Mechanisms of membrane toxicity of hydrocarbons.

A technical evaluation of stillage characterization, treatment, and by-product recovery in the ethanol industry was performed through a review of the scientific literature, with particular emphasis on solutions pertinent to a cellulosic-based ethanol production system. This effort has generated substantial information supporting the viability of anaerobic digestion for stillage treatment followed by land application on biomass crops for nutrient recovery. Generally, the characteristics of stillage from cellulosic materials appear comparable to those of conventional sugar- and starch-based feedstocks. However, the data on cellulosic stillage characteristics and treatment parameters are extremely limited and highly variable. This has significant impacts on the capital costs and biogas recovery of anaerobic treatment systems predicted from these data. In addition, technical questions remain unanswered with regard to stillage toxicity from untested feedstocks and the impact of heavy metal leaching when acid hydrolysis reactors are fabricated from corrosion-resistant alloys. Thermophilic anaerobic digestion of ethanol stillage achieves similar treatment efficiencies and methane yields compared to mesophilic treatment, but at almost twice the organic loading rate. Therefore, application of thermophilic anaerobic digestion would improve process economics, since smaller digesters and less stillage cooling are required. Downstream processes for stillage utilization and by-product recovery considered worthy of continued investigation include the production of feed (from single cell protein and/or algae production), color removal, and production of calcium magnesium acetate. This study finds that sustainable and economically viable solutions are available for mitigating the environmental impacts which result from large-scale biomass-to-ethanol conversion facilities. However, further research in some areas is needed to facilitate successful implementation of appropriate technology options.

Stillage characterization and anaerobic treatment of ethanol stillage from conventional and cellulosic feedstocks

Biological approaches for treatment of distillery wastewater: a review

Wastewater treatment in molasses-based alcohol distilleries for cod and color removal: a review

Laccases are multicopper proteins that use molecular oxygen to oxidize a broad spectrum of organic compounds by a radical-catalyzed reaction mechanism. Many articles over the past 15 years have touted the diverse potential applications of laccase in various biotechnological processes. This review covers the natural roles of the enzyme, its structural properties, substrates, reaction mechanism, and inhibitors, as well as its applications regarding the detoxification and bioremediation of polluted wastewaters and soils. Other applications are briefly covered as well. The authors critically assess the advantages, shortcomings, and future needs relating to laccase availability, effectiveness, and cost-efficiency, and also provide numerous references to the many divisions of research into this multifaceted enzyme.

Laccase:A review of its past and its future in bioremediation

Enhancement of the anaerobic digestion of olive mill wastewater by the removal of phenolic inhibitors

Enhancement of the anaerobic digestion of wine distillery wastewater by the removal of phenolic inhibitors

Removal of most of the phenolic compounds (88.5%) present in molasses by an aerobic pretreatment with Geotrichum candidum considerably increased the kinetics of anaerobic digestion of this wastewater. Inhibition phenomena were not observed in the range of COD studied (2.3–12.9 g/l). The yield coefficient of methane was 51 % higher than for untreated molasses.

R. Maestro

Papers

Enhancement of the anaerobic digestion of olive mill wastewater by the removal of phenolic inhibitors

Enhancement of the anaerobic digestion of wine distillery wastewater by the removal of phenolic inhibitors

Improvement of the kinetics of anaerobic digestion of molasses by the removal of phenolic compounds