Determination of sedimentation rates and absorption coefficient of insoluble metal carbonates

Studies on the sedimentation rates of insoluble metal carbonates showed that Zn2+ has a higher sedimentation rate of 5.10x10-2 s-1 while Ni2+ has the lowest sedimentation rates of 1.10 x10-3. The rate of sedimentation of the metal carbonates decreased in the order: Zn2+ > Cd2+ > Cu2+ > Co2+ > Ni2+. The order showed a decrease in the density of the carbonates and also correlated with the decrease in the mass (and particle) absorption coefficient of the metal carbonates

Heavy Metal Contents of Municipal and Rural Dumpsite Soils and Rate of Accumulation by Carica papaya and Talinum triangulare in Uyo, Nigeria

Dumpsites in Uyo and most cities in Nigeria are used nutrients rich soils for cultivating fruits and vegetables without regards to the risk of toxic metal pollution by the wastes. This development necessitated the research on the assessment of the impact of municipal and rural dumpsites on the metal levels of the underlying soils, the relationship between the dumpsite- soil metal content and the rate of bio-accumulation by plants, the effect of plant specie and plant part on the rate of metal uptake. Atomic absorption spectrophotometer was employed for the analysis of the samples and results obtained from municipal dumpsite soil indicated the following mean concentrations: Fe, 1711.20 μg/g; Pb, 43.28 ug/g; Zn, 88.34 ug/g; Ni, 12.18 ug/g; Cd, 14.10 ug/g and Cu, 56.33 ug/g. These concentrations were relatively higher than the following concentrations: Fe, 1016.98 ug/g; Pb, 18.57 ug/g; Zn, 57.90 ug/g; Ni, 7.98 ug/g; Cd, 9.25 ug/g and Cu, 33.70 ug/g recorded for the rural dumpsite soil. Consequently, plants grown on municipal dumpsites soil accumulated higher concentrations of the metals than those on rural dumpsites. Results obtained from this study also revealed that plants grown on dumpsite soils bio-accumulated higher metal concentrations than their counterparts obtained from normal agricultural soils. The ability of plants to bioaccumulate these metals were also observed as being different from one plant to the other and from one plant parts to the other. And apart from Fe and Zn which recorded higher concentrations in the leaves of the plants studied, other metals recorded higher concentrations in the roots. The general results obtained revealed that the levels of Cd in dumpsite-soil were above the standard while the levels of Cd and Pb in plants were also above the recommended levels in plants. The implications of these high concentrations of these metals in soil and plants have been discussed. Some useful recommendations on the proper handling of wastes to reduce toxic metal loads at dumpsites have also been highlighted

Production of Cellulosic Polymers from Agricultural Wastes

Cellulosic polymers namely cellulose, di-and triacetate were produced from fourteen agricultural wastes; Branch and fiber after oil extraction from oil palm (Elais guineensis), raffia, piassava, bamboo pulp, bamboo bark from raphia palm (Raphia hookeri), stem and cob of maize plant (Zea mays), fruit fiber from coconut fruit (Cocos nucifera), sawdusts from cotton tree (Cossypium hirsutum), pear wood (Manilkara obovata), stem of Southern gamba green (Andropogon tectorus), sugarcane baggase (Saccharium officinarum) and plantain stem (Musa paradisiaca). They were subjected to soda pulping and hypochlorite bleaching system. Results obtained show that pulp yield from these materials were: 70.00, 39.59, 55.40, 86.00, 84.60, 80.00, 40.84, 81.67, 35.70, 69.11, 4.54, 47.19, 31.70 and 52.44% respectively. The pulps were acetylated with acetic anhydride in ethanoic acid catalyzed by conc. H2SO4 to obtain cellulose derivatives (Cellulose diacetate and triacetate). The cellulose diacetate yields were 41.20, 17.85, 23.13, 20.80, 20.23, 20.00, 39.00, 44.00, 18.80, 20.75, 20.03, 41.20, 44.00, and 39.00% respectively while the results obtained as average of four determinations for cellulose triacetate yields were: 52.00, 51.00, 43.10, 46.60, 49.00, 35.00, 40.60, 54.00, 57.50, 62.52, 35.70. 52.00, 53.00 and 38.70% respectively for all the agricultural wastes utilized. The presence of these cellulose derivatives was confirmed by a solubility test in acetone and chloroform

Effluents and Solid Waste Analysis in a Petrochemical Company- A Case Study of Eleme Petrochemical Company Ltd, Port Harcourt, Nigeria

Effluents and soil samples where sediments from the treated effluents are dumped were analyzed for physicochemical properties, metallic and non-metallic ions. These parameters were compared with established international standard (FEPA). Effluents were classified as process waste water (PWW), clarified water (CW), and final discharge (FD). The petrochemical effluents contained very high concentration of TDS (284.00±014 mg/L) and significant concentrations of TSS (78.89±0.01 mg/L), COD (30.10±0.02 mg/L), DO (13.20±0.01 mg/L), BOD (6.12±0.00 mg/L), PO43- (4.34±0.00 mg/L), SO42- (3.59±0.00 mg/L), Cl- (55.52±0.01 mg/L) and NO3- (8.40±0.01 mg/L). Low concentrations of iron, zinc, copper, cadmium, lead, nickel and cobalt was also observed. Some heavy metals were not detected at all in some of the effluent samples analyzed. Apart from temperature and total dissolved solid TDS, all the other parameters were below FEPA effluent limitations for guidelines for Petroleum Refinery, Fuel/Gasoline oil category in Nigeria