Characteristics of “Black Water” in Lung Ngoc Hoang Natural Reserve, Phung Hiep District, Hau Giang Province, Vietnam

Abstract

The study was conducted to evaluate the characteristics of black

water arising in the rainy season at Lung Ngoc Hoang Nature

Reserve, Phung Hiep District, Hau Giang Province. Water samples

were collected at the strictly protected area and the ecological

rehabilitation area of Lung Ngoc Hoang Nature Reserve. Black

water is evaluated using the parameters of temperature, turbidity,

DO, TSS, H2S, EC, BOD, COD, NH4

+

-N, NO2

-

-N, NO3

-

-N, PO4

3-

-P,

SO4

2-

, TN, TP, Fe2+, Al3+, lignin, and coliform. The values of these

parameters are compared with those in QCVN 08-MT:

2015/BTNMT, column A1. The study results showed that black water

appears in rainy months from June to October from forest areas plot

6 and plot 85 where are small channels and poor flow. The results

of water quality analysis showed that BOD, COD, TSS, TP and TN

parameters all exceeded the allowable thresholds, especially DO

was very low compared to the standard from 20 to 21 times. Al3+ and

Fe2+ are both higher than the permissible limits. Water is seriously

polluted and can affect aquatic life in the study area.