To ensure safe reuse, biosolids are stabilized to reduce pathogens, odor, and volatile solids. Stabilization by lime addition have high material costs, high transportation costs, and loss of ammonia. Decreasing required lime additions would improve the sustainability of biosolids reuse. This study examined combining lime and heat treatment to reduce lime additions needed for required fecal coliform destruction. In contrast to the current best management practice requiring a pH of 12, fecal coliform reduction for final concentrations <1000 MPN/g (where MPN is most probable number) was achieved with pH as low as 10 when combined with a short (1-h) incubation at 60 °C. Analysis of D-values (the time required to destroy 1-log fecal coliform) supported a synergistic treatment response at moderate pH and heat treatments. Samples receiving higher temperature treatments had lower specific oxygen uptake rates, suggesting that readily-available carbon was lost during heat treatment. Samples with lower lime additions had higher final ammonia concentrations, which is a desired characteristic for biosolids reclaimed as a fertilizer. The study demonstrated that optimizing combined lime and heat stabilization can improve beneficial reuse as a means toward enhancing environmental sustainability and improving the circular economy.

为了确保安全地重复使用，生物固体被稳定以减少病原体，气味和挥发性固体。通过添加石灰来稳定具有高的材料成本，高的运输成本和氨的损失。减少所需的石灰添加量将改善生物固体再利用的可持续性。这项研究检查了石灰和热处理相结合以减少所需的粪便大肠菌群破坏所需的石灰添加量。与目前要求pH值为12的最佳管理方法相反，当最终浓度<1000 MPN / g（其中MPN是最可能的数字）时，粪便大肠菌群减少时，pH值短至10时（1-h）可降低）在60°C下孵育。D值（破坏1-log粪大肠菌群所需的时间）的分析支持在中等pH和热处理条件下的协同处理响应。接受高温处理的样品具有较低的比氧吸收率，这表明在热处理过程中会损失易获得的碳。添加较少石灰的样品具有较高的最终氨浓度，这对于回收用作肥料的生物固体来说是理想的特性。该研究表明，优化石灰和热稳定剂的组合可以改善有益的再利用，以此作为增强环境可持续性和改善循环经济的手段。