Abstract: The filler compaction and channeling during the phosphorus removal by traditional iron-carbon micro-electrolysis fillers not only undermine the removal effect, but also increase the amount of mud produced by carbon particles from the filler and raise the subsequent processing cost. In view of this, a new type of iron-carbon micro-electrolysis material composed of iron-based materials and carbon fiber was employed to remove total phosphorus in a lake in Wuhan. The removal effect and the influence of treatment time on total iron concentration and turbidity of water were also examined with comparisons with those of carbon fiber and iron-based materials. Results demonstrated that treated for 10 hours with intermittent aeration, the phosphorus removal rate by the present iron-carbon micro-electrolysis material, iron-based material, and carbon fiber were 80.00%, 76.73%, and 2.86%, respectively. Treated for 72 hours with iron-carbon micro-electrolysis and placed static for 96 hours, the total phosphorus concentration in water dropped from 0.052 mg/L to 0.012 mg/L, reaching class II standard in Surface Water Environmental Quality Standard (GB 3838-2002). The turbidity and total iron concentration in water barely changed, stabilizing at 4.14 NTU and 0.089 mg/L, respectively. Moreover, no filler compaction or channeling was observed for the new iron-carbon micro- electrolysis material suspended in the water body. Only iron floc was produced in the water treatment process, which overcame the increase in mud production caused by the loss of carbon particles in traditional iron-carbon filler. Therefore, the new type iron-carbon micro-electrolysis material can overcome the problems of filler compaction, channeling and large mud production in traditional iron-carbon micro-electrolysis reaction process, and in the meantime enhance the phosphorus removal rate with no evident increase in turbidity and total iron concentration.

Key words: iron-carbon micro-electrolysis material, lake water, eutrophication, total phosphorus, total iron, turbidity