Ayebaemi I. Spiff

Effects of temperature on the sorption of Pb2+ and Cd2+ from aqueous solution by Caladium bicolor (Wild Cocoyam) biomass

This report is based on the investigation of the effect of temperature on the removal of Pb 2+ and Cd 2+ in aqueous effluent using C. bicolor biomass in a batch sorption process. The result showed that the most suitable sorption temperature was 40oC with maximum sorption capacities of 49.02 mg/g and 52.63 mg/g for Pb 2+ and Cd 2+ respectively. Various thermodynamic parameters, such as ΔG o , ΔH o , ΔS o and E a have been calculated. The data showed that the sorption process is spontaneous and exothermic in nature and that lower solution temperatures favours metal ion removal by the biomass. The findings of this investigation suggest that physical sorption plays a role in controlling the sorption rate. The sticking probability model was further employed to assess the applicability of the C. bicolor biomass as an alternative adsorbent for metal ion contaminants in aqueous system.

Studies on the effect of pH on the sorption of Pb2+ and Cd2+ ions from aqueous solutions by Caladium bicolor (Wild Cocoyam) biomass

Environmental protection requires the use of natural products instead of chemicals to minimize pollution. This investigation studies the use of a non-useful plant material as naturally occurring biosorbents for the removal of cationic pollutants in wastewater. The effect of pH on the sorption of Pb 2+ and Cd 2+ ion onto Caladium bicolor corm biomass was investigated. The experimental results have been analysed in terms of Langmuir, Freundlich and Flory-Huggins isotherms. The data showed that the maximum pH (pH max ) for efficient sorption of Pb 2+ was 7.0 and for Cd 2+ 5.0. Evaluation using Langmuir equation gave the monolayer sorption capacity as 88.50 mg/g and 65.50 mg/g at the respective pH max for Pb 2+ and Cd 2+ . Surface characterization of acid and base treated C. bicolor biomass indicates a physiosorption as the predominant mechanism for the sorption process. The thermodynamic assessment of the metal ion - Caladium bicolor biomass system indicates the feasibility and spontaneous nature of the process.

RETENTION OF PB (II) ION FROM AQUEOUS SOLUTION BY NIPAH PALM (NYPA FRUTICANS WURMB) PETIOLE BIOMASS

The retention of Pb (II) from aqueous solution by pure (PB) biomass and thioglycolic acid (TGA) modified biomass (MB) of Nipah palm (Nypa fruticans Wurmb) petiole was studied using batch sorption technique. The equilibrium retention capacity of Pb (II) was determined from the Langmuir equation and found to be 15.06 mg g-1 and 17.60 mg g-1 for pure and modified biomass, indicating a small difference in Pb(II) retention after treatment with TGA. The data showed that chemisorption process could be the rate-limiting step in the retention mechanism. Studies on the retention of Pb (II) by Nipah palm petiole biomass are important because it may contribute in aiding the innovative removal and recovery of metal ions from contaminated industrial effluents

Distribution and partitioning of trace metals in sediments of the lower reaches of the New Calabar River, Port Harcourt, Nigeria.

The distribution of trace metals in sediments of the lower reaches of the New Calabar River, Nigeria was evaluated togetherwith the partitioning of their chemical species between fivegeochemical phases. Samplings were made in five zones at the lower reaches of the New Calaber River. All the trace metals were determined by AAS after selective chemical extractions andconcentrations given in μg gm-1 (dry weight basis). The average totalconcentrations found for trace metals in the sediment were (mean ± rsd.) Pb: 41.6 ± 0.29, Zn: 31.60 ± 0.42, Cd: 12.80 ± 0.92, Co: 92 ± 0.25, Cu: 25.5 ± 0.65 and Ni: 3.2 ± 0.25. Maxima and minima concentrations are inconsistent with previous studies in other rivers of this region. Spatial distribution revealed that the sources of trace metals into theriver appeared to be of non-point. Five contamination indices were applied in studying the partitioning of the trace metals inthe sediment. These indices provided bases for ascertaining the potential environmental risk of trace metals in the river system.The results denote high partition levels in the more mobile andmore dangerous phases.

Petroleum hydrocarbon pollution: the distribution in sediment and water of the New Calabar River, Port Harcourt, Nigeria

Abstract The hydrocarbon distribution in sediments and water samples of the Port Harcourt segment of the New Calabar River, Nigeria was sampled during the wet and dry seasons of 1990 and 1991. The results demonstrate that a very heterogenous distribution of petroleum hydrocarbon exists in this segment of the river and that the life-style and feeding habits of the organisms in this environment will have a dramatic effect on their hydrocarbon exposure. Site variability indicates that most of the hydrocarbons in sediment and water of the New Calabar River are of anthropogenic origin. The baseline station, BLF, is the least exposed to petroleum hydrocarbon pollution. Seasonal variation gave a high hydrocarbon level during the rainy season which resulted from slow rate of volatilization during this season. Contamination factor, measured as the ratio of the median concentration in the monitoring zones and the median concentration of the baseline values ranged from 1.73 to 8.47 in sediments and 2.02 to 2.62 in water.