Industrial effluents discharged into the environment pose a serious threat to our agricultural products and health. In view of this, levels of some heavy metals, Zn, Pb, Cr, Cu, Ni, Co, Ag, Fe and Mn were determined in water samples collected from two pollution prone areas around Kano (Sharada and Bompai industrial estates) and control site (Thomas Dam, Dambatta). The levels of the heavy metals were determined by Atomic Absorption Spectrophotometry. The results obtained show that the mean values of all heavy metals (with the exception of Zn) in water samples from the polluted areas studied were significantly higher than in the control site (P < 0.05). These mean values have also exceeded the acceptable limits.

Microbiological and color changes of catfish fillets were determined following dip treatment in solutions at 4 degrees C of 2% acetic, citric, hydrochloric, lactic, malic, or tartaric acid. Fillets were inoculated with an eight-strain mixture of Listeria monocytogenes prior to dipping. L. monocytogenes, coliform, and aerobic plate counts and surface pH and Hunter color were measured at 0, 2, 5, and 8 days of storage at 4 degrees C. Acid dipping reduced surface pH and L. monocytogenes, coliform, and aerobic microbial loads. Little microbial proliferation was observed on acid-treated fillets, however, controls had a distinct foul odor and microbial loads in excess of 10(6) CFU/g by day 8. On untreated fillets, L. monocytogenes counts did not increase during storage, perhaps due to competitive inhibition by normal catfish microflora. Hunter color analysis revealed lighter and yellower acid-treated fillets than untreated controls, with malic acid producing the least bleaching. The shelf life of refrigerated fillets increased when fillets were acid dipped. It remains to be established if this enhanced microbial quality also parallels sensory acceptability.

Bioadsorption phenomenon is more or less like a chemical reaction and several parameters are bound to affect the process. The pH, amount of adsorbent and agitation time influence the biosorptive potentiality. Hence, the present study on adsorption of Cr(VI) by activated Vetivera roots and Blue green algae Anabaena supports that it is an effective low cost adsorbent for the removal of Cr(VI) from plating effluent. Langmuir and Freundlich adsorption isotherm correlate the equilibrium adsorption data. In batch experiments both Vetiveria and Anabaena species were found to be cost effective biosorbent for the efficient removal of Cr(VI) from the effluent and comparatively Anabaena species was found to adsorb maximum Cr(VI) (88.86%) at a low contact time of 60 min. The data obtained from the experiments and modeling would prove useful in designing and fabricating an efficient treatment plant for Cr(VI) rich effluent.

Because land application of broiler litter is commonly made in the spring before cropping season and in the fall, it is essential to understand how environmental variations, such as temperature, affect the phosphorus (P) dynamics. A laboratory incubation study was conducted at Waste Management and Forage Research Unit, USDA-ARS with the objective of determining the effects of temperature and soil properties on water-soluble P (WSP), Mehlich 3 P, and P fractions in broiler litter-amended soils. Broiler litter was mixed with three soils (Leeper silty clay, Grenada silt loam, and Ruston sandy loam) at the rate of 10 Mg ha 21 . The mixtures were incubated at 188C, 258C, and 328C for up to 90 days and repeated three times. Soil samples were taken at eight time intervals (2, 5, 10, 15, 30, 60, and 90 days) and analyzed for water-soluble P and Mehlich 3-extractable P (MEP). Phosphorus also was fractionated chemically into inorganic and organic components by sequential extraction for soil samples taken at the end of incubation period (90 days). Water-soluble P decreased rapidly after a 15-day incubation in all soils for all temperatures and followed to a steady state to the end of incubation period. Averaged across temperatures, broiler litter application resulted in a significant increase in all fractions compared with controls. However, the increase was greater for inorganic than for organic fractions. The concentration of calcium (Ca)-P fraction was highest in calcareous Grenada soil, which suggests that the presence of carbonates influence the fate of P from applied broiler litter. The coarse textured Ruston contained a greater concentration of water-soluble P (WSP) than the other soils. At 328C, the concentration of plantavailable P fractions [bicarbonate inorganic P (IP) and hydroxide IP] significantly increased and WSP decreased. It is likely that the higher temperature (328C) promotes higher biological activity and lower water-soluble P than lower temperature.

The vacuum/steam/vacuum surface intervention process was applied to catfish surface inoculated with Listeria innocua. Studies were performed to determine the optimum process conditions of steam temperature, steam time, and number of cycles. Cycling the treatment significantly improved the microbiological kill. At the optimum conditions of steam time of 0.05 to 0.10 s at 143 Њ Њ Њ Њ ЊC and with 4 cycles, bacterial kill in excess of 2-log cfu/ml (colony forming units/ml) was attained. The surface intervention process should ensure that catfish reaching the consumer have greatly reduced levels or are free of Listeria contamination.