Efficiency evaluation of moringa seeds in the shrimp ponds effluents treatment

Abstract

The treatment of effluents of the aquiculture has been seen as a form of reducing the negative impacts of the activity. The present study was carried with the aimed of evaluate the efficiency of the aqueous extract of Moringa oleifera seeds in the treatment of shrimp culture effluent. So, effluents of Litopenaeus vannamei ponds were cropped in aquariums and were treated with aqueous extract of moringa seed, in a quantity which kept relation of 0.5; 1.0 and 2.0 seeds L-1. Before and during 24 hours after addition of extract, the physical-chemical characteristics of effluents were monitored. Flocculent process could be seen after the addition of the extract and it reached the maximum point of clarification 24 hours late. Dissolved oxygen reached concentration close to zero after 20 hours. The alkalinity and pH decreased with doses and contact duration, but the values were between 168.0 and 153.3 mg L-1 and 7.93 and 7.13, respectively. Carbonic gas remained between 13.0 and 20 mg L-1, hardness between 328 and 296 mg L-1 and electrical conductivity between 1346.67 and 1270.33 mS cm-1. The larger dose promoted a light increase in potassium, sulfate, bicarbonate and a light decrease in carbonate and chlorine.