Potential of Biotechnology in Phytoremediation

The accumulation of toxic substances involving the inorganic and organic contaminants in the soil is a global problem. Status of the World's Soil Resources Report (SWSR) recognized soil pollution as one of the main reasons affecting global soils and the ecosystem services provided by them. However, transgenic approaches utilizing the biodegradation capabilities of microbes and mammals into plants pledge an efficient and eco-friendly approach to renewing the environment. An effective method of phytoremediation involves an enhanced rate of pollutant uptake by the plant, followed by the detoxification of the chemicals absorbed or translocated. It also involves the production of genetically modified herbicide-resistant plants for herbicide remediation and exploits the principles of biotechnology and molecular biology for the introduction and improvement of potentially superior genes into plants. This review discusses the various transgenic approaches involved in the phytoremediation of persistent organic pollutants, metals, metalloids, and explosives. Besides, it also focuses on the limitations of transgenics and provides an insight into the future potential of emerging biotechnological tools and techniques in this field.

Preliminary Investigation of Inorganic and Organic Contaminants in Soils within Wukari Metropolis, Taraba State, Nigeria

This study aimed at the preliminary investigation of inorganic and organic contaminants in soils within Wukari metropolis and to assess the contamination status and metal bioavailability. Digested soil samples for total metals and fractionation were analyzed for heavy metal concentrations in triplicates using Flame Atomic Absorption Spectrophotometer while 5 Varian Bond Elu SI SPE cartridges was used for solid phase extraction and the soil sample extracts were analyzed by GC-MS. The percentage bioavailability of metals ranged from Fe: 13.81 – 98.85 %, Ni: 65.01 - 80.93 %, Cr: 34.82 – 77.19 %, Pb: 66.93 - 86.59 % and Co: 70.35 - 99.14 % respectively. The bioavailability of Fe, Ni, Pb and Co station ST3 which is an agricultural area were above 50.00%. This indicates that food crops grown in the area may be contaminated by the metals. Irrespective of sampling points, the distribution of metals in the soil samples generally followed the order Fe: residual > carbonate > exchangeable > oxidizable; Ni: exchangeable > carbonate > oxidizable > residual; Pb: exchangeable > residual > carbonate > oxidizable; Co: exchangeable > carbonate > oxidizable > residual. Organic contaminants such as Halo alkanes; bromodichloromethane (molecular weight 162.0 g/mol) and chloroform (molecular weight 118.0 g/mol) were detected in ST1 while, 1, 1, 2 trichloroethane (molecular weight 132.0 g/mol). Another contaminant phenol d5 was recorded in sample ST2, ST3 and ST4 respectively. BTEX compounds were also contaminants present in ST5 (Fuel station near some automobile workshops).

Potential of Biotechnology in Phytoremediation

The accumulation of toxic substances involving the inorganic and organic contaminants in the soil is a global problem. Status of the World's Soil Resources Report (SWSR) recognized soil pollution as one of the main reasons affecting global soils and the ecosystem services provided by them. However, transgenic approaches utilizing the biodegradation capabilities of microbes and mammals into plants pledge an efficient and eco-friendly approach to renewing the environment. An effective method of phytoremediation involves an enhanced rate of pollutant uptake by the plant, followed by the detoxification of the chemicals absorbed or translocated. It also involves the production of genetically modified herbicide-resistant plants for herbicide remediation and exploits the principles of biotechnology and molecular biology for the introduction and improvement of potentially superior genes into plants. This review discusses the various transgenic approaches involved in the phytoremediation of persistent organic pollutants, metals, metalloids, and explosives. Besides, it also focuses on the limitations of transgenics and provides an insight into the future potential of emerging biotechnological tools and techniques in this field.

A hydrostable Zn2+ Coordination Polymer for Multifunction Detection of Inorganic and Organic Contaminants in Water

From the perspective of human health and environmental safety, the development of hydrostable fluorescent sensors for detection of heavy metal ions and nitroaromatics is an important but challenging issue. To...

Electron Transfer Drives Metal Cycling in the Critical Zone

Electron transfer in the critical zone is driven by biotic and abiotic mechanisms and controls the fate of inorganic and organic contaminants, whether redox-sensitive or not. In these environments, Fe- and Mn-bearing minerals, as well as organic matter, are key compounds. They interact with each other and constitute important electron shuttles. As a result, not only their solubility but also their structure controls the mobility of many essential and toxic elements. In addition, microorganisms that form hot spots and are widespread in environmental systems are also primordial players in electron transfer processes by acting as a catalyst between an electron donor and an acceptor, and through their contaminant detoxification metabolism.

Atomic Absorption Spectrometer for Assessing the Inorganic Contaminants in Processed E Waste

E-waste handling appears to be national agenda towards hazardous waste management. The annual e-waste generation in India is approximated to be 4.1 million metric tonnes. In India, Bengaluru, Karnataka is popularly called as Silicon Valley of India as it hosts many software industries. The annual generation of e-waste at Bengaluru is 9,118.74 metric tonnes and expected to escalate at a rate of 2.25 tonnes/year. It is understood that e-waste comprises of obsolete electrical and electronic items. They are collected and transported to e-waste handling units. At the handling unit, they are segregated, dismantled and separated into plastic and metal items manually. Worn out copper cables, wires and printed circuit boards (PCBs) are shredded and pulverized to extract the metals. This results in generation of processed e-wastes such as Floor dust, Pulverized Epoxy Powder, PVC Cable Granule and PCB metal powder. These processed ewastes contain inorganic and organic contaminants and it requires safe handling and disposal. Inorganic contaminants such as metals are expected to be higher in the processed ewastes which needs to be examined for their levels. The present study attempts to investigate metals such as Copper (Cu), Zinc (Zn), Iron (Fe), Lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni) and Lithium (Li) in the processed e-wastes. As the processed e- wastes are expected to contain good metal residues, their levels are compared with statutory limits to comment on their toxicity. Further, existing methods of metal recovery are discussed along with their impact on environment upon disposal.