Application Research Of Potassium Ferrate In Coal Mining Water Treatment

Potassium ferrate (K2FeO4) is a kind of new and more effective treatment; it has a good oxidation decontamination effectiveness of the coagulation and excellent coagulant, excellent flavor deodorant from the sterilization and efficient function. In the process of water treatment, K2FeO4 does not react with organic compounds, so it does not produce the new pollutants like organochlorine, meanwhile, it does not cause secondary pollution and any other side effect, therefore, it is called green water treatment agent.The national mining quantity was 16～18 ten million Ton every year, mine water discharge is about 22 ten million Ton, average utilization rate is lower than 50%. As far as Huainan mining area is concerned, mine hydraulic discharge is 17.87 million Ton, utilization rate is 44%, discharge rate is 56%, discharge is 3.8 kiloton per tens kiloton coal. But most of the utilized mine water is used to watering and lowering dust at underground, controlling spontaneous combustion of coal gangue, greening and washing toilet on industry square. Therefore, author studied systematically coagulation, oxidation and sterilization of potassium ferrate in the mine water treatment, meanwhile, considered comprehensively of economic benefits, environmental benefit and treatment effect, the process of"modified fly ash+ K2FeO4-TiO2"was used, which can treat mine water into dringking water.The study that coagulation effect of potassium ferrate on the coal mining water shows that when the rate of Potassium Ferrate and suspended substance is 0.73, the removal rate of turbidity and suspended substance is over 94%.But the content of suspended substance is high, which makes the dosage of potassium ferrate too much and results to the cost too high, so the mine water must be pretreated by fly ash firstly. When using the process to carry small experiment, the effluent quality was better than Environmental quality standards for surface water (IV).Potassium ferrate (K2FeO4) was used to treat CODcr in mine water, and the results were used to study the influence factors of the oxidizability of potassium ferrate. The results showed that the oxidizability of potassium ferrate was rather difficult to bring into full play in acidic conditions, but play better when pH was 7 to 10. The hardness,SO42- and low concentration sodium(<7mg/L) had no effect on the oxidizability of potassium ferrate, but high concentration sodium(>30mg/L) was able to slightly increase the removal efficiency on organic matter.The orthogonal test was used to study the bactericidal capability of potassium ferrate and its influencing factors for bacteria and Escherichia coli when potassium ferrate was playing coagulation effect on treating micro-polluted water. The results showed that the order of the primary and secondary factors affecting the germicidal efficacy of potassium ferrate was oxidation time, reagent amount and pH value. When pH value is 8, oxidation time is 30min and reagent amount is 25mg/L, the killing rate of bacteria and Escherichia coli is respectively 99.75% and 100%, meanwhile, the removal rate of turbidity and suspended substance is respectively 84.4% and 83.3%.Potassium ferrate (K2FeO4) was used to study the removal effect of heavy metals of different species and different concentrations in mine water. The results showed that pH had great influence on removing high-concentration of Pb,Cd,Fe,Zn,Mn and Cu in mine water. The removal rate was continuously increasing with the increasing of pH but lower in acidic conditions.PH, suspended matter and,turbidity, fluoride, partial heavy metal, CODMn, total coliform groups, total colony counts and petroleum and so on are investigated after treated by the process of"modified fly ash+ K2FeO4-TiO2", the removal and degradation results of the indexes which exceed the standards are also very satisfactory, and the quality of the water treated by the new technique can meet the national health standards for drinking water quality(GB5749-2006),and also meet the requires of water quality standards for fine drinking water(CJ 94-2005).The analysis of the stabilities of the experiments and the economic benefits of the technique shows the effects of the new technique are very satisfactory, and it has a good prospect for popularization and application...