Physicochemical profile of microbial-assisted composting on empty fruit bunches of oil palm trees.
This study was carried out to investigate the physicochemical properties of compost from oil palm empty fruit bunches (EFB) inoculated with effective microorganisms (EM∙1™). The duration of microbial-assisted composting was shorter (∼7 days) than control samples (2 months) in a laboratory scale (2 kg) experiment. The temperature profile of EFB compost fluctuated between 26 and 52 °C without the presence of consistent thermophilic phase. The pH of compost changed from weak acidic (pH ∼5) to mild alkaline (pH ∼8) because of the formation of nitrogenous ions such as ammonium (NH4 (+)), nitrite (NO2 (-)), and nitrate (NO3 (-)) from organic substances during mineralization. The pH of the microbial-treated compost was less than 8.5 which is important to prevent the loss of nitrogen as ammonia gas in a strong alkaline condition. Similarly, carbon mineralization could be determined by measuring CO2 emission. The microbial-treated compost could maintain longer period (∼13 days) of high CO2 emission resulted from high microbial activity and reached the threshold value (120 mg CO2-C kg(-1) day(-1)) for compost maturity earlier (7 days). Microbial-treated compost slightly improved the content of minerals such as Mg, K, Ca, and B, as well as key metabolite, 5-aminolevulinic acid for plant growth at the maturity stage of compost. Graphical Abstract Microbial-assisted composting on empty fruit bunches.
Metabolites Profiling Laboratory, Institute of Bioproduct Development, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Bahru, Johor, Malaysia.
Li Yee
LY
Lim
Department of Bioprocess Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Bahru, Johor, Malaysia.
Cassendra Phun Chien
CP
Bong
Metabolites Profiling Laboratory, Institute of Bioproduct Development, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Bahru, Johor, Malaysia. lschua@ibd.utm.my.|Department of Bioprocess Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Bahru, Johor, Malaysia. lschua@ibd.utm.my.
Lee Suan
LS
Chua
Department of Bioprocess Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Bahru, Johor, Malaysia.
Chew Tin
CT
Lee
D002244:Carbon / Q000032:analysis; D055598:Chemical Phenomena; D003059:Cocos / Q000737:chemistry / Q000382:microbiology*; D008296:Malaysia; D009584:Nitrogen / Q000032:analysis; D000073878:Palm Oil; D035261:Plant Components, Aerial / Q000737:chemistry / Q000382:microbiology*; D010938:Plant Oils / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D012987:Soil / Q000737:chemistry*; D013696:Temperature; D018505:Waste Management / Q000379:methods*; D014866:Waste Products / Q000032:analysis*
D010938:Plant Oils; D012987:Soil; D014866:Waste Products; D000073878:Palm Oil; D002244:Carbon; D009584:Nitrogen
Carbon to nitrogen ratio; Composting; Effective microorganisms; Empty fruit bunches; Mineralization; Oil palm