Overview of manure treatment in France.

Manure treatment becomes a focal issue in relation to current EU and national policies on environmental, climate and renewable energy matters. The objective of this desk study was to collect all available data on the treatment of manure from cattle, pig and poultry farms for an overview of manure treatment in France. Specific surveys in 2008 showed that 12% of pig farms, 11% of poultry farms and 7.5% of cattle farms was concerned by manure treatment. Taken together, the treatment of pig, poultry and cattle manure accounted for 13.6milliontons corresponding to 11.3% of the total annual tonnage (120milliontons). The main processes, mostly applied on the farm, were composting (8.5milliontons), aerobic treatment (2.9milliontons of pig slurry) and anaerobic digestion (1milliontons). Other manure treatments, including physical-chemical treatment, were less frequent (0.4million of m3). Treated manure was mainly used to fertilize the soil and crops on the farm concerned. Manure treatment can thus be considered to be underused in France. However, anaerobic digestion is expected to expand to reach the European target of 20% of energy from renewable sources. Nevertheless, this expansion will depend on overcoming the constraint requiring registration or normalization of the use of the digestate as fertilizer. Thus, to avoid penalizing farmers, the further development or creation of collective processing platforms is recommended, combined with an N recovery process that will enable the production of organic amendments and fertilizers in an easy marketable form.

Best available technology for European livestock farms: Availability, effectiveness and uptake.

Concerns over the negative environmental impact from livestock farming across Europe continue to make their mark resulting in new legislation and large research programs. However, despite a huge amount of published material and many available techniques, doubts over the success of national and European initiatives remain. Uptake of the more cost-effective and environmentally-friendly farming methods (such as dietary control, building design and good manure management) is already widespread but unlikely to be enough in itself to ensure that current environmental targets are fully met. Some of the abatement options available for intensive pig and poultry farming are brought together under the European IPPC/IED directive where they are listed as Best Available Techniques (BAT). This list is far from complete and other methods including many treatment options are currently excluded. However, the efficacies of many of the current BAT-listed options are modest, difficult to regulate and in some cases they may even be counterproductive with respect to other objectives ie pollution swapping. Evaluation of the existing and new BAT technologies is a key to a successful abatement of pollution from the sector and this in turn relies heavily on good measurement strategies. Consideration of the global effect of proposed techniques in the context of the whole farm will be essential for the development of a valid strategy.

The efficiency of biological aerobic treatment of piggery wastewater to control nitrogen, phosphorus, pathogen and gas emissions.

Due to the water pollution and in order to reduce the nitrogen load applied on soils, biological nitrogen removal treatment of piggery wastewaters was developed in Brittany (France), with 250-300 units running. Four types of treatment processes were built including a biological reactor allowing to remove about 60-70% of the nitrogen content as gas by nitrification/denitrification. The addition of different mechanical separators (screw-press, centrifuge decanter ...) led to concentration of phosphorus in an exportable solid phase, allowing a reduction up to 80% of the phosphorus applied locally on soils. Moreover, a reduction of the gaseous emissions was observed using this management process as compared to conventional management (storage + land spreading) including ammonia (up to 68%) and greenhouse gases (55%). Finally, the level of enteric and pathogenic bacteria was also decreased with the treatment process as compared to conventional management systems. However, in spite of these results, the significant cost of the treatment must be underlined and alternative systems including anaerobic digestion will have to be studied.