Study on development of a device for assessment compost stability based on the determination of oxygen consumption using pressure measurement

Abstract

Organic fertilizer or compost is an essential product in the current trend of high-tech agricultural development. Compost stability is not only an important quality parameter but can also be used to monitor the efficiency of the composting process. This study developed a device to evaluate the stability of compost based on the oxygen consumption method using the principle of pressure measurement. This homemade device has improved design, overcoming existing weaknesses in commercial equipment with the same operating principle. In which, the compost sample is put in the containers placed in the middle of the bottle while the produced CO₂ is absorbed by the KOH solution at the bottom. The device is capable of working independently with the data recorded on the microSD card without connecting to a computer. The device is operationally tested in the laboratory to assess the oxygen consumption of two actual compost samples. The results showed that these samples both meet the EU's regulations on compost stability with oxygen consumption in 4 days (AT4) less than 10.0 mg O₂/g compost.