Concentrations of Cu, Fe, Mn, and Zn in tropical soils amended with sewage sludge and composted sewage sludge

Abstract

Sewage sludge may be used as an agricultural fertilizer, but the practice has been criticized because sludge may contain trace elements and pathogens. The aim of this study was to compare the effectiveness of total and pseudototal extractants of Cu, Fe, Mn, and Zn, and to compare the results with the bioavailable concentrations of these elements to maize and sugarcane in a soil that was amended with sewage sludge for 13 consecutive years and in a separate soil that was amended a single time with sewage sludge and composted sewage sludge. The 13-year amendment experiment involved 3 rates of sludge (5, 10, and 20 t ha(-1)). The one-time amendment experiment involved treatments reflecting 50, 100, and 200 % of values stipulated by current legislation. The metal concentrations extracted by aqua regia (AR) were more similar to those obtained by Environmental Protection Agency (EPA) 3052 than to those obtained by EPA3051, and the strongest correlation was observed between pseudo(total) concentrations extracted by AR and EPA3052 and bioavailable concentrations obtained by Mehlich III. An effect of sewage sludge amendment on the concentrations of heavy metals was only observed in samples from the 13-year experiment.

The effect of municipal sewage sludge on the quality of soil and crops

“…However, Fe has the highest limit in our results, which agrees with the findings of Nogueirol et al (2013) who reported that Fe concentration was the highest in their study especially at a depth ranging from 0 to 10 and from 10 to 20 cm, showing that Fe was mostly stuck to the mineral fraction found in the soil.…”

“…As appears in Tables 9, 10 and 11, Fe has the highest concentrations in plant samples; this agreed with the findings of Nogueirol et al (2013) who reported that Fe concentration was the highest when using the method of EPA 3052 among the other methods. Therefore, maybe the EPA 3050 method which was used to extract Fe in our study had a similar affect.…”

“…The statistical results of ANOVA for both EC and pH were not significant (p [ 0.05) among all treatments (see Table 12), this is in line with El-Nahhal et al (2013) who found that both EC and pH values were not significantly different among treatments and were high at the top soil profile of a depth ranging from 0 to 30 cm compared to a depth from 90 to 120 cm. This was because the top profile of soil is more acidic than the deep profile and the highest EC values at the upper layers of soils may have been affected due to the decomposition of organic compounds (Nogueirol et al 2013). Figure 2 shows the analysis of total organic carbon (TOC) in soil samples.…”

Efeito residual do lodo de esgoto na produtividade e na ciclagem de nutrientes em plantios de Eucalyptus grandis e no cultivo de plantas alimentícias (simulando alteração do uso agrícola do solo)

“…Mesmo assim, segundo esses autores, devido à grande diversidade de solos, clima e lodos de esgoto gerados no Brasil, há a necessidade ainda de se ampliar as pesquisas sobre este assunto. Vale lembrar, que a biodisponibilidade dos elementos metálicos em regiões tropicais aparenta não ser estreitamente relacionada à sua retenção pela matéria orgânica do solo (MO), como nas regiões temperadas, onde a decomposição da MO é lenta e gradual (NOGUEIROL et al, 2013).…”

Estudo de métodos para a determinação de As, Cd, Pb, Cr e Se em fertilizantes base orgânica por AAS e ICP OES

“…Também foram reportados estudos comparativos de métodos propostos por agências internacionais para determinação de elementos potencialmente tóxicos em fertilizantes minerais, produzidos nacionalmente, com posterior detecção por ICP OES (SILVA, et al, 2014). Esse tipo de preparo de amostra também foi utilizado para amostras de solos, tratadas com lodo de esgoto como fertilizantes orgânico, para a determinação de elementos traços por ICP OES (NOGUEIROL, et al, 2013).…”