An Experiment On The Treatmentof Groundwater Containing High Fe, Mn And Ammonia Using The Contact Oxidation-ultrafiltration Hybrid Process

Many groundwater sources in China are characterized by high concentration of Fe,Mn and ammonia, which involved in many aspects of the potential harm to humanhealth and industrial and agricultural water quality and safety. To investigate thetreatment of groundwater containing high concentration ofFe, Mn and ammonia using acombined process of contact oxidation and ultrafiltration, a pilot in Harbin wasconducted.Contact oxidation was defined as pretreatment, which used to remove Mn(â…¡),Fe(â…¡), ammonia and the most Fe(â…¢). Ultrafiltration was defined as advanced treatment,which mainly used to remove bacteria in the water. The results of filter columnexperiment showed that the effluent water quality reached Chinese Drinking WaterStandard (GB5749-2006) when manganese sand were used at the condition of differentdiameter size or filter speed, with the concentrations of iron, Fe(â…¡), manganese andammonia in the effluent of0.24mg/L,0.03mg/L,0.03mg/L and0.40mg/L. Meanwhile,manganese sand in the diameter size of0.6~1.3mm had great advantages in the removalof Mn than which in the diameter size of0.8~1.47mm. The former filter materialmaturity was30days. The latter was110days. And crude manganese sand removed Mnadmirable at the condition of a low filter speed. The results of ultrafiltration experimentshowed that the removal of bacteria was approximately100%. Total bacteria during theexperiment were not detected. Ultrafiltration technique reduced the used of disinfectant,which reduced the effect of disinfection byproducts to some extent. And the turbidity inthe UF effluent was less than0.10NTU. Furthermore, the total iron in the effluent wasdecreased. The total iron removal rate improved to more than99%. In a conclusion, theeffluent water quality of the combined process of contact oxidation and ultrafiltrationreached Chinese Drinking Water Standard (GB5749-2006), with the averageconcentrations of iron, Fe(â…¡), Mn and ammonia contents of0.02~0.04mg/L,0.03mg/L,0.03mg/L and0.40mg/L. And the total bacteria during the experiment were not detected.Furthermore, the turbidity in the effluent was less than0.10NTU. The colloidal particles formed in the process operation inevitably, whichaggravated the membrane fouling together with particles. Tests for investigatingmembrane fouling and technology of low-flux pollution control were conducted. Theresults showed that the degree of membrane fouling was lower. Fewer pollutantsdeposited on the membrane surface. And the UF film hole was blocked lightly.Furthermore, growth of TMP was slow when operated the UF membrane with the fluxof20~30L/(m2ï¹’h).