Sewage sludges are problematic due to the constant increase of urban population. The high level of organic matter in sludges can be valorized by co-composting with green waste. Many chemical changes occur in the compost maturation process, resulting on stabilized organic matter by humification which is recoverable as soil amendment. In this way, the knowledge of organic matter stability and maturity of compost is essential. However, estimation of chemical parameters allowing the management of compost quality usually need complex time consuming laboratory measurements. Indeed, there is not yet rapid, simple and robust method for their on site assessment at the moment. Among usual parameters used to monitor compost evolution, the C/N ratio is a fundamental chemical parameter. The aim of this work is the estimation of the C/N ratio using a Partial Least Squares regression based on UV and fluorescence spectroscopic data and pH from compost water extracts at various steps of composting process and measured on site. A mathematical linear model is established based on selected data (pH, spectroscopic indices) resulting on average relative error for C/N estimation of 5.26% (range between 0.5% min. and 9.5% max.). This tool leads to a rapid and simple on site estimation of the compost stabilization, allowing qualification of the end-product resulting on a global spectroscopic index of stability.

由于城市人口的不断增加，污水污泥存在问题。污泥中高含量的有机物可与绿色废物共同堆肥。堆肥成熟过程中发生了许多化学变化，通过腐殖化作用产生了稳定的有机物，可作为土壤改良剂进行回收。这样，有机物稳定性和堆肥成熟度的知识至关重要。然而，估计能够控制堆肥质量的化学参数通常需要耗时的实验室测量。的确，目前还没有一种快速，简单和可靠的方法来对其进行现场评估。在用于监控堆肥演变的常用参数中，C / N比是基本的化学参数。这项工作的目的是使用偏最小二乘回归法估算C / N比，该回归法基于堆肥过程中各个步骤并现场测量的来自堆肥水提取物的UV和荧光光谱数据以及pH值。根据选定的数据（pH，光谱指数）建立数学线性模型，得出C / N估计值的平均相对误差为5.26％（范围在最小0.5％和最大9.5％之间）。该工具可快速，简单地在现场估算堆肥的稳定性，从而对最终产品的合格性进行评估，而最终产品的稳定性取决于全球光谱学指标。基于所选数据（pH，光谱指数）建立数学线性模型，得出C / N估计值的平均相对误差为5.26％（范围在最小0.5％和最大9.5％之间）。该工具可快速，简单地在现场估算堆肥的稳定性，从而对最终产品的合格性进行评估，而最终产品的稳定性取决于全球光谱学指标。根据选定的数据（pH，光谱指数）建立数学线性模型，得出C / N估计值的平均相对误差为5.26％（范围在最小0.5％和最大9.5％之间）。该工具可快速，简单地在现场估算堆肥的稳定性，从而对最终产品的合格性进行评估，而最终产品的稳定性取决于全球光谱学指标。