Biosorption of Cu(II) and Zn(II) onto a lignocellulosic substrate extracted from wheat bran

We studied the removal of copper and zinc ions from aqueous solutions using a lignocellulosic substrate obtained by an acido-basic treatment of wheat bran. The sorption capacity of this material was investigated through batch and column experiments. Batch experimental results showed that the retention capacity of the lignocellulosic substrate was 0.20×10^–3 mol g^–1 at pH 4.5 for copper(II) and 0.24×10^–3 mol g^–1 at pH 6.5 for zinc(II). Column experiments showed a reduced sorption capacity for both ions compared to batch experiments. Batch and column data were analysed using the Langmuir equation in order to determine the affinity constant and the binding capacity of the sorbent and to compare both retention processes.     

Impact of ocean acidification on marine ecosystems: educational challenges and innovations

Population growth and social/technological developments have resulted in the buildup of carbon dioxide (CO₂) in the atmosphere and oceans to the extent that we now see changes in the earth’s climate and ocean chemistry. Ocean acidification is one consequence of these changes, and it is known with certainty that it will continue to increase as we emit more CO₂ into the atmosphere. Ocean acidification is a global issue likely to impact marine organisms, food webs and ecosystems and to be most severely experienced by the people who depend on the goods and services the ocean provides at regional and local levels. However, research is in its infancy and the available data on biological impacts are complex (e.g., species-specific response). Educating future generations on the certainties and uncertainties of the emerging science of ocean acidification and its complex consequences for marine species and ecosystems can provide insights that will help assessing the need to mitigate and/or adapt to future global change. This article aims to present different educational approaches, the different material available and highlight the future challenges of ocean acidification education for both educators and marine biologists.     

Ocean acidification induces budding in larval sea urchins

Ocean acidification (OA), the reduction of ocean pH due to hydration of atmospheric CO₂, is known to affect growth and survival of marine invertebrate larvae. Survival and transport of vulnerable planktonic larval stages play important roles in determining population dynamics and community structures in coastal ecosystems. Here, we show that larvae of the purple urchin, Strongylocentrotus purpuratus, underwent high-frequency budding (release of blastula-like particles) when exposed to elevated pCO₂ level (>700 μatm). Budding was observed in >50 % of the population and was synchronized over short periods of time (~24 h), suggesting this phenomenon may be previously overlooked. Although budding can be a mechanism through which larval echinoids asexually reproduce, here, the released buds did not develop into viable clones. OA-induced budding and the associated reduction in larval size suggest new hypotheses regarding physiological and ecological tradeoffs between short-term benefits (e.g. metabolic savings and predation escape) and long-term costs (e.g. tissue loss and delayed development) in the face of climate change.     

Combined integral and particle model for describing the dispersion,dilution, terminal layer formation and influence area from a point source discharge into a water body

Contamination of coastal water is a persistent threat to ecosystems around the world. In this study, a novel model for describing the dispersion, dilution, terminal layer formation and influence area from a point source discharge into a water body is presented and compared with field measured data. The model is a Combined Integral and Particle model (CIPMO). In the initial stage, the motion, dispersion and dilution of a buoyant jet are calculated. The output from the buoyant jet model is then coupled with a Lagrangian Advection and Diffusion model describing the far-field. CIPMO ensures that both the near- and far-field processes are adequately resolved. The model either uses empirical data or collects environmental forcing data from open source hydrodynamic models with high spatial and temporal resolution. The method for coupling the near-field buoyant jet and the particle tracking model is described and the output is discussed. The model shows good results when compared with measurements from a field study.