Increasing environmental pollution causes the search for new methods of purification. Currently, the remediation potential of nanoparticles is increasingly being studied. Unfortunately, there is still a lack of data on the impact of these compounds on living organisms, including plants. This study was designed to test the effects of nanoFER 25 and nanoFER 25S iron on Lolium westerwoldicum Breakw. After cultivation of plants in a soil contaminated with nanoparticles, the biometric parameters, content of polyphenols, flavonoids, chlorophyll changes, carotenoids, anthocyanins, superoxide dismutase, catalase and pyrogallol peroxidase were studied. The conducted experiment showed that nano zero-valent iron (nZVI) is slightly taken from the soil to the plants. The iron passes to the root but there is no further transport up the plant. The content of polyphenols and flavonoids in aboveground parts of plants decreases with a simultaneous increase in roots compared to the control sample. The chlorophyll content in the leaves is strongly related to the concentration of the contaminant. Similarly, the enzyme activity of the antioxidant system in the whole plant is strongly related to the concentration of the pollutant. The amount of vegetable pigments in the leaves increases for low concentrations of contamination and then decreases at higher levels of contamination. The study has shown that both types of nanoFER are not indifferent to the plants’ growth.

The use of nanoparticles in fertilisation has confirmed positive effects on plant growth and yield. Simultaneously, there is still little research into the effects of nanoparticles on the antioxidant system of plants. Due to the positive effect of nano zinc oxide on plants and the special property of nano zero-valent iron, these particles were selected for the research. The nano zero-valent iron is crucial for plants as it is present in agglomerations on the surface of roots where it increases the absorptive surface of the rhizosphere and causes elongation of the roots. The study aims to determine the influence of selected nanoparticles as a potential improvement for conventional fertilisation by magnesium (Mg), calcium (Ca), phosphorus (P) and nitrogen (N). After the cultivation, the influence of nanoparticles on the accumulation of macronutrients in plant tissues, biometric parameters, and physiological response (chlorophyll and antioxidant system) of radish (Raphanus sativus) were assessed. The solution used in this study helped to increase the content of nitrates (V) in radish roots by 31.7–73.2% compared to conventional fertilisation. Nevertheless, nanoparticles supplementation resulted in a decrease in the concentrations of magnesium, iron (Fe) and zinc (Zn) in plants. The high dose of used fertilisers increased the thickness and length of tubers by approximately 50.0%, compared to the control samples. The “Macro 2 + nano” variant caused an increase of plant biomass up to 70.0%. The analysis of the antioxidant system showed that the application of macronutrients with nanoparticles increased the concentration of polyphenols in plant tubers by 46.0–55.6%. Interestingly, while implemented conditions caused a 1.5-fold increase in CAT activity in leaves, at the same time the decrease in CAT activity in plant roots was observed. Based on the obtained results of the enzymatic antioxidant system and biometric parameters of plants, it can be concluded that (in laboratory conditions) nZVI and nanoZnO are efficient components of fertilisers. However, the effects on other organisms must be investigated before implementing a method for widespread use.