Lignin biodegradation in pulp-and-paper mill wastewater by selected white rot fungi

An investigation has been carried out to explore the lignin-degrading ability of white rot fungi, as B. adusta and P. crysosporium, grown in different media containing (i) glucose and mineral salts; (ii) a dairy residue; (iii) a dairy residue and mineral salts. Both fungi were then used as inoculum to treat synthetic and industrial pulp-and-paper mill wastewater. On synthetic wastewater, up to 97% and 74% of lignin degradation by B. adusta and P. crysosporium, respectively, have been reached. On industrial wastewater, both fungal strains were able to accomplish 100% delignification in 8-10 days, independent from pH control, with a significant reduction of total organic carbon (TOC) of the solution. Results have confirmed the great biotechnological potential of both B. adusta and P. crysosporium for complete lignin removal in industrial wastewater, and can open the way to next industrial applications on large scale

Aspergillus oryzae grown on rice hulls used as an additive for pretreatment of starch-containing wastewater from the pulp and paper industry

From an industrial point of view, the use of microorganisms as a wastewater bioremediation practice represents a sustainable and economic alternative for conventional treatments. In this work, we investigated the starch bioremediation of paper mill wastewater (PMW) with Aspergillus oryzae. This amylase-producing fungus was tested in submerged fermentation technology (SmF) and solidstate fermentation (SSF) on rice hulls. The tests were conducted to assay the concentration of the reducing sugars on paper mill wastewater. The bioremediation of starch in the wastewater was carried out by A. oryzae, which proved capable of growing in this complex media as well as expressing its amylase activity

Experimental approaches for size-based metal speciation in rivers

A review of the different methodologies employed to fractionate and characterize riverine suspended particulate matter is presented. The importance of size-based metal speciation is underlined and the possibility of studying it by the Sedimentation Field Flow Fractionation (SdFFF) technique is illustrated. The studies on the metal load in river Suspended Particulate Matter (SPM) performed over the last ten years are critically reviewed focusing on the different methods employed to collect, concentrate and size-fractionate samples. The fact that there is no homogeneity in methods and data collection in this field is underlined. Among the different fractionation techniques, Field Flow Fractionation (FFF) methodologies have proved to be a good approach to study the role of SPM in metal load and transport. The possibility of studying size-based metal speciation using the SdFFF technique is presented and the importance of metal speciation in rivers is underlined

Characterisation of River Po particles by sedimentation field-flow fractionation coupled to GFAAS and ICP-MS

A procedure for elemental composition determination of water-borne rixer particles (Po River) on both sizefractionated and unfractionated submicron particles (0.1 1 lam) by graphite furnace atomic absorption spectroscopy tGFAAS) and inductively coupled plasma-mass spectrometry (ICP-MSI is reported. Sample fractionation was performed using sedimentation field-flow fractionation (SdFFF). The distribution of relative mass vs. particle size was determined using UV detection. Fractions were collected over a narrow size range for scanning electron microscopy. With this combination of techniques the mass, elemental composition, and shape distributions can be ~btained across the size spectrum of the sample. The size distributions of the major elements (A1, Fe) were determined by coupling both GFAAS and ICP MS techniques to the SdFFF. The procedure was validated using a reference chty sample. Satisfactory agreement was found between both the GFAAS and ICP MS aluminium signal and the UV detector signal. Some discrepancies were observed in the Fe/AI ratios when comparing GFAAS and ICP MS. Thus further investigation is in order to fully assess the role of SdFFF-ICP MS and SdFFF-GFAAS techniques for elemental characterisation of aquatic colloids. Both GFAAS and ICP MS signals unambiguously indicate a significantly higher Fe content in the lower size range, which is consistent with previous investigations. Trace element levels in unfractionated Po River particles, determined by both GFAAS and ICP MS, show good agreement. The high levels of Cu, Pb, Cr and Cd found associated with the colloidal particles underlines the signiticance of the environmental role played by the suspended matter in rivers in both highly industrialised and intensively cultivated areas

Mercury Speciation in the colloidal fraction of a soil polluted by a chlor-alkali plant: a case study in the South of Italy.

Mercury (Hg) speciation in different size fractions of a soil sample collected nearby an industrial area located in the South of Italy and polluted by the dumping of Hg-containing wastes from a chlor-alkali plant has been investigated by XANES spectroscopy. In particular, a special procedure has been developed to study the soil colloidal fraction, either for sample preparation and for XANES data collection

Colloidal mercury (Hg) distribution in soil samples by sedimentation field flow fractionation coupled to mercury cold vapour generation atomic absorption spectrometry

Dimensional characterisation of potentially toxic elements present in soil is of crucial importance for determining their actual impact on the environment and understanding the role played by colloidal particles in mobilising pollutants. Recently, a number of measurement determinations have been available for this purpose; nevertheless a single technique is often not exhaustive enough to completely determine particle size distribution and element concentration. The present work concerns the investigation of mercury in soil samples collected from a polluted industrial site. The analytical approach here proposed makes use of sedimentation field flow fractionation (SdFFF) instrumentation coupled off-line to a cold vapour generation electrothermal atomic absorption spectroscopic (CV-ETAAS) technique to achieve the complete Hg characterisation in colloidal soil fractions. In the investigated samples the results demonstrated a predominant presence of Hg in the fraction between 400 and 700 nm. The apparent relation between concentration of Hg and organic matter (O.M.) content in the soil samples seems to be not related to Hg sorbtion to soil O.M. but rather to the presence of colloidal mercuric sulphides particles which size is likely to be controlled by the occurrence of dissolved O.M. This research pointed out how relatively high levels of mercury in the original soil samples can become even more alarming if concentrated in the submicronic fraction