Microbial, chemical and physical aspects of citrus waste composting.

Citrus waste supplemented with calcium hydroxide and with a C/N ratio of 24:1, pH of 6.3 and moisture content of 60% was composted by piling under shelter. With regular turning over of the pile and replenishment of moisture, the thermic phase lasted for 65-70 days and composting was completed after 3 months. Compost thus prepared had an air-filled porosity of 14%, water-holding capacity of 590 ml l(-1), bulk density of 1.05 g cm(-3) and conductivity of 480 mS m(-1). Phosphorus content (in mg l(-1)) was 15, potassium 1,170, calcium 362, magnesium 121, sodium 32, chloride 143, boron 0.31, and water-soluble nitrogen and organic matter 126 and 4788, respectively. Total carbon amounted to 8.85% and total nitrogen to 1.26% of the dry weight, giving a C/N ratio of 7. Mature compost showed some, but acceptable, levels of phytotoxicity. Raw citrus waste was predominantly colonised by mesophilic yeasts. Thermophilous microorganisms present during the thermic phase mainly comprised the bacterial species Bacillus licheniformis, B. macerans and B. stearothermophilus and, to a lesser extent, fungi such as Absidia corymbifera, Aspergillus fumigatus, Emericella nidulans, Penicillium diversum, Paecilomyces variotii, Rhizomucor pusillus, Talaromyces thermophilus and Thermomyces lanuginosus. Bacteria prevalent in the final product included B. licheniformis, B. macerans, Proteus vulgaris, Pseudomonas aeruginosa, P. fluorescens, P. luteola and Serratia marcescens, whereas fungi isolated most frequently comprised Aspergillus puniceus, A. ustus, E. nidulans. Paecilomyces lilacinus, T lanuginosus, yeasts and a basidiomycetous species, probably Coprinus lagopus.

Chemical and microbiological parameters in New Orleans floodwater following Hurricane Katrina.

Hurricane Katrina, rated as a Category 4 hurricane on the Saffir-Simpson scale, made landfall on the U.S. Gulf Coast near New Orleans, Louisiana on Monday, August 29, 2005. The storm brought heavy winds and rain to the city, and several levees intended to protect New Orleans from the water of Lake Pontchartrain were breached. Consequently, up to 80% of the city was flooded with water reaching depths in excess of three meters in some locations. Research described in this paper was conducted to provide an initial assessment of contaminants present in floodwaters shortly after the storm and to characterize water pumped out of the city into Lake Pontchartrain once dewatering operations began several days after the storm. Data are presented which demonstrate that during the weeks following the storm, floodwater was brackish and well-buffered with very low concentrations of volatile and semivolatile organic pollutants. Dissolved oxygen was depleted in surface floodwater, averaging 1.6 mg/L in the Lakeview district and 4.8 mg/L in the Mid-City district. Dissolved oxygen was absent (< 0.02 mg/L) at the bottom of the floodwater column in the Mid-City district 9 days afterthe storm. Chemical oxygen demand (Mid-City average = 79.9 mg/L) and fecal coliform bacteria (Mid-City average = 1.4 x 10(5) MPN/100 mL) were elevated in surface floodwater but typical of stormwater runoff in the region. Lead, arsenic, and in some cases, chromium, exceeded drinking water standards but with the exception of some elevated Pb concentrations generally were typical of stormwater. Data suggest that what distinguishes Hurricane Katrina floodwater is the large volume and the human exposure to these pollutants that accompanied the flood, rather than very elevated concentrations of toxic pollutants.

The nutritional composition of South African eggs.

Samples of hens' eggs produced throughout South Africa during the winter and summer of 1990 were analysed for nutrient content to obtain representative values for inclusion in food tables intended for local use. Proximate analyses and vitamin, mineral, fatty acid and amino acid determinations were carried out on all the samples. When the analysed values obtained for whole eggs, egg yolks and egg whites were compared with values listed in the Research Institute for Nutritional Diseases food tables, a number of differences were found. With regard to the inclusion of eggs in diets in general, the cholesterol content of whole eggs was found to be 23.5% lower and the total fat and saturated fatty acid contents 9% and 10% lower, respectively, than the listed values. The eggs were found to be rich sources of protein of animal origin, all the essential amino acids, thiamine, riboflavin, pantothenic and folic acids, vitamin B12, biotin, vitamin D3, vitamin E and phosphorus. Eggs are readily available and inexpensive and should be included in the diets of young children, adolescents, pregnant and breastfeeding women, adults, the elderly and particularly those of all ages who are undernourished.