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Liquefaction is an attractive technology for converting biomass into bio-oil without the requirement for drying feedstock, and the process can be conducted at relatively low temperatures. In the practical application, the treated biomass feedstocks are composed of a mixture of agricultural waste, forestry waste and some organic solid waste. The utilization of co-liquefaction technology is suitable for biomass as it can fully utilize different types of feedstocks and enhance the liquefaction degree of each feedstock. During the co-liquefaction of these blending biomass feedstocks, the individual biomass species can degrade according to their own reaction network that is governed by the unique structural compositions. Furthermore, the reaction intermediates from the degradation of different biomasses can potentially interact with each other. This will affect the reaction characteristics and alter the chemical constituents and properties of the bio-oil produced. The understanding of interaction for the blending biomasses during the co-liquefaction process is of significance for tuning the chemical species and yield of the resulting bio-oil. Thus, this review work focuses on the co-liquefaction behavior of the various biomass feedstocks including lignocellulose, organic solid waste and algae. The influences of the essential operation parameters including solvent types, catalyst types, reaction temperature and time, and the mixing ratio of different biomasses on co-liquefaction behavior are also evaluated in detail. The choice of the proper reaction parameters is dependent on the structural characteristics of mixed feedstocks. Additionally, the co-liquefaction impact on the composition and formation mechanism of bio-oils are investigated.

Phosphate rock has long been used for the production of phosphorus based chemicals. However, considering the depletion of the reservoirs and the decrease of the quality of phosphate rocks, a potential market is now emerging for the recovery of phosphate from waste and its reuse for different applications. Notably, phosphate recovery from wastewater could be included in a circular economy approach. This review focuses on the use of microbial systems for phosphorus accumulation and recovery, by considering the actual range of analytical techniques available for the monitoring of phosphorus accumulating organisms, as well as the actual biochemical and metabolic engineering toolbox available for the optimization of bioprocesses. In this context, knowledge gathered from process, system and synthetic biology could potentially lead to innovative process design.

Historically concentrated livestock production and, consequently, manure production and management in Belgium have resulted in severe environmental impacts. One major impact, nitrate leaching from soil to surface water, is being tackled through the European Nitrates Directive by imposing strict fertilization standards. However, another significant impact of manure management is the emission of greenhouse gasses (GHG - CO2, CH4, NH3 and N2O) into the air, thereby contributing to global warming. Calls have been made to reduce the high manure pressure and related environmental effects in Belgium by relocating and more evenly spreading livestock production. This paper explores the spatial spreading of CO2-equivalent emissions from livestock production in Belgium and attempt to answer the following question: ‘Can spatial reallocation of livestock production in Belgium reduce the impact of GHG emissions?’. This question is translated into several research objectives: 1) conduct an economic (cost minimization) and environmental (GHG minimization) optimization for 3 manure management scenarios, 2) determine the main differences between both approaches, and 3) determine the marginal spatial impact on CO2 emissions of a decrease in manure pressure (i.e., increased spreading of pig production). To conduct the analysis, a model was developed that builds on the spatial mathematical programming multi-agent manure allocation model developed by Van der Straeten et al. (2010). Three options for manure management are inserted: transport of raw manure from nutrient excess to nutrient deficit areas, biological treatment of manure (manure processing) and manure separation. The model optimizes, at municipal level, either the cost-efficiency, either the environmental effect of the manure market in Belgium based on Belgian fertilization standards. While cost-efficiency is calculated based on transport distances and cost of manure separation and processing, GHG emissions, and hence, carbon footprint, are determined based on a life cycle analysis type calculation. The results of the model simulations show that, while the economic optimum is reached by maximizing the transport of raw manure until fertilization standards are fulfilled and subsequently separating and processing the excess manure, the environmental optimum, from a carbon footprint point of view, is reached by separating all manure as this option has the lowest CO2 emissions, mainly due to the limited manure storage time. Moreover, the analyses indicate that rearrangement of the spatial spreading of livestock production in Belgium will not substantially decrease CO2 emissions. As manure storage is the main contributor to the carbon footprint, solutions should rather lie in changing these storage systems.

In June 2007, a project started in Flanders (Belgium) in which phytoremediation will be applied to clean soils that are diffusely polluted with heavy metals. Uptake ranges of heavy metals by rape seed, maize and wheat will be enhanced by increasing the bioavailability of these heavy metals by the addition of biodegradable physico-chemical agents and by stimulating the heavy-metal uptake capacity of the microbial community in and around the plant. In addition, the harvested biomass crops will be converted into bioenergy by using different energy­recovery-techniques. The energy and heavy metal mass balances will be compared for four different energy–recovery techniques (anaerobic digestion, incineration, gasification and production of biodiesel). All the information obtained will result in an economic evaluation of the use of phytoremediation combined with bioenergy production for the remediation of sites which are diffusely polluted with heavy metals. In the here presented review we will first explain the most important research steps investigated in our phytoremediation project. Secondly, an overview of literature discussing the phytoremediation capacity of rape seed to clean soils that are contaminated with heavy metals will be discussed in more detail., Proceedings of the 18th European Biomass Conference and Exhibition, 3-7 May 2010, Lyon, France, pp. 385-389