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It is critical to ensure the sustainability of biomass when used for energy, chemicals, and/or materials in the future bioeconomy. This does not only apply to the feedstock, a common focus within traditional bioenergy assessments; it also needs to consider the wider value chain, that is, from feedstock production through end use, including a range of coproducts, to end-of-life. The scope of such an assessment can vary but may be most practical at the “biorefinery” scale. Experience gained from first-generation biofuels offers lessons about sustainability challenges and prospects for the future bioeconomy. However, sustainability assessments of bioproducts require unique considerations, some of which are not necessarily addressed in the assessments of biofuels. We find that sustainability assessments are not “one-size-fits-all” and should engage stakeholders in determining clear goals and objectives for the assessment, consider the specific context, and maintain transparency in approach and assumptions. Sustainability is also not a steady state or fixed target. Sustainability assessments are most useful when they help decisionmakers and technology developers make continuous improvements across social, environmental, and economic dimensions. In addition to the traditional three-pillar approach, good governance is of equal importance and has to be implemented in sustainability assessment frameworks. As such, methodologies must continuously evolve to accommodate the increasingly diverse range of biomass-derived products within the future bioeconomy.

This chapter focuses on techno-economic assessments of biobased products from fermentation and fast pyrolysis. We briefly describe underlying methodologies and summarizea number of literature studies dealing with conversion pathways using fermentation and fast pyrolysis. However, data are limited on the techno-economic evaluation of innovative biorefinery processes. We identify methodological challenges for techno-economic assessment of biofuels and biobased chemicals and describe limits of comparing results from different studies. We depict the lessons learned from lignocellulosic ethanol and show examples of biobased chemicals and bio-oil that are already produced at large scale. In the longterm, biobased chemicals and biofuels must compete on cost and performance with petrochemicals and petroleum fuels, however at present biofuels and biobased chemicals derived from lignocellulosic biomass are hardly cost-competitive.

A wide range of nonfood biomass and conversion technologies can be used for the production of bioenergy and biobased products. The fermentation of lignocellulosic-derived sugars and the thermochemical conversion of biomass (eg, fast pyrolysis) are examples of relevant conversion technologies. The main product of fast pyrolysis is bio-oil, which can be used directly in stationary boilers or after upgrading as a drop-in blend component in existing refineries. Bio-oil requires chemical upgrading, before it is suitable as fuel. The commercial use of bio-oil for material/chemical purposes is currently limited to minor food uses (ie, smoke aroma and flavor enhancers). Different pretreatment technologies can be used in the initial conversion of biomass to sugars for fermentation. Technical obstacles in those pretreatment processes differ among the various approaches, but can include insufficient separation of cellulose and lignin, formation of byproducts that inhibit downstream fermentation, high use of chemicals and/or energy, as well as high costs for cellulase enzymes, although the latter has decreased substantially in recent years. There is currently no consensus on a preferred pretreatment method or combination of methods. A wide range of biofuels and biobased chemicals can be produced from sugars via fermentation and/or chemical conversion, including advanced biofuels and chemical intermediates. The integration of different pretreatment and conversion technologies in biorefineries can maximize the use of biomass components and improve the efficiency of the entire value chain. In the mid- to long term, thermochemical and biochemical conversion of lignocellulosic biomass are promising technologies for the production of biofuels and biobased chemicals.

Dedicated to Prof. Dr. Ulrich Forstner on his 65th birthday Sediments in harbours and nearby shipyards demonstrate widespread contamination with tributyltin (TBT). Therefore, reuse and relocation of dredged material from these locations are prohibited. Even if the International Marine Organization (IMO) convention concerning TBT-based paints is ratified (Champ, 2003) the TBT problem in sediments will continue to remain for many years due to the persistence of TBT. An electrochemical process has been developed to treat polluted sediments. Dredged materials with high and low TBT-contents were studied on a technical and a pilot scale. The treatment process was assessed by chemical analysis and a biotest battery. Additionally, an economic analysis was performed to check the economic feasibility of the process to treat dredged material from two different locations at different operating conditions. Furthermore an up-scaling estimation was performed to evaluate treatment costs at a larger scale, i.e. for a plant having a capacity of 720 000 t/a. Butyltin species and polycyclic aromatic hydrocarbons (PAH) were decomposed due to electrochemically-induced oxidation, while the treatment did not alter heavy metal and PCB concentrations. The bacteria luminescence test indicated a reduced toxicity after the electrochemical treatment, while the algae growth inhibition test and bacteria contact test did not confirm these results. Based on a small consumer price of €0.12/kWh, treating the high-contaminated sediment in the pilot plant would cost €21/m3 and €31/m3 for the low contaminated sediment, respectively. Assuming an industrial consumer price of €0.06/kWh for electricity in an up-scaled process with a capacity of 720 000t/a, the total treatment costs for the low contaminated sediment would be €13/m3. The results of treating dredged material from Bremerhaven and the fine-grained fraction from the METHA plant show that the effectiveness of the process performance is more related to the binding form and sediment composition than to the initial concentration of TBT. The electrochemically treated material complies with chemical criteria for relocation of dredged material, but post-treatment, e.g. washing and/or reduction of remaining oxidants with Fe-II-salts, is needed to fulfil ecotoxicological criteria for relocation. Economic investigations have shown that the electrochemical treatment might be a technical option to treat TBT contaminated, dredged material. However, the technique is not fully developed and cannot remove all chemicals of concern, e.g. heavy metals. The decision as to whether this technique can be applied is site-specific and should be taken based on the case-by-case approach. Since biotests integrate the effects of all contaminants present in a sample, process-accompanying evaluation procedures need additional assessment methods such as TIE (toxicity identification evaluation) as a second tier following ecotoxicological tests, in which the reasons for the effects are identified. For reasons of sustainability, a much more effect-oriented and long-term cost effective approach should be applied in future to avoid the release of harmful substances into the environment. Life cycle assessment should be carried out to identify and quantify impacts of sediment treatment processes in order to take into account both the distant effects of local actions and local effects of distant actions.

Since at least three decades tributyltin had been commonly used in paint formulations to protect ship hulls and submersed surfaces from fouling. This has resulted in negative and Technology, effects to the marine environment due to its high toxicity towards non-target organisms and to its accumulation in sediments, especially near point sources of pollution. Even if a ban of TBT for its application in anti-fouling paints is enforced the problem of TBT-contaminated sediments will remain for the coming years due to the low degradation rates of organotin in sediments. In this work an electrochemical process at a pilot scale to destroy TBT in sediments was investigated. Previous experiences at a laboratory and technical scale have demonstrated the potential of this process to electrolytically degrade organotin species in sediments. This article deals with the optimisation of the pilot plant performance in terms of organotin degradation and operation costs monitoring additionally the effect of the electrochemical treatment on other pollutants such as heavy metals, PCBs, and PAHs. The aim was to investigate by means of a parametric study the range of operating conditions required to destroy TBT down to concentrations lower than 100 μg/kg; to determine the influence of those parameters on the performance of the process; and to evaluate the operation costs associated to the process. It was determined that it was possible to destroy TBT down to 100 μg/kg at current densities in the range of 4.4 to 6.6 mA/cm2 and chloride concentrations of least of 0.2 mol/L with operation costs of 13 to 18 EUR/m3. Betriebsoptimierung eines elektrochemischen Prozesses zur Behandlung TBT-kontaminierter Sedimente im Pilotmasstab Tributylzinnverbindungen (TBT) wurden ca. 30 Jahre lang als Antifoulingbestandteil in Schiffsfarben verwendet, mit denen Schiffsrumpfe gestrichen wurden, um biologischen Bewuchs zu verhindern. Wegen der hohen Giftigkeit dieser Verbindungen und ihrer starken Anreicherung in Sedimenten kam es, besonders in der Nahe von Punktquellen, zu gravierenden Beeintrachtigungen mariner Organismen wie Schnecken und Muscheln. Auch nachdem im letzten Jahr ein Verbot fur TBT-haltige Antifoulingfarben vereinbart wurde, bleibt das Problem TBT-kontaminierter Sedimente die nachsten Jahre wegen der langsamen naturlichen Abbauraten von Organozinnverbindungen weiter bestehen. Bei vielen Punktquellen mangelt es immer noch an effektiven Kontrollstrategien. In der vorliegenden Arbeit wird ein Prozess im Pilotmasstab vorgestellt, mit dem TBT in Sedimenten elektrochemisch abgebaut werden kann. Vorangegangene Untersuchungen im Labor- und Technikum-Masstab hatten gezeigt, dass eine elektrochemische Zerstorung von Organozinnverbindungen prinzipiell moglich ist. Der Artikel beschreibt die Optimierung der Anlage im Pilotmasstab hinsichtlich maximaler Abbauraten und minimaler Betriebskosten sowie zusatzlich die Auswirkungen der elektrochemischen Behandlung auf andere Schadstoffe wie Schwermetalle, PCB und PAK. Ziel war es, mit Hilfe parametrischer Untersuchungen die erforderlichen Betriebsbedingungen so zu optimieren, dass TBT-Konzentrationen im Sediment von unter 100 μg/kg erreicht wurden, die Einflusse der einzelnen Parameter auf die Leistungsfahigkeit des Prozesses zu bestimmen sowie die Betriebskosten abzuschatzen. Die Untersuchungen haben gezeigt, dass bei Stromdichten im Bereich zwischen 4.4 mA/cm2 und 6.6 mA/cm2 und einer Chloridkonzentration von mindestens 0.2 mol/L TBT-kontaminierte Sedimente auf unter 100 μg/kg abgereichert werden konnen. Die berechneten Betriebskosten liegen zwischen 13 EUR/m3 und 18 EUR/m3.

In contaminated sediments butyltin compounds and PAH can be diminished by means of an electrochemical treatment. The butyltin concentrations of the fine fraction (particle size

Publisher Summary This chapter discusses a system-oriented perspective to the way of assessing contaminated sediment treatment chains to complement the parceled site-specific environmental information that is considered along with economic and social criteria in decision-making procedures. Environmental evaluation methods—such as risk assessment (RA) of the potential environmental risks that contaminated dredged materials pose and environmental impact assessments (EIAs) to evaluate the impact of a given project or site—are the tools that are widely applied for decision making and that have been integrated to regulations at national and European levels. While, these methodologies in practice normally are focused on the evaluation of environmental issues on a plant scale, elements of life-cycle assessment (LCA) can be useful to supply valuable information for process comparison and assessment not normally considered in EIAs—for example, impacts on global, regional, and local scales, which would enable to account for almost all relevant effects and perform a fair comparison. An LCA study can cover part of the environmental aspects related to the assessment of sediment treatment chains. Along with RA and EIA tools, it can provide the necessary information to evaluate and compare sediment treatment chains considering all relevant aspects of the process chain.

A hydrometallurgical circuit process combining the leaching of metals with the electrolytic regeneration of the mass separating agent is an option to effectively treat heavy metal contaminated solids. This process aims towards a dosed loop utilisation of the extractant by its regeneration and recycling, enabling the use of high cost extractants and the recovery of the heavy metals as well. The circuit process, in which each cycle consists of an extraction step followed by the electrolytic regeneration of the mass separating agent and a second extraction to finally recycle the separating agent and start a new cycle, was applied on a lead contaminated soil from an accumulator manufacturing facility and for the removal of copper from a municipal solid waste incinerator bottom ash. For the first case a 0.13 M citrate solution was used at a pH of 5; for the second 10%; sulphuric acid (pH=0.5). The results showed that above 80% of lead and copper were removed from soil and ash, respectively, when the concentration of mass separating agent was controlled and kept constant. The extraction efficiency of metals from the solid materials was in the same range as the one obtained by two extaction steps using fresh extracting agent. However, due to losses of the mass separating agent the operation in a complete closed loop configuration was not possible. Nevertheless, a substantial reduction in separating agent consumption was achieved. The process proved to be suitable for treating highly contaminated materials, for which the operation parameters of extraction and regeneration are more favourable, also increasing the recovery of metals.

Preliminary experiments have shown that dibutyl and tributyltin can be decomposed by the electrochemical treatment of sediment. Two different process pathways have been described and compared. A slurry electrolysis of the suspended sediment seemed to be more efficient than column leaching followed by electrolysis. Tributyltin was destroyed under oxidising as well as under reducing process conditions. The detoxification mechanism seemed to be stepwise removal of the butyl groups. A partial debutylation of tri- and dibutyltin could be achieved, although monobutyltin was not affected. This technique is promising, but further investigation is necessary to improve the experimental conditions and to characterise the real potential of these process pathways.

Heavy metal contamination of soils is still an unsolved problem although metals are associated with human life and have been used for thousands of years. Mining activities in particular have led to the spreading of large amounts of heavy metals in the environment. In many industrial processes (e.g., in the plating industry, accumulator production, chlorine-alkali-electrolysis, pesticide production), metals and their compounds are used, produced and subjected to different finishing proc­esses, and then applied in various fields of human life. When introduced into soils, heavy metal compounds are hazardous pollutants because they are not biodegrad­able, toxic at relatively low concentrations, and they may be mobilised under changing physical-chemical conditions like redox potential or pH. Soils have a limited capacity to accumulate pollutants, and if this retention capacity is ex­ceeded, the environment, (e.g. ground and surface water, plants and livestock) is likely to be at further risk.

The application of a dc electric field to fine-grained soil evokes two electrokinetic transport mechanisms: an electrolytic migration of ionic species and an electroosmotic water flow.