Efficiency of using microbiological products for wastewater treatment in intensive white leg shrimp culture pond on sand floor

Abstract

Experiments on the use of microbiological products for wastewater treatment in the
intensive white leg shrimp culture ponds on sand floor were conducted with 4 different
treatments (T) . Pond C1, pond C2: using microbiological products with dosages: 5ppm
(T1), 10ppm (T2), frequency 5 days/time, 4 times in 20 days. Pond D2 (T3), pond D3 (T4):
using probiotics with the doses of 5ppm, 10ppm, frequency 7 days/time, 3 times in 21 days.
Microbiological products used in the treatments containing bacteria strains, such as: Bacillus
sp. with density in products was about 109 CFU per gram, Nitrosomonas sp., Nitrobacter sp.
and fungi Saccharomyces sp. with density in products was about 108 CFU per gram for each
type. Analysis of environmental parameters of wastewater before treatment in the experiments
showed that: pH = 8.2-8.3, NH4+=10.65-12.64 mg/l and total N = 21.51-23.18 mg/l were under
the allowable limits of QCVN 02–19:2014/ BNNPTNT and QCVN 40:2011/BTNMT; total TSS
=185-196 mg/l, COD =276.53-294.35 mg/l, BOD5=112.4-124.38 mg/l, total P=8.41-23.18 mg/l and total Coliform =6130-6700 MPN/100 ml, exceeded permissible limits of QCVNs. After 21
days of using microbiological inoculants to treat wastewater, the environmental parameters
that exceeded the permitted threshold were reduced, meeting the allowable limits of QCVN.
The result of comparing economic efficiency when using microbiological products at different
doses between experimental treatments showed that using a dosage of 5ppm products, at
the frequency of 7 days/time, in 3 times was able to treat wastewater in the intensive white
leg shrimp culture ponds on sand floor. It is suggested that the establishments can apply this
study result in intensive shrimp culture ponds on sand floor