Textile wastewater biocoagulation by Caesalpinia spinosa extracts

Abstract

(Received: 2014/12/06 - Accepted: 2015/03/24)

The textile industry in Ecuador is still a matter of concern because of the inappropriate disposal of their effluents into the local water supply. The present research was carried out in Pelileo (Tungurahua-Ecuador) where textile wastewaters are discharged into waterways. An environmentally friendly solution to treat highly contaminated organic textile wastewaters is herein evaluated: a remediation process of biocoagulation was performed using extracts from the Caesalpinia spinosa plant also known as guarango or tara. It was determined that using C. spinosa extracts to treat wastewater has the same statistical effect as when applying a chemical coagulant (polyaluminum chloride 15%). Activated zeolite adsorbed color residuals from treated water to obtain turbidity removal more than 90%. A mathematical model showed that turbidity removal between 50-90% can be obtained by applying 25-45 g/L of guarango extracts and zeolite per 700 mL of textile wastewater. The natural coagulation using C. spinosa extracts produced 85% less sludge than polyaluminum chloride, and removed high organic matter content in the wastewater (1050 mg/L) by 52%.