Phytoremediation of nickel by quinoa: Morphological and physiological response

The amount of soil contaminated with heavy metal increases due to urbanization, industrialization, and anthropogenic activities. Quinoa is considered a useful candidate in the remediation of such soil. In this pot experiment, the phytoextraction capacity of quinoa lines (A1, A2, A7, and A9) against different nickel (Ni) concentrations (0, 50, and 100 mg kg-1) were investigated. Required Ni concentrations were developed in polythene bags filled with sandy loam soil using nickel nitrate salt prior to two months of sowing and kept sealed up to sowing. Results showed that translocation of Ni increased from roots to shoots with an increase in soil Ni concentration in all lines. A2 line accumulated high Ni in leaf compared to the root as depicted by translocation factor 3.09 and 3.21 when grown at soil having 50 and 100 Ni mg kg-1, respectively. While, in the case of root, A7 accumulated high Ni followed by A9, A1, and A2, respectively. There was a 5–7% increased seed yield by 50 mg kg-1 Ni in all except A1 compared to control. However, growth and yield declined with a further increase in Ni level. The maximum reduction in yield was noticed in A9, which was strongly linked with poor physiological performance, e.g., chlorophyll a, b, and phenolic contents. Ni concentrations in the seed of all lines were within the permissible value set (67 ppm) by FAO/WHO. The result of the present study suggests that quinoa is a better accumulator of Ni. This species can provide the scope of decontamination of heavy metal polluted soil. The screened line can be used for future quinoa breeding programs for bioremediation and phytoextraction purpose.

Biosorption Potentials of Pleurotus tuber-regium (Fr.) Sing in Lead and Cadmium Polluted Soil

Background/Aim: The heavy metals, cadmium (Cd) and lead (Pb), are often implicated as environmental pollutants. Therefore, the biosorption potential of Pleurotus tuber-regium in lead and cadmium polluted soil was investigated by this work. Methods: Four kilograms of each humus soil sample was weighed into eight different black nursery cellophane bags and polluted with 0.5 g, 1.0 g and 2.0 g of lead and cadmium in triplicate. Pleurotus sclerotia were then planted in these polluted soil samples, and distilled water was added ad libitum. Results: The results showed that the growth performance was dose-related in lead-polluted soil. The Pleurotus tuber regium mushroom in the lead-polluted soil samples indicated a dose-dependent absorbed lead concentration in the results. Cadmium-polluted soil samples did not support the growth of the Pleurotus tuber regium mushroom at the various concentrations of cadmium used after day 30. Therefore, the findings suggest that the Pleurotus tuber regium mushroom and its sclerotia have intrinsic properties for the absorption of lead and cadmium. Conclusion: The findings suggest that the Pleurotus tuber regium mushroom and its sclerotia have intrinsic properties for the absorption of lead and cadmium.

Effect of EDTA chelate, cow manure, elemental sulfur application and Thiobacillus inoculant on Cd, Zn and Fe phytoremediation efficiency in a Cd-polluted soil

Background and Purpose: Phytoremediation efficiency of heavy metals is one of the important points in environmental studies. This research was conducted to investigate the effect of cow manure, elemental sulfur and EDTA on Cd uptake by Indian mustard in a Cd-polluted soil in the presence of Thiobacillus thiooxidans. Materials and Methods: Treatments consisted of applying cow manure (0, 5 and 10 g/kg soil), soil application of elemental sulfur (2 g/kg soil), and Cd-polluted soil (0 and 20 mg Cd/kg soil) with 1.5 mmol EDTA/kg soil in the presence of Thiobacillus spp. After 90 days, Indian mustard plant was harvested and plant Zn, Fe and Cd concentration was measured using atomic absorption spectroscopy. In addition, the soil microbial respiration was measured. Results: The use of 2 g/kg soil of elemental sulfur significantly increased the plant Cd concentration in the presence and absence of Thiobacillus by 14.2 and 11.7%, respectively. Adding cow manure to the soil at the rates of 5 and 10 g/kg soil significantly increased the plant Cd concentration by 15.7 and 18.1%, respectively. Also, the application of EDTA chelate at the rate 0f 1.5 mmol/kg soil significantly increased the Cd concentration of the plants grown in the Cd-polluted soil (20 mg Cd/kg soil) by 13.6%. Conclusion: The results of the present study showed that using elemental sulfur in the Cdpolluted soil can increase the Cd concentration of the plant which was cultivated in the soil amended with cow manure in the presence of Thiobacillus bacteria. However, the role of soil physic-chemical properties on phytoremediation efficiency cannot be ignored.

The Use of Plants, Nanotechnology and Surfactants in Lindane Remediation: A Mini Review

Lindane is an organochlorine chemical and an isomer of hexachlorocyclohexane that has been used both as an agricultural insecticide and as a pharmaceutical treatment for lice and scabies. Lindane accumulates in the agricultural soil and plants thereby causing environmental and health deteriorative effects. A lot of soil remediation methods used are highly expensive and require a lot of expertise. Phytoremediation (rhizofiltration, phytostabilization), which involve the use of the plant to stabilize or remove environmental toxicants is presently much in use because of its cost-effectiveness and ecological friendliness. Adsorption has emerged as the most efficient, easy, and promising nanotechnology method of wastewater treatment out of the several approaches now employed. Recently, biosurfactants are used for the production of nanoparticles which will be further applied in the area of pesticide remediation. The use of phytoremediation is the most important fully green approach as no new chemicals are added to the polluted soil. Other emerging technologies where phytoremediation might not be applicable especially groundwater has begun to evaluate the use of green nanobiotechnology.

Biostimulatory Influence of Biochar on Degradation of Petroleum Hydrocarbon Impacted Soil

Soil pollution caused by petroleum hydrocarbon and its derivatives has become a grave global issue. Physico-chemical techniques are often expensive. However, bioremediation of petroleum hydrocarbon polluted soil is cost-effective. Therefore, the study was carried out to assess the biostimulatory influence of biochar on the degradation of petroleum hydrocarbon impacted soil in NNPC Depot, kano state. Soil samples were randomly collected from the polluted site to obtain a composite sample. About 400 g of the polluted soil was filled into pots and arranged in a 2x2 factorial experiment in a completely randomized design with three replications. Bone and wood char was at 2 levels (0 and 50 g/pot) each. Data were collected on the physicochemical properties (pH, TN, and Av. P) of the soil, Total Petroleum Hydrocarbon (TPH), and bacterial population. Data were analyzed using ANOVA at α0. 05. Results obtained from the study show that biochar application significantly (p<0.05) enhanced TPH degradation and bacterial population in the polluted soil. However, Bone char significantly(p<0.05) enhanced TPH degradation and bacterial population the most compared to wood char. Combined bone and wood char application resulted in significantly (p<0.05) lower residual TPH content in the polluted soil compared to using bone or wood char alone. Thus, bone and wood char should be used in the bioremediation of petroleum hydrocarbon impacted soils.