Study On NOM-Iodide Ion Combined Pollution In Drinking Water By Coagulation

The pollution of drinking water and its health risk control are the important problems in the current drinking water purification,among which the control work of disinfection of the by-products in drinking water is of vital importance.As the main precursor material of disinfection by-products,the potential health hazards caused by iodine ion and natural organic-iodide ion compound pollution in water are very obvious.In the process of drinking water,coagulation can effectively remove organic pollutants in water,and coagulation has obvious economic feasibility in traditional water treatment process.In this study,we have studied the effects of iodide and NOM?Natural organic matter?-iodide ion compound pollution on the coagulation of the coagulant by controlling the coagulant dosage of FeCl₃·6H₂O and HPAC?High poly aluminium Chloride?,controlling the pH value,adding the coexisting ions and the effects of these two kinds of coagulants on the removal of iodide and NOM-iodide compound pollution were investigated.The optimum dosage and optimum pH are determined.The effects of coagulation on the removal of turbidity and the change of zeta potential are investigated.The coagulation mechanism has been discussed.It was found that the best dosage of coagulant is 0.5mmol/L,and the low p H value?pH<6?is beneficial to remove the iodide ion in the water sample and the removal rate of HPAC is higher than that of FeCl₃·6H₂O,and the removal of NOM-iodide compound pollution of the best pH value is 7.Coexisting ions which have no effects on the removal of iodide and NOM-iodide ion compound pollution in drinking water.The biopolymers help to remove the dissolved organic matter in drinking water.When the dosage is 1mg/L,the effect of coagulation to remove NOM-iodide compound pollution is the best.There is a high correlation between UV254 and TOC?Total organic carbon?under the experimental conditions carried out in this study.The mechanism of the main action in the coagulation process changes with the change of operating conditions.For FeCl₃·6H₂O,in the coagulation process,not only the electrical neutral is essential,the adsorption-bridging and net catch-roll sweep also play a role;For HPAC,in the coagulation process,adsorption-bridging and net catch-roll sweep have great effects.Maintaining the water sample neutral can help achieve effects of good coagulation.