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

Heavy metal bioaccumulation by the organs of Phragmites australis (common reed) and their potential use as contamination indicators

Nine units in new-born intertidal zone of the Yellow River estuary, China were examined for concentrations of heavy metals (Pb, Cr, Cu, Zn and Ni) in sediments and plants. Heavy metal levels in surface sediments were in the order of Zn > Pb approximate to Cr > Cu approximate to Ni and generally increased in a seaward direction except for Z6 (Tamarix chinensis-Suaeda salsa zone) and Z7 (S. salsa-T. chinensis zone) units. Significant differences in metal concentrations of the 9 units were observed in the profiles (p Cu > Pb > Ni > Cr and differed among plants or tissues. The roots at Z2 (Calamagrostis pseudophragmites zone), Z3 (Imperata cylindrical zone) and Z4 (Phramites australis zone) units accumulated greater metals than shoots [TFs (translocation factors) 1), implying that intertidal plants showed different pathways in metal accumulation and internal transportation. Except for Pb, the concentrations of Cr, Cu, Zn and Ni in sediments were lower than the criteria of Class I recommended by the Environmental Quality Standard for Soils of China, Although heavy metal levels in intertidal zone were generally the lowest (Cr, Cu, Zn and Ni) or relatively moderate (Pb) compared with other estuaries or bays in Asia and Europe, high eco-toxic risk of Pb and Ni exposure still could be observed at Z4, Z6 and Z9 (mudflat zone) units. S. salsa was more suitable for the potential biomonitor or phytoremediation of all five heavy metals if intertidal sediments was seriously contaminated with increasing of pollutants loading in the Yellow River estuary. (C) 2014 Elsevier B.V. All rights reserved.

http://ir.yic.ac.cn/bitstream/133337/8649/1/Spatial%20variations%20and%20bioaccumulation%20of%20heavy%20metals%20in%20intertidal%20zone%20of%20the%20Yellow%20River%20estuary%2c%20China.pdf

Spatial variations and bioaccumulation of heavy metals in intertidal zone of the Yellow River estuary, China

Treatment of a high-strength sulphate-rich alkaline leachate using an anaerobic filter

Introduction 367 Selected factors affecting metal accumulation 368 Plant species 368 Season 373 pH 374 Other factors 375 Metal accumulation factor 380 Reported studies on metal accumulation by aquatic macrophages 381 Laboratory studies 381 Field studies 393 Summary 401 References 408 Additional literature 413 Appendix 1. Common and Latin names mentioned in this chapter 416

Metal accumulation by aquatic macrophytes

The state-of-the-art of biotechnology for degradation of toxic chemicals in hazardous wastes is discussed in this book. In particular, it discusses the applicability of using biotechnology for the treatment of hazardous/toxic wastewaters. Full-scale application of biotechnology for the treatment of municipal and industrial wastewaters has been practiced for many years. However, whether this technology can be employed for detoxification and destruction of hazardous chemicals in aqueous and solid media is not yet fully understood. Removal of toxic and refractory organics in wastewater, groundwater, and leachate may be more efficient as a result of combining biological treatment with other treatment technologies such as chemical and physical methods. Development of standard techniques for biotoxicity detection and toxicity reduction evaluation is essential and extremely important to both technical determination and decisions on the future policy for hazardous waste management. The various chapters in the book describe current research in biotechnology for degradation of toxic chemicals in hazardous wastes.

Y.C. Wu

Papers

Biotechnology for Degradation of Toxic Chemicals in Hazardous Wastes