Raumkonkurrenz bei Ätzmuscheln

Space competition is documented in lithophages, off the Istrian coast (North Adriatic Sea). Due to high population-density, borehole crossings occur. Spatial relationships between competing bivalves determine which one will be successful, or whether competition remains undecided and “stenomorphs” (Bartsch, 1923, as quoted by Turner, 1955) are formed. There is no spatial competition in gastrochaenes in the area investigated, but probably in petricoles. In areas best suited to its own living requirements, e.g. steep and overhanging “declivium”, Lithophaga lithophaga represses Gastrochaena dubia and Petricola lithophaga.     

Environmentally friendly system for the degradation of multipesticide residues in aqueous media by the Fenton’s reaction

A Fenton oxidation system employing zero-valent iron (whose source was swarf, a residue of metallurgical industries, in powder form) and hydrogen peroxide for the treatment of an aqueous solution with six pesticides was developed, and the effect of the iron metal content, pH, and hydrogen peroxide concentration was evaluated. The characterization of the aqueous solution resulted in: pH 5.6, 105 mg L^?1 of dissolved organic carbon, and 44.6 NTU turbidity. In addition, the characterization of the swarf by FAAS and ICP-MS showed 98.43?±?7.40 % of zero-valent iron. The removal was strongly affected by the content of iron metal, pH, and hydrogen peroxide concentration. The best degradation conditions were 2.0 g swarf, pH 2.0, and 5 mmol L^?1 H₂O₂. At the end of the treatment, the pesticide degradation ranged from 60 to 100 %, leading to 55 % mineralization. Besides, all hydrogen peroxide was consumed and the determination of total dissolved iron resulted in 2 mg L^?1. Thus, the advantages of this system are rapid degradation (up to 20 min), high-degradation rates, simple handling, and low cost.