Metal contamination is a matter of serious concern throughout industrial areas of the world. Most industrially polluted regions are laden with heavy metals and among them Cu, Cd, and Cr are the most important especially in tannery-and textile-polluted areas. The process of phytoextraction can be enhanced with biological or chemical assistants. Among the chelating agents, EDTA has been the most effective in hastening the process of phytoextraction [1, 2]. A few plant species with high biomass show the capacity to translocate high amounts of heavy metals from roots to shoots [3]. Zhivotovsky et al. [4] have reported that complexation of metals with EDTA reduces their bioaccumulation in roots and thus enhances translocation of metals to aerial parts of plants. Nevertheless, Barrutia et al. [5] argued that

The current research encompasses utilization of peanut shells (PS) as feedstock for pyrolysis carried out at various temperatures (250, 400, and 550 °C) for deriving biochar, namely PS-BC250, PS-BC400, and PS-BC550. After analyzing the biochar types physicochemically, it was applied as a soil ameliorant for the growth of cucumber. The results showed that in prepared biochar type, bulk density, volatile contents, hydrogen, oxygen, and nitrogen content decreased, whereas pH, electrical conductivity, ash content, fixed carbon content, and surface area increased with the increasing temperature. Scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) presented high porosity, re-orientation of vessels, and a greater number of aromatic compounds, respectively, for PS-BC prepared at 550 °C. On applying PS-BC250, PS-BC400, and PS-BC550 as amendments in potted soil at 2, 4, and 6% (w/w), it improved soil quality (viz pH, ECe, BD, and soil water holding capacity) and increased the yield of cucumber. Because of improved soil properties and crop yield, PS-BC550 at the rate of 4% (w/w) demonstrated a great potential for agricultural application while provisioning dual circular economic indicators in the form of diverting PS waste to an effective alternative of chemical fertilizer having intensive carbon footprints in cucumber production.

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A greenhouse trial was conducted to investigate the role of mycorrhizal and resistant fungi on heavy metal phytoextraction from different concentrations of tannery solid waste amended soil (10, 20, 50, and 100%) by Tagetes patula. The four treatments included were, the control (C) without any inoculum, mycorrhizal (M) inoculated with strongly mycorrhizal roots of Cynodon dactylon, fungal (F) inoculated with Trichoderma pseudokoningii and the combined inoculation with both mycorrhizal and fungal inocula (M ? F). The dual inoculation increased plant biomass and phytoextraction ability of plant for metals like Cd, Cr, Cu, and Na. Plants given only fungus (F) and only mycorrhizal (M) treatment also showed significant growth rate as compared with control treatment. The statistical analysis of data indicated synergistic interaction between mycorrhizal and fungal inoculum promoting high biomass and enhanced metal phytoextraction. Thus using more than one group of rhizosphere fungi in association with a high biomass producing plant may be employed for rendering tannery solid waste free of metals.

We investigated the antibacterial activity of alligator weed (Alternanthera philoxeroides) organic extracts against three bacterial phytopathogens (Erwinia carotovora, Ralstonia solanacearum and Xanthomonas axonopodis). The extracts were prepared by soaking the dry powder of leaf, stem and root of A. philoxeroides into methanol, n-hexane, chloroform and ethyl acetate. The disk diffusion method was used to determine the antibacterial activity at 100 mg/mL extract concentration. The n-hexane extract of A. philoxeroides leaves showed the maximum inhibition zone diameter (IZD)= 28.1 mm against R. solanacearum, while, the corresponding value for the positive control (Penicillin) was 48 mm IZD. There was no antibacterial activity of negative control, dimethyl sulfoxide (DMSO). Gas Chromatography Mass-Spectrometry (GC-MS) analysis revealed the presence of acetic acid, 2-(2-methoxycarbonylamino-5-nitrophenylthio)-, methyl ester, at the highest concentration (31.9 %), followed by 1, 4-benzenediol, 2, 5-bis (1,1-dimethylethyl)- (15.06 %),. It was concluded that the observed biological activity in this study may be due to the presence of these compounds.