Impact of drilling waste and sludge on eucalyptus growth and soil and water quality

Abstract

The Brazilian forestry sector stands out for its eucalyptus production and the reuse of industrial waste to improve soil fertility. However, environmental monitoring in planting areas is important to assess potential contamination risks, with a focus on soil and water quality. Thus, the objective of this study was to evaluate the initial development of eucalyptus plants and the impacts on soil and water quality, as a function of different doses of the combined application of drill cuttings and sewage sludge. The morphological variables and quality parameters evaluated were: height, shoot and root biomass, crown and stem diameter, chlorophyll index, and concentration of nutrients and heavy metals in the soil and water. The levels of Ca, Mg, K, P, and N in the waste favored the nutrition of eucalyptus plants, but if not managed properly, they can affect soil quality. The same occurs for some metals such as Ba and Pb, which were found in high concentrations in the waste and require care. The water quality results show that some heavy metals in the drained water did not exceed the limits of Brazilian regulations, with the exception of Cu, Mn, Ni, Pb and Ba, whose high levels can be attributed to the composition of the waste. The use of gravel and sludge promoted improvements in plant development, but requires monitoring to avoid risks of soil and water contamination, especially with regard to heavy metals.

Keywords: environmental quality, reuse of waste, water resources, well gravel.