Understanding the potential impact of the Three Gorges Reservoir (TGR) on regional extreme precipitation and its mechanisms is critical for the safe operation of the reservoir and the efficient management of regional water resources. This study uses the regional climate model RegCM4 to conduct a double-nested simulation experiment (50 km to 10 km) from 1989 to 2012, evaluated against the CN5.1 observation dataset. Sensitivity experiments with three different lake area ratios (0%, 20% and 100%) were performed using the sub-grid partitioning method in the Community Land Model Version 4.5 to analyze the spatiotemporal distribution, intensity, and frequency of precipitation under varying TGR water areas. The results show that with a 20% lake area ratio, precipitation slightly decreases, but the impact on extreme precipitation indices is not statistically significant. However, with a 100% lake area ratio, significant decreases in both total and extreme precipitation indices occur. The reduction is primarily driven by the formation of anomalous mountain-valley circulation between the TGR and surrounding mountains, which leads to atmospheric subsidence and reduced convective activity. These findings indicate that while the TGR has a negligible impact on extreme precipitation under its current configuration, the exaggerated sensitivity experiments reveal potential mechanisms and localized effects. This research enhances the understanding of the TGR's influence on regional extreme precipitation and provides valuable insights for water resource management and reservoir operation.

Extreme natural events such as typhoons can amplify the effect of hydrodynamics on the lake ecosystems. Here we presented data on the effect of typhoons on algal cell size based on field observation. Then turbulence simulation systems were used to decipher the response of natural phytoplankton communities to a range of turbulence regimes (linked to typhoon-induced turbulence intensity) under laboratory conditions. Turbulence intensities of 6.17 × 10−3, 1.10 × 10−2 and 1.80 × 10−2 m2/s3 benefited algal growth and triggered abrupt switches from unicellular Chlorella dominated to colonial Microcystis dominance, and the abundance of colonial algae depended on the turbulence intensity. Under the influence of elevated turbulence, Microcystis dominated biomass increased by 2.60–6.58 times compared with that of Chlorella. At a given phytoplankton density and community composition, we observed a significant increase in extracellular microcystins (MCs) and a 47.5-fold increase in intracellular MCs with intensified turbulent mixing, suggesting that the damage of algal cells concomitantly the stimulation of toxin-producing Microcystis. Our results confirmed that the formation of large colonial algal cells, enhancement of the succession of algal species, and most importantly, the induction of toxin-producing Microcystis, were the active adaption strategy when phytoplankton were impacted by strong turbulence. The result implies that the ongoing climates changes and typhoon events are likely to contribute to undesirable outcomes concerning phytoplankton populations. © 2019 Elsevier B.V.

在好氧条件下,异养硝化和好氧反硝化细菌能将水体中的含氮化合物转化为气态氮,从而达到脱氮目的,因其具有脱氮效率高、节能环保等特点,受到了国内外研究者们的密切关注,并作为生物脱氮系统中的潜在微生物进行了深入研究。但这类细菌在异养脱氮性能、脱氮途径和细菌种类等方面具有不同的特点,有必要从不同环境介质中分离出新的异养硝化和好氧反硝化细菌以丰富生物脱氮菌的种类及生物脱氮理论。本研究通过富集、分离、纯化的方法获得了一株新型耐冷生物脱氮菌,对其进行了形态学、分子生物学鉴定;并分别以氨氮、硝态氮和亚硝态氮为唯一氮源,研究了该菌对不同氮源的去除效果以及产生反硝化产物N2O的情况;在此基础上,以氨氮和硝态氮或亚硝态氮为混合氮源,研究了该菌对混合氮源的去除效果,探究其同时硝化反硝化作用;最后,通过向含不同氮源的培养基中加入不同浓度的Fe3+与Cu2+,进一步探究了Fe3+与Cu2+对该菌脱氮作用的影响。通过研究,得出了以下主要结果:（1）在15℃条件下,通过富集、分离、纯化的方法从长期淹水的冬水田泥土中获得一株具有好氧反硝化能力的菌株D51,通过形态学观察、磷脂脂肪酸（PLFAs）鉴定和16S rRNA基因序列分析,菌株D51被鉴定为烟草节杆菌（Arthrobacter nicotianae）,经革兰氏染色法确认其属革兰氏阳性细菌。本文首次报道了Arthrobacter nicotianae具有异养硝化和好氧反硝化功能,丰富了生物脱氮菌的种类。（2）菌株D51能分别以氨氮、硝态氮和亚硝态氮为单一氮源进行生长繁殖及脱氮。当以氨氮（51.59mg/L）为唯一氮源时,15℃,150r/min培养48h后,氨氮和总氮去除率分别为95.21%和86.48%,生物量氮积累25.21mg/L（占氨氮含量的48.87%）,未检测到中间产物硝态氮和/或亚硝态氮;当以硝态氮（53.78mg/L）为唯一氮源时,硝态氮和总氮去除率分别为74.04%和72.92%,生物量氮积累16.52mg/L（占硝态氮含量的30.72%）;当以亚硝态氮（58.39mg/L）为唯一氮源时,亚硝态氮和总氮去除率分别为70.11%和56.37%,生物量氮积累18.45 mg/L（占亚硝态氮含量的31.60%）。（3）在温室气体产物检测实验中,当分别以氨氮、硝态氮和亚硝态氮为单一氮源时,15℃,150r/min培养48h后,检测到N2O的净生产量分别为0.0271、0.0144和0.2163mg/L。菌株D51能够将铵态氮、硝态氮和亚硝态氮转化为N2O,进一步表明菌株D51具有异养硝化和好氧反硝化作用。N2O是一种温室气体,但在本过程中产生量很少,对环境危害程度较小。（4）15℃条件下,当以氨氮（28.21mg/L）和硝态氮（29.30mg/L）为混合氮源时,氨氮、硝态氮和总氮的去除率分别为98.62%,58.53%和68.60%,有中间产物亚硝酸盐氮积累;当以氨氮（29.40mg/L）和亚硝态氮（28.46mg/L）为混合氮源时,氨氮、亚硝态氮和总氮的去除率分别为95.88%,65.95%和73.87%。菌株D51能够同时利用铵态氮和硝态氮或亚硝态氮,具有同时硝化反硝化功能。硝态氮与亚硝态氮的加入不会影响铵态氮的去除效果,但铵态氮的加入会使硝态氮与亚硝态氮的去除受到抑制。（5）Fe3+对菌株D51的生长及硝化作用影响较小,但对反硝化作用的影响较大。当Fe3+浓度为15mg/L时,硝态氮（52.42mg/L）去除率达100%,平均去除速率为2.18 mg/L/h,与未加Fe3+时相比,硝态氮去除率提升了近30%;当加入10mg/L Fe3+时,亚硝态氮（61.17mg/L）去除率达97.45%,平均去除速率为1.24mg/L/h,与未加入Fe3+时相比,亚硝态氮的去除率提升了近36%。（6）Cu2+会抑制菌株D51的生长及硝化作用,但对反硝化作用的影响与浓度有关。当培养基中加入Cu2+时,菌株D51的生长及硝化作用就会受到抑制;当分别以硝态氮和亚硝态氮为唯一氮源时,加入0.05mg/L Cu2+,15℃,150r/min培养48h后,硝态氮（56.38mg/L）的平均去除速率为0.96mg/L/h,去除率比未加入Cu2+时提升了8%左右;亚硝态氮（55.36mg/L）平均去除速率为0.80mg/L/h,去除率比未加Cu2+时提升了14%左右;但当Cu2+浓度高于一定范围（≥0.1mg/L）时,菌株D51的反硝化作用就会受到抑制。综上所述,菌株D51能在有氧条件下发挥硝化作用、反硝化作用和同时硝化反硝化作用。当以铵态氮和硝态氮或亚硝态氮为混合氮源时,该菌仍能够快速高效的去除水体中铵态氮;当废水中存在Fe3+与Cu2+时,菌株D51仍能去除铵态氮、硝态氮和亚硝态氮。因此,该菌可作为秋冬季节含Fe3+与Cu2+的氮污染废水脱氮的候选菌株,对保护我国环境水体及水资源的再生利用具有重要意义。

在氮污染废水处理技术中,微生物修复具有绿色环保、高效经济等优点,尤其是发现好氧反硝化细菌以后,微生物脱氮技术得到了快速发展,采用好氧反硝化微生物进行生物脱氮处理废水具有许多新的优势,如:（1）生长繁殖快、代时短、培养成本低;（2）有的好氧反硝化细菌能进行同时硝化与反硝化作用,因此,无需额外添加酸碱调节剂;（3）能同时去除多种无机氮等。然而,微生物脱氮过程复杂,不同微生物的脱氮途径有很大差异,目前,对于耐冷微生物的脱氮途径研究缺乏;其次,微生物脱氮会受到许多环境因素的影响,金属离子普遍存在于废水中,不同金属离子对生物脱氮过程的影响系统性研究较少,尤其是对耐冷微生物的影响研究更为缺乏。本文建立在已分离筛选获得的耐冷好氧反硝化菌株Arthrobacter arilaitensis Y-10的基础上,分别研究了耐冷菌株Y-10的脱氮特点及途径,在不同金属离子冲击下的脱氮效率及金属离子对其脱氮影响的机理,主要结果如下:1.在15℃条件下,采用模拟废水研究了菌株Arthrobacter arilaitensis Y-10的脱氮特点。结果表明,铵态氮是最有利于菌株Y-10进行生物脱氮的无机氮。在异养硝化过程中,铵态氮的去除效率可达100%。在同时硝化与反硝化过程中,铵态氮能促进硝态氮的还原。在好氧反硝化过程中,以硝态氮为唯一氮源时,硝态氮的去除效率仅为73.3%。加入等量的铵态氮后会显著提高硝态氮的去除效率,如在铵态氮和硝态氮各5 mg/L的混合氮源中,硝态氮的去除效率可显著增加至85.3%;当铵态氮和硝态氮分别增加至100 mg/L的混合氮源时,硝态氮的去除效率可高达100%。在低浓度的铵态氮和硝态氮混合氮源中只积累了0.02 mg/L的亚硝态氮;在高浓度的铵态氮和硝态氮混合氮源中会产生大量的亚硝态氮积累,最高可达122.23 mg/L。当以初始浓度为10.31 mg/L的亚硝态氮为唯一氮源时,亚硝态氮的去除效率可达100%,在该过程中既不会有铵态氮的产生,也不会有硝态氮的积累。综上所述,菌株Arthrobacter arilaitensis Y-10在15℃条件下能单一地去除铵态氮、硝态氮和亚硝态氮,也能进行同时硝化和反硝化作用去除铵态氮与硝态氮、铵态氮与亚硝态氮混合氮源。2.通过对耐冷菌株Arthrobacter arilaitensis Y-10脱氮中间产物、脱氮酶活性、胞外及胞内亚硝态氮积累等分析,推测该菌的生物脱氮过程。结果表明,以铵态氮为氮源进行异养硝化时,胞外能检测到羟氨的产生,但无亚硝态氮积累,以羟氨为氮源时,胞外产生了0.65 mg/L亚硝态氮的积累。在好氧反硝化过程中,以初始浓度为101.04 mg/L的硝态氮为唯一氮源时,胞外积累了43.66 mg/L亚硝态氮。当以100.03 mg/L的亚硝态氮为氮源时,胞外可检测到2.15 mg/L的铵态氮积累。对氮转化过程中酶活测定发现,氨单加氧酶（AMO）、羟氨氧化还原酶（HAO）和硝酸盐还原酶（NR）的比活分别为0.42、0.0014和0.0049 U/mg蛋白质。此外,亚硝酸盐还原酶能被二乙基二硫代氨基甲酸盐（DDC）完全抑制。在氮转化实验过程中,无论是以有机氮（Luria-Bertani medium LB）为氮源还是以铵态氮、硝态氮或亚硝态氮为单一氮源,均能在胞内检测出大量亚硝态氮积累,积累的亚硝态氮浓度分别为43.0、42.26、39.94和35.01 mg/L,对应的蛋白质浓度分别为532.30、537.15、741.54和718.54 mg/L,因此,胞内亚硝态氮占细胞蛋白质浓度的百分比分别为8.08、7.37、5.38和4.87,这表明以LB为氮源时,胞内亚硝态氮的积累量最大,以铵态氮、硝态氮和亚硝态氮为单一氮源的胞内亚硝态氮积累量呈依次递减趋势。迄今为止,还没有明确的生物化学机制能解释高浓度亚硝态氮积累在胞内的现象。对于菌株Arthrobacter arilaitensis Y-10进行异养硝化和好氧反硝化过程中温室气体CO2和N2O释放量的研究结果表明,分别以铵态氮、硝态氮和亚硝态氮为氮源时,产生CO2的量分别为79.68、74.78和67.18 mg/L,产生的N2O浓度分别为0.06、0.08和0.84 mg/L。由此可看出,产生的N2O浓度显著低于CO2浓度,表明菌株Y-10在生物脱氮过程中产生的氮氧化物对温室气体贡献小,在实际应用过程中比较安全。结合脱氮中间产物、硝化与反硝化抑制剂对生物脱氮过程的影响作用、总氮的去除量及N2O的产生,推测菌株Y-10进行异养硝化脱氮的途径为:铵态氮→羟氨→亚硝态氮→气态氮,好氧反硝化途径为:硝态氮→亚硝态氮→气态氮。且明确N2O不是菌株Y-10进行生物脱氮的主要产物。3.研究了碱土金属[Ca（Ⅱ）、Mg（Ⅱ）]和重金属[Zn（Ⅱ）、Ni（Ⅱ）]离子对菌株Arthrobacter arilaitensis Y-10生物脱氮能力的影响。实验结果表明,菌株Y-10能耐受20 mg/L的Ca（Ⅱ）,在该条件下对铵态氮的去除效率可达100%。以亚硝态氮为唯一氮源时,添加0.5 mg/L的Ca（Ⅱ）能显著提高总氮的去除效率。添加Mg（Ⅱ）能显著提高微生物的生长速率和脱氮效率。当Mg（Ⅱ）浓度由0增加至2 mg/L时,铵态氮、硝态氮和亚硝态氮的去除效率分别增加了40.62%、69.91%和64.68%。然而,菌株Y-10的脱氮能力会受到重金属Zn（Ⅱ）和Ni（Ⅱ）的显著抑制作用。尽管如此,当Zn（Ⅱ）浓度高达30 mg/L时,氮的去除依然能持续进行。但添加8 mg/L的Ni（Ⅱ）时,铵态氮和总氮的去除几乎停止。添加1 mg/L的Ni（Ⅱ）时,菌株Y-10反硝化脱氮能力完全消失。总体表明,碱金属Ca（Ⅱ）和Mg（Ⅱ）,尤其是Mg（Ⅱ）,比重金属Zn（Ⅱ）和Ni（Ⅱ）更有利于提高菌株Y-10的脱氮效率。4.采用非竞争性抑制模型评估铜离子对菌株Y-10去除铵态氮、硝态氮和亚硝态氮的影响。结果表明,铜离子对菌株Y-10去除铵态氮、硝态氮与亚硝态氮的影响趋势基本一致。添加0.25 mg/L的铜离子均能显著提高菌株Y-10去除铵态氮、硝态氮和亚硝态氮的能力。通过改进的非竞争性抑制模型拟合表明,铜离子影响菌株Y-10去除硝态氮和亚硝态氮的半抑制浓度分别为0.195和0.090 mg/L。更为特别的是,添加微量的镁离子可显著提高菌株Y-10的生长速率、氮的去除效率以及对铜离子的耐受性。5.研究了重金属Cd（Ⅱ）、Co（Ⅱ）和Mn（Ⅱ）离子对菌株Y-10异养硝化与好氧反硝化过程的影响。在不同重金属离子的冲击下,同时考虑菌株Y-10的脱氮效率和不同重金属离子影响菌株Y-10生物脱氮的半抑制浓度发现,金属离子对菌株Y-10的生长与脱氮能力的抑制强度顺序为Co（Ⅱ）＞Cd（Ⅱ）＞Mn（Ⅱ）。分别来说,当添加的Cd（Ⅱ）浓度低于2.5 mg/L时,对铵态氮的去除效率没有影响,其去除效率可达100%。当分别添加0.1和0.25 mg/L的Cd（Ⅱ）时,可提高硝态氮和亚硝态氮的去除效率,但高于0.25和0.5 mg/L的Cd（Ⅱ）会分别降低硝态氮和亚硝态氮的去除效率。与之不同的是,添加Co（Ⅱ）会强烈抑制菌株Y-10的生物脱氮过程,尤其是对反硝化过程的影响更为强烈。在反硝化系统中只要添加Co（Ⅱ）,菌株Y-10的生长与生物脱氮过程则立即停止。对添加Mn（Ⅱ）而言,即使Mn（Ⅱ）浓度达到30 mg/L,对菌株Y-10去除铵态氮均无显著影响。添加0.5 mg/L的Mn（Ⅱ）还能显著提高硝态氮和亚硝态氮的去除效率。但继续增加Mn（Ⅱ）离子浓度会显著降低硝态氮和亚硝态氮的去除效率。所有结果表明,与异养硝化去除铵态氮相比,好氧反硝化过程对重金属Cd（Ⅱ）、Co（Ⅱ）和Mn（Ⅱ）的抑制作用更为敏感。6.利用转录组差异基因表达分析,研究锰离子对生物脱氮过程的影响机理。结果表明,无论是以铵态氮还是硝态氮为氮源,与对照组相比,添加锰离子后的处理组与氮代谢相关的基因均发生了明显差异性表达。以铵态氮为氮源时,差异表达基因被注释到GO数据库中与氮代谢相关的有6个基因sdaA、sugE、glnA、NirS、nirK和nirB分别上调了0.77、0.48、0.35、5.17、0.90和0.88倍,与氮代谢相关的另10个基因hutH、aspA、ilvA、amt、nadE、narG、narH、narJ、narI和nirD分别下调了1.77、1.24、1.06、1.02、0.52、2.01、1.80、1.41、1.36、1.33、1.00倍。但这些上调和下调的基因与铵态氮代谢没有直接的关联。在KEGG代谢通路中,仅被注释到的与硝化相关的基因NxrAB表现出了下调作用,余下与硝化过程相关的基因没有受到显著影响。在反硝化过程中,以硝态氮为氮源时,添加锰离子后,菌株Y-10有众多基因表达水平发生了变化,与氮代谢相关的上调基因种类和基因数量均高于下调的基因种类和数量。差异表达基因被注释到GO数据库中与氮代谢相关的10个基因amt、glnA、hutH、nadE、sdaA、sugE、nirB、nirD、nirS和NarK分别上调了3.07、1.82、1.73、1.72、0.67、0.38、3.25、1.84、0.86和0.83倍,与氮代谢相关的另7个基因aspA、glnA、ilvA、narI、narG、narH和narJ分别下调了1.98、0.73、0.68、0.79、0.67、0.41、0.34倍。在KEGG代谢通路中,与铵态氮氧化相关的所有基因包括AmoCAB、Hao和NxrAB均未受到影响,与硝态氮代谢相关的NasB、NirBD、NRT、narK、nrtP和nasA表现出了上调的作用,由于硝态氮转化的过程中会积累大量的亚硝态氮,而在研究亚硝态氮转化效率的实验中,发现亚硝态氮是可以被菌株Y-10继续还原的成气态氮的,在本实验中,亚硝酸盐还原酶基因nirB同样表现出了上调的作用。此外,谷氨酸合酶基因gltB和gltD也表现出了上调作用。综上所述,锰离子对菌株Y-10进行生物脱氮过程的影响主要是通过影响硝化与反硝化过程中基因的转录量来实现的,在反硝化过程中受影响的基因种类和数量比硝化过程中要多,这从基因水平上阐明了菌株Y-10的反硝化过程比硝化过程对金属锰离子的促进或抑制影响更为敏感。

In this study, an eco-friendly Fe2(MoO4)3 was synthesized via template assistant methods for peroxymonosulfate activation to remove RodanminhB (RhB). X-ray photoelectron spectroscopy (XPS) and UV–vis results illustrated the high valence Mo(VI) was the active center to initiate the nonradical-dominated pathway. Electron paramagnetic resonance (EPR) with chemical quenching experiments confirmed the leading role of 1O2 in RhB degradation, which originated from the Mo(IV)/Mo(VI) redox cycle and Mo(VI) peroxo-complex MoO(O2)22–. Also, the improved Fe(II)/Fe(III) cycle produced radicals, like SO4•−and •OH, to assist the degradation process, and promoted Mo(VI) regeneration alongside. 10 mg/L RhB can be completely removed after adding 0.2 g/L Fe2(MoO4)3–4 and 0.1 g/L PMS within 30 min. The effects of PMS and catalyst dosages, initial pH, inorganic anions, and humic acid on RhB degradation were studied and analyzed. Due to the anti-interference of 1O2, Fe2(MoO4)3–4 could sustain its high reactivity from pH 3 to 11. It also contained its original crystal structure with a high degradation rate after five cycle runs. Multiple kinds of dyes and antibiotics were eliminated efficiently within 30 min. The intermediates involved in the reaction were examed by liquid chromatography-mass spectrometry (LC-MS) to propose the degradation pathway of RhB. This work shed light on the overlooked key role of high valence Mo(VI) during PMS activation, instead of traditional low valence Fe(II) or Mo(IV). © 2023 Elsevier B.V.

Conventional perovskite oxides (ABO(3)) tend to suffer from their inactive surfaces and limited active sites that reduce their catalytic activity and stability, while interface engineering is a facile modulating technique to boost the catalyst's inherent activity by constructing heterogeneous interfaces. In this study, perovskite/spinel LaCoO3/Co3O4 nanocomposites with heterogeneous interfaces were synthesized via sol-gel and in-situ gradient etching methods to activate peroxymonosulfate (PMS) for degrading levofloxacin (LEV). LaCoO3 on the surface was etched into spinel Co3O4, and LaCoO3/Co3O4 nanocomposites with two crystal structures of perovskite and spinel were successfully formed. The surface-modified LaCoO3/Co3O4 exhibited superior catalytic performance with a reaction rate constant more than 2 times that of the original LaCoO3, as well as excellent pH adaptability (3-11) and reusability (more than 6 recyclings) for LEV degradation. Besides, multiple characterization tech-niques were carried out to find that LaCoO3/Co3O4 possessed a larger specific surface area and richer oxygen vacancies after surface modification, which provided more active sites and accelerated mass transfer rate. The mechanism of reactive oxygen species involved in the reaction system was proposed that LaCoO3/Co3O4 not only reacted with PMS directly to produce SO4 center dot- and (OH)-O-center dot but also its surface hydroxyl group helped to form the [equivalent to Co (III)OOSO3](+) reactive complex with PMS to produce O-2(center dot-) and O-1(2). In addition, electrochemical experiments demonstrated that the surface electronic structure of LaCoO3/Co3O4 was effectively regulated, exhibiting a faster electron transfer rate and facilitating the redox process. By detecting and identifying degradation intermediates, three degradation pathways for LEV were proposed. Our work provided profound insights into the design of efficient and long-lasting catalysts for advanced oxidation processes.

智慧水务背景下，如何基于人工智能理论与技术深化城市降雨径流模型研究，是一项值得探索的课题。由于城市降雨径流时间分辨率高且样本特征分布不具有规律性，直接采用长短期记忆（LSTM）模型进行预测面临着挑战。基于此，提出用数据挖掘（DM）算法及规则对城市降雨径流时序数据集进行聚类和重构，并基于深度学习算法对LSTM模型的结构和参数进行优化，构建了DM-LSTM耦合模型，并用于研究区域的降雨径流模拟。结果表明，对于各类降雨事件，与LSTM模型相比，DM-LSTM耦合模型的均方根误差（RMSE）降低了2.1%～41.9%，纳什效率系数（NSE）提高了0.4%～56.4%，决定系数（R2）提高了0.3%～65.6%。DM-LSTM耦合模型不仅对各类降雨事件均表现出更好的预测性，而且模型运行时间仅为2.044 s，能够很好地满足城市降雨径流预测对实时性、准确性和稳定性的需求。

为缓解城市化进程中内涝频繁发生、水生态恶化等一系列突出的水环境问题,提高雨水管理措施的效率,城市雨洪模型在城市雨水系统的规划设计和管理中得到了广泛的应用。针对目前国内外广泛使用的城市雨洪模型软件SWMM的参数数量繁多、参数间存在复杂的相关性且大量参数无法直接测定导致模拟结果具有高度不确定性这一科学问题,对关键参数之间的相关性及参数率定过程中可能的影响因素进行探究,以提高参数率定的准确性,从而提高SWMM模型模拟精度。该文以贝叶斯统计理论作为基本框架,结合先进的DREAM（zs）（DiffeRential Evolution Adaptive Metropolis）抽样方法构建了可用于模型参数率定的算法,并以SWMM模型作为研究对象,对可能影响SWMM水文模块参数率定效果的雨强、雨型、汇水区水文特征等一系列外界因素进行探究。分别从参数的抽样轨迹、参数后验分布、参数间相关性、模型模拟值与实测值的拟合情况几个方面分析这些外界因素对参数率定效果的影响,旨在找出用于SWMM模型参数率定的最佳条件,以期进一步提高SWMM模型的率定精度。该研究中的主要方法及结论如下:（1）建立贝叶斯-SWMM模型水文参数率定算法以贝叶斯理论为框架,结合先进的DREAM（zs）抽样方法,选择合适的似然函数,在Matlab中进行贝叶斯理论和DREAM（zs）抽样算法的编程,构建适用于模型率定的算法,并采用一个数值模型论证该率定算法可靠性和效率。利用Matlab编程软件将SWMM模型与上述贝叶斯-DREAM（zs）率定算法进行集成,实现该率定算法在迭代过程中与SWMM模型间的数据交互,可直接用于SWMM模型的参数率定。（2）研究降雨强度对SWMM模型水文参数率定效果的影响设计了9种不同降雨强度的场次降雨,利用以上建立的率定算法探究降雨强度对SWMM模型中8个水文参数率定效果的影响,分别从参数后验分布、参数间的相关性、模型模拟值与实测值的拟合情况几个方面进行分析。结果表明:Width与N-imperv、N-perv,Slope与S-imperv、S-perv之间存在较大的线性相关性;参数间的相互作用对Width、Slope、Zero-imperv三个参数的影响较大,使其灵敏度明显降低;Imperv、S-imperv、N-imperv三个参数的灵敏度较高、识别性好,受雨强影响小,其余参数只有在部分降雨强度下才能有较好的识别效果。结合各降雨强度下参数的率定情况,对本研究中的参数识别效果优劣进行综合排序的结果是:Imperv＞S-imperv＞N-imperv＞Zero-imperv＞N-perv＞S-perv＞Width＞Slope。（3）研究汇水区地表水文特征对SWMM模型水文参数率定效果的影响设置20%、50%和80%三类典型的不透水率,分别代表低、中和高开发程度的地区,以及0.4%和4%两类典型的坡度,分别代表平原和山地城市汇水区域,组合形成6种不同水文特征的汇水区域。选取5种常见雨强的场次降雨进一步探究地表水文特征对参数灵敏度、识别效果的影响。最终得出了不同水文特征下,各参数率定适用的降雨强度表,可供参考。结果表明:汇水区地形对部分参数率定效果的影响存在一定规律性,S-imperv参数在坡度大时,敏感性、识别效果较好（雨强大时除外）;在20%、50%不透水率下,汇水区地形对N-imperv、N-perv、S-perv、Zero-perv四个参数的率定效果有一定影响,但均在雨强较大时表现较为明显。汇水区开发程度对各参数的灵敏度、识别效果的影响差异较大,没有显著规律。汇水区开发程度与地形这两种地表水文特征参数对SWMM模型水文参数后验分布影响较小,不会改变参数间相对灵敏度和识别效果。（4）研究其它外界因素对（降雨峰型、率定数据量）SWMM模型水文参数率定效果的影响除降雨强度外,该研究还进一步探究了单峰、双峰、三峰三种雨型对参数率定效果的影响。结果表明,雨型对参数灵敏度、识别效果影响较大。除Slope和S-Imperv两个参数在单峰雨型下率定效果略好外,其余参数均是在双峰时的灵敏度、识别效果较好。增加率定数据量仅对两个参数的灵敏度、识别效果有提升,但算法的复杂程度、率定过程的计算成本却明显增加。以重庆市悦来新城某一流域作为研究对象,构建SWMM模型。结合建立的贝叶斯-SWMM率定算法以及工程案例中相应的监测数据,分别采用三场降雨进行率定,确定参数取值,并另外选取两场降雨进行验证。结果表明,三场降雨率定的参数后验分布规律与前期研究结论基本一致,且率定期和验证期模拟值与观测值的拟合情况均较好。

Developing a Co-based heterogeneous activator with efficient electron migration is vital for peroxymonosulfate (PMS) activation. Herein we fabricate the Co3O4–MgO@C composite via pyrolysing mixture of ZIF-67 and precursors of MgO and C. The density functional theory calculation and experiment results unveil that the incorporation of MgO@C, which has reversed electronegativity compared to Co, into Co3O4 promoted the overlapping of Co 3d and O 2p orbitals for a faster electron transport ability in the activator. The uplifting d-band center and increasing electron density of Co active sites significantly enhance intrinsic reactivity for PMS activation. TEM and Mott-Schottky plot ((M-S) plot) confirm the formation of p-n heterojunction. Levofloxacin (LEV) removal rate constant (kapp) is 1.04 min−1. It is 2.4-fold and 38.4-fold times those of Co3O4 (0.44 min−1) and MgO@C (0.037 min−1). It exceeds many state-of-art Co-based PMS catalysts. Quenching experiments and electron paramagnetic resonance (EPR) demonstrated SO4•− and 1O2 were the dominant reactive oxygen species. A high degradation rate is maintained from pH 3 to 10 with outstanding reusability and universality towards antibiotics. The effects of ambient ions and humic acid on LEV removal were studied. Reaction temperature experiments revealed the activation energy of Co3O4–MgO@C was 37.3 kJ/mol. This work provides a novel co-doping strategy to modulate electronic configuration for active centers in Co-based heterogeneous activators. © 2023 Elsevier B.V.

The input of pollutants into the lake has ainfluence on the water quality of the lake. Detailing the contribution of water and nutrients from the inflow rivers are essential for lake water management. Major ions Na+ and Cl− were applied to trace contributions of water and total nitrogen (TN) from the inflow rivers to West Dongting Lake. By using the two-source mixing model and the two-component TN mixing model, the results showed that water and TN in West Dongting Lake were mainly contributed by local rivers rather than the three outfalls, in which the contribution of Yuan River was larger than that of Li River. However, the contribution rates of water and TN of the three outfalls to West Dongting Lake during the wet season reached above 20% and 30%, respectively, indicating that the contribution of the three outfalls to West Dongting Lake could not be ignored. Among them, the contributions of Songzi outfall were higher than those from Taiping and Ouchi outfalls. Therefore, we suggest that the relevant departments should identify key river management targets during different water periods, implement refined management over water pollution in West Dongting Lake, and prioritize the pollutant input of Yuran River and Songzi outfall (especially during the wet season). This study demonstrates that major ion tracing is suitable for estimating the contribution rates of different nutrient sources in the river-lake system, which will provide valuable information for protecting the water quality of West Dongting Lake in the future. © 2022 by the authors.