Open windrow composting of fish waste in Estonia

M. Lanno¹*, M. Silm², M. Shanskiy¹, A. Kisand², K. Orupõld³ and M. Kriipsalu⁴

¹Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Chair of Soil Science, Fr.R. Kreutzwaldi 5, EE51006 Tartu, Estonia
²Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Chair of Hydrobiology and Fishery, Fr.R. Kreutzwaldi 5, EE51006 Tartu, Estonia
³Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Chair of Environmental Protection and Landscape Management, Fr.R. Kreutzwaldi 5, EE51006 Tartu, Estonia
⁴Estonian University of Life Sciences, Institute of Forestry and Rural Engineering, Chair of Rural Building and Water Management, Fr.R. Kreutzwaldi 5, EE51006 Tartu, Estonia
*Correspondence: marge.lanno@emu.ee

Abstract:

By-catch fish is caught unintentionally during the fishing and is currently thrown back in water bodies to cause the water pollution. Currently fishermen does not have a motivation to bring the by-catch fish to the shore, as it needs to be sorted by fish species, causing fishermen extra work without additional income. Estonian Ministry of Rural Affairs decided to give funding to present study with purpose to find solution to this matter. One possible solution for by-catch fish utilization is to produce high value nutrient rich fertilizer in order to close nutrient cycle and return valuable nutrients into soil. The adaptive study of outdoor windrow composting was conducted with consecutive treatments, rather than simultaneously, in order to make adaptive improvements to the set-up of each consecutive treatment. The consecutive treatments showed that fish waste composting is manageable from a technical perspective, feasible in a temperate climate, and that this type of compost holds high potential as an organic fertiliser or soil improver. Composting process started rapidly and, as required by the EU Commission regulation EU 142/2011, temperatures exceeded 70 °C for at least 1 h in all windrows. While initial treatments suffered from odours, as well as events inhibitive to the composting process, these disadvantages were successfully avoided in later treatments by adding a biofilter and inoculant from previous composting windrows, as well as lake sediments. Rather than disposing of low-value fish, these can be recycled into stable and nutrient-rich compost on-site, near fishing harbours.

Key words:

biofilter, by-catch, clay minerals, lake sediment, organic fertiliser, wheat straw

Use of pyrophyllite to reduce heavy metals mobility in a soil environment

S. Murtić¹*, H. Čivić², E. Sijahović², I. Koleška³, J. Jurković⁴ and M. Tvica⁵

¹University of Sarajevo, Faculty of Agriculture and Food Sciences, Department of Plant Physiology, Zmaja od Bosne 8, BA71000 Sarajevo, Bosnia and Herzegovina
²University of Sarajevo, Faculty of Agriculture and Food Sciences, Department of Plant Nutrition, Zmaja od Bosne 8, BA71000 Sarajevo, Bosnia and Herzegovina
³University of Banja Luka, Faculty of Agriculture, Department of Plant Physiology and Nutrition, Bulevar vojvode Petra Bojovića 1A, BA78000 Banja Luka, Bosnia and Herzegovina
⁴University of Sarajevo, Faculty of Agriculture and Food Sciences, Department of Chemistry, Zmaja od Bosne 8, BA71000 Sarajevo, Bosnia and Herzegovina
⁵University of Sarajevo, Faculty of Agriculture and Food Sciences, Department of Pedology, Zmaja od Bosne 8, BA71000 Sarajevo, Bosnia and Herzegovina
*Correspondence: murticsenad@hotmail.com

Abstract:

This study revealed the effects of pyrophyllite ore materials on heavy metals mobility in soil plots located near the steel mill in Zenica (Bosnia and Herzegovina). The experiment was set up in a randomized block design with four pyrophyllite treatment rates i.e. 0, 200, 400 and 600 kg ha^-1 in three replications. Analyses of the heavy metals (Cu, Zn, Mn, Ni, Cr, Pb, Cd) in soil and plant samples were performed using atomic absorption spectrophotometry. Pyrophyllite addition in soil was found to reduce the availability of all tested heavy metals in the studied soil. The pyrophyllite addition at a rate of 200 kg ha^-1 reduced Mn, Cu and Zn available forms in soil by 11.1, 20.4 and 11.2%, respectively, compared with control. The pyrophyllite addition at higher rates i.e. 400 and 600 kg ha^-1 had an even higher impact on the decrease in Mn and Zn mobility in studied soil in comparison with 200 kg ha^-1. Additionally, these pyrophyllite rates have the ability to reduce Ni mobility in studied soil. The study also found a positive effect of all pyrophyllite treatments to reduce heavy metals accumulation in the leaves of potato grown on the studied soil. In sum, the results of this study indicate that pyrophyllite treatment could be an effective technique for improving the environmental quality of soils and alleviating the hazards of heavy metals to plants. However, further studies are necessary to confirm or denied this hypothesis.

Key words: