High-efficient nutrient removal in a single-stage electrolysis-integrated sequencing batch biofilm reactor (E-SBBR) for low C/N sanitary sewage treatment.

To efficiently remove nutrients from low C/N sanitary sewage by conventional biological process is challenging due to the lack of sufficient electron donors. A novel electrolysis-integrated sequencing batch biofilm reactor (E-SBBR) was established to promote nitrogen and phosphorus removal for sanitary sewage with low C/N ratios (3.5-1.5). Highly efficient removal of nitrogen (>79%) and phosphorus (>97%) was achieved in the E-SBBR operating under alternating anoxic/electrolysis-anoxic/aerobic conditions. The coexistence of autotrophic nitrifiers, electron transfer-related bacteria, and heterotrophic and autohydrogenotrophic denitrifiers indicated synergistic nitrogen removal via multiple nitrogen-removing pathways. Electrolysis application induced microbial anoxic ammonia oxidation, autohydrogenotrophic denitrification and electrocoagulation processes. Deinococcus enriched on the electrodes were likely to mediate the electricity-driven ammonia oxidation which promoted ammonia removal. PICRUSt2 indicated that the relative abundances of key genes (hyaA and hyaB) associated with hydrogen oxidation significantly increased with the decreasing C/N ratios. The high autohydrogenotrophic denitrification rates during the electrolysis-anoxic period could compensate for the decreased heterotrophic rates resulting from insufficient carbon sources and nitrate removal was dramatically enhanced. Electrocoagulation with iron anode was responsible for phosphorus removal. This study provides insights into mechanisms by which electrochemically assisted biological systems enhance nutrient removal for low C/N sanitary sewage.

Effectiveness of an online/offline mixed-mode Tai Chi cardiac rehabilitation program on microcirculation in patients with coronary artery disease: A randomized controlled study.

OBJECTIVE: We explored the effectiveness of an online/offline mixed-mode Tai Chi cardiac rehabilitation program on the microcirculation of patients with coronary artery disease (CAD). DESIGN: Prospective, randomized controlled study. SETTING: It was conducted in a tertiary hospital. SUBJECTS: Twenty-six patients who met the diagnostic criteria for coronary artery disease were recruited. INTERVENTIONS: Patients were randomized divided into a 12-week Tai Chi cardiac rehabilitation program(TCCRP) or a conventional exercise rehabilitation program(CERP) in a 1:1 fashion, 4 weeks of in-hospital rehabilitation and 8 weeks of online rehabilitation at home (a total of 12 weeks of intervention). MAIN OUTCOME MEASURES: Nailfold microcirculation (Morphological integrals, Blood flow integrals, Periphery capillary loop integrals, Overall integrals). MAIN OUTCOME MEASURES: Twenty patients completed the study. The Morphological integrals (baseline: 2.875±1.171 vs 12weeks: 1.863±0.414, t = 2.432, P = 0.045 < 0.05) and Overall integrals (baseline: 5.563±2.001 vs 12weeks: 3.688±1.167, t = 3.358, P = 0.012 < 0.05) decreased significantly in the TCCRP, The nailfold microcirculation integra decreased not significantly in the CERP (P > 0.05). The nailfold microcirculation integra was not significantly different between the two groups after the intervention (P > 0.05). CONCLUSIONS: The TCCRP improved the microcirculation of patients with CAD.

Inhibition of sediment erosion and phosphorus release by remediation strategy of contaminated sediment backfilling.

The management of sediment-water interfaces, especially bed stability, is essential for controlling accumulated contaminants in the sediment. In this study, the relationship between sediment erosion and phosphorus (P) release under the remediation strategy of contaminated sediment backfilling (CSBT) was explored through a flume experiment, i.e. the dredged sediment was calcined into ceramsite after dewatering and detoxification and then backfilled to the dredged area for sediment capping, thus avoiding the introduction of foreign materials via in-situ remediation and the large-scale land occupation associated with ex-situ remediation. Acoustic Doppler velocimeter (ADV) and optical backscatter sensor (OBS) were used to measure the vertical distributions of flow velocity and sediment concentration in the overlying water, respectively, and diffusive gradients in thin films (DGT) was used to measure the P distribution in the sediment. The results revealed that improving bed stability from CSBT can considerably improve the robustness of sediment-water interface and reduce sediment erosion by more than 70%. The corresponding P release from the contaminated sediment could be inhibited with an inhibition efficiency as high as 80%. CSBT is a potent strategy for managing contaminated sediment. This study provides a theoretical reference for controlling sediment pollution, further supporting river and lake ecological management and environmental restoration.

Co-exposure of sulfur nanoparticles and Cu alleviate Cu stress and toxicity to oilseed rape Brassica napus L.

Experiments were performed to explore the impact of sulfur nanoparticles (SNPs) on growth, Cu accumulation, and physiological and biochemical responses of oilseed rape (Brassica napus L.) inoculated with 5 mg/L Cu-amended MS medium supplemented with or without 300 mg/L SNPs exposure. Cu exerted severe phytotoxicity and inhibited plant growth. SNPs application enhanced the shoot height, root length, and dry weight of shoot and root by 34.6%, 282%, 41.7% and 37.1%, respectively, over Cu treatment alone, while the shoot and root Cu contents and Cu-induced lipid perodixation as the malondialdehyde (MDA) levels in shoots and roots were decreased by 37.6%, 35%, 28.4% and 26.8%. Further, the increases in superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and glutathione S-transferase (GST) enzyme activities caused by Cu stress were mitigated in shoots (10.9%-37.1%) and roots (14.6%-35.3%) with SNPs addition. SNPs also positively counteracted the negative effects on shoot K, Ca, P, Mg, Mn, Zn and Fe contents and root K, Ca, Mg and Mn contents from Cu exposure alone, and significantly promoted the nutrients accumulation in plant. Additionally, in comparison with common bulk sulfur particles (BSPs) and sulfate, SNPs showed more positive effects on promoting growth in shoots (6.7% and 19.5%) and roots (10.9% and 15.1%), as well as lowering the shoot Cu content (40.1% and 43.3%) under Cu stress. Thus, SNPs application has potential to be a green and sustainable technology for increasing plant productivity and reducing accumulation of toxic metals in heavy metal polluted soils.

Establishment and efficiency analysis of a single-stage denitrifying phosphorus removal system treating secondary effluent.

For advanced phosphorus and nitrogen removal, denitrifying phosphorus removal (DPR) was used to treat secondary effluent of sewage plants based on alternating anoxic/anaerobic process within single-stage biofilter. Under the hydraulic load of 3 m3/(m2·h), average removal rates of TP and TN in the system were 61.05% and 90.54%. 82.7% of the NO3--N removal occurred in the upper of the packing layer. TP removal occurred in upper and lower of the packing layer, accounting for 42.02% and 57.98% of the total removal, respectively. Biomass and bioactivity decreased proportional to the height incensement of packing layer. Nitrogen and phosphorus removal rates increased with anaerobic time while decreased with hydraulic load. 16S rDNA sequencing results showed dominant DNPAOs in the system included Acinetobacter and Dechloromonas, while dominant denitrifying bacteria included Flavobacterium, Comamonadaceae, Hydrogenophaga, Thauera and Azospira. The study further provided an effective and feasible way for advanced wastewater treatment.