Effectiveness of Phytomining of Vanadium (V) and Chromium (Cr) Using Cymbopogon citratus and Portulaca grandiflora in Red Mud with Manure Addition

¹ Department of Environmental Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia
² Research Center for Infrastructure and Sustainable Environment, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia
³ School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore

^* Corresponding author: voijant@its.ac.id

Abstract

The highly alkaline nature of red mud, coupled with the presence of heavy metals, represents a significant environmental risk. Phytomining has the potential to facilitate the extraction of heavy metals, including vanadium (V) and chromium (Cr), from red mud. In this study, phytomining employs the use of Cymbopogon citratus and Portulaca grandiflora plants. The objective of this study is to evaluate the capacity of both plants to engage in phytomining and extract valuable metals from red mud. The methodology employed in this study entails the incorporation of stimulants in the form of manure at concentrations of 0%, 5%, and 10%. The study was conducted over a period of 28 days, during which time toxicity testing and the phytomining ability of the two plants were observed. The phytomining capacity of the plants was determined by measuring the concentration of vanadium (V) and chromium (Cr) in the plant extractions using inductively coupled plasma-optical emission spectroscopy (ICP-OES) equipment. The findings indicated that the Cymbopogon citratus and Portulaca grandiflora plants were capable of surviving on a red mud medium with the addition of 10% manure. The highest absorption of V metal was observed in Cymbopogon citratus, with a value of 23.3 mg/kg, when 10% manure and 90% red mud were added. The highest absorption of Cr metal was 18.02 mg/kg by Portulaca grandiflora with the addition of 10% manure and 90% red mud. Therefore, the results demonstrated that the addition of 10% manure enhanced the capacity of plants to absorb metals.