Bacteria, especially antibiotic-resistant bacteria, in water threaten public health in countries. Simultaneous flocculation, sterilization and identification of bacteria are great challenge in water treatment. Herein we presented a three-in-one compound through combining a novel Bacitracin-based flocculant (B-g-PAMDAC) and surface enhanced Raman scattering (SERS) labels, the modified Au@AgNPs using graphene oxide (GO) and 4-mercaptophenylboronic acid (4-MPBA). B-g-PAMDAC with bactericidal groups and microblock structure was synthesized via copolymerization and self-assembly. Its functional groups and microblock structure contributed to the excellent performance in flocculation of bacteria. 4-MPBA as bacterial capture bound to the bacterial cell membrane and contributed to recognition of bacteria in flocculation. Bacteria aggregating around Au@AgNPs resulted in abundant "hot spots" and strong Raman signals. SERS labels obviously improved the sensitivity, accuracy and stability of bacteria identification even at low bacterial concentration of 1 x 10(3) CFU mL(-1). They presented distinct fingerprints of bacteria, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus and Enterococcus faecalis, in Raman mappings. Bacitracin improved sterilization efficiency of B-g-PAMDAC in four bacteria treatment in terms of sterilization rate and time. beta-galactosidase and respiratory activity of bacteria revealed sterilization mechanism of B-g-PAMDAC that changed permeability of cell membrane before it reduced the respiration activity of bacteria and ruptured cell wall.

Thallium (Tl) as a prominent priority contaminant in aquatic environment necessitates rigorous regulation. However, limited horizon devotes the impact of selective oxidation on the process of thallium purification. In this study, selective active radical of singlet oxygen (1O2) was continually generated for Tl(Ⅰ) oxidation accomplished with efficient Tl(Ⅲ) immobilization using iron-driven copper oxide (CuFe)/peroxymonosulfate (PMS). Fe-doping changed the active center of electronic structure for enhancing the catalytic and adsorptive reactivities, and installed magnetism for solid-liquid separation. Rapid reaction rate (0.253 min−1) coupled with vigorous elimination efficiency (98.32%) relied on electrostatic attraction, surface complexation, and H-bond interaction. EPR and XPS analyses demonstrated that the synergistic effects of ≡ Cu(Ⅰ)/≡Cu(Ⅱ) and ≡ Fe(Ⅲ)/≡Fe(Ⅱ) redounded to the sustained generation of 1O2 through the pathway of PMS → •O2− → 1O2, and 1O2 exploited an advantage to selectively oxidize Tl(Ⅰ) to Tl(Ⅲ). 3D isosurface cubic charts revealed that the immobilizing ability of Tl(Ⅲ) hydrate for CuFe was notably superior to that of Tl(Ⅲ) hydrate for CuO and Tl(Ⅰ) hydrate for CuO/CuFe, which further attested surface reactivity promoted stable immobilization form. This work develops the continuous generation of 1O2 and stable immobilization with the goal of efficiently cleansing Tl-containing wastewater. © 2024 Elsevier Ltd

Hydrogen (H2) recovery during wastewater treatment has been considered as a promising direction to accomplish environmental sustainability. However, the effective H2 evolution in contaminants degradation process was still a major challenge. In this research, an advanced piezo-photocatalytic induced hydro-energy system is proposed, in consideration of improving the separation and transfer efficiency of photogenerated electrons and holes. As expected, the catalytic performance was significantly enhanced under the stress of ultrasound-induced piezoelectric field (major nitenpyram degradation within 60 min, H2 evolution was 746.56 μmol g−1 h−1). Experiments and density functional theory calculations illustrated that the introduced piezoelectric field directionally tuned the energy band structure of heterostructure, triggering a change in the electron transfer path within the heterostructure, which facilitated the major electrons transferred to zinc oxide (H2 evolution) and holes accumulated in molybdenum sulfide (hydroxyl radical generation), further accelerating contaminants degradation and H2 evolution. Furthermore, the in-depth mechanism of contaminants degradation and H2 evolution under the influence of piezoelectric field was further explored. The piezo-photocatalytic system of this work first accomplished H2 recovery in wastewater treatment on heterostructure, providing a constructive strategy for the design of environmentally sustainable catalytic systems. © 2024 Elsevier Ltd

The co-contamination of dyes and heavy metal ions often used as mordants poses potential risks to environment and public health, and is a challenging problem that needs to be solved in water treatment. Meanwhile, improving the solid-liquid separation capability of adsorbents is of great significance for the application of adsorption technology. Herein, amidation modified hollow composite microspheres were prepared using hollow glass microsphere (HGM) as matrix through hydrolysis and condensation of silane coupling agent (A-1100) and subsequent amidation reaction. The material (HGMNE) not only exhibited good adsorption performance for DB86 and Ni2+ but also had stable self-floating capability. The adsorption of DB86 by HGMNE is mainly carried out by the electrostatic interaction between positively charged quaternary amine nitrogen and negatively charged DB86, while the adsorption of Ni2+ is achieved by the carboxyl group in EDTA group through complexation interaction to adsorb Ni2+ to form Ni complex. This research not only is devoted to the utilization of HGMNE to achieve the co-removal of DB86 and Ni2+ and flexible self-floating solid-liquid separation but also verifies the feasibility and applicability of the modification method of introducing organic adsorption functional groups through amidation reaction, so as to expand the preparation path of HGM-based adsorbents. © 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Periodate-based advanced oxidation processes (PI-AOPs) exhibited a promising future for the reduction of emerging refractory organic pollutants. However, the underlying mechanism and the sulfuretted effect of sulfide-modified metal silicate materials for PI activation were still unclear. In this study, sulfide-modified metal silicates (S-CoSi) were first synthesized and applied in the PI-AOPs system. Different from traditional metal silicate materials, sulfurization improved the catalytic performance. The enhanced degradation performance was from the increase in specific surface area and charge transfer efficiency, which derived from the sulfurization in metal silicate. DFT calculations revealed that the enhanced charge densities of Co-S bonds promoted the existence of Co (Ⅱ), which was more conducive to PI activation. Experimental and calculation results further demonstrated that Co was the active site in S-CoSi, and sulfur species strengthened the radical pathway by assisting Co (Ⅱ) regeneration (electron transfer from S to Co) rather than participating in the PI activation. Moreover, sulfurization promoted the generation of 1O2 (non-radical pathway) by increasing oxygen vacancy in the metal silicate. This study provided new insights into the effect of sulfurization on the radical and non-radical pathways in the metal silicates PI system. © 2023

Bimetallic catalysts and single metal photo-catalytic products displayed excellent PMS-activated ability for a long time. However, the synergistic mechanism of bimetallic with photo-generated electrons and the mechanism of O-1(2) generation and conversion were still obscure. In this work, CuMo@TiO2 was coupled with PMS to confirm the synergistic effect of Cu-Mo bimetallic with photo-generated electrons and this effect on the generation and conversion of ROS. IDM (20 ppm) almost achieved complete degradation in CuMo@TiO2/PMS system within 30 min, and the reaction system remained efficient with the presence of common inorganic anions or over a wide pH range (5.0-8.0). Experimental and analysis demonstrated that Cu-Mo bimetallic provided metal activation sites for PMS activation and those activation sites derived electron transfer enhanced the radical and non-radical pathway. Photo-generated electrons offered a powerful driving force for the redox of Cu-Mo bimetallic. The photo-generated electrons under the solar light and increased electron transfer between Cu-Mo promoted the generation and conversion of active species (.OH, O-2(center dot-), SO4 center dot-, SO5 center dot-) to O-1(2). This work provides the theoretical and experimental foundation for the further research of bimetallic photo-catalytic systems.

As emerging contaminants, tetracyclines pose a severe threat to aquatic environments and human health. Therefore, developing efficient approaches to remove tetracyclines from water has attracted a large amount of interest. Herein, a novel core-shell structural magnetic nanoadsorbent (FSMAS) was facilely prepared by graft copolymerization of acrylamide (AM) and sodium p-styrene sulfonate (SSS) monomers on the surface of vinyl-modified Fe3O4@SiO2 (FSM). From single factor experiments, the optimal graft copolymerization conditions were concluded to be the following: initiator concentration = 1.2 parts per thousand, reaction pH = 9, monomer molar ratio = 7 : 3. The surface morphology, microstructure and physicochemical properties of as-prepared FSMAS were fully evaluated by different characterization techniques, including SEM, TEM, FTIR, XPS, XRD and VSM. The adsorption performance of FSMAS towards tetracycline hydrochloride (TCH) was systematically studied by batch adsorption experiments. Results showed that the adsorption capability of the adsorbent was largely enhanced after graft copolymerization. The removal rate of TCH by FSMAS reached 95% at solution pH = 4.0, almost 10 times higher than FSM. Besides, the adsorption process of TCH by FSMAS was very efficient, 75% of pollutant could be adsorbed after only 10 minutes, attributed to the stretch of polymer chains and the strong affinity provided by abundant functional groups. Furthermore, TCH-loaded FSMAS was easily regenerated with HCl solution, the regeneration rate was higher than 80% after five adsorption-desorption cycles. Superior adsorption capability, fast solid-liquid separation speed and satisfactory reusability demonstrated the great potential of FSMAS in practical tetracycline removal.

水处理剂的开发与应用是提高水污染控制技术的一个重要手段,可有效增强对水体多种污染的去除效果,提高出水质量。絮凝剂作为水处理剂领域中重要的一部分,开发高效、安全环保的新型絮凝剂成为研究的热点。针对天然生物絮凝剂存在的活性官能团少、水溶性差和絮凝效果不理想的问题,论文选取天然多糖类材料壳聚糖（CS）为接枝主链,旨在提高絮凝剂的可生物降解性;选取丙烯酰胺（AM）和两亲型单体丙烯酰氧乙基二甲基苄基氯化铵（AO）为接枝侧链,旨在增加絮凝剂活性位点数目、改善CS的溶解特性、提高天然接枝絮凝剂的絮凝效果。基于上述构思,论文通过紫外光引发方式合成了絮凝增强型壳聚糖基高分子接枝共聚物CS-g-P（AM-AO）。AO分子结构中亲水型阳离子季铵基团与疏水型苄基基团增强了接枝共聚物的表面活性和疏水缔合效应。在接枝共聚过程中,两亲特性有助于接枝侧链中形成功能型单体AO的微嵌段分布,从而增强CS-g-P（AM-AO）的絮凝性能。在此基础上,结合新型的磁分离技术,合成了核壳型磁性壳聚糖基接枝共聚物Mag@CS-g-PAO,旨在提高磁性天然接枝絮凝剂对有机染料分子的特性吸附能力。论文通过一系列的表征方法系统探究了两种接枝共聚物的结构特点,并将其应用于污泥脱水和染料废水处理,进一步系统探究了其对污染物的去除机制。论文具体研究内容及结论如下:（1）红外光谱图、核磁共振氢谱图和差热-热重结果证实了紫外光引发CS-g-P（AM-AO）的成功合成。扫描电镜结果表明CS-g-P（AM-AO）呈现更不规则,多孔状的表面结构。这种特殊的表面形貌有助于改善接枝共聚物的水溶性。在CS-g-P（AM-AO）的优化合成实验中,通过单因素实验探究了总单体摩尔浓度、引发剂摩尔浓度、单体AO与CS的摩尔比、光照时间及p H值的对接枝共聚物的特性粘度和接枝效率的影响。在此基础上,通过Box-Behnken响应面实验探究了单体AO和CS的摩尔比、引发剂摩尔浓度和光照时间对CS-g-P（AM-AO）合成过程的显著性影响和交互影响。确定了CS-g-P（AM-AO）在最佳合成条件下CS-g-P（AM-AO）的特性粘度和接枝效率分别为551.2 m L/g和78.1%。通过溶解性测试结果可知,在p H=2.0～10.0的水溶液中,CS-g-P（AM-AO）呈现出较好的水溶性,这有助于提高CS-g-P（AM-AO）的实际应用效果。（2）通过计算单体竞聚率,深入探究了CS-g-P（AM-AO）接枝共聚过程中接枝侧链的序列分布。计算得到两种单体AM和AO的竞聚率分别为0.497和1.450。结果表明接枝共聚过程中,单体AM更倾向于共聚反应,单体AO更倾向于均聚反应。序列长度分布结果表明随着表面活性单体AO投加量的增加,接枝共聚物侧链中AO序列分布变宽且长链段比例变高。由于AO单体的两亲特性,在接枝聚合反应中,AO分子之间易形成疏水微区,从而有助于单体AO在CS骨架上形成均聚侧链链段,进一步揭示了CS-g-P（AM-AO）接枝聚合机理。（3）将CS-g-P（AM-AO）与前驱体CS-g-PAM、市售阳离子絮凝剂CPAD应用于市政污泥的脱水实验。整个污泥脱水过程中,CS-g-P（AM-AO）的脱水性能优于CPAD和CS-g-PAM。CS-g-P（AM-AO）投加量为6 mg/g TSS时,污泥FCMC、SRF和CST值分别为77.98%、3.83×1011 cm/g和4.9 s。CS-g-P（AM-AO）的电中和作用和微嵌段结构的疏水缔合作用增强了其污泥脱水效果,减弱了CS-g-P（AM-AO）投加过量时的再稳定效应。此外,CS-g-P（AM-AO）的疏水缔合作用提高了S-EPS和TB-EPS组分中的PN的去除率,降低了污泥体系的粘度和可压缩性。污泥絮体形貌、沉降速率、粒径分布等结果发现CS-g-P（AM-AO）调理后的污泥絮体表面有较多空隙,形成的絮体沉降速率更快,具有更大的平均粒径,抗剪切能力更强。（4）将CS-g-P（AM-AO）应用于模拟染料废水的处理,探究了絮凝剂的投加量、初始p H值、染料初始浓度对絮凝效果的影响。结果表明:与CS、CS-g-PAM及阳离子絮凝剂CPAD相比,CS-g-P（AM-AO）的除浊脱色效果最好,而且具有良好的抗酸碱能力。Zeta电位及絮体红外光谱结果进一步证明了在CS-g-P（AM-AO）染料废水去除过程中,功能型单体AO的微嵌段结构分布,大大提高了絮凝剂功能型链段与污染物相互作用的可能性,增强了CS-g-P（AM-AO）的电中和作用及疏水缔合效应,从而改善了絮凝剂对染料分子的去除效果。（5）红外光谱图、热重分析等表征结果表明核壳型磁性壳聚糖表面成功接枝共聚物PAO,制备得到Mag@CS-g-PAO。通过磁滞曲线得到Mag@CS-g-PAO的饱和磁化强度为12.03 meu/g,在水溶液中具有良好的磁响应性能。将磁性接枝共聚物Mag@CS-g-PAOs应用于橙黄II、酸性红和酸性苋红三种高浓度偶氮染料废水的处理。实验结果表明:相同投加量下,Mag@CS-g-PAOs对橙黄II、酸性红和酸性苋红的去除率均远远优于Mag@CS,Mag@CS-g-PAO对三种染料的去除效果排序为:酸性红＞橙黄II＞酸性苋红。光学显微镜、FTIR和XPS图谱分析结果表明:Mag@CS-g-PAO的电中和作用及苄基基团与染料分子芳香基团的π-π堆积作用增强了Mag@CS-g-PAO对偶氮染料的特性吸附效果。由于Mag@CS-g-PAO的架桥能力较弱,无法形成明显的絮状体。此外,Mag@CS-g-PAO的再生回用性能良好。

Phosphorus (P) contamination has become a worldwide issue due to its adverse impacts on water security and human health. Additional research is required because the selectivity and adsorption capacity of P adsorbents continue to impede their practical application. Herein, a novel NaCe(CO3)2/Fe3O4 nanocomposite (NCF) with good magnetic properties were synthesized through a modified hydrothermal method for P removal from water. With an adsorption capacity of 86.69 mg P g−1, the NCF demonstrates outstanding phosphate uptake efficiency. At low P concentrations, the removal rate exceeded 90.0%, and the residual P concentration was below 0.1 mg P L−1. Notably, NCF demonstrated exceptional P selectivity in actual water containing multiple substances, with negligible interference from competing ions and humic acid (HA). The adsorption processes of NCF were well described by the pseudo-second-order kinetic model (PSO) and Langmuir isotherm model, corresponding to its kinetics and thermodynamics, respectively. The exhausted NCF can be regenerated and retain an effective phosphorus removal capability even after regeneration. Characterization results demonstrated that electrostatic attraction and ligand exchange were responsible for P adsorption, forming stable CePO4 crystals with low solubility. Moreover, the NCF demonstrated some efficacy in removing typical organic and inorganic phosphorus. © 2023 Elsevier B.V.