RESUMEN
Vegetable waste (VW) is a potential organic fertilizer resource. As an important way to utilize vegetable wastes, aerobic composting of VW generally has the problems of long fermentation cycle and incomplete decomposition of materials. In this study, 0.3-1.2% of potassium persulfate (KPS) was added to promote the maturity of compost. The results showed that the addition of KPS promoted the degradation of materials, accelerated the temperature rise of compost. KPS also promoted the formation of humic substances (HS). Compared with the control, HS contents of treatments with KPS addition increased by 7.81 ~ 17.52%. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM) analysis reveal the mechanism of KPS affecting the composting process: KPS stimulated the degradation of various organic substances such as lignin at high temperature stage, and the degradation of lignin could accelerate the release and decomposition of other components; KPS made the structure of the material looser, with more voids and pores, and more specific surface area of the material, which was more suitable for microbial degradation activities. Therefore, the addition of KPS can promote the decomposition of organic matter in the early stage of composting, accelerate the process of thermophilic phase, and shorten the composting process and improve product maturity.
Asunto(s)
Compostaje , Compuestos de Potasio , Sulfatos , Suelo , Verduras , Lignina , Sustancias Húmicas/análisisRESUMEN
Strong oxidants can reduce the emission of NH3 during composting. But as a commonly used oxidant, the influence of persulfate on nitrogen transformation during composting is unclear. In this study, the effects of 0.3 %-1.2 % potassium persulfate (PS) on nitrogen losses and microbial community during air-dried cow manure composting were investigated. The results showed that PS could reduce nitrogen losses compared to the control. This was because it decreased pH and the maximum NH4+-N content of treatments, which was beneficial to nitrogen retention. In addition, Pseudoxanthomonas and Chelativorans were enriched compared to the control, which might be associated with NH4+-N transformation and nitrogen fixation. Meanwhile, PS increased the abundance of thermophilic lignocellulose degrading bacteria, and 0.3 % and 0.6 % PS increased the maximum temperature and the duration of the thermophilic period. This study indicated that PS could reduce nitrogen losses in composting and greatly influence nitrogen transforming and lignocellulose degrading bacteria.
Asunto(s)
Compostaje , Microbiota , Animales , Bovinos , Femenino , Estiércol/microbiología , Nitrógeno/análisis , Oxidantes , Compuestos de Potasio , Suelo , Sulfatos , Zea maysRESUMEN
The effects of FeSO4 on nitrogen loss and humification were investigated in the composting of cow dung and corn straw. The results showed that all groups met the ripening requirements after 50 days: the temperature was above 50 °C for 12- 17 days; the products had pH values of 6.4-7.6, electrical conductivities of 1.06-1.33 ms·cm-1, NH4+-N contents of 37.2-61.8 mg kg-1, and the seed germination index of 95%-101%. FeSO4 reduced nitrogen losses by 9.21-15.65% compared to the control group. FeSO4 also improved the compost humification process: the humus substances (HS) contents in the compost product with FeSO4 were 109.82-129.86 g·kg-1, higher than 106.31 g·kg-1 in the control group. The compost product in 3.75% FeSO4 treatment had the highest maturity degree. This study showed that FeSO4 could inhibit the mineralization of organic matter during the composting and accelerate the formation of HS.