Assessment of <i>In-Situ</i> Natural Dendroremediation Capability of <i>Rhizophora racemosa</i> in a Heavy Metal Polluted Mangrove Forest, Rivers State, Nigeria

Abstract

Environmental pollution is assuming frightening dimensions in many parts of the world. This is not excluding Niger-Delta region of Nigeria where most of the country's oil and gas are sourced with attendant production of noxious substances as byproducts/residues/waste. Many of these noxious substances have been noted to be removable from polluted environment through proper application of phytoremediation techniques, particularly using native plant species. Consequently, this research was conceived to evaluate potentials for phytomediation by native red mangrove tree (Rhizophora racemosa G.F.W. Meyer). This was carried out by evaluating the presence of heavy metals ions and their bioconcentration levels in the samples of root and wood tissues axially along the stem of this tree. The sorrounding soil and water were also sampled and evaluated for presence and concentration of these metal ions in comparison with those for the sampled plant tissues. All the samples were sourced from a mangrove forest in Okrika, Rivers State, Nigeria. The samples from the root, butt, 50% and 90% bole length were oven-dried at 60±5 o C to constant weight, pulverised and heated with trioxonitrate (v) acid to achieve total dissolution before subjecting them to atomic absorption spectroscopy (AAS). Similarly, samples from sorrouding soil were dried at 35±2 o C to constant weight, crushed and sieved using a ≤ 2mm mesh before performing metal extraction and detection using AAS while water samples were also subjected to AAS for heavy metal analyses, in line with appropriate standard methods. The data obtained were statistically analysed using basic descriptive tools, Analyses of Variance and Fishers' Least Significant Difference (P < 0.05). Outcomes of these statistical analyses showed that, in terms of bio-concentration values, the evaluated metal ions that include Fe, Cu, Mn, Cd, Pb, Ni and Cr were more in the root than the surrounding soil and water. The bio-concentration trends, for the metal ions, also progressively declined from the root towards the crown of the trees. The bio-concentration distribution in all the tree sections showed an inconsistent pattern with Fe ions having higher bio-concentration. In addition, Cr, Ni, Pd and Cu also inconsistently followed Fe in terms of bio-concentration level. © JASEM http://dx

Accumulation of Pb, Cd and Ni in sediments and root of mangrove plant (<i>Laguncularia</i> sp) from the fringes of the Upper Bonny Estuary, Nigeria

“…Sediment content of heavy metals in May were Pb (0.2 -3.2 µg/g), Cd (0.001 -0.4 µg/g), Ni (<0.001 µg/g) while those in roots were Pb (0.04 -3.2 µg/g), Cd (0.2 -0.5 µg/g) and Ni (0.04 -0.7 µg/g). The values of Pb, Ni and Cd in sediments of this study also fall within the range reported by Gbosidom et al, (2017) but such values of metals observed in roots (current study) were well below those (Cd: 342.08 mgkg-1, Pb: 502.04 mgkg-1 and Pb 609.59 mgkg-1) reported by Erakhrumen (2015) in the root of other Mangrove plants in similar environments of the Niger Delta area. Age variation was not noticed during the month of May but metal accumulations were more in roots compared to sediments.…”

Penerapan Wanamina: Kelulushidupan Semai Mangrove, Variasi Kualitas Lingkungan dan Perubahan Kandungan Logam Berat

“…Akumulasi logam pada sedimen mangrove ditentukan oleh beberapa faktor, antara lain laju sedimentasi dan laju penyerapan oleh tegakan. Beberapa penelitian menunjukkan bahwa tegakan mangrove secara aktif mengakumulasi logam berat dalam organ tanaman (Kathiresan et al, 2014;Pakzadtoochaei, 2013;Erakhrumen, 2015;Kamaruzzaman et al, 2009). Penelitian Kaewtubtim et al (2016) -0,305 -0,435 -0,300 -0,118 -0,305 -0,435 0,120 ± 0,382 x -0,094 ± 0,209 x 0,013 ± 0,299 p 2 m 0,402 -0,845 -0,063 -0,620 -0,063 -0,845 0,641 ± 0,224 x 0,226 ± 0,354 x 0,433 ± 0,349 q 3 m -0,375 -0,263 -0,255 -0,405 -0,375 -0,405 -0,043 ± 0,320 x -0,025 ± 0,373 x -0,034 ± 0,311 p (Rerata) -0,375 -0,845 -0,300 -0,620 0,269 ± 0,413 a 0,036 ± 0,313 a Keterangan : kelompok perlakuan yang ditandai dengan huruf yang sama menunjukkan tidak ada perbedaan yang signifikan pada taraf kepercayaan 95%…”

Heavy metals concentration in teak (<i>Tectona grandis</i> Linn. F.) and topsoil at roadside in University of Benin, Benin City, Nigeria

“…This phenomenon/function is simply referred to as bioindication (Erakhrumen, 2014). Some plants, among these organisms, possess the ability to allow high concentrations of noxious/toxic substances in their tissues and/or participate in controlling them in the environment through processes collectively known as phytoremediation (Erakhrumen, 2007;Erakhrumen, 2015;Erakhrumen and Akhigbe, 2016). Apart from the earlier stated benefits derivable from different types of plants, there are others, such as the production of harvestable resources and participation of some plants in environmental stabilisation.…”