Characteristics And Treatment Effects Of Lignite-Coke As Baf Filter

Industrial wastewater after traditional first or secondary treatment, is often difficult to achieve water reuse standards, which result in pollution and waste of water resources. The treatment of urban industrial wastewater is becoming more and more serious nowadays, especially the treatment technology of refractory industrial wastewater. It has always become a hot topic in the field of wastewater treatment. This paper uses lignite-coke as biological aerated filter (BAF) filter, with the properties of wide ranges of sources for raw materials, low prices and a good adsorption effect for biodegradable industrial waste water. After analyzing the physical and biological properties of lignite-coke and investigating its feasibility as a filler BAF, then apply it as a deep treatment method of lignite-coke BAF to deal with different types of biochemical tail water of refractory industrial wastewater such as pharmaceutical wastewater of a pharmaceutical factory in Inner Mongolia and lignite quality wastewater. The results showed that:(1) According to the physical and biological properties of lignite-coke, it not only has a large number of micropores, but also a large number of pore structure. It can be seen that lignite-coke can be used as filler of BAF, since its internal pore structure is suitable for the adsorption of macromolecules in wastewater contaminants and the growth of biofilm, it also has a good bleaching effect of coloring macromolecular substances.(2) In dealing with tailrace of pharmaceutical wastewater of a pharmaceutical factory in Inner Mongolia, HRT was set as 10 h and the aeration rate was 0.05m3/h. After four months of continuous experiments, compared to four lignite-coke filter column effluents, it showed that inoculation biofilm can quickly complete the start compared to natural biofilm and after the treatment of tailrace by BAF, the average concentration of CODCr decreased from 438mg/L to 302mg/L, with the average removal rate was 31.1%. We can see that the treatment effect was not satisfied. However, the raw water through 100:1 water coke adsorption treatment before entering the filter column, tail water color decreased to 28 degrees with the removal rate of 94%. The average CODCr concentration decreased from 208mg/L to 165mg/L with the average removal rate of 20.7%. Besides, the average amount of biodegradable alone reached 15mg/L and the biodegradability increased nearly three times from 0.11. CODCr of the effluent can reach the park sewage plant inlet concentration requirements (200mg/L).(3) In the application of two-stage BAF lignite mention qualitative wastewater treatment pilot trial, after nearly six months of continuous running, the results showed that lignite-coke BAF has a strong ability for impact resistance and a very good buffer for volatile water with better removal of pollutants. When the influent CODCr average of 96.9 mg/L, the average concentration of two BAF final effluent CODCr reduced to 38.1 mg/L, with total average removal rate of 60.9%; the average effluent concentration of NH4+-N of the two BAF was 3.63 mg/L, with total average removal rate of 82.5%. When the average concentration of SS was 134 mg/L with volatile situation, secondary aeration biological filter effluent SS average fell to 23 mg/L with the removal rate of 82.8%, and the fluctuation range is obviously reduced. Turbidity of an average dropped from 229.5NTU to 91.45NTU with the average total removal rate of 60.2%.Through theoretical analysis and experimental verification effect, lignite-coke is not only suitable as BAF filler, but also has a good water treatment effect of tailwater of refractory industry. It can provide data support and reference for related fields of wastewater treatment.