[Physiological responses of tubificidae to heavy metal chromium stress].
Huan Jing Ke Xue
; 35(11): 4205-11, 2014 Nov.
Article
em Zh
| MEDLINE
| ID: mdl-25639096
ABSTRACT
Tubificidae is now used in the wastewater treatment systems to successfully minimize the sludge production, which has been proved an effective, economical and sustainable technology. But the excess sludge inevitably contains a variety of heavy metals, especially the sludge from industrial wastewater treatment plant. In order to apply tubificidae to these systems, Chromium was selected as pollutant object and the physiological responses of tubificidae to Chromium were studied in this paper. Acute toxicity was analyzed and Median lethal concentrations (LC50) were determined over 96 h periods for Cr. Results indicated that 24 h LC50 and 96 h LC50 were 7.94 mg x L(-1) and 0.49 mg x L(-1), respectively. The duration f tubificidae in Cr solution decreased with increasing Cr concentration. Under the Cr stress, a highest respiration rate was obtained when the concentration of Cr(VI), temperature, pH and DO was 2.50 mg x L(-1), 26 degrees C, 6.0 and 6.0 mg x L(-1), respectively. The order of these factors was the concerntration of Cr(VI), temperature, DO and pH. The respiration experiments demonstrated that low concentration (< 2.50 mg x L(-1)) of Cr could promote the respiration rate of tubificidaes. On the other hand, when the concentration of Cr was 8.00 mg x L(-1), it could remarkably inhibit the respiratory rates of tubificidae.
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Base de dados:
MEDLINE
Assunto principal:
Oligoquetos
/
Cromo
Idioma:
Zh
Ano de publicação:
2014
Tipo de documento:
Article