Search Results (2)

This study aimed to investigate the possibility of eliminating cadmium (Cd) from contaminated agricultural soil using a combination of microbial inoculants of Penicillium chrysogenum fungus and Bacillus licheniformis with Limnocharis flava plants. Limnocharis flava (L. flava) and microbial inoculants with four Cd levels, including 2.05 (T1 control), 5 (T2), 10 (T3), and 20 mg/kg (T4), respectively, were tested in green house conditions. Cd accumulation was evaluated to assess the safety limit of the Cd concentration in the edible parts of L. flava. The results showed that the application of the microbial inoculants facilitated the stress tolerance of the plants caused by a Cd accumulation in the soil matrix. The use of Penicillium chrysogenum and Bacillus licheniform in combination with L. flava increased the Cd accumulation in plant biomass. The total Cd after the experiment varied between 4.86 and 18.44 mg/kg in dry, clean soil, equivalent to reduction rates of 2.80, 4.40, and 7.80%, respectively. Meanwhile, the availability of Cd in soil was significantly reduced by 12.50, 13.04, 13.33, and 13.93%, respectively. Consequently, the microbial inoculants helped the plants to grow healthily, increased the yield, and reduced the total and available Cd content of contaminated agricultural land up to a concentration level of 5 mg/kg. Full article

The aim of this study is to evaluate the application of the main hazardous waste management techniques in mining operations and in dumping sites being conscious of the inter-linkages and inter-compartment of the contaminated soils and sediments. For this purpose, a systematic review of the literature on the reduction or elimination of different potential toxic elements was carried out, focusing on As, Cd and Hg as main current contaminant agents. Selected techniques are feasible according to several European countries’ directives, especially in Spain. In the case of arsenic, we verified that there exists a main line that is based on the use of iron minerals and its derivatives. It is important to determine its speciation since As (III) is more toxic and mobile than As (V). For cadmium (II), we observed a certain predominance of the use of biotic techniques, compared to a variety of others. Finally, in mercury case, treatments include a phytoremediation technique using Limnocharis flava and the use of a new natural adsorbent: a modified nanobiocomposite hydrogel. The use of biological treatments is increasingly being studied because they are environmentally friendly, efficient and highly viable in both process and energy terms. The study of techniques for the removal of potential toxic elements should be performed with a focus on the simultaneous removal of several metals, since in nature they do not appear in isolation. Moreover, we found that energy analysis constitutes a limiting factor in relation to the feasibility of these techniques. Full article