降低。从耗氧量曲线中获得了比耗氧速率（SOUR）的即时值，并为所有样品计算了两个常用的呼吸测量指标（RI(24)和 AT(4)）。RI(24)（24 小时最大活性期内 SOUR 值的平均值）和 AT(4)（4 天后的总耗氧量）均是欧盟在 2001 年生物处理生物废物工作文件第二稿中推荐用于估计堆肥稳定性的参数。这两个指标随堆肥时间呈指数下降，且两者之间存在良好的线性相关性。90 天后的 RI(24)和 AT(4)的最终值分别为 600mgO2kgVS(-1)h(-1)和 26mgO2gTS(-1)。我们还考虑了这种技术是否可以归类为动态或静态方法，这两种主要的呼吸测量技术用于测量堆肥稳定性。假设所提出的程序被认为是一种动态方法（对氧气供应没有限制），则获得的最终 RI(24)与欧盟提出的动态呼吸指数（DRI）（1000mgO2kgVS(-1)h(-1)）进行比较。结果表明，90d 后得到稳定的堆肥。然而，如果考虑静态限制（欧盟提出的 AT(4)低于 10mgO2gTS(-1)），则结果表明需要更多的停留堆肥时间。考虑到这些结果，讨论了所提出方法的优缺点和有效性。
