Follow the degradation of organic matter during composting of date palm (phoenix dactylifera L) waste by physicochemical properties, UV-visible and FT-IR analysis

Palm tree waste is considered among the most widespread organic waste in nature and the least exploited in our days. In the Arabic region and the North of Africa, the date palm tree cultivation represents the lion's share compared to the other trees. But the wastes will stay always represent a risk on the environment due to their limits uses. The composting process is considered the most effective technique to exploiting these wastes and to eliminate environmental pollution. In this work, we prepared four mixtures from date palm waste (DPW) named C1, C2, C3, and C4. The composting process was evaluated through the physicochemical properties like; temperature, pH, electronic conductivity (EC), total organic carbon (TOC), total Kjeldahl nitrogen (TKN), C/N ratio, humic substance, UV spectroscopy and FTIR spectroscopy. The obtained results showed that the temperature increased up to 40.3 degrees C, 40.8 degrees C, 42.5 degrees C, and 45.7 degrees C, then decreased to 22.7 degrees C, 22.7 degrees C, 21.5 degrees C and 21.2 degrees C at the end of process for C1, C2, C3, and C4, respectively. The final organic compost had a natural soil odour and brown in colour. The C/N ratio of final compost recorded as 20.6, 16.0, 14.9, and 13.8 for C1, C2, C3, and C4, respectively. The loss in organic carbon reached 8.9% (C1), 10.3% (C2), 10.4% (C3) and 10.5% (C4). These results were confirmed by UV-visible and FTIR spectra analysis which showed different absorption bands from one mixture to another, as well as variable absorption ratios at the same compost level.