Characterization of humic acids extracted from biosolid amended soils

Abstract

The aim of this study was to evaluate the changes produced in the chemical, acid-base and structural properties of soil amended (biosolids) and humic acids HAs incubated at different times.In the current work the amendments were conducted with biosolids at different doses (30, 90 and 180 t ha -1 ) on Colina (CLN) soil for 1, 2, 4 and 6 months.The acid-base characterization of extracted humic acids (HAs) showed a slight impact on Atotal (total acidity, mEq g -1 ), at 30 and 90 t ha -1 while at 180 t ha -1 the greatest increase was observed from 10.5±1.61 (control) to 17.9±0.30 (6 months of incubation). without evolution over the incubation time. The Aphenolic (phenolic acidity, mEq g -1 ) acidity behaves similarly while Acarboxylic (carboxylic acidity mEq g -1 )) remains constant over time and applied doses. The application of 13 C solid state NMR technique revealed higher abundance of aromatic C (CLN 43.5%) over alkyl C (21.4%) compounds. Aromatic C presents a decrease at high biosolid doses, which occurs simultaneously with alkyl C increase when using the same surveyed doses. Therefore, it might be considered that through the addition of biosolids, components such as fatty acids, amino acids or paraffinic structures are incorporated. As a result of biosolids addition, carboxylic C content remains steady, which agrees with the Accarboxylic behavior previously determined.

Producción y Aplicación de Compost con Alto Contenido de Nitrógeno Proveniente de un Residuo Orgánico Queratínico / Production and Application of Compost with High Nitrogen Content Coming from an Organic Keratin Waste

“…La T varió entre 20°C +/-5°C, sin fase termofílica. Los coeficientes Q2/4 (A280/A472), Q2/6 (A280/664), Q4/6 (A472/A664) determinan el grado de humificación de los componentes orgánicos (Antilén et al, 2014) donde valores de Q4/6 entre "3 y 5,5" indican que predominan compuestos de PM elevados, altamente polimerizados y/o aromáticos de los AH (Zambrano et al, 2011). En el tratamiento 4 (To4), Q4/6 arrojó un valor final de 4,9, con características organolépticas de humus.…”

Assessing Factors Controlling Structural Changes of Humic Acids in Soils Amended with Organic Materials to Improve Soil Functionality

“…Biochar and brown coal waste (BCW) are carbonised organic materials which have high proportions of recalcitrant OM, and by extension higher levels of HAs with aromatic characteristics, compared with other organic amendments such as farmyard manure (FYM) and composts [17][18][19]. Thus, the differences in the contents of aromatic compounds or degree of humification in such materials create significant variation in the structure of HAs [5,7,20]. In addition, this is influenced by the field age of OM, amendment dosage, and amendment frequency [7,15,16,21].…”

Biosolids as soil-amendment: evaluation of nutrient leaching in loamy-silty soil

“…The use of BS on soil offers economic and environmental benefits because they: a) allow the recycling of micro-and macronutrients (nitrogen, phosphorus, and potassium); b) enhance soil organic carbon storage; c) promote the formation of stable aggregates; d) improve water holding capacity, soil cationic exchange and aeration and e) promote erosion resistance. (Alvarenga et al, 2017;Antilén et al, 2014).…”