为了解决富营养化河道中内源磷释放的问题,合成了一种新型磷负荷控制材料,即负载有碳酸钙微粒的高岭石复合材料(CLK),研究了其对底泥磷释放和磷组分的影响.结果发现,CLK能有效抑制底泥释磷,最佳投加量为100mg/g,2h内即将水中溶解态磷(SRP)浓度控制在0.021 mg/L.CLK的添加促使底泥中的可交换态磷(Ex-P)、铝结合态磷(Al-P)和铁结合态磷(Fe-P)向钙结合态磷(Ca-P)转变,其中Fe-P含量减少了 17.31％,Ca-P含量增加了 27.91％,有效降低了底泥磷释放的风险.

为研究芽孢杆菌投加到黑臭水体中不同位置对河道水体的修复效果,以某黑臭河道底泥和水体为研究对象,利用芽孢杆菌生物降解技术,分别将芽孢杆菌投加至底泥、泥水分界面、上覆水体3个不同位置,并测定相应指标进行分析.结果表明:芽孢杆菌投加至不同位置对黑臭水体均有修复效果,其中将芽孢杆菌投加至泥水分界面时对黑臭底泥和水体的修复效果最佳,此时对水体中氨氮、总氮、TP和COD的去除率分别为63.65％、42.71％、39.14％和63.13％,对底泥中氨氮、总氮、TP和有机质的去除率分别为59.88％、65.99％、59.07％和57.07％,底泥颜色由黑变黄,厚度下降18％,底泥生物降解能力增强.

为去除生活与工业污水中的磷酸盐,通过氧化钙与碳酸钠的联合作用,对高岭石进行连续改性,将碳酸钙引导至黏土层,制备了改性高岭石/碳酸钙复合吸附材料(KCA).利用SEM,XRD,FT-IR对KCA进行表征,并结合零电荷点 、吸附动力学 、吸附等温线 、实际废水研究KCA对磷酸盐的吸附特性.结果表明:KCA吸附量显著提升达到8.03 mg/g;KCA表面硅醇基团增加,并负载有碳酸钙颗粒层;KCA在水溶液中表面带正电,吸附磷酸盐的过程符合准二级动力学与Langmuir吸附模型.

Carbon dots (CDs) and Bi-riched bismuth oxyhalide have great potential in the field of photocatalysis. Here, a series of CDs/Bi4O5Br2 at different loading ratios were successfully synthesized by solvothermal method. Experiments of visible light degradation of ciprofloxacin (CIP) showed that 3 wt% CDs/Bi4O5Br2 had the highest activity (5.39 times that of Bi4O5Br2) and the degradation rate reached 98%. The samples were characterized by XRD, SEM, TEM, EDS, Mapping, UV-vis DRS, Raman, and PL spectra. The absorption edge of 3 wt% CDs/Bi4O5Br2 was red-shifted from 455 nm to 580 nm compared with Bi4O5Br2. The enhancement of photocatalytic activity was mainly due to the fact that the addition of CDs not only broadened the photo-response range, but reduced the recombination rate of photo-induced carriers with good electron transport interfaces formed. (C) 2019 Elsevier B.V. All rights reserved.