Historical mine pollution and environmental resilience: biomineralization processes and biogeochemical barriers

Three streams in SW Sardinia were studied to evaluate the transport of metals in the environment, and to characterize the natural processes that lead to decreased metal loads. Here we focus on Zn. Although the metal load varies by 2-3 orders of magnitude, we have observed natural biologically mediated attenuation processes, including uptake by vegetation and biomineralization. In this paper, we review the chemical and physical processes that lead to natural Zn attenuation, and discuss the merits of mimicking those processes when designing remediation schemes.