Formación de suelos en depósitos de residuos mineros mediante la aplicación de biocarbón y fitoestabilizaciónfactores reguladores del secuestro de carbono y de la formación de agregados estables

Abstract

The present research is composed by three complementary tasks to evaluate the effectiveness of the application of biochar and marble waste, independently and in combination with the development of vegetation, to rehabilitate deposits of contaminated tailing mine, evaluating its effect on the formation of Aggregates (structured soil formation) and stable carbon retention in newly created technologies. In the first task, the optimum operational parameters were identified to produce the most suitable biochar for soil remediation from pig manure, crop residues and municipal solid waste, the three residues generated in large quantities in the region of Murcia - Spain, being able to be valorized for the rehabilitation of contaminated soils and to contribute to the sequestration of carbon by generating a pyrolyzed amendment with high proportions of stable carbon, of slow degradation. In the second task a laboratory incubation was carried out in plastic pots, the biochar produced from pig manure, crop residues and municipal solid waste was used according to the operational conditions selected in task 1, and it was added together with marble residue (calcium carbonate To increase pH and immobilize trace elements) to the mining soil as a rehabilitation strategy. The effectiveness of each biochar, alone and combination with calcium carbonate, was evaluated to create a structured soil and to sequester carbon in a stable way. The effectiveness of the amendments to trace element immobilization and the emission of greenhouse gases were also analyzed. The formation of structure and accumulation of organic carbon are necessary processes for the development of a quality soil that allows the establishment of vegetation. In addition, it contributes to mitigating climate change by carbon sequestration in the soil, which does not pass into the atmosphere in the short term as CO2. In the third task once the biochar that most intensely improves soil structure, trace element immobilization and stable carbon accumulation was identified, a pot experiment was designed to evaluate the effect of rhizosphere on the formation of aggregates and carbon accumulation in the soil. Two different doses of biochar were evaluated which were added to the soil together with calcium carbonate. Piptatherum miliaceum (P. miliaceum) was planted, with a fasciculated root system. This experiment elucidated the contribution of the root system to soil formation and carbon sequestration, with possible repercussions on the future rehabilitation of contaminated soils using assisted phytostabilization. This work is specialized in soil remediation, phytoremediation, organic matter dynamics, waste recovery and minimization of environmental risks. It brings more knowledge to the use of phytostabilization assisted with biochar for the formation of tecnosols from tailing mine, minimizing environmental risks and contributing to carbon sequestration. http://repositorio.bib.upct.es/dspace/