Coliforms and Helminth Eggs Removals by Coagulation-Flocculation Treatment Based on Natural Polymers

Abstract

Wastewater from a municipal wastewater treatment plant (Mexico) was\rtreated by a coagulation-flocculation using natural gums. The residual water\rwas characterized in terms of organic load, and biological contaminants, i.e. total Coliforms (TC), fecal\rColiforms (FC) and helminth eggs (HE). The sample has values of 2.8 × 107 MPN/100 ml, 8.48 × 106 MPN/100 ml and 470 HE/L is regarded to TC, FC and\rHH, respectively. The HE identified in the wastewaters were Diphyllobothrium latum, Ascaris lumbricoides, Hymenolepis nana and Toxocara canis. From several gums, Hydroxypropyl\rtriammonium chloride guar gum (HPTAC-guar) was selected as the most adequate\rcoagulant-flocculant for the class of municipal wastewater (MWW). A diminution\rof 82% for TC, 94% for FC and 99% for HE was obtained. Besides, the reduction\rof chemical oxygen demand (COD) and turbidity removals were 46% and 39%\rrespectively. The natural gum mixed with Ca(OH)2, obtained removals\rof 52% for TC, 100% for HE, 47% for COD and 30% for turbidity.