Sustainable valorisation pathways mitigating environmental pollution from brewers' spent grains.

In this work, valorisation pathways of brewers' spent grains (BSG) towards biofuels production under the biorefinery concept were studied utilizing experimental data that provide a common base for straightforward comparison. The dehydration and the recovery of used oil, bioethanol and biogas from BSG were studied. The process units involved were thoroughly investigated and optimized.

Towards upscaling the valorization of wheat straw residues: alkaline pretreatment using sodium hydroxide, enzymatic hydrolysis and biogas production.

Lignocellulosic biomass is considered as a recalcitrant substrate for anaerobic digestion due to its complex nature that limits its biological degradation. Therefore, suitable preprocessing for the improvement of the performance of conventional anaerobic digestion remains a challenge in the development of anaerobic digestion technology. The physical and chemical characteristics of wheat straw (WS), as a representative lignocellulosic biomass, have a significant impact on the anaerobic digestion process in terms of quantity and quality of the produced biogas.

Effect of alkaline pretreatments on the enzymatic hydrolysis of wheat straw.

Lignocellulosic materials are mainly consisted of lignin, cellulose, and hemicellulose. Lignin is recognized as the main obstacle for the enzymatic saccharification of cellulose towards the fermentable sugars' production. Hence, the removal of lignin from the lignocellulosic feedstock is beneficial for reducing the recalcitrance of lignocellulose for enzymatic attack.

Effect of temperature and aeration rate on co-composting of olive mill wastewater with olive stone wooden residues.

Co-composting of the solid residues and wastewater from the olive oil production process was examined as a potential bioremediation treatment for these wastes. Experimental results from a semi batch laboratory pilot plant were reported. Composting was performed for 20 days under constant moisture 40% and the temperature ranged from 55 to 72°C and the oxygen partial pressure from 10 to 17%.

Inhibition kinetics of phenolic compounds in aerobic degradation of organic wastewaters.

This study proposed a kinetic model for the aerobic degradation of high strength organic wastewaters with high concentrations of phenolic compounds. The model was based on the conventional Monod kinetic equation incorporating phenols' inhibition. Furthermore, a methodology for determining biokinetic constants was proposed.

Granulation mechanism of a UASB reactor supplemented with iron.

The aim of this paper was to propose a granulation mechanism in order to interpret all the experimental observations that arose during experiments on two UASB reactors, where one was supplemented with ferrous iron at a dose of 0.01 g Fe(2+) per g COD feed. This supplementation with ferrous iron allowed COD removal of more than 98% at a loading rate of 9 g COD/L per day, which was 24% higher than for the reactor not receiving the ferrous iron.

Determination of granule size distribution in a UASB reactor.

Granular sludge is the key factor for an efficient operation of an upflow anaerobic sludge blanket (UASB) reactor. In order to monitor the granularity of anaerobic sludge, the determination of the granule size distribution is of vital importance. For this reason, several techniques have been proposed; however, they are either tedious, imprecise or expensive and hardly applicable in full-scale treatment plants.

Effect of ferrous ion on the biological activity in a UASB reactor: mathematical modeling and verification.

The effect of ferrous ion on the biological activity in a upflow anaerobic sludge blanket (UASB) reactor was studied. A mathematical model was developed and validated in order to simulate the dynamic behavior of a UASB reactor. This model took into consideration of all the biological and physicochemical reactions.

Electrochemical detoxification of four phosphorothioate obsolete pesticides stocks.

The phosphorothioate pesticides are widely used for crop production and fruit tree treatment, but their disposal causes serious environmental problems. Four commercial phosphorothioate pesticides (Demeton-S-methyl, Metamidophos, Fenthion and Diazinon) were treated by an electrolysis system using Ti/Pt as anode and stainless steel 304 as cathode. A number of experiments were run in a laboratory scale pilot plant and the results are presented.

Degradation of methylparathion in aqueous solution by electrochemical oxidation.

The electrochemical degradation of methylparathion has been investigated by using Ti/Pt as anode, Stainless Steel 304 as cathode, and sodium chloride as electrolyte. The pesticide is rapidly degraded, but full mineralization is not observed. Degradation products have been monitored through gas chromatography and mass spectrometry, and the overall degradation process has been monitored through dissolved and particulate organic carbon, sulfur, and phosphorus measurements.