Cultivation of C4 perennial energy grasses on heavy metal contaminated arable land: Impact on soil, biomass, and photosynthetic traits.

The objective of this study was to evaluate the potential of three C4 perennial grasses (Miscanthus x giganteus, Panicum virgatum and Spartina pectinata) for biomass production on arable land unsuitable for food crop cultivation due to Pb, Cd and Zn contamination. We assessed soil properties, biomass yield, metal concentrations, and the photosynthetic performance of each species. Physico-chemical and elemental analyses were performed on soil samples before plantation establishment (2014) and after three years of cultivation (2016), when leaf area index, plant height, yield and heavy metal content of biomass were also determined. Physiological measurements (gas exchange, pigment content, chlorophyll a fluorescence) were recorded monthly between June and September on mature plants in 2016. Cultivation of investigated plants resulted in increased pH, nitrogen, and organic matter (OM) content in soil, although OM increase (13%) was significant only for S. pectinata plots. During the most productive months, maximal quantum yield values of primary photochemistry (Fv/Fm) and gas exchange parameter values reflected literature data of those plants grown on uncontaminated sites. Biomass yields of M. x giganteus (15.0 ±â€¯0.4 t d.m. ha-1) and S. pectinata (12.6 ±â€¯1.2 t d.m. ha-1) were also equivalent to data published from uncontaminated land. P. virgatum performed poorly (4.1 ±â€¯0.4 t d.m. ha-1), probably due to unfavourable climatic conditions, although metal uptake in this species was the highest (3.6 times that of M. x giganteus for Pb). Yield and physiological measurements indicated that M. x giganteus and S. pectinata were unaffected by the levels of contamination and therefore offer alternatives for areas where food production is prohibited. The broad cultivatable latitudinal range of these species suggests these results are widely relevant for development of the bioeconomy. We recommend multi-location trials under diverse contaminant and environmental regimes to determine the full potential of these species.

Case study on phytoremediation driven energy crop production using Sida hermaphrodita.

The cultivation of energy crops on heavy metals contaminated (HMC) areas offer opportunities, which combine site remediation with energy recovery. Numerous tests have been conducted using phytoremediation in HMC soils with energy crop species. Sida hermaphrodita L. Rusby, has shown potential as an energy crop useful in the phytoextraction of HMs. The aim of the study was to investigate the efficiency of using S. hermaphrodita in energy crop production in HMs contaminated sites. The study investigated the impact of different fertiliser treatments on the composition of elements in cultivated biomass on HMC arable land and sewage sludge dewatering sites to determine its suitability for energy production in gasification processing. It was found that S. hermaphrodita is a species accumulating HMs mainly due to their bioavailability in soil (Cd r = 0.877, Zn r = 0.876). Calculated Cd and Zn bioaccumulation factors for plants cultivated on HMC arable land were 12-fold and 18-fold higher respectively, when compared to a sewage sludge dewatering site. Lower heating value of biomass was higher by about 7% for biomass cultivated on HMC arable land. Despite the presence of HMs in ash after the gasification process, some of it could be used as fertilizer, especially on heavy metal contaminated sites.

Sewage sludge and fly ash mixture as an alternative for decontaminating lead and zinc ore regions.

Many years of heavy industrial processes in the Upper Silesian Industrial Region in Poland (ore flotation, metal smelting and battery scrap processing) have resulted in lead, zinc and cadmium pollution of the air and soil. The most significant issues stem not only from elevated levels of these metals in environmental compartments, but also from the uneven pattern of their distribution. Point sources of local metal concentration are to be found dispersed over areas of contaminated soil. Such distribution is a challenge for remediation technology, as it precludes the introduction of standard procedures. Metals present in the soil pose a constant risk for living organisms. One of the most effective ways of limiting their ecological impact is by decreasing their mobility. In this study, the effect of introducing sewage sludge and fly ash mixtures (sluash material) into contaminated soil was evaluated. We tested the mixture in terms of the probability of its ecotoxicological impact on plant growth and development. The data obtained have shown that even low doses (3%) of sluash are effective in reducing the bioavailability of lead, cadmium and zinc, resulting in a decrease of their concentration in plants. The application of sluash also led to stabilize soil pH. It also had a positive impact on the total number of soil bacteria and soil fungi.

[Comparative investigations of changes in the ocular fundus of divers]. / Badania porównawcze zmian na dnie oczu u nurków.

It was established that professional divers who never suffered from decompression sickness had fundus changes similar to those changes which could be seen in divers who have had this disease. A many years diving may lead to permanent degenerative changes at the eye fundus.

A case of delayed-onset pulmonary barotrauma in a scuba diver.

A 23-yr-old male scuba diver was admitted to the hyperbaric chamber of the Polish Army Training Centre of Divers and SCUBA Divers for treatment of pneumomediastinum and possible decompression sickness. Medical history suggested a case of pulmonary barotrauma with delayed and exacerbated symptoms. About 36 h after the onset of symptoms the patient was treated successfully according to U.S. Navy Treatment Table 6-A. A recurrence of symptoms was observed more than 3 d after the initial hyperbaric therapy. Signs and symptoms suggested the presence of air in the vessels of the nervous system, and possibly in the heart muscle and bones of the upper limbs. A second recompression therapy began according to method III of the Polish Navy Treatment Tables. Adjunctive therapy included intravenous aspirin, steroids, isosorbide dinitrate, and fluids. Symptoms resolved and did not recur after this second hyperbaric therapy.