Surface engineered iron-rich biochars derived from waste biomass as simultaneous slow-release fertilizers and habitat for decomposers of organochlorine-compounds

Biochars are stable carbon-rich solids that can enhance the properties of soil and contribute to long-term carbon storage.

Here we will study how multitasking biochars can be made from biowastes and be modified into slow-release fertilizers with an integrated function to decompose organochlorine pollutant.

We will transform oat husks and stillage as important agriculture wastes in Sweden via pyrolytic carbonization into biochars, and functionalize their surface by zero-valent iron (ZVI) particles and ionic biopolymers.

The former gives the dechlorination function, and the latter will build up an electric double layer to assure that the loaded fertilizer components (NH4+, NO3−, PO43−, and K+) will be released more slowly into the soil than the bare biochars.

Finally, biochars will be evaluated as facilitator for decomposers of organochlorine compounds in the lab, and as slow-release fertilizer in desorption experiments and in pot experiments with crops in greenhouse.

To conduct this interdisciplinary project, we bring together competencies in materials and polymer chemistry from two groups at Stockholm University and an ecology and soil science group at the Swedish University of Agricultural Sciences.

As environmental benefits to transform organic waste into multifunctional biochars, we may mitigate soil pollution and climate change via sequestration of carbon, and reduce toxic compounds in soil, and eutrophication via increased fertilizer utilization efficiency.