Optimum resource allocation among selected smallholder root and tuber crops farmers in Abia State, Nigeria

This study examined optimum cropping patterns for selected root and tuber crop based production and resource allocation of smallholder farmers in Abia State, Nigeria, using the linear programming approach. The objective function was to maximize gross revenue from the production of selected root and tuber crop based production activities subject to land, labour and minimum subsistence family staple food consumption. Cost route approach was used to collect data from a random sample of 60 smallholder farmers in the state using the multistage stratified technique for location. The activities incorporated in the LP model include crop production activities, labour activities and product selling activities. Crop production activities comprise sole crops and crop mixtures. Existing selected crop activities were compared with their optimum counterparts. Resource allocation was compared between farm land owners and tenants with the aim of investigating their relative competitiveness in major root crop based production combination. Results showed that the sampled farmers were not optimal in their resource allocation. There was gross misallocation of labour for both land owners and tenant farmer. For the selected root and tuber crops, yam, cocoyam and cassava crop activities were found in their soles in the existing plan whereas crop mixtures were dominance in the optimal plan except cocoyam for the tenants’ category. However, optimal farm plans favoured fewer crops than in the existing plan. Cassava/melon, yam/maize and cocoyam/melon were the crop activities prescribed for an average land owner to maximize gross margin of N231,119.40K as against N190,265.00K in the existing plan (an increase of 21.48%) while for the farm tenants N190,671.30K was prescribed as optimal gross margin as against N184,600.00K (an increase of 3.29%). Yam/melon and Cassava/cocoyam/maize had the least tendency to depress farm income if forced into the plan for the land owners and farm tenants respectively. Farmers’ purchasing power would be enhanced given optimal crop production activity combination and land resource allocation.Keywords: Optimum, activities, crops, smallholder farmer

Multielement analyses of human scalp hair samples from three distant towns in southeastern Nigeria

Hair samples were collected from three distant towns in Southeastern Nigeria and analyzed for their contents of the trace metals, Pb, Cd, Zn, Ni, Cu, and Cr by atomic absorption spectrometry. Higher geometric mean values for Pb, Zn, Ni, Cu, and Cr were obtained in hair samples of donors from theindustrialized areas, Aba and Onitsha. Higher levels of Pb and Cr were observed in hair samples of male donors while higher levels of Zn and Cu were obtained in hair samples from the unindustrialized area, Isuochi. For the general population studied, geometric mean values of 65.4 ìg/g (range 9.1 to 194.5 ìg/g); 1.2 ìg/g (0.4 to 6.6 ìg/g); 146.2 ìg/g (57.7 to 510 ìg/g); 26.4 ìg/g (5.0 to 143.2 ìg/g); 117.2 ìg/g (29.4 to 363.5 ìg/g); 35.1 ìg/g (19.5 to 60.6 ìg/g) were obtained for the metals, Pb, Cd, Zn, Ni, Cu, and Cr, respectively. Our result indicates that ~ 89% of the population had Pb levels >30 ìg/g, indicative of occupational exposure, while about 20% had levels >110ìg/g which is considered dangerous

A bioseparation process for removing heavy metals from waste water using biosorbents

of conventional adsorbents to the use of biosorbents. The presence of heavy metals in the environment is of major concern because of their toxicity, bioaccumulating tendency, and threat to human life andthe environment. In recent years, many low cost sorbents such as algae, fungi bacteria and lignocellulosic agricultural by-products have been investigated for their biosorption capacity towards heavy metals. In this comprehensive review, the emphasis is on outlining the occurrences and toxicology of heavy metals and the biosorption capacity of biosorbents compared to conventional adsorbents. A detailed description of the adsorption properties and mode of action of these biosorbents is offered in order to explain the heavy metal selectivity displayed by these biosorbents. The role of cell structure, cell wall, micropores and macropores is evaluated in terms of the potential of these biosorbents for metal sequestration. Binding mechanisms are discussed, including the key functional groups involved and the ion-exchange process. Quantification of metal-biomass interactions is fundamental to the evaluation of potential implementation strategies, hence, sorption isotherms, sorption kinetics, intraparticle diffusivities as well as models used to characterize biosorbent sorption are reviewed. The sorption behavior of some biosorbents with various heavy metals is summarized, their relative performance evaluated and a bioseperation process flow diagram for heavy metal removal from wastewater using biosorbents was propose

The role of pH in heavy metal detoxification by biosorption from aqueous solutions containing chelating agents

The high level of toxic metal pollution in the environment is a result of increased human activities. The hydrogen ion concentration of solutions has been known to affect reactions in solutions. The role of pH in As(V), Pb(II) and Hg(II) ions detoxification by bio-sorption from aqueous solutions using coconut fiber and sawdust waste biomass, containing chelating agents was studied. pH characteristically influenced adsorption. Maximum adsorption occurred at pH 2 and 12 whereas minimum adsorption occurred at pH 6-8. Modification of the adsorbent by carboxymethylation and thiolation decreased the absorption capacity. As(V) metal ion was adsorbed more than Hg(II), then followed by Pb(II) ion. A model was proposed for the action of pH on the adsorption pattern of the metal ions on the adsorbents used. Desorption studies was investigated using NaOH and H2PO4. Therefore, these results can serveas parameters for design of treatment plants for heavy metal detoxification using agricultural byproducts, such as sawdust and coconut fiber

Effect of particle size on adsorption of heavy metals using chemically modified and unmodified fluted pumpkin and broad-leafed pumpkin pods

The effect of particle size on the bioremediation of Pb(II), Zn(II), Cd (II) and Hg(II) ions from synthetic aqueous effluents using unmodified and carboxymethylated fluted pumpkin and broad-leafed pumpkin pods was investigated in a batch system. 1.2 g of adsorbents was used in each sorption experiment at 25 °C and pH 6.5-8.5 for one hour interval. The results showed that the two adsorbents were good for the removal of these metal ions. Unmodified fluted pumpkin pod was found to be better than the other tested adsorbents with removal efficiencies of 92.62%, 81.88%, 75.21% and 49.67% for Pb (II), Zn (II), Cd (II) and Hg (II), respectively. Carboxymethylation decreased the adsorption capacity of the cellulose materials mostly for fluted pumpkin pod. Particle size below 600 μm was found to be the optimum size for unmodified absorbent, while 600-1000 μm was observed for modified adsorbent. Fluted pumpkin pod was found to be a more effective adsorbent for these metal ions than the broad leafed pumpkin pod especially when unmodified. Therefore these results show that fluted pumpkin and broad-leafed pumpkin pods could serve as very good adsorbents in the treatment of these metal ions from aqueous effluents.Keywords: agricultural waste, bioremediation, heavy metals, pollution control, surface chemistry

Kinetics of radionuclides and heavy metals behaviour in soils: Implications for plant growth

The extent of metal and radionuclide contamination in the world is immense. In soils, metals and radionuclide can be dissolved in solution, or ion exchanged in reaction, complexed with soil organics or precipitate as pure or mixed solids. Soluble contaminants are subject to migration with soil  water, uptake by plants or aquatic organisms or loss due to volatilization. Lead, chromium, zinc, arsenic and cadmium are the most frequently identified inorganic contaminants in soil and ground water. Unlike degradable organic contaminants and ever short-lived radionuclides that can become less toxic over time, metals can be considered conservative. However, many metals, especially radio-sensitive elements such as arsenic and chromium can undergo transformation or sorption reaction that alter both mobility and relative toxicity. This paper therefore, makes a review of these behaviours of radionuclides and heavy metals in soils, in connection to soil contamination and their effects on plant growth

Studies on the kinetics and intraparticle diffusivities of BOD, colour and TSS reduction from palm oil mill effluent (POME) using boiler fly ash

The palm oil industry has been identified as one of the main contributors of organic pollution. These industries generate large volumes of effluent and solid waste including boiler fly ash. The kinetics and intraparticle diffusivities of BOD, TSS and colour reduction from palm oil mill effluent (POME) using boiler fly ash was reported in this paper. The amount of BOD, colour and TSS adsorbed increased as the weight of the boiler fly ash was increased. Also, the smaller adsorbent particle size of 425 mm adsorbed more than the 850 mm size. Attempts were made to fit the experimental data with the pseudo - first order and pseudo-second order kinetic equations. The pseudo - second order model gave a better fit to the sorption process. The rate constants obtained for the pseudo-second order model are 2.26 x 10-5 mg/g-min for BOD, 6.48 x 10-4 mg/g-min for colour and 9.55 x 10-4 mg/g-min for TSS at 30°C. The mechanism of sorption was investigated by using the intraparticle diffusion model. The regression coefficient for the intraparticle diffusion model showed that BOD with a value of 0.9744 was well correlated than TSS (R2 = 0.1018) and colour (R2 = 0.1450). This means that BOD adsorption was particle diffusion controlled while colour and TSS were film diffusion controlled. Therefore, this study reveals that boiler fly ash can effectively be used as an adsorbent for POME treatment and also established the kinetic and mechanisms of the sorption process. Also, the results of this study could serve as effective design parameters for a treatment plant to further reduce BOD, colour and TSS from POME

Risk and health implications of polluted soils for crop production

Studies of polluted soils have shown heavy metals contamination of the soils as well the uptake of these toxic elements by plants. Consequently, there are reasons for concern over elevated concentration levels of heavy metal/toxic elements in polluted soils. This can ultimately result in high human and animal exposure to these toxic elements through food-chain transfer, ingestion of wind blown dust or direct ingestion of soils. The toxic effects caused by excess concentrations of heavy metals in living organisms include competition for sites with essential metabolites, replacement of essential ions, reactions with –SH groups, damage to cell membranes and reactions with the phosphate groups

Trace metal contents of facial (make-up) cosmetics commonly used in Nigeria

Several facial cosmetics available in Nigeria were analyzed for their contents of the heavy metals; lead, cadmium, chromium, nickel, zinc and iron. The levels of chromium, iron and zinc were much higher in the samples than those of the non-essential toxic metals; lead, cadmium and nickel. The range of the geometric average for the various cosmetics is: Fe, 97-256 g/g; Ni, 8-13 g/g; Pb, 87-123 g/g; and Zn, 88-101 g/g. The geometric mean values obtained for Cr and Cd were generally below 40 g/g and about 1 g/g, respectively. Our result indicates that these cosmetics are relatively safer to use when compared to the lead-based kwali eye make-up commonly available in Nigeria. These data indicate that the continuous use of these cosmetics could result in an increase in the trace metal levels in the ocular system and the human body beyond acceptable limits. The application of these cosmetics needs to be considered as a source of lead in evaluating patients with symptoms of lead intoxication in regions where this practice is common

Detoxification of copper fungicide using EDTA-modified cellulosic material

Pesticides are poisons and can be particularly dangerous when misused or carelessly disposed. The detoxification of a copper fungicide (KOCIDE 101) using maize cob, a cellulosic material, was studied. Based on copper as the active agent (after a sorption period of 1 h), the concentration of the fungicide reduced from an initial value of 2000 to 206.25 ppm for the unmodified maize cob and to 24.31 ppm for the modified maize cob. The pseudo-first and second order rate equations were used to model thedetoxification process. The intraparticle diffusivity and mechanism of the sorption was proposed. Also, equilibrium sorption isotherms were evaluated using the Freundlich, Langmuir and Dubinin-Radushkevich isotherm models. This results show that maize cob is an effective adsorbent for copper fungicide deactivation and detoxification