The concentration of Cadmium (Cd), Chromium (Cr), Copper (Cu), Iron (Fe), Nickel (Ni), Lead (Pb) and Zinc (Zn) which may affect human health and the "health" of the aquatic ecosystem were determine in the River Ijana Ekpan, using a pye unicam Atomic Absorption Spectrometry SP model 2900. The level of heavy metal in the study area varied between Cd (0.010 ± 0.004mgl -1 ) and (0.100 ±0.014mg1 -1 ); Cr (0.037 ± 0.006mg1 -1 ) and (0.067 ± 0.020mg1 -1 ), Cu (0.020 ± 0.004mg1 -1 ) and (0.050 ± 0.029mg1 -1 ); Fe (0.046 ± 0.007 mg1 -1 ) and (0.229 ± 0.008mg1 -1 ); Ni (0.030 ± 0.004mg1 -1 ) and (0.080 ± 0.010mg1 -1 ); Pb (0.025 ± 0.006mg1 -1 ) and (0.058 ± 0.008mg1

The sorption of highly toxic Cr(VI) ions by cassava waste biomass was quantitatively investigated. The sorption was found to be influenced by several physico-chemical factors such as agitation speed, temperature, contact time, pH, and sorbent/sorbate ratio. The adsorption data at equilibrium were fitted to Freundlich and Langmuir isotherms. The monolayer sorption capacity was found to be 61.79 mg of Cr(VI) per gram of biomass. The kinetics of Cr(VI) adsorption to pure cassava-tuber-bark wastes were determined based on a pseudo-second-order-rate model using the batch-sorption technique at a temperature of 30 degrees. The kinetics data suggest that the adsorption process is exothermic, and that the rate-limiting step is physisorption. Negative DeltaG(ads) values indicate that the adsorption is spontaneous and exothermic in nature. Also, under optimal conditions (in agitated 1M H(2)SO(4) at 30 degrees), the cassava waste biomass appears to be recyclable.

The effects of acidic, basic and neutral reagents on the recovery of Pb 2+ and Cd 2+ from metal-loaded biomass of wild cocoyam (C. bicolor) were investigated by eluting the biomass in five successive cycles using 0.01 M HCl, 0.1 M HCl, 0.01 M NaOH, 0.1 M NaOH and distilled water at different contact times. The data showed that the ease of metal ion recovery from metal -loaded biomass by the eluent solutions is of the order 0.01 M HCl > 0.1 M HCl > 0.01 M NaOH > 0.1 M NaOH > distilled water. Over 94% Pb 2+ and 74% Cd 2+ of the initially adsorbed metals were recovered by 0.01 M HCl, while < 20% of both metals was recovered by basic reagent. Distilled water recovered less than 9% of both metal ions from the biomass. Macroscopic changes were also observed as the concentration of recovery reagent increased. This study has demonstrated that the selection of a recovery reagent for metal ions on a biomaterial should give consideration to the reusability of the biomass.Metal ion recovery studies from spent biomass are an important aspect of the waste management and *Corresponding author environmental remediation goals. These studies may help to elucidate the nature of recovery of metal ions from wastewater and the recycling of adsorbent. The possibility of regeneration of spent biosorbent is crucially important to keeping the process costs of remediation down and to opening the possibility of recovering the metal(s) extracted from the liquid phase. The deposited metals are washed out (recovered) and biosorbent regenerated for another cycle of application. The recovery process should result in (1) -highconcentration metal effluent; (2) -undiminished metal uptake upon re-use; (3) -no biosorbent physico-chemical damage. The recovery of metal ions and sorbent regeneration studies might require somewhat different methodologies. Screening for the most effective regenerating solution is the beginning. Different affinities of metal ions for the biosorbent result in certain degree of metal selectivity on the uptake. Similarly, selectivity may be achieved upon the elution-recovery operation which may serve as another means of eventually separating metals from one another if desirable.A number of studies have demonstrated the feasibility of

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The physical (pH, Dissolved Solids, Dissolved Oxygen, conductivity, water depth temperature) and bacteriological (Total coliforms, Faecal coliforms) characteristics of 22 hand-dug wells in oil-rich Niger Delta of Nigeria were investigated. All coliforms counts (Log(10) MPN/100 ml) varied from well to well ranging from 0 to 6.0 although faecal coliform counts were markedly lower (0-3.5 vs 1.0-6.0). When both seasons were compared, faecal coliform counts were significantly higher (t test; P < 0.05) during the wet season whereas no significant difference was observed in respect of total coliforms. Unlike the total coliforms, faecal coliform counts increased in wells close to septic tanks during the wet season. Although a declining trend was observed during the wet season, the values of the physical parameters were within WHO limits. The pH was slightly acidic (Mean +/- SD: dry season, 6.04 +/- 0.66; wet, 6.43 +/- 0.62) and may be attributed to emissions from gas flaring and petroleum refining activities, which is common in the area. While the total coliform counts reflected the unsanitary habits of the well users, the detection of faecal coliforms exceeding recommended numbers in 63% of the wells render them unfit for domestic use. The public health implication is obvious considering the increasing number of people using the wells due to the rapid urbanization of the oil-rich region.