Beijing Enterprises Water Group (China)

ABSTRACT In this study, a modified coagulation sludge (MCS) from a real landfill leachate coagulation pretreatment was first prepared with polymerized ferric sulfate (PFS) as the activator for PMS to degrade bisphenol A (BPA). The results showed that 43.34% of BPA was adsorbed by MCS when [BPA]0 = 20 mg/L, [MCS]0 = 0.8 g/L, and time = 80 min. Thereafter, by adding 3000 mg/L PMS to initiate the oxidation process, complete BPA removal, i.e. 100%, was achieved in 60 min. In addition, in tap water and municipal wastewater scenarios, 100% and 90.07% removal of BPA were obtained, respectively, and MCS exhibited outstanding performance after repeated use. MCS displayed an excellent adsorption capacity in which chemical adsorption was the main effect, and hydroxyl radicals were the major contributor to BPA degradation. Characterizations of fresh and reacted MCS were conducted, and the results showed that the MCS structure was stable after repeated use, and the surface functional groups, surface defect sites, and iron oxides participated in PMS activation. Overall, this study demonstrated successful recycling of coagulation sludge from landfill leachate pretreatment to activate PMS for environmental pollution control, which is in accordance with the goal of using waste to control waste.

Twenty antibiotics were investigated to evaluate the degree of antibiotic pollution, the temporal and spatial antibiotic distribution and the ecological risks in the Xiaoqing River basin (main stream). The total antibiotic concentrations in surface water and sediment were 0.99 to 832.4ngL-1 and 9.71 to 7841.61ngg-1, respectively, and that ofloxacin was the dominant antibiotic. However, ofloxacin, erythromycin, clarithromycin and sulfamethoxazole posed high risks to algae, among which clarithromycin presented the highest risk quotients (23.8). In addition, there were spatial and temporal differences in the antibiotic concentration distribution. Temporally, the following trend was detected: dry season > normal season > wet season; spatially, the following trend was detected: Jinan > Dongying > Binzhou > Zibo > Weifang. Meanwhile, we used the PCA-MLR model to quantify the contribution rate of the four sewage treatment plants A, B, C and D. Factor 1 (co-sources A, B, C, D) contributed 64.1% of the total antibiotic concentration in the Xiaoqing River. According to the estimated flux into the sea, approximately 972.31kg of antibiotics were discharged into Bohai Bay in 2017, posing a potential threat to the marine ecosystem. As a comprehensive river channel used for flood control, waterlogging, irrigation and shipping, its water quality safety is of great significance to the surrounding residents and ecological safety. Therefore, further investigations of antibiotic pollution and source contribution are necessary.

The host–guest binding characteristics of cyclopentanocucurbit[6]uril (CyP6Q[6]) and cyanine dye trans-4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide (t-DSMI) have been studied. The results show that CyP6Q[6] and t-DSMI form a 1:1 inclusion system, generating strong fluorescence. On this basis, the fluorescent probe t-DSMI@CyP6Q[6] has been constructed, and its anion recognition ability has been investigated. In a neutral environment, BF4−, H2PO4−, and I− elicit obvious specific responses from the probe, since they have stronger binding forces. This probe shows greater sensitivity than the previously reported probe t-DSMI@HMeQ[6]. Since the complex formed by CyP6Q[6] and t-DSMI can produce strong fluorescence at pH > 4.6, t-DSMI@CyP6Q[6] was constructed to recognize the anions at pH ≅ 5. The results show that in a near neutral environment, BF4−, H2PO4−, and I− elicit obvious specific responses from the probe.