水质监控技术-Water quality monitori

水质监控技术Waterqualitymonitoringtechnology--水质监控技术课程组WaterqualitymonitoringTechnologyCoursegroup养殖水质亚硝酸盐氮的检测与调控Detectionandregulationofnitritenitrogeninaquaculturewater《水质监控技术》课程WaterQualityMonitoringTechnology水体中亚硝酸盐氮对养殖生物的毒性及影响因素

Toxicityandinfluencingfactorsofnitritenitrogeninwatertoaquacultureorganisms

学习目标Learningobjective掌握水体亚硝酸盐氮的毒性机理和养殖生物的中毒表现；Tounderstandthetoxicmechanismofnitritenitrogeninwaterandthetoxicmanifestationsofaquacultureorganisms;掌握水体亚硝酸盐氮毒性的影响因素。Tounderstandtheinfluencingfactorsofnitritenitrogentoxicityinwater.学习目标1.Learningobjective1学习目标2.Learningobjective2水体亚硝酸盐氮的毒性机理Toxicitymechanismofnitritenitrogeninwater.亚硝酸盐会影响鱼虾蛙等动物体内抗氧化酶的活性，同时也影响溶菌酶的活力，从而降低动物的免疫能力；Nitritecanaffecttheactivityofantioxidantenzymesandlysozymeinfish,shrimp,frogandotheranimals,thusreducingtheimmunityofanimals.养殖水体亚硝酸盐浓度过高时，可通过鱼虾类体表的渗透与吸收作用进入血液，使血液中的亚铁血红蛋白被氧化成高铁血红蛋白，由于高铁血红蛋白不能与氧气结合，从而导致血液载氧能力下降甚至丧失。Whentheconcentrationofnitriteinaquaculturewateristoohigh,itcanenterthebloodthroughtheinfiltrationandabsorptionofthebodysurfaceoffishandshrimp,sothattheferrohemoglobininthebloodisoxidizedtomethemoglobin.Becausemethemoglobincannotcombinewithoxygen,theoxygencarryingcapacityofthebloodisreducedorevenlost.不同浓度的亚硝酸盐对鱼虾的影响Effectsofdifferentconcentrationsofnitriteonfishandshrimp.0~0.1㎎/L(以氮计)(innitrogen)正常养殖水体的亚硝酸盐浓度低于0.1㎎/L，鱼虾水生动物在此条件下，能够正常自由地生活，不会造成任何健康损害。Theconcentrationofnitriteinnormalaquaculturewaterislowerthan0.1㎎/L,andaquaticanimalsoffishandshrimpcanlivenormallyandfreelyundersuchconditionswithoutcausinganyhealthdamage.不同浓度的亚硝酸盐对鱼虾的影响Effectsofdifferentconcentrationsofnitriteonfishandshrimp.0.1~0.5㎎/L(以氮计)(innitrogen)

养殖对象的生理功能紊乱，影响其生长或引起其他疾病的发生，造成鱼、虾慢性亚硝酸盐中毒，表现为摄食量下降，生长不明显，活动力减弱，鳃及鳃盖内表面血管呈暗紫红色，呼吸困难，游动缓慢，骚动不安或反应迟钝，同时体表呈现不正常的色泽。Thephysiologicaldisordersoftheculturedobjectsaffecttheirgrowthorcausetheoccurrenceofotherdiseases,resultinginchronicnitritepoisoningoffishandshrimp,whichismanifestedasdecreasedfoodintake,insignificantgrowth,weakenedactivity,darkpurpleredbloodvesselsontheinnersurfaceofthegillsandgillcovers,dyspnea,slowswimming,agitationorslowresponse,andabnormalcoloronthebodysurface.

亚硝酸盐中毒的对虾外表症状有黑鳃、黄鳃、肝胰脏模糊不清晰，解剖后显微镜观察，鳃丝肿胀充水，甚至糜烂粘有污物，肠道充血发炎，肝胰脏空泡甚至糜烂。Theoutwardsymptomsofnitritepoisoningofshrimpincludeblackgills,yellowgillsandvaguehepatopancreas.Microscopicobservationafterdissectionshowsthatthegillfilamentsareswollenandfilledwithwater,andthereareevenfilamentsstickytoerosion,intestinalcongestionandinflammation,hepatopancreasvacuoleandevenerosion.黑鳃病不同浓度的亚硝酸盐对鱼虾的影响Effectsofdifferentconcentrationsofnitriteonfishandshrimp.>0.5㎎/L(以氮计)(innitrogen)鱼中毒症状继续加剧，体力衰退，游泳无力，某些代谢器官功能衰竭，并大量死亡。Thesymptomsoffishpoisoningcontinuetoworsen,withphysicaldecline,inabilitytoswim,failureofcertainmetabolicorgans,andalargenumberofdeaths.亚硝酸盐偏高的危害更主要是表现在对虾蜕壳期。会引起蜕壳期的对虾因为缺氧、中毒而蜕壳不遂，出现大量软壳虾，常常引起蜕壳期大量“偷死”。Theharmofhighnitriteismainlymanifestedinthemoultingperiodofprawn.Itwillcausetheshrimpsinthemoultingperiodtomoultbecauseofhypoxiaandpoisoning,andtherearealargenumberofsoft-shellshrimps,whichoftencausealargenumberof"stealingdeath"inthemoultingperiod.急性中毒和浮头很相似，都呈现缺氧症状，但是两者最大的区别是亚硝酸盐中毒在太阳出来后鱼还不下水，有时甚至整天都在水面活动，晴天也不例外。Acutepoisoningandfloatingheadareverysimilar,bothpresenthypoxiasymptoms,butthebiggestdifferencebetweenthetwoisthatnitritepoisoningfishdonotgointothewaterafterthesuncomesout,sometimesevenalldaylongonthesurfaceofthewater,evenonsunnydays.不同浓度的亚硝酸盐对鱼虾的影响Effectsofdifferentconcentrationsofnitriteonfishandshrimp.亚硝酸盐的安全浓度和致死浓度Safeandlethalconcentrationsofnitrite.品种variety安全浓度(mg/L)Safeconcentration品种variety致死浓度(mg/L)Lethalconcentration一般淡水鱼Generalfreshwaterfish<1虹鳟Rainbowtrout0.24一般海水鱼CommonMarinefish<1鲤鱼carp2.6一般海水虾Commonseashrimp0.25草鱼Grasscarp4.6罗氏沼虾Macrobrachium

rosenbergii0.1罗非鱼tilapia16水生动物不同种类、品种及个体对亚硝酸盐的耐受性不同，因而，对不同种类鱼虾蟹的安全密度差异很大。为确保鱼虾蟹的安全（尤其在育苗期），亚硝酸盐含量应控制在0.1㎎/L以下。Differentkinds,varietiesandindividualsofaquaticanimalsTolerancetonitriteisdifferent,so,Thesafetydensityofdifferentkindsoffish,shrimpandcrabsispoorIt'sabigdifference.Toensurethesafetyoffish,shrimpandcrabs(especiallyIntheseedlingstage),nitritecontentshouldbecontrolledBelow0.1㎎/L.影响亚硝酸盐毒性的因素Factorsinfluencingnitritetoxicity溶氧：

低氧会使动物受到高浓度亚硝酸盐影响的风险增加Dissolvedoxygen:Lowoxygenputsanimalsatincreasedriskofhighconcentrationsofnitrite氨氮：氨氮浓度高会增加亚硝酸盐的毒性Ammonianitrogen:Highconcentrationsofammonianitrogenincreasethetoxicityofnitrites氯化物：水中氯化物浓度高可阻止动物对亚硝酸盐的吸收，降低毒性氯化物与亚硝酸盐之比为10:1时可消除亚硝酸盐对沟鲶的毒性Chloride:Highchlorideconcentrationinwatercanpreventtheabsorptionofnitritebyanimals,andreducethetoxicityofnitritetocatfishwhentheratio