Elevated CO₂ Concentration On Surface Water Quality And Carassius Auratus Research

Carbon Dioxide Capture and Storage is an effective way to reduce carbon dioxide levels in the atmosphere, but there is the risk of leakage during the CCS in practice. Once the sequestration of carbon dioxide leaks through water, there will be some significant impacts on the water quality, aquatic ecosystem and fisheries of the leakage areas.Therefore, the study of CCS sealed leak impacts on water quality and fish, the basis of preventing CO2 leakage of CCS project and the potential effects on water and fish, is of great theoretical and practical significance.The experiment is based on aquarium, and we make CO2 gas bubbled into the aquarium. Crucian carp is choosed as experiment object. The research on the water quality of CO2, median lethal experiment of fish, and blood gas analysis obtained the following main conclusions.(1)Three indicators which include pH, DO and C-Ba(OH)2 are chosen to indicate the influence of CO2 to the surface water. When CO2 is bubbled into water, the concentration of pH and DO increases while the concentration of C-Ba(OH)2 decreases.both of the three can balance quickly. And the more CO2 is C-Ba(OH)2, the shorter it takes to achieve balance. The final concentrations of pH and DO reduce with the increasing of CO2, while C-Ba(OH)2 changing with opposite trend. Comparing the indicator in clean water and fishbowl water under the same CO2 concentration, we can see pH and concentration of C-Ba(OH)2 increases and concentration of DO decreases.(2)In acute toxicity experiments, the mortality of the carp increases as time passed by under the same CO2 flow rate; At the same time, the crucian carp’s mortality rate increased with the increase of C02 flow rate. The half lethal flow of Crucian carp at 24 h,48 h,72 h and 96 h are 0.4287 L/min,0.2297 L/min,0.1454 L/min and 0.1231 L/min.(3) the blood pH,PCO2 and PO2 of the crucian in the water with CO2 bubbled in are bigger than those in purify water. The concentration of Ka+ and Ca2+ decreases with CO2 increasing while Na+ and lactate changing in opposite trend. The difference of HCO3-concentration between measured and standard valau is beyond zero, which indicate the influence of CO2 to crucians respiration action.Six Steps for blood gas analysis are used to analyse the major indicators of blood gas analysis of a comprehensive evaluation. The evaluation results shows that all the fish have respiratory acidosis In addition, fish of the time nodes 6h、12h、24h �'� 48h of the 20mL/min flow experimental groups,6h and 12h of the 40mL/min flow experimental groups,6h of the 60mL/min flow experimental groups, and 6h and 12h of the 100mL/min flow experimental groups are all judged Low anion gap (AG) metabolic acidosis.