The Role of Nano Clay and Soil Properties in the Phytoremediation Process

Surface water contamination that caused by run-off fertilizer threatens the raw water sources. Compared to the chemical-based treatment methods, the phytoremediation process is preferable due to its low-cost sustainable process and scale-up capabilities. However, the process is limited by the low treatment efficiency due to the nature condition of the plant. This study highlights the significance of increasing the treatment efficiency by changing the soil properties to improve the plant drawbacks. A prepared soil was varied from nano- to sub-micron meter order as well as its surface charge prior to the treatment process before subjecting the samples to the contaminated surface water that consist of the lotus plant. In thirty days of treatment, the BOD removal was 95.9 % when treated with fine soil and followed by 92.8 %, 82.6 %, 81.8 % and 78.9 % when using coarse soil and nano clay soil of pH 4,8,6 respectively. The efficiency was further reduced to -188.5 % in control condition. The COD removal efficiency showed the highest values when treated with nano clay with 74.6 %, 73.3 % and 70% for pH 4, pH 6 and pH 8 respectively. The highest NO3- removal efficiency up to 99.17 % and 98.3 % were noticed when the samples were treated with the highest surface charged nano clay of pH 4 and pH 8. The lowest COD and NO3- removal efficiency were noticed when the samples were treated with control, lotus plant, coarse and fine soil. Here, we suggest that the surface charged of particles is the important parameter to ensure the adsorption of the contaminant occurring at the maximum values even though the BOD removal efficiency was limited by the plant gas transportation rate which is fixed to 0.2–2.1 mL/min O2 gas according to our previous work.