College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan 610225, China.
College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan 610225, China.
Sci Total Environ. 2019 Mar 1;654:338-344. doi: 10.1016/j.scitotenv.2018.10.429. Epub 2018 Nov 2.
Enhancement of the dewatering of the sludge by using rice straw biochar (RSB) modified by aluminum chloride (AlCl) was investigated, and the possible enhancing mechanisms were discussed. Results showed that the settled volume after 30 min (SV%), specific resistance to filtration (SRF), moisture content (MC) and capillary suction time (CST) of the sludge were decreased and the net sludge solids yield (Y) was increased by the increasing raw or modified RSB, which indicated a higher sludge dewaterability. When the dosage of the modified RSB was adjusted to 0.3 g(RSB)/g(dry sludge), SV%, SRF, MC and CST were decreased to 79.8%, 1.2 × 10 m/kg, 81.4% and 38 s, respectively, Y was increased to 19.4 kg/(m·h). Furthermore, performance of the modified RSB in the dewatering of the sludge was significantly better than that of the raw RSB. For the enhancing mechanisms, charge neutralization occurred when the modified RSB (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. Another main enhancing mechanism was that after conditioned by the modified RSB, certain skeleton structures were formed in sludge cake to make water pass through easily by decreasing the extracellular polymeric substances (EPS) of the sludge. We found that the effectiveness of using the modified RSB to enhance the dewatering of the sludge is substantial and promising.
研究了用氯化铝（AlCl）改性的稻草生物炭（RSB）增强污泥脱水的效果，并探讨了可能的增强机制。结果表明，随着原始或改性 RSB 的增加，污泥的沉降体积（SV%）、过滤比阻（SRF）、水分含量（MC）和毛细吸水时间（CST）降低，净污泥固体产率（Y）增加，这表明污泥的脱水性能更高。当改性 RSB 的用量调整为 0.3g(RSB)/g（干污泥）时，SV%、SRF、MC 和 CST 分别降低至 79.8%、1.2×10m/kg、81.4%和 38s，Y 增加至 19.4kg/(m·h)。此外，改性 RSB 在污泥脱水中的性能明显优于原始 RSB。对于增强机制，当改性 RSB（表面带有正电荷的铝物种）被投加到污泥系统中时，会发生电荷中和，从而破坏稳定的污泥胶体系统，使得污泥颗粒更容易聚集，从而增强了污泥的脱水能力。另一个主要的增强机制是，经过改性 RSB 调理后，在污泥饼中形成了一定的骨架结构，通过减少污泥中的胞外聚合物物质（EPS），使水更容易通过，从而提高了污泥的脱水性能。我们发现，使用改性 RSB 增强污泥脱水的效果是显著的，具有广阔的应用前景。
