Received: 31-08-2020 / Accepted: 30-10-2020
Thestudywasconductedtoassesswaterqualityinsnakeheadfishfarms inTraOndistrict,VinhLongprovinceusingwastewaterqualityparameterssuchaspH,temperature,dissolvedoxygen(DO),biochemicaloxygendemand(BOD),chemicaloxygendemand(COD),totalnitrogen(TN),andtotalphosphorus(TP).Watersampleswerecollectedinsnakeheadfishpondswiththreestockingdensitiesof60fish/m2,80fish/m2,and100fish/m2,fromthestartoftheculturetimetoharvest.Theresultsshowedthattemperaturewasstable,pHinthepondwaterwasslightlyacidic.Thedissolvedoxygenwasverylow.ThemeanconcentrationsofBOD(12.9-32.7mg/l),COD(35.9-70.34mg/l),totalnitrogen(7.0-15.05mg/l),totalphosphorus(0.59-2.46mg/l)increasedduringthecultureperiodandwasenhancedathigherstockingdensities.Inapondwithadensityof100fish/m2,concentrationsofBODandCODinthefourthmonthexceededQCVN08-MT:2015/BTNMT.ThecalculationresultsshowedthattheloadsofBOD,COD,TNandTPwere2.16-3.86;5.13-6.93;1.21-1.66;0.213-0,296kg/m2/season,respectively.Thestudyresultsshowedthattheconcentrationsoforganicmatterandnutrientswererelativelyhighinsnakeheadfishpondwastewater,soitneedstobetreatedbeforebeingdischargedintotheenvironment.