芦苇和玉米芯制生物炭对雨水吸持与净化效果的比较

Comparison Between Reed and Corn Cob Biochars in Retention and Purification for Rainwater Runoff

生物炭易制备、成本低、孔隙发达、稳定性高、吸附性强,在海绵城市建设中具有重要的应用前景.以芦苇和玉米芯制备的生物炭作为雨水滞留池填料,通过模拟渗水实验,研究其对雨水的吸持和净化效果.结果表明,玉米芯生物炭填料的水力性能优于芦苇生物炭,其渗水速率达到0.45 mL/(cm·s),储水量达到106 mL;芦苇和玉米芯生物炭均能提高雨水的pH值、降低其氧化还原电位,其中玉米芯生物炭的作用更大;芦苇生物炭对雨水总磷的去除率为55.48%,对Zn2+和Cu2+的去除率分别为74.62%,98.65%,对悬浮颗粒物的去除率为94.12%,这些指标优于玉米芯生物炭.因此,芦苇和玉米芯生物炭有望成为雨水滞留池的新型填料.

Biochar is considered a kind of materials that are easy to prepare,low cost,well-developed pores,high stability,and strong adsorption so it has important application prospects in the construction of sponge city.A simulation test on water penetration was carried out to study the effectiveness of rainwater retention and purification by the reed and corn cob-derived biochar as filling medium,respectively.The results showed that the corn cob-derived biochar resulted in a better hydraulic performance than the reed-derived one,presenting 0.45 mL/(cm·s)of seepage rate and 106 mL of water-storage capacity.Both two kinds of biochars led to the increase of pH value and the reduction of redox potential of the simulated rainwater.However,the effect of corn cob biochar was greater.It was observed that the reed-derived biochar was used to remove total phosphorus(TP),Zn2+,Cu2+ and total suspended particles(TSS) from the simulated rainwater by 55.48 %,74.62 %,98.65 % and 94.12 %,respectively,which all were larger than that of the corn cob-derived biochar.Therefore,both corn cob-and reed-derived biochars are expected to be used as new fillers for rainwater retention systems.