Efficacy of fresh and air-dried biosolids as amendments for remediation of acidic and metal-polluted soils: A short-term laboratory assay

Abstract

Biosolids have been used as amendments on mine degraded soils for in situ immobilization of metals, neutralization, and improvement of nutritional, microbiological, and physical characteristics to reestablish a self-sustaining plant community. Fresh and air-dried biosolids have been used but dried ones are preferred as they are cheaper to transport, contain less pathogens and are much easier to handle. The same efficacy has been assumed for both biosolids. The study evaluated the effects of fresh and air-dried biosolids on physical, chemical and microbiological characteristics of an acidic and metal/As-rich soil of the Puchuncaví valley, central Chile, and on plant yield under laboratory conditions. Two doses of each biosolids were used (50 and 100 ton ha -1 , dry weight). Fresh and air-dried biosolids similarly increased organic matter, total nitrogen (N) and available N and phosphorous contents of study soil. However, air-dried biosolids exhibited lower field capacity and higher wilting point, salinity, higher levels of dissolved organic carbon, concentrations of total dissolved copper and zinc, and lower activity of free Cu 2+ ions in pore water. Basal respiration was significantly increased by incorporation of biosolids into soils, irrespective of being fresh or air-dried ones. In terms of aerial plant productivity, fresh biosolids and low doses of air-dried biosolids significantly increased this characteristic. However, high doses of air-dried biosolids limited aerial biomass and root cover, probably due to soil salinity and water stress. Therefore, fresh biosolids are suggested for remediation of this mine degraded soils.

Carbon mineralization in acidic soils amended with an organo-mineral bentonite waste

“…Organic carbon mineralization has been studied in soils amended with different types of winery wastes (Bustamante et al, 2007(Bustamante et al, , 2010; Mosse et al, 2012). The effect of wastes and other organic matter sources application to the soil on organic carbon mineralization can be quite variable, and increases (Ginocchio et al, 2013;Hasbullah and Marschner, 2016) and decreases (Meli et al, 2002) have been reported. The short-term increases or decreases in soil organic carbon mineralization caused by the organic matter amendments are defined as positive or negative priming effects (Kuzyakov et al, 2000).…”

Solubility, partitioning, and activity of copper‐contaminated soils in a semiarid region

“…This partitioning approach assumes that dissolved metals are mobile and could possibly be taken up by plant roots or otherwise be interacting with various soil organisms ( Sauvé et al, 2000). Finally, the free Cu 2+ pool is considered to be the primary bioavailable form of soil Cu ( Thakali et al, 2006; Ginocchio et al, 2013), and the best indicator of Cu phytotoxicity ( Sauvé et al, 1998; Oliver et al, 2005). Therefore, discerning among the different pools of Cu is crucial in evaluating the potential environmental and human health risk.…”

COMPORTAMIENTO DE EVASIÓN Y REPRODUCCIÓN DE LA LOMBRIZ Eisenia foetida EN SUELOS AGRÍCOLAS IMPACTADOS POR ACTIVIDADES MINERAS

“…En algunas áreas de la cuenca, los suelos de uso agrícola presentan elevados niveles de metales como cobre y plomo, los cuales estarían asociados a las emisiones proveniente de fundiciones y termoeléctricas (Aguilar et al 2011, Ginocchio et al 2013, González et al 2014). Los estudios de toxicidad en esta zona se han realizado mediante bioensayos de toxicidad de reproducción, crecimiento y biomarcadores moleculares.…”