Environmental risk assessment of heavy metal extractability in a biosludge from the biological wastewater treatment plant of a pulp and paper mill

Synthesis and Characterisation of Nano-Biosorbents and Their Applications for Waste Water Treatment

Nanotechnology is one of the most reliable techniques for the remediation of heavy metals. As nanoparticles have a higher surface area to volume, ratio, and high surface energies, so nano-based absorbents are very efficient. Adsorption technique is the most preferred for the remediation of wastewater pollutants. In the current study, a comparative study was done between bio sorbents, nanosorbents and bio nanosorbents. The chapter studies with the synthesis and characterization of the bio sorbents, bionanosorbents, their mechanism of sorption, their synthesis, in addition, application for the remediation of heavy metals from wastewater. The fly ash is an industrial byproduct. Biosorbents have immense applications in the field of bioremediation of heavy metals. Further, their components have also enhanced removal efficiency from the wastewater.

Repeated annual paper mill and alkaline residuals application affects soil metal fractions

The application of industrial residuals in agriculture may raise concerns about soil and crop metal accumulation. A complete study using a fractionation scheme would reveal build-up in metal pools occurring after material addition and predict the transformation of metals in soil between the different forms and potential metal release into the environment. An experimental study was conducted from 2000 to 2008 on a loamy soil at Yamachiche, Quebec, Canada, to evaluate the effects of repeated annual addition of combined paper mill biosolids when applied alone or with several liming by-products on soil Cu, Zn, and Cd fractions. Wet paper mill biosolids at 0, 30, 60, or 90 Mg ha and calcitic lime, lime mud, or wood ash, each at 3 Mg ha with 30 Mg paper mill biosolids ha, were surface applied after seeding. The soils were sampled after 6 (soybean [ (L.) Merr.]) and 9 [corn ( L.)] crop years and analyzed using the Tessier fractionation procedure. Results indicated that biosolids addition increased exchangeable Zn and Cd, carbonate-bound Cd, Fe-Mn oxide-bound Zn and Cd, organically bound Cu and Zn, and total Zn and Cd fractions but decreased Fe-Mn oxide-bound Cu in the uppermost 30-cm layer. With liming by-products, there was a shift from exchangeable to carbonate-bound forms. Even with very small metals addition, paper mill and liming materials increased the mobility of soil Zn and Cd after 9 yr of application, and this metal redistribution resulted into higher crop grain concentrations.