Conservation and restoration of wetlands have become a global priority as awareness of their importance increases. At present, efforts to restore wetlands have primarily focused on enhancing water quality and biodiversity, with little attention paid to analyzing the recovery of the food web. We investigated the differences in food web attributes between natural and restored wetlands in Qingtongxia wetlands on the upper reaches of the Yellow River, China. Our results showed that there were no significant differences in the community structure of aquatic organism (fish, macroinvertebrates, zooplankton, phytoplankton and macrophytes) and water parameters (TP, TN, DO, et al.) between natural and restored wetlands. Restored wetlands had higher total system throughput and primary productivity compared to natural wetlands, which increased the proportion of the detritus food chain in the energy supply. However, energy transfer at the system level was less efficient than in natural wetlands. Indices of cycling, path length and network analysis showed that the restored wetland was less mature but more stable than the natural wetland. Given the inconsistency of food web recovery with water variables and aquatic assemblages, integrating community and food web approaches in future wetland restoration will be critical to refining restoration goals and enhancing conservation efforts.

Mountain ecosystems exhibit rapid changes in vegetation cover and climate conditions along elevation gradients, offering an ideal natural experiment to examine variations in the molecular composition of soil organic carbon (SOC) responsing to environmental change. We examined molecular composition, diversity, and network complexity of SOC using the pyrolysis-gas chromatography/mass spectrometry technology and the Shannon diversity index (SHDI) in Changbai Mountain (CBS). Results indicated that molecular composition of SOC differed greatly across different vegetation zones, which were predominated by mixed coniferous and broad-leaved forests (HJL), mixed coniferous forests (ZYL), birch forest covered (YHL), and tundra vegetation (TYD). ZYL had remarkably more abundant moieties with aromatic structures, 36% on average, than those in HJL, TYD, and YHL, 18.31%, 12.75% and 16.51% on average, respectively. O-alkyl, alkyl, and terpene compounds showed an increasing trend, whereas aromatic, lignin and nitrogen-containing compounds exhibited a notable decrease with elevation to a significant level. Either alpha diversity or beta diversity of SOC varied significantly among TYD, YHL, ZYL, and HJL, with HJL exhibiting the lowest alpha diversity. SOC from ZYL was the most complex, showing the highest number of edges and graph density. Leaf litter elements greatly regulated the molecular diversity and network complexity of SOC. Positive correlations between SHDI and SOC contents, as well as ratios of SOC to total iron, suggested that high molecular diversity promoted SOC persistence in mountain ecosystems.

Healthy aquatic ecosystems are essential for human beings. However, anthropogenic activities severely worsen water quality. In this study, using assembling mesocosms, we developed an efficient and easy-to-handle method to monitor the water quality by measuring the electrical conductivity (EC) of water. Our data demonstrate that the growth of two submersed macrophytes, Vallisneria natans and Vallisneria spinulosa, improves water quality by decreasing EC. Furthermore, using high-throughput DNA sequencing, we analyzed the microbial community abundance and structure in sediment and water columns with or without plant growth. We generated 33,775 amplicon sequence variants from 69 samples of four sediment groups (BkM, CtM, VnR, and VsR) and three water column sample groups (CtW, VnW, and VsW). The results show that the relative abundance of bacteria was higher in the sediment than in the water column. Moreover, the diversity and composition of microbiomes were altered by Vallisneria spp. growth, and the α-diversity of the microbial communities decreased due to submersed macrophytes in both the sediment and water columns. The β-diversity of the microbial communities also varied significantly with or without Vallisneria spp. growth for both the sediment and water columns.

Conventional methodology for accurate identification of breast tumor subtypes is complex and time-consuming. Label-free SERS (surface-enhanced Raman scattering) enables rapid detection of biomolecules and provides intrinsic fingerprint information of analytes. Exploring reliable SERS bioprobes with high sensitivity and repeatability is essential for efficient typing of cancer cells. In this study, a novel core-shell noble metal-semiconductor Cu2O@Ag heterostructure with uniform morphology and outstanding SERS activity for label-free detection has been proposed. The Cu2O@Ag SERS substrates exhibit exceptional sensitivity to detect 4 nitrophenthiol (4NTP) at extreme low concentration (10−15 M), and the SERS spectra demonstrate excellent selectivity and repeatability (RSD ≈ 8.84%). The enhancement mechanism is attributed to the synergistic enhancement of photoinduced charge transfer and boosted surface plasmon resonance effect, confirmed by reduced fluorescence lifetime of methylene blue on SERS substrates and enhanced electromagnetic field intensity via finite-difference time-domain computational simulation. The ultrahigh sensitivity and good signal stability endow Cu2O@Ag SERS bioprobe potential for accurate detection of four breast cancer cells subtypes. The rich fingerprint information from SERS spectra is processed using linear differentiation analysis, revealing a high accuracy of 93.3% for subtypes classification. These results demonstrate an excellent SERS bioprobe with high sensitivity and repeatability for precision diagnosis has been developed.

Ammonium (NH4+) is a significant component of fine aerosol particles (PM2.5), and its behavior in the atmosphere is crucial to air pollution. We present a novel study that analyzes the vertical distribution and temporal trends of NH4+ in the urban boundary layer of Beijing, tracking hourly concentrations throughout a complete haze episode. Our results unveil a surprising single-peak profile of NH4+ at heights of 300-700 m in the urban boundary layer with its hourly concentration reaching similar to 50 mu g m(-3), which is 3 times higher than that at the ground level, in contrast to the conventional patterns of decreasing concentrations with height. The vertical structure is closely related to the observed escape of ammonia (NH3) or NH4+ from upwind industrial sources via elevated chimneys. The NH4+ plumes emitted through these sources are prone to transport at an altitude of 270-750 m for approximately 6 h, covering >250 km to Beijing. This study reveals that non-agricultural point emissions of NH4+ impact the vertical patterns of aerosol NH4+ in the urban boundary layer, demonstrating potential opportunities for limiting such emission sources to curb PM2.5 pollution in the North China Plain.

以石墨烯基膜电容电吸附对质量浓度2000,3000,4000 mg/L模拟苦咸水进行了脱盐试验研究,测试了进水流量、通电电压等操作条件对其脱盐性能的影响,在相同条件下与反渗透对质量浓度2000 mg/L苦咸水的脱盐情况进行了对比.结果表明:石墨烯基膜电容电吸附对3种浓度苦咸水的脱盐率均先在极短时间内升至最大,达到95％以上,然后再缓慢减小.当进水流量相同时,在一定范围内,电压越高,脱盐率越高,运行能耗越大,但随着苦咸水浓度的提升,电压对脱盐率的影响逐渐减弱,当电压恒定时,在一定范围内,进水流量越小,脱盐率越高,运行能耗越大.反渗透对质量浓度为2000 mg/L的苦咸水的脱盐率先在短时间内迅速升至最大,达到99.57％,后维持稳定,反渗透在脱盐率方面优于石墨烯基膜电容电吸附,但在能耗方面稍占劣势.

传统生物滞留池氮磷去除效果差,对抗生素等新兴污染物的去除效能尚不清晰,通过添加活性炭层、铁粒构建微生物燃料电池改进生物滞留池,考察了其对化学需氧量(COD)、氨氮(NH4+-N)、总氮(TN)、总磷(TP)、磺胺甲恶唑(SMX)、四环素(TC)的去除效能.结果表明,较常规生物滞留池,强化型生物滞留池对TP的去除率提高了20％,稳定运行105 d且无释磷现象;在进水投加0.8 mg/L抗生素(SMX/TC)的条件下,强化型生物滞留池对SMX和TC的去除率分别为99.62％和99.67％,较常规生物滞留池分别提高了67.66％和35.24％;投加SMX/TC并未对强化型生物滞留池COD、TP的去除产生抗生素胁迫,且对TN和NH4+-N的去除产生显著性促进作用,去除率分别提高了29.47％和26.09％.

建立饮用水中8种有机氯的自动固相微萃取(SPME)与气相色谱-三重四极杆质谱法(GC-QQQ-MS/MS)同时测定的快速分析方法.通过实验,优化了固相微萃取纤维涂层的选择、萃取时间、温度和质谱参数等萃取条件.使用三重四极杆质谱的多反应监测(MRM)模式扫描,以聚二甲基硅氧烷(PDMS)萃取头(100μm),在50℃下转速350 r/min萃取40 min.在质量浓度为2.0～50.0μg/L线性范围内,该方法对水中8种有机氯所得的回归方程均具有较好的线性关系,R值为0.9977～0.9995,检出限为0.059～0.103μg/L.质量浓度20.0μg/L加标水样的8种有机氯回收率在79.2％～112.8％之间,6次平行测定的RSD范围在6.9％～10.9％之间.该方法分析速度快、灵敏度高,能够同时准确定性,且无需溶剂对环境友好.

氟是焦化废水中的待去除的主要污染物.采用FeCl3和AlCl3作为絮凝剂,研究了絮凝对焦化废水中氟和有机物的去除效果,并考查了不同剂量和pH条件下氟和有机物的去除率.结果 表明:AlCl3和FeCl3对F-的最高去除率分别为94.4％和27.3％;在投量为20 mmol·L-1时,FeCl3和AlCl3的TOC去除率分别达到27.6％和23.9％.因此,AlCl3对氟的去除率比FeCl3的更高,但FeCl3对有机物的去除率相对更高.加入Ca2+可以促进氟的去除,但有机物的去除率会下降.另外,通过考察不同pH和铁铝配比对去除率的影响,探讨了同时加入FeCl3和AlCl3的去除效果.结果 表明,最适合去除有机物和氟的工作条件是pH为6.5,AlCl3和FeCl3的比值为8∶2.本研究探索了FeCl3和AlCl3对焦化废水中氟和有机物的去除机理,实验结果可为焦化废水的深度处理提供参考.

Capping water body sediments with a thin layer of sand is an effective technique to decrease nutrient concentrations in the water column and accelerate ecological restoration of eutrophic water bodies. However, long-term effects of thin-layer sand capping in shallow lakes are reported less often. Using clean fine sand and geotextile mats as capping materials for sediments collected from Wuhan Donghu Lake in China, we designed a 290-day tank experiment with 3 cm of sand capping at four percentages of sediment coverage from 25 to 100% and a control (no capping). We monitored total nitrogen (TN), total phosphorus (TP), nitrate (NO 3 − ), ammonia (NH 4 + ), and soluble reactive phosphorus (SRP) in the overlying water every 7 days. Mean TN and NO 3 − concentrations were significantly the lowest ( P < 0.05) at 50% coverage. Further increase in coverage kept them slightly fluctuating. NH 4 + concentration was significantly lowest ( P < 0.05) at 75% coverage. The relation between coverage and mean TP and SRP concentrations indicated that 75% coverage significantly decreased ( P < 0.05) them, and increasing coverage to 100% decreased them even more. The fluxes of TN and TP estimated between sediments and overlying water showed that the thin fine-sand layer significantly increased the function of sediments as a sink of TN from overlying water and the potential of a sand layer to block release of TP from sediments ( P < 0.05). Our results suggested that if thin-layer sand capping were applied to Wuhan Donghu Lake, more than 50% coverage is required to decrease nutrients in the lake’s water.

为考察乡土植物对当地生活污水的净化效果,探究乡土植物替代外来引种植物应用于水体修复的可能性,选取聚花草(Floscopa scandens)、疏穗莎草(Cyperus distans)、线叶水芹(Oenanthe linearis)、石龙芮(Ranunculus sceleratus)和鱼腥草(Houttuynia cordata)5种广东省乡土植物,以不同浓度梯度的自配溶液模拟生活污水,分析几种植物对化学需氧量(COD)、总氮(TN)、氨氮(NH4-N)和总磷(TP)的去除效果.结果 表明,5种乡土植物对生活污水均具有明显的净化效果,且各植物之间净化效果差异显著.疏穗莎草处理生活污水的效果最好,高浓度污水处理下,对COD、TN、NH4+-N和TP的去除率分别为89.56％、82.66％、88.89％和83.32％(20 d);鱼腥草对TN和NH4+-N的去除效果明显,各浓度污水处理下,其对TN的去除率为83.52％～85.50％,NH4+-N的去除率为77.40％～89.33％,但对磷元素的净化效果较差,适合治理高氮低磷污染类型;聚花草对TP的去除效果明显,不同浓度梯度污水处理下,其去除率最高可达91.43％,建议应用于低氮高磷的生活污水治理.

文章在圆柱状填充床生物反应器中成功启动硫自养反硝化过程,系统运行稳定后,第60天,在反应器进水中加入适量的葡萄糖(C/N=5∶1)将自养条件改变为混养条件,NO3--N去除率由75％提升到95％以上,并消除NO2--N积累现象.通过分析高通量测序结果发现:葡萄糖的加入对系统的微生物群落有很大的影响,变形菌门(Proteobacteria)和绿弯菌门(Chloroflexi)丰度减少,酸杆菌门(Acido-bacteria)和Latescibacteria几近消失,而拟杆菌门(Firmicutes)和硬壁菌门(Bacteroidetes)的丰度却有较大的提升.从属水平的分析结果对比发现:硫酸杆菌属(Th iobacillus)和硫磺菌属(Sulfurimonas)在硫自养反硝化系统中占比高达33.7％和16.9％,加入葡萄糖后丰富度分别降到11.7％和9.6％,而unclassified_f_Enterobacteriaceae,Gemmobacter,明串珠菌属(Trichococcus)以及假单胞菌属(Pseudomonas)等异养或者混养反硝化菌属丰度明显增加.

目的 探究碱性电解水对农产品中的黄曲霉毒素的消除作用.方法 用不同浓度的碱性电解水处理黄曲霉毒素样品,去离子水处理样品作为对照品,氮吹仪干燥,样品衍生后采用进行高效液相色谱法检测,确定碱性电解水对大米样品中黄曲霉毒素B1(aflatoxin B1,AFB1)的去除量.结果 高浓度的碱性电解水的AFB1去除率接近100％.电解水体积(V)与样品质量(m)的比值2:1(V:m)时,去除效率接近90％,且不引入二次污染物.细菌培养实验表明,处理后的化合物不存在细胞毒性.不同处理组的色泽、味觉和其他感官指标均无显著差异(P>0.05),在处理过程中没有明显的营养流失.结论 本方法快速简便、准确, 适用于消除农产品中的黄曲霉毒素.

为了解乡土水生植物净化富营养化水体的效果,研究了广东地区5种乡土水生植物对2种富营养化水体总氮(TN)、总磷(TP)的净化效果和植物的生长状况.结果表明,与无植物空白相比,5种乡土植物使低、高浓度水体的TN去除率分别提高了3.8％～13.3％和13.2％～17.1％,TP去除率分别提高了15.2％～22.1％和11.3％～57.6％,其中野荸荠(Eleocharis plantaginei-formis)适用于净化低氮水体;酸模叶蓼(Polygonum lapathifolium)适用于高氮水体;三白草(Saururus chinensis)适用于低磷水体;菱角(Trapa komarovii)适用于低氮或高磷水体;水龙(Ludwigia adscendens)对2种水体均有较好的净化效果,对高磷水体效果极佳.5种乡土植物在低、高浓度水体中均旺盛生长,水龙的生物量净增长率分别达375.5％和539.8％,表现最优,其次为菱角;水葫芦(Eichhornia crassipes)则在高浓度水体中腐烂死亡,加重了水体污染.水龙、菱角对污染物的吸收作用较强,对P的吸收能力显著优于其他植物(P<0.05).因此,5种乡土植物均可作为广东地区富营养化水体修复的备选植物,其中水龙和菱角的开发潜力最大.

探讨了影响国标法测定水中硫化物准确度的主要影响因素.研究表明:为减少干扰,反应温度设置为20 ± 2℃,显色反应时间设置为10 min较佳, 在该条件下, 方法校准曲线具有良好的线性, 相关系数>0.999, 加标回收率为90.0%~101%,相对标准偏差()<3.7%(= 6).质控样的测量结果均在保证值范围内,说明实验室监测能力处于受控状态.

采用浸渍法在多孔氧化铝基板表面依次制备微孔过渡膜和超滤膜,形成具有梯度孔结构的陶瓷超滤膜.详细考察了浸浆次数和烧结温度对膜微观结构和孔径大小的影响.结果表明,通过二次涂膜,在多孔氧化铝基板表面获得了膜厚约30 μm,孔径约200 nm的微孔过渡膜,其最佳烧结温度为1200℃;通过一次涂膜,在过渡膜表面获得了孔径小于3.6nm的超滤膜,其最佳烧结温度为1100℃.

以苯乙酮与4-羟基苯甲酰肼为原料,N,N-二苯基硫脲为催化剂合成了苯乙酮-2-羟基苯甲酰腙,并通过元素分析、红外光谱分析、核磁共振H谱、热重分析等手段对其结构进行了表征。结果表明:在回流条件下,催化剂用量为0.7991g,反应6h时,酰腙收率可达52.43%;导电性能测试结果表明,配合物溶液比配体溶液导电性能好,Mn配合物溶液电导率高达3.160×102μs/cm。

A new acylhydrazone compound of 4-hydroxybenzaldehyde benzoyl hydrazone was synthesized through the condensation of 4-hydroxybenzaldehyde and benzoyl hydrazine. It catalyzed by 1,5-diphenylcarbazide. The effects of the amount of catalyst and the reaction time on the yield was discussed. The results show that the amount of catalyst was 15% of the reactant and the reaction time was 6. 0 h under reflux,the yield of 4-hydroxybenzaldehyde benzoyl hydrazone reached 88. 61%.