THE RESISTANCE AND LIVESTOCK WASTEWATER TREATMENT EFFICIENCY OF UMBRELLA SEDGE (Cyperus alternifolius) AND CUMBUNGI (Typha orientalis) AFTER BIOGAS PROCESS

Abstract

Basing on characteristics of wastewater quality after biogas process in pig farmings, two aquatic plant species had been selected for study in constructed wetland treatmenting piggery wastewater. An experiment was conducted to evaluate the tolerance of Cyperus alternifolius and Typha orientalis to COD, NH₄⁺ and pH in different levels via monitoring plant growth. The results indicated that two selected plants can resist to pH of 5 - 9, NH₄⁺ from 50 - 250 mg/L and tolerate to COD up to 1000 mg/L. The average removal efficience of the TSS, COD, NH₄-N, T-N of Cyperus alternifolius was 85.9%, 76.8%, 76.8%, 66.8%, respectively while the result by Typha orientalis was 85.4%, 66.5%, 61.5%, 52.0%, respectively. The water quality after treatment met the Vietnamese standards for livestock wastewater (QCVN62/2016-BTNMT, column B), and besides, Cyperus alternifolius performed the higher ability to removal the nutrients and organic matter thanks to its optimal resistance level and treatment efficiency.