Certain rhizobacteria can be applied to remove arsenic in the environment through bioremediation or phytoremediation. This study determines the minimum inhibitory concentration (MIC) of arsenic on identified rhizobacteria that were isolated from the roots of Ludwigia octovalvis (Jacq.) Raven. The arsenic biosorption capability of the was also analyzed. Among the 10 isolated rhizobacteria, five were Gram-positive (Arthrobacter globiformis, Bacillus megaterium, Bacillus cereus, Bacillus pumilus, and Staphylococcus lentus), and five were Gram-negative (Enterobacter asburiae, Sphingomonas paucimobilis, Pantoea spp., Rhizobium rhizogenes, and Rhizobium radiobacter). R. radiobacter showed the highest MIC of >1,500 mg/L of arsenic. All the rhizobacteria were capable of absorbing arsenic, and S. paucimobilis showed the highest arsenic biosorption capability (146.4 ± 23.4 mg/g dry cell weight). Kinetic rate analysis showed that B. cereus followed the pore diffusion model (R² = 0.86), E. asburiae followed the pseudo-first-order kinetic model (R² = 0.99), and R. rhizogenes followed the pseudo-second-order kinetic model (R² = 0.93). The identified rhizobacteria differ in their mechanism of arsenic biosorption, arsenic biosorption capability, and kinetic models in arsenic biosorption.

The aim of this study was to investigate the effect of applying a six-rhizobacterial consortium and nitrogen phosphate potassium (NPK) fertilizer in inorganic arsenic (arsenate) phytoremediation using Ludwigia octovalvis (Jacq.) Raven plants. The experiment included control L. octovalvis plants and three phytoremediation treatments with L. octovalvis plants, namely an arsenic (As) concentration of 39mgkg−1 only, the addition of a six-rhizobacterial consortium at 2% (v/v) with an As concentration of 39mgkg−1 and the addition NPK fertilizer at 0.02% (w/w) with an As concentration of 39mgkg−1. In the As phytoremediation treatment with the presence of As only, plants showed signs of phytotoxicity such as wilting and senescent leaves. L. octovalvis grew well until the end of exposure (Day 42) in the phytoremediation treatment with 2% rhizobacteria consortium or with 0.02% NPK fertilizer addition. The As phytoremediation treatment with 2% rhizobacteria showed the highest removal percentages of bioavailable As (89%), total extractable As (78%) and As in the leachate of the reed beds (98%) resulting in lower As uptake by L. octovalvis than in the other two phytoremediation treatments. This indicates that the bioremediation process played a role in the treatment with 2% rhizobacteria. The fresh weight of L. octovalvis biomass in treatment with 0.02% NPK fertilizer increased by almost five-fold compared with the As only treatment. The effectiveness of phytoremediation in terms of As uptake at Day 42 reached 49.8% in the phytoremediation treatment with 0.02% NPK fertilizer addition. It was the highest than in the other two phytoremediation treatments. In conclusion, NPK fertilizer addition gave the best results in As uptake using L. octovalvis plants in terms of the effectiveness of phytoremediation

Aluminium recycling is one of currently growing industries in Indonesia. Abundant amounts of aluminium waste leads to the emergence of new industries. The waste produced from this kind of industry is not well processed yet. Bioremediation using isolated indigenous bacteria is one of the best...

Lead (Pb) is a heavy metal often discovered to be polluting the water areas. One of the efforts made to overcome the heavy metal pollution in estuaries was phytoremediation technique using mangroves. The Wonorejo River was one of the rivers that received industrial waste loads. There were various...