The Adjustment of Medium-High Range of the C/N for Commercial Composting

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Banjarata Jolanun
Monchaya Panphan
Rotsukon Jawana
Anuruk Junthong

Abstract

This study aimed to evaluate effectiveness of composting performance and cost of raw materialunder the adjustment of medium-high initial C/N ratio. The methodology was divided into three phases.Phase 1 was to investigate the effect of initial C/N ratio on composting by varying the C/N ratios of 30, 40,50, and 60 and using batch reactors (working volume 4.61 l). Phase 2 was to scale up the appropriatecondition which obtained from the Phase 1 to the pilot scale in the factory. Phase 3 was to examine theoptimum compost to soil ratio by testing the plant growth (Chinese mustard) at the ratios of 0:100, 5:95,10:90, and 15:85 respectively. Throughout the study, physical and chemical changes of compost weremonitored and the parameters of plant growth were also measured. Results show that the composting canbe efficiently managed at the initial C/N ratio up to 40, where the process had achieved thermophiliccomposting (>55°C) for 2 weeks which satisfied the regulatory requirement for a process to further reducepathogens (USEPA 40CFR503). Dry mass loss and organic matter degradation rate constant which followedfirst-order model (r2=0.8) were 33% and 0.004 day-1. The study was found that composting performedby turning significantly promoted the N loss during the first 2 weeks, especially the composting atlower C/N40 afterwards. The production cost (chicken dunk, cow manure, waste from mushroom cultivation,and coconut coir) was 0.40 Baht/kg and the quality of compost obtained was qualified the recommendedcriteria set by Department of Agriculture of Thailand (2548 B.E.). The significant differences(P<0.05) indicated the compost to soil ratio of 10:90 was the optimum condition for the plant growth.

Keywords : C/N ratio / Composing / Chicken Dunk / Cow Manure / Waste from MushroomCultivation / Coconut Coir

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Original Articles
Author Biographies

Banjarata Jolanun, Rajamangala University of Technology Lanna, Chiangmai 50300

Lecturer, Department of Environmental Engineering, Faculty of Engineering.

Monchaya Panphan, Rajamangala University of Technology Lanna, Chiangmai 50300

Lecturer, Department of Environmental Engineering, Faculty of Engineering.

Rotsukon Jawana, Rajamangala University of Technology Lanna, Chiangmai 50300

Lecturer, Department of Environmental Engineering, Faculty of Engineering.

Anuruk Junthong, Rajamangala University of Technology Lanna, Chiangmai 50300

Lecturer, Department of Environmental Engineering, Faculty of Engineering.