玉米秸秆生物炭改善污泥脱水性能

本实验以玉米秸秆为原料，制备了生物炭和AlCl₃改性生物炭，研究了2种生物炭分别调理污泥后的脱水效果，并探讨了污泥脱水性能的改善机理.结果表明，经过2种生物炭调理后，污泥比阻（SRF）、泥饼含水率（MC）、污泥沉降体积指数（SV₃₀）、毛细抽吸时间（CST）均下降，污泥净产率（Y_N）升高，说明污泥脱水性能得到了改善，且AlCl₃改性生物炭对污泥脱水性能的改善效果明显优于生物炭.当AlCl₃（溶液浓度3mol/L）改性生物炭的用量为3g/L时，调理后的污泥SRF，MC，SV₃₀，CST分别降低至1.3×10¹²m/kg，81.9%，78.6%，35s，Y_N增加至17.8kg/（m²·h）.分析原因：一方面，经过生物炭调理后，泥饼中会形成一定的骨架结构，使得污泥中的水和EPS能够更容易地释放；另一方面，经过AlCl₃改性后，改性生物炭携带的正电荷（Al³⁺）能够与污泥颗粒所带的负电荷发生电中和作用，使得污泥颗粒更容易聚集，从而提高污泥的脱水效果.

Preparation of corn stalks biochar and improvement of dewatering performance of sludge

Biochar and AlCl₃-modified biochar were prepared by using corn stalks as materials to enhance the dewatering of the sludge. The performances of these two biochar for the enhancement of the dewatering of the sludge and possible enhancing mechanisms were discussed. Results showed that SRF, MC, SV₃₀ and CST of the sludge were decreased and Y_N was increased after conditioned by the two biochar, indicating higher sludge dewaterability. Furthermore, dewatering of the sludge conditioned by the AlCl₃-modified biochar was significantly better than that conditioned by the biochar that without modification. Especially, when the dosage of the biochar modified by 3mol/L of AlCl₃ solution was adjusted to 3g/L, SRF, MC, SV₃₀ and CST were decreased to 1.3×10¹²m/kg, 81.9%, 78.6% and 35s, respectively, Y_N was increased to 17.8kg/(m²·h). For the enhancing mechanism, on the one hand, after conditioned by the biochar, certain skeleton structures were formed in sludge cake to make water cut across easily by decreasing the sludge EPS; on the other hand, charge neutralization occurred when the AlCl₃-modified biochar (loaded with positively charged aluminum species on its surface) was dosed into the sludge system, thus destroying the stable sludge colloidal system, thus far easier to congregate the sludge particles, which enhanced the dewatering of the sludge.