turbidity

浊度
  • 文章类型: Journal Article
    由于浊度变化,水库中的水的数量和质量会发生变化。本研究明确描述了浊度对水库中水量的影响。本研究旨在评估浊度对Gilgel-GibeI水库水的影响。通过在整个过程中对储层水进行纵向分层来获得样品。用透明的白色塑料包裹的十个洞穴池来保水,用于检测浊度和地表水温度之间的关联,并演示水温的垂直变化。使用放置在现场的两个A级平底锅测量平底锅的蒸发速率,以指示由于水库浊度变化而从水库蒸发的水量的差异。使用SPSS和MSExcel电子表格软件对数据进行分析。根据这项研究的结果,浊度和水温有显著的直接关系,即9:00和13:00时呈正,17:00时呈负。从池水的顶层到底层,水温垂直下降。吸收和散射的光线的强度随着浊度的变化而改变,并且大量的光线在最浑浊的水中被吸收和散射。在13:00观测小时时,顶层和底层之间报告的水温差为9.78°C和1.53°C,对于最多和最不浑浊的池水,分别。浊度通过增加水温和蒸发速率直接影响水库水。在所有浑浊的水样中,大量的水从最浑浊的水中蒸发。对于最多和最不浑浊的水样,水库蒸发水的体积差约为65.812m3。根据这些发现,如果水库水浊度增加,由于大量的水损失,水库中的水量显着减少。
    Quantity and quality of the water held in the reservoir fluctuates due to turbidity alterations. The influence of turbidity on the amount of the water held in a reservoir was described explicitly in this research. This study aimed to evaluate turbidity\'s impact on the Gilgel-Gibe I reservoir water. The samples were obtained by longitudinally stratifying the reservoir water throughout its course. Ten burrowed pools wrapped in transparent white plastic were used to retain water, for detection of the association between turbidity and surface water temperature, and to demonstrate the vertical variation in water temperature. The pan evaporation rate was measured using two Class A pans placed in the field to indicate the disparity in the amount of water evaporated from reservoir owing to reservoir turbidity variation. SPSS and MS Excel spreadsheet softwares were used to analyze the data. According to the results of this study, turbidity and water temperature have a significant direct relationship that is positive at 9:00 and 13:00 and negative at 17:00 observation hours. From the top layer of pool water to the bottom layer, the water temperature decreased vertically. Intensity of the light rays absorbed and scattered alters with turbidity variation and significant amounts of light rays was absorbed and scattered in the most turbid water. The reported water temperature differences between the top and bottom layers at 13:00 observation hour were 9.78 °C and 1.53 °C, for the most and least turbid pool water, respectively. Turbidity directly affects reservoir water by increasing both the water temperature and evaporation rates. Among all turbid-water samples, substantial quantity of water evaporated from the most turbid-water. For the most and least turbid water samples, the volume difference of the evaporated water from the reservoir was approximately 65.812 m3. According to these findings, if the reservoir water turbidity increases, the amount of water held in the reservoir significantly reduced due to substantial water loss.
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  • 文章类型: Journal Article
    本研究涉及不同物理化学参数(pH,电导率(E.C.),浊度,总溶解固体(TDS),和溶解氧)在不同的地表水中,如池塘,河,和运河水在四个不同的季节,viz.March,六月,九月,2023年12月。该研究试图评估阳离子聚电解质的影响,特别是聚(二烯丙基二甲基氯化铵)(PDADMAC),用作与石灰一起进行水处理的助凝剂。采用传统的罐子测试设备,研究了从不同水样中去除浊度的情况。此外,样品进行表征利用X射线衍射(XRD)和扫描电子显微镜(SEM)技术。该研究还对电导率(EC)、pH值,总溶解固体(TDS),原水浊度,聚电解质用量,以及不同水源的浊度去除百分比。利用社会科学统计软件包(SPSS)软件,这些分析旨在建立初始浊度之间的稳健关系,温度,浊度去除百分比,助凝剂的用量,电导率,和池塘水中的总溶解固体(TDS),河水,运河水。在所有地表水的浊度去除百分比与初始浊度值之间可以发现强正相关。然而,聚电解质用量与原水浊度呈负相关。通过阐明这些相关性,该研究有助于更深入地了解PDADMAC和石灰在不同环境条件下的水处理过程中的有效性。这项研究增强了我们对地表水处理方法的理解,并为优化水处理策略提供了有价值的见解,以应对变化的水源和季节性波动带来的挑战。
    The present study deals with the assessment of different physicochemical parameters (pH, electrical conductivity (E.C.), turbidity, total dissolved solids (TDS), and dissolved oxygen) in different surface water such as pond, river, and canal water in four different seasons, viz. March, June, September, and December 2023. The research endeavors to assess the impact of a cationic polyelectrolyte, specifically poly(diallyl dimethyl ammonium chloride) (PDADMAC), utilized as a coagulation aid in conjunction with lime for water treatment. Employing a conventional jar test apparatus, turbidity removal from diverse water samples is examined. Furthermore, the samples undergo characterization utilizing X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The study also conducts correlation analyses on various parameters such as electrical conductivity (EC), pH, total dissolved solids (TDS), turbidity of raw water, polyelectrolyte dosage, and percentage of turbidity removal across different water sources. Utilizing the Statistical Package for Social Science (SPSS) software, these analyses aim to establish robust relationships among initial turbidity, temperature, percentage of turbidity removal, dosage of coagulant aid, electrical conductivity, and total dissolved solids (TDS) in pond water, river water, and canal water. A strong positive correlation could be found between the percentage of turbidity removal and the value of initial turbidity of all surface water. However, a negative correlation could be observed between the polyelectrolyte dosage and raw water\'s turbidity. By elucidating these correlations, the study contributes to a deeper understanding of the effectiveness of PDADMAC and lime in water treatment processes across diverse environmental conditions. This research enhances our comprehension of surface water treatment methodologies and provides valuable insights for optimizing water treatment strategies to address the challenges posed by varying water sources and seasonal fluctuations.
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  • 文章类型: Journal Article
    北极峡湾是海洋碳埋藏的热点地区,硅藻在生物碳泵中起着至关重要的作用。在全球变暖的大背景下,在许多高纬度峡湾,硅藻在浮游植物群落中的比例一直在下降,这是由于冰川融化导致的浊度和寡营养化增加。然而,由于斯瓦尔巴峡湾的栖息地异质性,硅藻对冰川融化的反应也很复杂,这将进一步导致生物碳泵和碳封存的变化。为了解决复杂性,从斯瓦尔巴群岛的三个对比峡湾(Krossfjorden,Kongsfjorden,Gronfjorden),记录了近几十年来显著冰川融化期间峡湾变化的历史。核心K4和KF1中的氨基酸分子指标表明这两个位点之间的有机物降解状态相似。与浑浊的Kongsfjorden和Gronfjorden相反,Krossfjorden中保存的岩藻黄质表明自1980年代中期以来硅藻的持续增加,相当于生物碳泵增加了59%,由沉积有机碳的δ13C量化。Krossfjorden不断增加的生物碳泵进一步归因于其冰川盆地的坚硬岩石类型,与Kongsfjorden和Gronfjorden相比,而是被柔软的岩石覆盖,正如一维模型所证实的。鉴于斯瓦尔巴群岛盆地之间的岩石类型分布,我们推断我们的发现,并提出大约五分之一的斯瓦尔巴峡湾,尤其是那些有坚硬岩石盆地和持久海洋终止冰川的人,仍然有潜力增加硅藻的分数和有效的生物碳泵。我们的发现揭示了峡湾浮游植物响应和生物碳泵对冰川融化增加的复杂性,并强调有必要根据坚硬岩石下的峡湾的结果来修改北极海洋碳对气候变化的反馈。
    Arctic fjords are hotspots of marine carbon burial, with diatoms playing an essential role in the biological carbon pump. Under the background of global warming, the proportion of diatoms in total phytoplankton communities has been declining in many high-latitude fjords due to increased turbidity and oligotrophication resulting from glacier melting. However, due to the habitat heterogeneity among Svalbard fjords, diatom responses to glacier melting are also expected to be complex, which will further lead to changes in the biological carbon pumping and carbon sequestration. To address the complexity, three short sediment cores were collected from three contrasting fjords in Svalbard (Krossfjorden, Kongsfjorden, Gronfjorden), recording the history of fjord changes in recent decades during significant glacier melting. The amino acid molecular indicators in cores K4 and KF1 suggested similar organic matter degradation states between these two sites. In contrast to the turbid Kongsfjorden and Gronfjorden, preserved fucoxanthin in Krossfjorden indicated a continuous increase in diatoms since the mid-1980s, corresponding to a 59 % increase in biological carbon pumping, as quantified by the δ13C of sedimentary organic carbon. The increasing biological carbon pumping in Krossfjorden is further attributed to its hard rock types in the glacier basin, compared to Kongsfjorden and Gronfjorden, which are instead covered by soft rocks, as confirmed by a one-dimensional model. Given the distribution of rock types among basins in Svalbard, we extrapolate our findings and propose that approximately one-fifth of Svalbard\'s fjords, especially those with hard rock basins and persistent marine-terminated glaciers, still have the potential for an increase in diatom fractions and efficient biological carbon pumping. Our findings reveal the complexity of fjord phytoplankton responses and biological carbon pumping to increasing glacier melting, and underscore the necessity of modifying Arctic marine carbon feedback to climate change based on results from fjords underlain by hard rocks.
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  • 文章类型: Journal Article
    目的:使用光学相干断层扫描(OCT)和ImageJ软件评估软性隐形眼镜配戴者(SCL)的泪液半月板参数。
    方法:这项前瞻性研究包括50名软性隐形眼镜配戴者(第1组:25名症状症状性症状性症状性症状配戴者(SCLW),第2组:25名无症状SCL佩戴者(ASCW)和25名健康非CL佩戴者(第3组(NCLW))。SCL安装在CL佩戴者的每只眼睛上,下泪液半月板在CL插入前使用OCT成像,紧接着,并在插入后2、5和10小时重新成像。撕裂弯月面参数,包括撕裂弯月面高度(TMH),深度(TMD),浊度,在所有组中测量颗粒占据的面积百分比(PAOP)。
    结果:SCLW基线时的浊度和PAOP测量值明显高于其他组(p<0.05)。TMH之间无显著差异,TMD,浊度,和PAOP参数计算在基线访视和SCL插入后两小时在所有组(2比较p>0.05)。有症状的SCL使用者在第5小时内TMH和TMD显着降低。SCLW和ASCW在第5小时和第10小时的浊度和PAOP测量值显著高于NCLW(p<0.05)。
    结论:TMD和身高TMH在所有参与者中全天都在下降;然而,仅在第5小时有症状的SCL使用者中观察到这些参数的显着下降,最早。随着CL磨损持续时间的增加,即使无症状的SCL佩戴者的浊度和PAOP也明显高于健康的非CL佩戴者。
    结论:已知情况•佩戴隐形眼镜与干眼症的风险增加有关。•泪液量在隐形眼镜佩戴期间逐渐减少。新增内容•有症状的隐形眼镜佩戴者的泪液半月板浊度和颗粒占据的颗粒面积(PAOP)较高,并且在隐形眼镜佩戴期间逐渐增加。•泪液半月板浊度和PAOP可以是泪膜和半月板在隐形眼镜配戴者中的功能如何的量度。
    OBJECTIVE: To evaluate tear meniscus parameters in soft contact lens wearers (SCL) using optical coherence tomography (OCT) and ImageJ software.
    METHODS: This prospective study included 50 soft contact lens wearers (group 1: 25 symptomatic SCL wearers (SCLW), group 2: 25 asymptomatic SCL wearers (ASCW)) and 25 healthy non-CL wearers (group 3 (NCLW)). SCLs were fitted on each eye of CL wearers, and the lower tear meniscus was imaged using OCT before CL insertion, immediately afterward, and reimaged 2, 5 and 10 h after insertion. Tear meniscus parameters, including tear meniscus height (TMH), depth (TMD), turbidity, and percentage area occupied by particles (PAOP) were measured in all groups.
    RESULTS: Turbidity and PAOP measurements at baseline in SCLW were significantly higher than in other groups (p < 0.05). There was no significant difference between TMH, TMD, turbidity, and PAOP parameters calculated at baseline visit and two hours after SCL insertion in all groups (p > 0.05 for 2 comparisons). The symptomatic SCL users had a significant decrease in TMH and TMD in the fifth hour. The turbidity and PAOP measurements of SCLW and ASCW at the fifth and tenth hours were significantly higher than those of NCLW (p < 0.05).
    CONCLUSIONS: TMD and height TMH decrease throughout the day in all participants; however, a significant decrease in these parameters was observed only in symptomatic SCL users at the fifth hour, at the earliest. As the duration of CL wear increases, turbidity and PAOP even in asymptomatic SCL wearers become significantly higher than those in healthy non-CL wearers.
    CONCLUSIONS: What Is Known • Contact lens wear is associated with an increased risk of dry eye. • Tear volume decreases gradually during contact lens wear. What Is New • Tear meniscus turbidity and particle area occupied by particles (PAOP) were higher in symptomatic contact lens wearers and they increase gradually during contact lens wear. • Tear meniscus turbidity and PAOP may be measures of how well the tear film and meniscus are functioning in contact lens wearers.
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  • 文章类型: Journal Article
    石英砂强化混凝(QSEC)是一种改进的处理水的混凝方法,以石英砂为重介质,加快絮凝物的沉降速率,减少沉降时间。影响QSEC效应且可手动控制的因素包括石英砂用量,混凝剂用量,污水pH值,搅拌时间,稳定时间,等。,它们的合理设置对水处理的结果至关重要。本文旨在研究QSEC的最优条件;首先,进行了单因素试验,以探索影响因素的最佳范围,其次是响应面方法(RSM)测试,以准确确定重要因素的最佳值。结果表明,加入石英砂并没有改善混凝处理的水质,絮凝物仅用了140秒就沉到了底部,泥沙量仅占污水总量的12.2%。石英砂用量,混凝剂用量,和污水pH值均对混凝效果有显著影响,并导致拐点。通过RSM测试得出了QSEC指导模型,和随后的模型优化和实验验证揭示了处理生活污水的最佳条件如下:聚合氯化铝(PAC)用量,阳离子聚丙烯酰胺(CPAM)用量,污水pH值,石英砂用量,搅拌时间,沉降时间为0.97g/L,2.25mg/L,7.22,2g/L,5分钟,30分钟,分别,处理后的污水浊度降至1.15NTU。
    The quartz sand-enhanced coagulation (QSEC) is an improved coagulation method for treating water, which uses quartz sand as a heavy medium to accelerate the sedimentation rate of flocs and reduce the sedimentation time. The factors that influence the QSEC effect and can be controlled manually include the quartz sand dosage, coagulant dosage, sewage pH, stirring time, settling time, etc., and their reasonable setting is critical to the result of water treatment. This paper aimed to study the optimal conditions of QSEC; first, single-factor tests were conducted to explore the optimal range of influencing factors, followed by response surface methodology (RSM) tests to accurately determine the optimum values of significant factors. The results show that the addition of quartz sand did not improve the water quality of the coagulation treatment, it took only 140 s for the floc to sink to the bottom, and the sediment volume only accounted for 12.2% of the total sewage. The quartz sand dosage, the coagulant dosage, and sewage pH all had a significant impact on the coagulation effect, and resulted in inflection points. A QSEC-guiding model was derived through RSM tests, and subsequent model optimization and experimental validation revealed the optimal conditions for treating domestic sewage as follows: the polyaluminum chloride (PAC) dosage, cationic polyacrylamide (CPAM) dosage, the sewage pH, quartz sand dosage, stirring time, and settling time were 0.97 g/L, 2.25 mg/L, 7.22, 2 g/L, 5 min, and 30 min, respectively, and the turbidity of the treated sewage was reduced to 1.15 NTU.
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  • 文章类型: Journal Article
    透明乳液由于其有利的光学性质而被饮料工业用作风味载体。具有小液滴的透明微乳液需要高浓度的表面活性剂,并且通常是不可稀释的,对它们在食品工业中的应用构成了重大挑战。研究了通过调节油组合物和助溶剂的相容性来形成可稀释微乳液。虽然单倍柠檬油总体上表现出较差的装载能力,由于单萜和蔗糖单棕榈酸酯(SMP)之间更强的相互作用,没有发生沉淀。相反,用20%乙醇乳化五倍柠檬油显示出比其他柠檬油更高的负载能力和更强的稀释稳定性。这可能是由于五倍柠檬油中表面活性单萜和其他组分的平衡组成,这促进了胶束空间的有效利用,并有助于稀释后表面活性剂和助溶剂的保留。高级折叠柠檬油的乳化,然而,使用丙二醇作为表面活性剂比乙醇具有更强的稀释稳定性,尽管它需要两倍的共溶剂。较低折叠的柠檬油中高浓度的表面活性单萜与丙二醇竞争界面掺入。这项研究表明,共溶剂和油组合物在生产可稀释的光学透明乳液中起相互作用的作用,它为食品工业设计使用最少表面活性剂的胶体体系提供了蓝图。
    Clear emulsions are used as flavor carriers by the beverage industry because of their favorable optical properties. A transparent microemulsion with small droplets requires a high concentration of surfactants, and is often non-dilutable, posing a significant challenge to their application in the food industry. The formation of dilutable microemulsions by modulating the compatibility of oil composition and co-solvents was studied. While single-fold lemon oil exhibited poor loading capacity overall, no precipitation occurred due to the stronger interaction between monoterpenes and sucrose monopalmitate (SMP). Conversely, emulsification of five-fold lemon oil with 20 % ethanol demonstrated a higher loading capacity and a stronger dilution stability than other lemon oils. This is likely due to the balanced composition of surface-active monoterpenes and other components in five-fold lemon oil which facilitated the effective use of micellar space and aided in the retention of both surfactants and co-solvents post-dilution. The emulsification of higher-folded lemon oil, however, was favored by the use of propylene glycol as a surfactant exhibiting stronger dilution stability than ethanol, though it required twice as much co-solvent. The high concentration of surface-active monoterpene in the lower-folded lemon oils competes with propylene glycol for interfacial incorporation. This study demonstrated that co-solvents and oil composition play interactive roles in producing dilutable optically clear emulsions, and it provides a blueprint for the food industry to design colloidal systems using a minimum of surfactants.
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  • 文章类型: Journal Article
    蓬勃发展的棕榈油行业与全球人口增长和需求激增保持一致。这导致棕榈油厂流出物(POME)的大量产生。POME由灭菌器冷凝液(SC)组成,分离器污泥(SS),和水力旋流器废水(HCW)。相对而言,SS表现出最高的有机含量,造成各种环境影响。然而,过去的研究主要集中在处理最终废水。因此,这项开创性的研究调查了通过生物修复的不同方面优化SS中的污染物去除,包括实验条件,治疗效率,机制,和降解途径。
    采用两级析因设计来优化使用黑曲霉对化学需氧量(COD)和浊度的去除。SS的生物修复是通过深层发酵(SmF)在几个独立变量下进行的,包括温度(20-40°C),搅拌速度(100-200RPM),发酵持续时间(72-240小时),和初始样品浓度(20-100%)。然后将处理过的SS的特性与原始污泥的特性进行比较。
    在37°C100RPM下实现了最佳的COD和浊度去除,156小时,100%污泥方差分析(ANOVA)揭示了选择性个体和相互作用变量的显着影响(p<0.05)。最高COD和浊度去除率分别为97.43%和95.11%,分别,与预测值的误差小于5%。值得注意的是,选定的优化条件也减少了其他污染属性,即,生物需氧量(BOD),油和润滑脂(OG),颜色,和碳含量。总之,这项研究通过应用两级因子设计证明了黑曲霉治疗SS的有效性。
    UNASSIGNED: The booming palm oil industry is in line with the growing population worldwide and surge in demand. This leads to a massive generation of palm oil mill effluent (POME). POME is composed of sterilizer condensate (SC), separator sludge (SS), and hydro-cyclone wastewater (HCW). Comparatively, SS exhibits the highest organic content, resulting in various environmental impacts. However, past studies mainly focused on treating the final effluent. Therefore, this pioneering research investigated the optimization of pollutant removal in SS via different aspects of bioremediation, including experimental conditions, treatment efficiencies, mechanisms, and degradation pathways.
    UNASSIGNED: A two-level factorial design was employed to optimize the removal of chemical oxygen demand (COD) and turbidity using Aspergillus niger. Bioremediation of SS was performed through submerged fermentation (SmF) under several independent variables, including temperature (20-40 °C), agitation speed (100-200 RPM), fermentation duration (72-240 h), and initial sample concentration (20-100%). The characteristics of the treated SS were then compared to that of raw sludge.
    UNASSIGNED: Optimal COD and turbidity removal were achieved at 37 °C 100 RPM, 156 h, and 100% sludge. The analysis of variance (ANOVA) revealed a significant effect of selective individual and interacting variables (p < 0.05). The highest COD and turbidity removal were 97.43% and 95.11%, respectively, with less than 5% error from the predicted values. Remarkably, the selected optimized conditions also reduced other polluting attributes, namely, biological oxygen demand (BOD), oil and grease (OG), color, and carbon content. In short, this study demonstrated the effectiveness of A. niger in treating SS through the application of a two-level factorial design.
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  • 文章类型: Journal Article
    在三天的热熔挤出(HME)连续制造期间监测挤出物制剂的外观。制剂基质由聚合物组分组成,共聚维酮,和低分子量表面活性剂,聚山梨酯80.根据连续制造之前的研究,目标挤出物的所需外观是半透明的。尽管在连续制造过程中,诸如进给速度和螺杆速度等工艺参数是固定的,挤出物外观随时间从浑浊变为半透明。对于根本原因调查,通过差示扫描量热法(DSC)和高级聚合物色谱法(APC™)离线分析挤出物。尽管浑浊和半透明挤出物的聚山梨酯80含量均在目标范围内,混浊挤出物的玻璃化转变温度为高于预期值2°C。观察到的浊度可追溯到连续制造中使用的聚山梨酯80的批次间差异。其中APC™分析揭示低分子量组分的相对含量从23%变化到27%,与从浑浊到半透明挤出物的演变相关。这项工作强调了在连续制造过程中考虑进料可变性的重要性。
    The appearance of an extrudate formulation was monitored during hot-melt extrusion (HME) continuous manufacturing over 3 days. The formulation matrix consisted of a polymeric component, copovidone, and a low molecular weight surfactant, polysorbate 80. Based on studies prior to the continuous manufacturing, the desired appearance of the target extrudate is translucent. Although process parameters such as feed rate and screw speed were fixed during the continuous manufacturing, the extrudate appearance changed over time from turbid to translucent. For root-cause investigation, the extrudates were analyzed offline by differential scanning calorimetry (DSC) and advanced polymer chromatography (APC™). Although the polysorbate 80 content of both turbid and translucent extrudates was within target, the glass transition temperature of the turbid extrudate was 2 °C above expected value. The observed turbidity was traced to lot-to-lot variability of the polysorbate 80 used in the continuous manufacturing, where APC™ analysis revealed that the relative content of the low molecular weight component varied from 23% to 27% in correlation with the evolution from turbid to translucent extrudates. This work stresses the importance of taking feeding material variability into account during continuous manufacturing.
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  • 文章类型: Journal Article
    城市化,农业,气候变化影响湖泊水质和水葫芦生长。本研究考察了湖泊地表水温度的时空变化,浊度,塔纳湖的叶绿素a(Chl-a)及其与水葫芦生物量的关系。MODIS陆地/湖泊地表水温度(LSWT),前哨2MSI图像,并使用了原位水质数据。验证结果表明,MODISLSWT与现场实测水温(R=0.90)有很强的正相关关系。原位浊度和归一化差异浊度指数(NDTI)(R=0.92),和原位Chl-a和归一化差异叶绿素指数(NDCI)(R=0.84)。整个湖泊的LSWT趋势各不相同,随着东北地区趋势的增加,西北,西南地区和西部地区的下降趋势,南方,和中部地区(2001-2022年)。雨前空间平均LSWT趋势显著下降(0.01℃/年),多雨(0.02℃/年),雨季和雨季后(0.01℃/年),而旱季(0.00℃/年)无显着增加(2001-2022年,P<0.05)。各季节空间平均浊度显著下降,除了雨季前(2016-2022年)。同样,雨前和雨季空间平均Chl-a显著下降,而在旱季和雨季后(2016-2022年),它表现出不显著的增加趋势。水葫芦生物量与LSWT(R=0.18)呈正相关,而与浊度(R=-0.33)和Chl-a(R=-0.35)呈负相关。在LSWT中观察到高时空变异性,浊度,Chl-a,随着整体下降趋势。研究结果提出了综合管理策略,以平衡水葫芦的根除及其在水净化中的作用。这些结果对于决策支持系统和制定可持续水资源管理战略计划至关重要,环境保护,和污染预防。
    Urbanization, agriculture, and climate change affect water quality and water hyacinth growth in lakes. This study examines the spatiotemporal variability of lake surface water temperature, turbidity, and chlorophyll-a (Chl-a) and their association with water hyacinth biomass in Lake Tana. MODIS Land/ Lake surface water temperature (LSWT), Sentinel 2 MSI Imagery, and in-situ water quality data were used. Validation results revealed strong positive correlations between MODIS LSWT and on-site measured water temperature (R = 0.90), in-situ turbidity and normalized difference turbidity index (NDTI) (R = 0.92), and in-situ Chl-a and normalized difference chlorophyll index (NDCI) (R = 0.84). LSWT trends varied across the lake, with increasing trends in the northeastern, northwestern, and southwestern regions and decreasing trends in the western, southern, and central areas (2001-2022). The spatial average LSWT trend decreased significantly in pre-rainy (0.01 ℃/year), rainy (0.02 ℃/year), and post-rainy seasons (0.01℃/year) but increased non-significantly in the dry season (0.00 ℃/year) (2001-2022, P < 0.05). Spatial average turbidity decreased significantly in all seasons, except in the pre-rainy season (2016-2022). Likewise, spatial average Chl-a decreased significantly in pre-rainy and rainy seasons, whereas it showed a non-significant increasing trend in the dry and post-rainy seasons (2016-2022). Water hyacinth biomass was positively correlated with LSWT (R = 0.18) but negatively with turbidity (R = -0.33) and Chl-a (R = -0.35). High spatiotemporal variability was observed in LSWT, turbidity, and Chl-a, along with overall decreasing trends. The findings suggest integrated management strategies to balance water hyacinth eradication and its role in water purification. The results will be vital in decision support systems and preparing strategic plans for sustainable water resource management, environmental protection, and pollution prevention.
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  • 文章类型: Journal Article
    饮用水(DW)生产处理可能会受到气候变化的影响。特别是在强降雨事件中,对水源的可用性和质量有影响。本研究提出了一种评估地表水(SW)和地下水(GW)不同处理步骤成本的方法,通过对主要成本项目的分析和量化。它提供了详细信息,以计算严重降雨后进水关键质量参数的强烈变化(即浊度,铁,锰,和大肠杆菌)。然后将此方法应用于意大利的大型饮用水处理厂(DWTP),既对待SW,70%左右,GW,30%左右。它讨论了2019-2021年期间的总DW生产成本(从7.60c€/m3到10.43c€/m3),并分析了水和污泥列车中不同处理步骤的贡献。然后,它着重于由于强烈的降雨而引起的SW浊度(高达1863NTU)显着变化的处理效果,以及DW相对于年度评估的平均(基准)成本的每日成本。它出现了,当SW具有低浊度水平时,基于能源的步骤对成本的贡献最大(SW的最终抽水为22%,GW的最终抽水为10%,提取15%和14%,分别),而在非常高的浊度水平下,污泥大大增加,其处理和处置成本变得巨大(高达14%和50%)。现正努力在这些不利条件下采取最佳策略管理DWTPs,目的是保证饮用水和优化水生产成本。缓解措施包括将GW提取增加到授权流量,从而减少SW撤回。在这种情况下,通过仅处理从河岸过滤中提取的GW,讨论了DWTP的潜在升级,从而完成了这项研究。DW生产成本为7.76c€/m3,低于当前工厂配置的同年(2021年)(8.32c€/m3)。
    Drinking water (DW) production treatments can be affected by climate change, in particular intense rainfall events, having an impact on the availability and quality of the water source. The current study proposes a methodology for the evaluation of the costs of the different treatment steps for surface water (SW) and groundwater (GW), through the analysis and quantification of the main cost items. It provides the details to count for strong variations in the key quality parameters of inlet water following severe rainfalls (namely turbidity, iron, manganese, and E. coli). This methodology is then applied to a large drinking water treatment plant (DWTP) in Italy, which treats both SW, around 70 %, and GW, around 30%. It discusses the overall DW production costs (from 7.60 c€/m3 to 10.43 c€/m3) during the period 2019-2021 and analyzes the contributions of the different treatment steps in water and sludge trains. Then it focuses on the effects on the treatments of significant variations in SW turbidity (up to 1863 NTU) due to intense rainfalls, and on the daily costs of DW with respect to the average (baseline) costs evaluated on the annual basis. It emerges that, when SW has low turbidity levels, the energy-based steps have the biggest contribution on the costs (final pumping 22 % for SW and 10 % for GW, withdrawal 15 % and 14 %, respectively), whereas at very high turbidity levels, sludge greatly increases, and its treatment and disposal costs become significant (up to 14 % and 50 %). Efforts are being made to adopt the best strategies for the management of DWTPs in these adverse conditions, with the aim to guarantee potable water and optimize water production costs. A mitigation measure consists of increasing GW withdrawal up to the authorized flow rate, thus reducing SW withdrawal. In this context, the study is completed by discussing the potential upgrading of the DWTP by only treating GW withdrawn from riverbank filtration. The DW production cost would be 7.76 c€/m3, which is lower than that seen for the same year (2021) with the current plant configuration (8.32 c€/m3).
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