Details

REMOÇÃO DE NUTRIENTES DE SISTEMAS DE CULTIVO DE CAMARÕES COM BIOFILME ASSOCIADO À BACIA DE SEDIMENTAÇÃO. REMOÇÃO DE NUTRIENTES DE SISTEMAS DE CULTIVO DE CAMARÕES COM BIOFILME ASSOCIADO À BACIA DE SEDIMENTAÇÃO.

by D'Avila, Graziele

Abstract (Summary)
The shrimp farms with high densities, release effluents with high loads of nutrients, causing water quality degradation. This creates concern about the release of effluents of cultures. In this work, we aimed to assess the efficiency of an integrated system of settling ponds and biofilm in the nutrients removal. The study was conducted in an openenvironment, for 45 days. We used three treatments: a) treatment TC, without vertical substrate b) treatment T50, inner surface of the tanks increased by 50% and c) treatmentT100, inner surface of the tanks increased by 100%. The tanks were supplied with the effluent of a shrimp culture. Daily were measured pH, salinity, dissolved oxygen (OD) andtemperature. During the first 15 days the collections were made every 5 days, after that period the collection of water were every 2 days, and biofilm daily. Analyzes of ammoniumwere performed on all days of sampling. Analyzes of nitrite, nitrate and phosphate, were made of all collections until the 15 th day, and after this period every 6 days. Of the biofilm, the dry matter was determined in every day collected. The chlorophyll-a reviewed every 5 days. And the estimate of ciliates and flagellates on days 5, 10, 15 and 20. The results showed that the treatments TC and T50 reduced more than 80% of ammonium and phosphate in 10 days. The treatment T100 in the first few days showed the lowest values of OD, pH and chlorophyll-a, causing a peak in the concentrations of ammonium and phosphate, delaying the removal of these nutrients. For all treatments after the 15 th day the concentration of phosphate has an elevation which remained until the end of the experiment. Concluding that to double the area available for setting biofilm there is a difficulty in circulation in tanks, and an increase in microbial respiration, making the system less efficient. Already the settlement ponds without biofilm, or with 50% increase in substrate, both are effective. Therefore, the effluent must remain in the basin settling ponds for a minimum time of 10 days but not exceeding 15 days, for no elevation in the levels of phosphate. The shrimp farms with high densities, release effluents with high loads of nutrients, causing water quality degradation. This creates concern about the release of effluents of cultures. In this work, we aimed to assess the efficiency of an integrated system of settling ponds and biofilm in the nutrients removal. The study was conducted in an openenvironment, for 45 days. We used three treatments: a) treatment TC, without vertical substrate b) treatment T50, inner surface of the tanks increased by 50% and c) treatmentT100, inner surface of the tanks increased by 100%. The tanks were supplied with the effluent of a shrimp culture. Daily were measured pH, salinity, dissolved oxygen (OD) andtemperature. During the first 15 days the collections were made every 5 days, after that period the collection of water were every 2 days, and biofilm daily. Analyzes of ammoniumwere performed on all days of sampling. Analyzes of nitrite, nitrate and phosphate, were made of all collections until the 15 th day, and after this period every 6 days. Of the biofilm, the dry matter was determined in every day collected. The chlorophyll-a reviewed every 5 days. And the estimate of ciliates and flagellates on days 5, 10, 15 and 20. The results showed that the treatments TC and T50 reduced more than 80% of ammonium and phosphate in 10 days. The treatment T100 in the first few days showed the lowest values of OD, pH and chlorophyll-a, causing a peak in the concentrations of ammonium and phosphate, delaying the removal of these nutrients. For all treatments after the 15 th day the concentration of phosphate has an elevation which remained until the end of the experiment. Concluding that to double the area available for setting biofilm there is a difficulty in circulation in tanks, and an increase in microbial respiration, making the system less efficient. Already the settlement ponds without biofilm, or with 50% increase in substrate, both are effective. Therefore, the effluent must remain in the basin settling ponds for a minimum time of 10 days but not exceeding 15 days, for no elevation in the levels of phosphate.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Luis Henrique da Silva Poersch; Wilson Francisco Britto Wasielesky Junior; Paulo Cesar Oliveira Vergne de Abreu; Osvaldo Luis Vieira Faria

School:Fundação Universidade Federal do Rio Grande

School Location:Brazil

Source Type:Master's Thesis

Keywords:biofilme effluent treatment settling ponds biofilm CARCINOCULTURA

ISBN:

Date of Publication:03/31/2008

© 2009 OpenThesis.org. All Rights Reserved.