Toxic Effects Of Typical Industrial Wastewater And Chemical Mixtures On Organisms

In this study, the toxic effects of three typical wastewater (pharmaceutical wastewater pigment wastewater and petrochemical wastewater) and cadmium (Cd) and sulfamethoxazole (SMX) was investigated using Photobacterium Phosphoreum and Daphnia magna, and influences of different dissolved organic matters, fulvic acids (FA) and humic acids (HA),on toxic effects of Cd and SMX were compared.Firstly, the acute toxicity of pharmaceutical wastewater on Photobacterium Phosphoreum and Daphnia magna was investigated. The main toxic substances of petrochemical wastewater in different treatment processes was explored using toxicity identification evaluation method. The correlation between wastewater toxicity and physical-chemical indexes was explored, and the reproduction toxicity of pigment effluent on Daphnia magna was also studied. The results showed that, compared to Daphnia magna, Photobacterium Phosphoreum was more sensitive to the toxicity of pharmaceutical wastewater. The results of correlation analysis between petrochemical wastewater effluent toxicity and its physical-chemical indexes and toxicity identification evaluation tests showed that main toxic substances of petrochemical wastewater was organic pollutants. Pigment effluent will increase the offspring number of Daphnia magna, but does not affect its time of first reproduction and births of breeding.Secondly, the single and joint toxicity of SMX and Cd was studied using Photobacterium Phosphoreum. Moreover, the joint toxicity of Cd and SMX were evaluated by using the toxic unit (M), addictive index (AI) and isobologram. The results showed that, the 15min-EC50 values of Cd and SMX to Photobacterium Phosphoreum were 27 mg/L and 100 mg/L, and Cd was more dangerous than SMX. The results of three kinds of assessment methods for evaluating joint toxicity of Cd and SMX were same, which indicated that the joint effects were antagonism when Cd and SMX mixed with the ratio of 1:1,1:2 and 1:4 and combined effects were synergism when the ratio were 2:1 and 4:1.Finally, the influences of two kinds of dissolved organic matters (FA and HA) in a certain concentration (25 mg/L) on single and joint toxicity effects of Cd and SMX were investigated using Photobacterium Phosphoreum. The results showed that, FA and HA had no significant effects on the single toxicity of Cd and SMX, FA and HA both decreased the effects on joint toxicity of Cd and SMX with the mixture ratio of 1:1, as well as, the effects were no significant with the increase of Cd in mixture.