What should we pay attention to when using manganese sand filter?

Manganese sand filter, also known as iron-removing manganese filter, is commonly used in underground well water and sewage treatment. It is a very common water treatment equipment. It is different from ordinary quartz sand filter, activated carbon filter, multi-media filter and other mechanical filters. Manganese sand filter mainly removes iron and manganese ions from water. my country's drinking water hygiene standards stipulate that the iron content is ≤0.3mg/L and the manganese content is ≤0.1mg/L. Long-term drinking of water with high iron and manganese content is not good for the human body. In textile, papermaking, brewing, food and other industries, excessive iron and manganese will affect product quality, cause spots on items, and corrode equipment. Commonly used iron removal filters are aerated groundwater containing iron (manganese) flowing through a manganese sand or special quartz sand filter layer to oxidize, solidify and remove iron (manganese).

When cleaning manganese sand filters, you should pay attention to the following considerations:

1. PH Value

In the process of removing iron and manganese from groundwater, pH value is the key factor affecting the removal of iron and manganese. The higher the pH value, the faster the oxidation rate of Fe2+ and Mn2+, and the easier it is for iron and manganese to be removed. When pH>5.5, the oxidation rate of Fe2+ will increase 100 times for every 1.0 increase in pH value, and the oxidation rate of Mn2+ will also be significantly accelerated when pH>9.

2. Backwash Intensity

During the use of iron and manganese removal filters, there is a common phenomenon of "saturation" or "passivation" of manganese sand, and the manganese removal capacity is greatly reduced. The main cleaning method is backwashing. The backwashing method is combined air and water backwashing. The intensity of the backwash flow is 16-18L/m2·s. The duration of backwashing will vary depending on the specific usage conditions. It is generally about 30 minutes. , the general principle is to observe the backwash water when the water flow gradually becomes clear or is close to the end of the clean water backwash process. It can also be rinsed three times with regenerant, and finally rinsed with tap water until neutral, and then it can be reused.

3. Chemical Cleaning

During the operation of the manganese sand filter, the impurities are unevenly distributed in the filter layer, and the penetration depth of the impurities is different. Moreover, it is impossible to fully remove the sludge attached to the filter material and crush the large mud particles during each backflush. When the manganese sand filter is filtered or backwashed, the hydraulic conditions experienced by the filter layer are also uneven. In this way, when impurities penetrate the surface of the deep filter layer, a large amount of impurities are trapped, and the filter layer forms a "mud felt", causing the filter material to be damaged. At this time, chemical cleaning is required, and a special cleaning agent is used to soak and circulate to remove colloids and organic particles, remove scale and metal oxides, and restore the normal processing effect of the filter material.