Study On Manganese Removal Technology Of Chemical Oxidation In Row Water And Bacteria Oxidation In Sludge Water

In recent years,the surface water soluble manganese exceeded the allowed standards,the water can not be treated in time by the water treatment plant leading to an excessive level of manganese,manganese level of drinking water source used to exceed in groundwater,the tech and development of manganese removal was also concentrated on groundwater,but surface water has few related studies.In this paper,various oxidants were used to remove manganese and the effect has been compared,then the influence of lake water quality parameters on manganese removal by KMnO4has been investigated,at last,the native sludge was used to reuse high level manganese water,specific studies as follows:1)The effects of dosages of oxidants?KMnO₄,ClO₂,NaClO,Na₂S₂O₈,KHSO₅and ozone?which were available in water treatment,multi-oxidants,UV light,pH value and coexist ions were investigated.The results showed that the KMnO₄ and O₃ were effective oxidants for the removal of Mn²⁺,when the molar ratio of KMnO₄ and Mn²⁺was 2:3,the residual manganese was 0.006mg.5min later Mn²⁺decrease to 0.056 mg/L under 0.6L/min O₃ air flow rate.The performance of the removal can be best improved when KMnO₄ or O₃ were used under high p H;ClO₂ performed a certain effect;Under UV light,in UV₂₅₄/Cl O₂,UV₂₅₄/KHSO₅ and UV₂₅₄/Na₂S₂O₈ system,The molar ratio of oxidants and Mn²⁺were 8:5,4:1 and 4:1,residual manganese decreased to 0.006,0.006 and 0.001 mg/L respectively,these were better than the national standard.NaClO were not effective oxidants for Mn²⁺removal in a short time,but UV₂₅₄/NaClO performed a certain effect.The molar ratio of KHSO₅/KMnO₄ and Mn²⁺were 5:2,Mn²⁺decreased to 0.06 mg/L,the performance can be highly improved than used separately.2)The lake water with added Mn²⁺was used as the research object,the effect of turbidity?COD_Mn?pH?coexisting ions and coagulants on Mn²⁺removal by KMnO₄were investigated,the effect of coagulants dosage was also discussed while the new-formed manganese dioxide produced in the process of the pre-oxidation was existing.The result show that 95%or more Mn²⁺has been removed when the dosage of KMn O₄was 83%or less of the calculated;the reaction between KMnO₄ and Mn²⁺quickly occurred and the balance achieved simultaneously in 2 min;The COD_Mn change of the lake water has less influence of on Mn²⁺removal;The turbidity could promote Mn²⁺removal rate,but the rate promoted by turbidity decreased as KMnO₄ dosage increasing;Mn²⁺removal rate was increasing as pH value increasing,initial pH value was 6.54 and9.57,KMnO₄ dosage of 95%Mn²⁺removal was 1.6 mg/L and 0.8 mg/L separated;Fe³⁺/Al³⁺ion coagulants?HCO₃^-?H₂PO₄^-?SiO₃^2-has some influence on Mn²⁺removal;Hydrated manganese dioxide could reduce 29%Al₂?SO4?₃ or 43%PAFC dosage for turbidity removal.3)Native sludge of sludge lagoon was used to enhance manganese removal by aeration in SBR reactor,the lake water and the lagoon water with high level manganese were treated by the reactor;the sludge of the reactor was sampled to analyze the taxonomy by High-Throughput Sequencing?HTS?machines;the sludge of the reactor was diluted to investigated manganese removal rate and removal kinetics;the reactor with 831mg/L MLSS was operated for 27days,manganese removal rate and other water quality parameters pH value,turbidity and COD_Mn was included was detected.The result showed that:after a day of cultivated the sludge could reduce the soluble manganese to 0.01mg/L in 180min or less,the level of manganese was better than national limit;5.0mg/L soluble manganese of the beaker with 831mg/L MLSS was reduced to 3.05mg/L in 5min,then the removal rate slowed down,soluble manganese was reduced to 0.25mg/L in 180min;microbial manganese removal followed the first-order kinetics model;HTS data show the manganese removal rate change was irrelevant to the taxonomy change;the reactor has operated for 27days,manganese removal rate changed less,other water quality parameters changed less but turbidity increased after reactor operated.