Effect of nitrogen source on phytoremediation of heavy metals in plant-sand systems

Filip Bokros

Bachelor's thesis

Abstract:

As human civilization develops and living standards increase, so do demands, technical advancements, and environmental consequences. Contamination of the environment with heavy metals is among the most important sorts of contaminants. Heavy metals, as well as numerous herbicides, insecticides, and low-cost fertilizers, are an issue in the environment. Plants are used as a source of food, fuel, and fibber, but their potential to deal with pollution and actively participate in its cleanse has been discovered just lately. Artificial plant-based systems, such as constructed wetlands, have been successfully developed to treat wastewater as a biological filter that removes heavy metals and other organic compounds. Our study investigates the effects of several nitrogen sources (Urea, NH4+-N, NO3-N) on the phytoremediation of heavy metals and other organic compounds by using laboratory size built reactors. Further analysis of water samples proceeded in the laboratory with measurement of proposed parameters for TOC, IC, TC, TN, NH4+N, NO3 –N. Plant samples were dried for determination of the amount of heavy metals concentration which was obtained from CECs measurement. When the initial concentrations of HMs in the soil solution emerged, plant growth rates were reduced. In the reactors without HMs, NO3-N produced the highest rate of biomass, followed by urea, while NH4+-N produced the lowest rate of biomass. In the case of HMs reactors, the highest average rate was achieved while using an NH4+-N source, followed by urea, and eventually NO3-N. Under the N source, plants demonstrated the ability to develop significant biomass concentrations while also removing HMs from the substrate. The favorable influence of various N forms on lowering heavy metal concentrations in the substrate was reflected in heavy metal concentrations on the observed plant Iris Wilsonii. As a result, it can be determined that using phytoremediation in wastewater treatment can result in a more cost-effective and environmentally friendly using nitrogen technology.

Keywords

Effect of nitrogen, phytoremediation, nitrogen source, constructed wetlands, heavy metals

Language used: English

Date on which the thesis was submitted / produced: 28. 3. 2022

Thesis defence

• Supervisor: doc. Zhongbing Chen
• Reader: Shanshan Hu, Ph.D.

Czech University of Life Sciences Prague

Faculty of Environmental Sciences

Bachelor programme:
Environmental Engineering