Research On The Biological Toxicity In The Coexistence Of Multiple Drinking Water Toxicological Indexes

In order to protect the health of the people's drinking water,China has formulated the"Sanitation Standard for Drinking Water"GB5749-2006.The current standards set limits for toxicological indexes of various types to protect drinking water safety.There are often many different toxicological indexes in drinking water.In order to study the changes in the biotoxicity of various toxicological indexes,which single concentration met the requirements of the"Healthy Standard for Drinking Water",and the impact on the safety of drinking water,we conducted the experiment to explore changes in biotoxicity and its impact on drinking water safety when indexes of organic chemicals,pesticides,and heavy metals coexisted at the limit concentration stipulated in the"Sanitation Standard for Drinking Water".In this study,we selected organic chemicals indexes:CH₂Cl₂,CH₂O,CCl₄,C₈H₁₀,C₈H_8,pesticides indexes:C₃H₈NO₅P,C₁₀H₁₉O₆PS₉,C₈N₂Cl₄,heavy metals indexes:Cd³⁺,Mn²⁺,and prepared the single index solution and indexes coexisting solutions as the tested samples according to the limit concentration stipulated in the"Sanitation Standard for Drinking Water".By adopting the algae infrared technology and its supporting evaluation methods independently researched and developed by the research group,we tested whether each single index and each indexes's coexisting solution is biologically toxic to algae,and analyzed the coexistence type,coexisting numbers,total indexes'concentration on the occurrence and impact of biological toxicity.The conclusions of this study are as follows:?1?The single indexes of five organic chemicals and three pesticide had no response to algal infrared technology text,which indicated that the limit of the single toxicological index does not produce biological toxicity.This result met with the premise of drinking water safety when a single index is limited.?2?The response results were found in two and above indexes coexistence in the same or heterogeneous coexistence combinations.The proportion of responding to each type of combination was as follow:the organic chemicals combinations was 73.08%,the pesticides combinations was 100%,the combinations of pesticides and heavy metals was 44.44%,the combinations of pesticides and organic chemicals was 44.44%,the combinations of organic chemicals and heavy metals was 66.67%,the combinations of heavy metals,pesticides and organic chemicals was 62.69%.Which indicated that the multi-coexistence of toxicological indexes at the limit can produce biological toxicity,and there is a certain risk of drinking safety.?3?The biological toxicity of toxicological indexes coexisting was positively correlated with coexisting numbers and the total concentration of coexisting combinations.Algae response rates for different coexisting numbers of toxicological indexes were that binary was 25%⁷0%,ternary was 38%¹00%,quaternion was58%¹00%,quinary was 100%,six kinds was 100%.The Pearson correlation coefficients for the total concentration of various types of coexisting combinations and their cumulative response to total algae were:the organic chemicals coexistence combination'r=0.874,the pesticides coexistence combination'r=0.882,the heterogeneous indexes coexistence combination'r=0.677.The biotoxicity of the test solution on algae was significantly increased in the following cases:The total concentration of organic chemicals?0.542 mg/L or coexisting numbers?4,the total concentration of pesticides?0.710 mg/L or coexisting numbers?2,the total concentration of heterogeneous indexes?1.705 mg/L.?4?The influence of each index on algae response results were as follows:Organic chemical combinations was CH₂O=CH₂Cl₂=CCl₄>C₈H₈>C₈H₁₀,pesticides combinations was no significant difference,heterogeneous combinations was Mn²⁺>CH₂Cl₂>C₃H₈NO₅P>Cd³⁺>CH₂O>C₁₀H₁₉O₆PS₂.There is a greater risk of biological toxicity on the pesticides combinations,the organic chemical combinations of CH₂O-containing and the heterogeneous combinations of Mn²⁺-containing,which should be noted.?5?Based on this test data,the feasibility of the algae infrared technology was re-verified:the algae response rate of a single indicator was 0%,the algae response rate of the highest coexisting numbers combination was 100%,and there was a positive correlation between the proportion of response results and coexisting numbers,indicating that the technology was controllable.The total reproducibility of the first test result was 82.6%,which was reproducible.The final test results of each combination were reproducible,indicating that the technology was stable.In summary,the technology was controllable,reproducible and stable,validating again that this technology can be used for rapid detection of biological toxicity in drinking water.