Banca de DEFESA: FERNANDO JOSÉ PEREIRA FERREIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : FERNANDO JOSÉ PEREIRA FERREIRA
DATE: 15/09/2023
TIME: 09:00
LOCAL: Online
TITLE:

Use of biochar to reduce the solubility of heavy metals during chicken litter composting.

KEY WORDS:

Bioavailability. Organic fertilizer. Poultry farming.

PAGES: 86
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Química do Solo
SUMMARY:

The use of agricultural waste to fertilize crops, mainly vegetables, such as chicken litter (CF), has been adopted by producers throughout Brazil. However, the application of organic waste without prior treatment and indiscriminately has contributed to the contamination of the environment and food produced by heavy metals. The composting process reduces the bioavailability of some heavy metals in the waste, however this reduction has not been observed for lead. Therefore, the objective of the present work was to evaluate the potential of biochar (BC) added to CF, in reducing the bioavailability of heavy metals during the composting process. The treatments consisted of different proportions of BC that were added to CF, prior to composting (absence (0%); 5%; 10%, and 15%, based on dry weight), and the different composting times evaluated. (fresh CF (0); 30; 60, and 90 days). The test was carried out in a completely randomized experimental design. It was found that treatments with the addition of BC reached higher temperatures when compared to treatments without BC. Regarding pH, the composted CF, with the lowest doses of BC (0% and 5%), showed a more significant increase in pH compared to treatments with the highest doses (10% and 15%). With regard to electrical conductivity and density, the highest dose (15%) presented higher values in relation to the other treatments. Considering the evolution of CO2, in treatments that received BC, after 30 days of composting there was a greater emission of CO2 in treatments with 10% and 15% BC. However, in relation to carbon content, a reduction in carbon content was observed in treatments with the addition of BC. These results clearly demonstrated that the addition of BC to CF favored microbial activity, accelerating the mineralization of CF during composting. It was also found that the addition of biochar to CF during composting reduced N losses in the form of NH3. The results of the bioavailable levels of heavy metals in the compost and accumulated in the plant demonstrated the effective potential of biochar in reducing bioavailability, including for lead. For the chicken litter composting process, the addition of biochar showed the best results for the immobilization of heavy metals. Since, among the composting times and dosages tested, the retention of metals was more notable in the 90-day period and with a dosage of 15% biochar.

COMMITTEE MEMBERS:
Presidente - 387263 - NELSON MOURA BRASIL DO AMARAL SOBRINHO
Externa ao Programa - 1412091 - ERICA SOUTO ABREU LIMA - UFRRJExterna à Instituição - ANA CAROLINA CALLEGARIO PEREIRA - UNIFOA