Solid Peroxy Compounds as Additives to Organic Waste for Reclamation of Post-Industrial Contaminated Soils

Solid peroxy compounds have been increasingly applied for the removal of organic pollution from contaminated groundwater and soil due to their ability to release oxygen and hydrogen peroxide. The influence of two solid peroxy compounds (sodium percarbonate, 2Na2CO3·3H2O2 and calcium peroxide, CaO2) with poultry manure (PM) added to contaminated soil on the growth of the tested plants (Sinapis alba, Lepidium sativum L. and Sorghum bicolor L. Moench) and the quality of soil water leachates was investigated. A series of experiments involving the addition of CaO2 and 2Na2CO3·3H2O2 at the dose of 0.075 g/g PM improved the growth of tested plants. The conducted study indicated that the use of peroxy compounds not only removed pathogens from livestock waste, but also improved the quality of plant growth. The calculated factors for the growth of roots (GFR) and growth of shoots (GFS) in soils treated with a mixture of peroxy compounds and PM were higher than in soils treated only with PM. The physicochemical analysis of soil water leachates indicated that solid peroxy compounds may be a promising alternative compared to the currently used hygienizing agent such as calcium hydroxide (Ca(OH)2). Solid peroxy compounds increased the bioavailability of components necessary for proper seed germination and plant growth (N, P, K, Ca, Mg and S). In most of the studied cases, the obtained plant shoot and root growth rates were higher for soil mixtures containing organic waste deactivated by biocidal compounds, compared to soils that contained only poultry manure.

Ecological and Geochemical Conditions for the Accumulation of Antioxidants in the Leaves of Lathyrus maritimus (L.) Bigel

The article explores how location affected the dynamics of accumulation of ascorbic acid (AC) and oxidized forms of AC—dehydroascorbic acid (DAA) and diketogulonic acid (DKGA) in beach pea during ontogenetic development. Our analysis focuses on research of the ecological and geochemical conditions growing of the plant on the Curonian Spit. The level of hydrogen peroxide and the activity of enzymes that break it down were analyzed. Antioxidant activity and the total concentration of phenolics were evaluated in the leaves of beach pea on the leeward and windward sides of the foredune. It was established that the level of AC, DAA, and DKGA was higher in the plants growing on the windward side of the foredune. A higher concentration of peroxy compounds, which stimulate the biosynthesis of antioxidant enzymes (catalase, ascorbate peroxidase), polyphenols, and other low molecular antioxidants (AOA) was observed in the leaves of these plants. The plants on the windward side enter phenological stages one or two weeks later than their counterparts on the leeward side of the foredune do. There was a generally negative correlation between the temperature of the soil and the accumulation of ascorbate system acids in the leaves of the studied plants (r = −0.46/(−0.68), p < 0.05). The accumulation of low molecular antioxidants and enzymes in beach pea suggests their adaptation to the adverse conditions of the windward side of the foredune.