| In natural environment, today's phenomenon of pollution are growing caused by arsenic pollution, in particular, the pollution of water bodies is even more seriously, it gives people to produce great impact on their lives, arsenic containing waste water treatment has become an urgent priority in the current water problems. This research project aimed at Yangzonghai arsenic containing spring water concentrations of arsenic higher, no or low levels of other heavy metal ions at other characteristics, selected coagulation-oxidation coagulation-ceramic filter absorption deal with new ceramic technology, in addition to removal arsenic of coagulation mechanism,oxidation mechanism and ceramic filter adsorption mechanism removing arsenic has been studied. Meanwhile, process resulting from the stability of the arsenic residue, arsenic residue disposal methods, experiment mechanism, the economic costs of this process, reached the following conclusions:The first coagulation experiment results show that the optimum processing conditions of treat arsenic water using Fe2(SO4)3·6H2O:pH was 7.8, coagulation time was 90 min, the dosage of the Fe2(SO4)3·6H2O was 17 g·L-1, at this point the best arsenic removal, the remove rate was 61.7%; the optimum processing conditions of treat arsenic water using FeCL3:pH was 7～8, coagulation time was 100 min, the dosage of FeCL3 was 14 g·L-1, at this point the best arsenic removal, the remove rate was 61.2%; the optimum processing conditions of treat arsenic water using PFS:pH was 6.5-8.5, coagulation time was 90 min, the dosage of PFS was 15 g·L-1, the arsenic remove rate was 65%. Through the optimum processing conditions of the first coagulation experiment and remove rate, select PFS was coagulation agent in this experiment.At the basis of the first experiment, select two style while aeration oxidation and H2O2 oxidation to investigate effects on arsenic remove rate, experimental results shows:the optimum processing conditions of the aeration oxidation was that pH was 6.7～8.2, Aeration time was 100 min, aeration volume was 0.1 m3/h·L, at this point the best arsenic removal, the remove rate was 51.3%, the optimum processing conditions of the aeration oxidation was that pH was 4.5, oxidation time was 30 min, the dosage of the H2O2 was 24 mL·L-1, arsenic remove rate was 50.3%.By the comparison of two oxidation ways, aeration oxidation of the best pH was between 6.7 and 8.2, while the raw water samples of pH value between 6.5 and 7.5, range closer; while H2O2 oxidation needs the best pH was lower, need to add a large number of acid to adjust pH of the water sample. results from the treatment point of view, two almost arsenic removal rate, aeration oxidation was 51%, H2O2 oxidation was 50.3%. Taken together, the final select aeration oxidation as an oxidation method.Before the second coagulation sedimentation, need to determine the best conditions for aeration oxidation. Using PFS as a coagulant, from the pH,coagulation time and the dosage of the PFS to investigate its effect on arsenic removal. The results shows that the best conditions for the secondly coagulation pH was 7.6, coagulation time was 100 min, the dosage of PFS was 14 g·L-1, arsenic removal rate reached 51.7%, the arsenic concentration was 1.4 mg·L-1.The arsenic concentration of the second coagulation out water was 1.4 mg·L-1, still can not meet the standard at 0.5 mg·L-1. Selected ceramic filter for treatment after the secondary coagulation for further processing. The results showed that:The static experiment when the dosage of the ceramic powder was 5 g, pH was 6.5, the baking temperature was 700℃, adsorption equilibrium time was 90 min, the treated water sample residual arsenic concentration was 0.51 mg·L-1; moving experiment when the filter thickness was 60 cm, the arsenic removal efficiency was 38.6%, the remaining concentration of arsenic was only 0.31 mg·L-1, cagulation-oxidation-ceramic powder adsorption of arsenic treatment of sewage, influent arsenic concentration of 8.3 mg·L-1, the effluent arsenic concentration was 0.31 mg·L-1, the removal rate reached 96.3%.Studying the results showed that:the stronger stability of arsenic residue, through comparison of the disposal of arsenic residue, taken together, this study select two ways which curing and landfill; for coagulation mechanism and oxidation mechanism was discussed, from handling cost for this experiment was analyzed, the results showed that arsenic containing waste water treat 1 L total cost of about 0.126 yuan。... |
PDF Full Text Request