Análise da contaminação parasitária em compostos orgânicos produzidos com biossólidos de esgoto doméstico e resíduos agropecuários

Abstract

RESUMO Este estudo avaliou a contaminação por ovos de helmintos, cistos e oocistos de protozoários em compostos

Parasitological Contamination in Organic Composts Produced with Sewage Sludge

“…Study conducted in Brazil had as objective to evaluate the contamination by eggs, cysts and oocysts of protozoa in organic compounds, using sewage sludge and agricultural residues, before and after heat treatment (Duarte et al, 2008). In the experiment conducted in Montes Claros, Minas Gerais, Brazil, 25 different organic compounds were prepared, with approximate volume of 0.5 cubic meters.…”

“…In the experiment conducted in Montes Claros, Minas Gerais, Brazil, 25 different organic compounds were prepared, with approximate volume of 0.5 cubic meters. The materials were kept during the first fifteen days, and daily irrigated and raked (Duarte et al, 2008). The compounds were prepared with carbon /nitrogen relation of 25:1, 30:1, 35:1, 40:1 and 45:1.…”

“…Faeces were from 40 Holstein cows with an average of 5.5 years. Each compound received 220g of rock phosphate, 21kg of gypsum and 21kg of limestone (Duarte et al, 2008). First two samples of 500g sewage sludge were collected from the Juramento Town, in North of Minas Gerais, Brazil.…”

“…The sludge was collected in the dry bed of the sewage treatment station of this local that uses flow anaerobic reactor ascending. The physical and chemical analysis of sewage sludge were performed according to techniques recommended by Tedesco et al (1995) and showed pH-H 2 0 4.8 and levels of nitrogen, carbon and humidity of 2.4, 9.4 and 6.0%, respectively (Duarte et al, 2008). Subsequently, were collected 500g samples from compounds with fifteenth day of composting, avoiding contamination from one compound to another and put them in plastic bags, clean and free from contamination by parasites.…”

“…The effectiveness of heat treatment and their uniformity was checked in all the materials produced and three different samples from several parts of these compounds corresponding to the parts A, B and C, were collected after twenty-two days of thermal treatment. Was obtained 500g for each sample (A, B and C), using the same hygienic measures to prevent the contamination (Duarte et al, 2008).…”