The removal of sanitary indicator bacteria (total coliforms, faecal coliforms, and faecal streptococci) was studied in an experimental constructed wetland system consisting of (1) a 2-m3 three-chamber sedimentation tank, (2) a 5 m2 vertical flow constructed wetland, (3) a filter-unit with calcite aimed at removing phosphorus, and (4) a 10 m2 vertical flow constructed wetland. The indicator bacteria were enumerated before and after each unit of the wetland system during four monitoring episodes with different loading conditions. At a hydraulic loading rate of 520-1,370 mm/d, the first-stage vertical flow beds removed about 1.5 log-units of total coliforms, 1.7 log-units of faecal coliforms and 0.8 log-units of faecal streptococci. In the second stage bed receiving lower loadings both in term of concentration and quantity (260-690 mm/day), the eliminations were lower. It was not possible in the present study to identify any seasonal effects, but no measurements were done during summer. Recycling of treated effluent back to the sedimentation tank did not affect elimination. Area-based rate constants for the vertical flow wetland receiving effluent from the sedimentation tank averaged 3.2 m/d for total coliforms, 3.3 m/d for faecal coliforms and 2.1 m/d for faecal streptococci. The rate constants depended on loading rates. It is suggested that filtration is a major removal mechanism for bacterial indicator organisms in vertical flow constructed wetland systems.
Acid hydrolysis of dried fodder's yeast Candida utilis was studied by a central composite design taking into account three independent variables: temperature (105–165C), processing time (30–70 min) and HCl concentration (7.5–17.5%). Response variables were: color, dry matter solubilization and amino nitrogen. Temperature was the most significant variable followed by acid concentration and processing time. Response surfaces were generated from fitted polynomials. Higher temperatures to prevent amino nitrogen degradation were not investigated. As different effects were found for color development and amino nitrogen, a combined function was tested which yields the behavior of all responses simultaneously. The best conditions were: 150C, 15% HCl and 40 min. After neutralization with 6N NaOH and centrifugation, the raw sauce was supplemented with 12% NaCl, 0.1% monosodium glutamate, 2% vinegar and 0.1% sodium benzoate and evaluated by sensory analysis for eight distinct attributes. Imitation sauce from yeast was at least as good as commercial hydrolyzed soybean sauce.
Animal production from sugarcane co-products is an alternative to diminish hunger and malnutrition in many sugar producing countries and to overcome low sugar prices. Due to the big differences of local market prices and cost considerations of feed, animal products and energy, average international market prices forecast by OECD-FAO have been used. The aim was to evaluate the comparative economical efficiency of milk, beef cattle and swine meat based on bagasse, blackstrap molasses and 'B' molasses respectively according to reported results and compared with their alternative uses. The net value of bagasse for producing milk has been estimated in the range of 20-30$/tonne, and depends heavily on the price of non sugarcane ration components and transportation costs, and is lower than its use for electricity generation at the sugar mill. Blackstrap molasses gives negative revenue when used for fattening cattle as compared with its export price or ethanol production. Swine fattening based on 'B' molasses shows a better revenue than converting it to sugar and blackstrap molasses for export. The obtained values do not take into account important factors affecting the economical revenue of each alternative, but may serve as a primary reference for the use of the sugarcane co-products for different purposes.
An evaluation of different kinds of treatments to enhance the biological degradability of sugarcane bagasse‐pith is presented. NaOH treatment, gamma ray irradiation and inoculation of the material with the white rotting mold Sporotrichum pulvurulentum and combinations of above mentioned alternatives were evaluated by measuring the increase in water solubility and the susceptibility to cellulose degradation as well as by the change in the chemical composition of the material.NaOH treatment at 6% concentration and the combined treatment with NaOH at 2% and further fermentation with the mold gave the best results. Gamma irradiation up to a dose of 60 Mrad didn't show an important effect.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.