TY - JOUR A1 - Wang, Hao A1 - Wang, Xue-jiang A1 - Wang, Wei-shi A1 - Yan, Xiang-bo A1 - Xia, Peng A1 - Chen, Jie A1 - Zhao, Jian-fu T1 - Modeling and optimization of struvite recovery from wastewater and reusing for heavy metals immobilization in contaminated soil JF - Journal of chemical technology & biotechnology N2 - BACKROUND: Few studies have been carried out to connect nutrients recovery from wastewater and heavy metals immobilization in contaminated soil. To achieve the goal, ammonia nitrogen (AN) and phosphorus (P) were recovered from rare-earth wastewater by using the formation of struvite, which was used as the amendment with plant ash for copper, lead and chromium immobilization. RESULTS: AN removal efficiency and residual P reached 95.32 +/- 0.73% and 6.14 +/- 1.72mgL(-1) under optimal conditions: pH= 9.0, n(Mg): n(N): n(P)= 1.2: 1: 1.1, which were obtained using response surface methodology (RSM). The minimum available concentrations of Cu, Pb and Cr (CPC) separately reduced to 320.82 mg kg(-1), 190.77 mg kg(-1) and 121.46 mg kg(-1) with increasing immobilization time at the mass ratio of phosphate precipitate (PP)/plant ash (PA) of 1: 3. Humic acid (HA) and fulvic acid (FA) were beneficial to immobilize Cu, both of which showed no effect or even a negative effect on Pb and Cr immobilization. KW - precipitation KW - experimental design KW - immobilization KW - heavy metals KW - environmental remediation Y1 - 2016 U6 - https://doi.org/10.1002/jctb.4931 SN - 0268-2575 SN - 1097-4660 VL - 91 SP - 3045 EP - 3052 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Wang, Wei-shi A1 - Oswald, Sascha A1 - Gräff, Thomas A1 - Lensing, Hermann Josef A1 - Liu, Tie A1 - Strasser, Daniel A1 - Munz, Matthias T1 - Impact of river reconstruction on groundwater flow during bank filtration assessed by transient three-dimensional modelling of flow and heat transport JF - Hydrogeology journal : official journal of the International Association of Hydrogeologists N2 - Bank filtration (BF) is an established indirect water-treatment technology. The quality of water gained via BF depends on the subsurface capture zone, the mixing ratio (river water versus ambient groundwater), spatial and temporal distribution of subsurface travel times, and subsurface temperature patterns. Surface-water infiltration into the adjacent aquifer is determined by the local hydraulic gradient and riverbed permeability, which could be altered by natural clogging, scouring and artificial decolmation processes. The seasonal behaviour of a BF system in Germany, and its development during and about 6 months after decolmation (canal reconstruction), was observed with a long-term monitoring programme. To quantify the spatial and temporal variation in the BF system, a transient flow and heat transport model was implemented and two model scenarios, 'with' and 'without' canal reconstruction, were generated. Overall, the simulated water heads and temperatures matched those observed. Increased hydraulic connection between the canal and aquifer caused by the canal reconstruction led to an increase of similar to 23% in the already high share of BF water abstracted by the nearby waterworks. Subsurface travel-time distribution substantially shifted towards shorter travel times. Flow paths with travel times <200 days increased by similar to 10% and those with <300 days by 15%. Generally, the periodic temperature signal, and the summer and winter temperature extrema, increased and penetrated deeper into the aquifer. The joint hydrological and thermal effects caused by the canal reconstruction might increase the potential of biodegradable compounds to further penetrate into the aquifer, also by potentially affecting the redox zonation in the aquifer. KW - bank filtration KW - groundwater KW - surface-water relations KW - groundwater modelling Y1 - 2019 U6 - https://doi.org/10.1007/s10040-019-02063-3 SN - 1431-2174 SN - 1435-0157 VL - 28 IS - 2 SP - 723 EP - 743 PB - Springer CY - Berlin ; Heidelberg [u.a.] ER - TY - GEN A1 - Wang, Wei-shi A1 - Oswald, Sascha A1 - Gräff, Thomas A1 - Lensing, Hermann-Josef A1 - Liu, Tie A1 - Strasser, Daniel A1 - Munz, Matthias T1 - Correction: Impact of river reconstruction on groundwater flow during bank filtration assessed by transient three-dimensional modelling of flow and heat transport. - Hydrogeology Journal. - Berlin: Springer. - 28 (2020) , S. 723. - https://doi.org/10.1007/s10040-019-02063-3 T2 - Hydrogeology journal : official journal of the International Association of Hydrogeologists T2 - Erratum: Impact de la reconstruction d’une rivière sur l’écoulement des eaux souterraines via la filtration sur berge évalué par un modèle tridimensionnel en régime transitoire de l’écoulement et du transport de chaleur. - Berlin: Springer. - 28 (2020) , S. 723. - https://doi.org/10.1007/s10040-019-02063-3 T2 - Erratum: Impacto de la restauración de un río en el flujo de agua subterránea durante la filtración en las márgenes, evaluado mediante la modelización tridimensional transitoria del flujo y el transporte de calor. - Berlin: Springer. - 28 (2020) , S. 723. - https://doi.org/10.1007/s10040-019-02063-3 Y1 - 2020 U6 - https://doi.org/10.1007/s10040-020-02221-y SN - 1431-2174 SN - 1435-0157 VL - 28 IS - 7 SP - 2633 EP - 2634 PB - Springer CY - Berlin ; Heidelberg ; New York, NY ER - TY - JOUR A1 - Wang, Hao A1 - Wang, Xuejiang A1 - Wang, Weishi A1 - Su, Yinglong A1 - Zhao, Jianfu T1 - Reuse of a phosphorus recovery product (struvite/palygorskite) from nutrient wastewater for copper remediation in aqueous solution and soil JF - Geoderma : an international journal of soil science N2 - In this study, a phosphorus recovery product, struvite palygorskite (S-PAL), obtained from nutrient-rich wastewater by using MgO modified palygorskite was applied for copper remediation in aqueous solution and contaminated soil to achieve waste recycling. The effects of contact time, initial pH, initial Cu(II) concentration and reaction temperature on Cu(II) adsorption in aqueous solution were intensively testified. Pseudo-second-order model was able to properly describe Cu(II) adsorption kinetics by using palygorskite (PAL) and S-PAL, and S-PAL exhibited higher adsorption amount (106.27 mg/g) than PAL (8.46 mg/g) at pH of 4. Cu(II) adsorption on PAL and S-PAL could be well fitted by Freundlich isotherm and Langmuir isotherm, respectively. The calculated thermodynamic parameters indicated that Cu(II) adsorption onto PAL and S-PAL were spontaneous and endothermic. A 28-day soil incubation experiment was conducted to evaluate the effects of PAL and S-PAL with three different rates (1%, 5% and 10% w/w) on Cu immobilization in contaminated soil. In the immobilization test, Cu extracted by 0.01 mol/L CaCl2 after seven days incubation significantly decreased with increasing rate of PAL and S-PAL. BCR sequential extraction results showed the significant decrease of acid soluble Cu and a concomitant increase of the residual fraction of Cu after S-PAL and PAL addition. XRD patterns of soil samples after treatment by PAL and S-PAL showed the formation of Cu0.6Mg1.3Si2O6 and Cu-3.04(PO4)(2)OH0.08 center dot 2H(2)O, which indicated that silanol groups and phosphate exhibited affinity for Cu in the soil. KW - palygorskite KW - struvite KW - adsorption KW - copper immobilization KW - waste reuse Y1 - 2020 U6 - https://doi.org/10.1016/j.geoderma.2019.113955 SN - 0016-7061 SN - 1872-6259 VL - 357 PB - Elsevier Science CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Pan, Xiaohui A1 - Wang, Weishi A1 - Liu, Tie A1 - Huang, Yue A1 - De Maeyer, Philippe A1 - Guo, Chenyu A1 - Ling, Yunan A1 - Akmalov, Shamshodbek T1 - Quantitative detection and attribution of groundwater level variations in the Amu Darya Delta JF - Water N2 - In the past few decades, the shrinkage of the Aral Sea is one of the biggest ecological catastrophes caused by human activity. To quantify the joint impact of both human activities and climate change on groundwater, the spatiotemporal groundwater dynamic characteristics in the Amu Darya Delta of the Aral Sea from 1999 to 2017 were analyzed, using the groundwater level, climate conditions, remote sensing data, and irrigation information. Statistics analysis was adopted to analyze the trend of groundwater variation, including intensity, periodicity, spatial structure, while the Pearson correlation analysis and principal component analysis (PCA) were used to quantify the impact of climate change and human activities on the variabilities of the groundwater level. Results reveal that the local groundwater dynamic has varied considerably. From 1999 to 2002, the groundwater level dropped from -189 cm to -350 cm. Until 2017, the groundwater level rose back to -211 cm with fluctuation. Seasonally, the fluctuation period of groundwater level and irrigation water was similar, both were about 18 months. Spatially, the groundwater level kept stable within the irrigation area and bare land but fluctuated drastically around the irrigation area. The Pearson correlation analysis reveals that the dynamic of the groundwater level is closely related to irrigation activity within the irrigation area (Nukus: -0.583), while for the place adjacent to the Aral Sea, the groundwater level is closely related to the Large Aral Sea water level (Muynak: 0.355). The results of PCA showed that the cumulative contribution rate of the first three components exceeds 85%. The study reveals that human activities have a great impact on groundwater, effective management, and the development of water resources in arid areas is an essential prerequisite for ecological protection. KW - groundwater level variation KW - climate change KW - human activities KW - statistical analysis KW - Amu Darya Delta Y1 - 2020 U6 - https://doi.org/10.3390/w12102869 SN - 2073-4441 VL - 12 IS - 10 PB - MDPI CY - Basel ER - TY - THES A1 - Wang, Weishi T1 - Influence of river reconstruction at a bank filtration site T1 - Wasserqualität und 3D-Modellierung des Grundwasserflusses und des Wärmetransports BT - water quality field investigation and 3D modelling of groundwater flow and heat transport N2 - Bank filtration is an effective water treatment technique and is widely adopted in Europe along major rivers. It is the process where surface water penetrates the riverbed, flows through the aquifer, and then is extracted by near-bank production wells. By flowing in the subsurface flow passage, the water quality can be improved by a series of beneficial processes. Long-term riverbank filtration also produces colmation layers on the riverbed. The colmation layer may act as a bioactive zone that is governed by biochemical and physical processes owing to its enrichment of microbes and organic matter. Low permeability may strongly limit the surface water infiltration and further lead to a decreasing recoverable ratio of production wells.The removal of the colmation layer is therefore a trade-off between the treatment capacity and treatment efficiency. The goal of this Ph.D. thesis is to focus on the temporal and spatial change of the water quality and quantity along the flow path of a hydrogeological heterogeneous riverbank filtration site adjacent to an artificial-reconstructed (bottom excavation and bank reconstruction) canal in Potsdam, Germany. To quantify the change of the infiltration rate, travel time distribution, and the thermal field brought by the canal reconstruction, a three-dimensional flow and heat transport model was created. This model has two scenarios, 1) ‘with’ canal reconstruction, and 2) ‘without’ canal reconstruction. Overall, the model calibration results of both water heads and temperatures matched those observed in the field study. In comparison to the model without reconstruction, the reconstruction model led to more water being infiltrated into the aquifer on that section, on average 521 m3/d, which corresponded to around 9% of the total pumping rate. Subsurface travel-time distribution substantially shifted towards shorter travel times. Flow paths with travel times <200 days increased by ~10% and those with <300 days by 15%. Furthermore, the thermal distribution in the aquifer showed that the seasonal variation in the scenario with reconstruction reaches deeper and laterally propagates further. By scatter plotting of δ18O versus δ 2H, the infiltrated river water could be differentiated from water flowing in the deep aquifer, which may contain remnant landside groundwater from further north. In contrast, the increase of river water contribution due to decolmation could be shown by piper plot. Geological heterogeneity caused a substantial spatial difference in redox zonation among different flow paths, both horizontally and vertically. Using the Wilcoxon rank test, the reconstruction changed the redox potential differently in observation wells. However, taking the small absolute concentration level, the change is also relatively minor. The treatment efficiency for both organic matter and inorganic matter is consistent after the reconstruction, except for ammonium. The inconsistent results for ammonium could be explained by changes in the Cation Exchange Capacity (CEC) in the newly paved riverbed. Because the bed is new, it was not yet capable of keeping the newly produced ammonium by sorption and further led to the breakthrough of the ammonium plume. By estimation, the peak of the ammonium plume would reach the most distant observation well before February 2024, while the peaking concentration could be further dampened by sorption and diluted by the afterward low ammonium flow. The consistent DOC and SUVA level suggests that there was no clear preference for the organic matter removal along the flow path. N2 - Die Uferfiltration, eine wirksame Wasseraufbereitungstechnik, ist an Europas großen Flüssen weit verbreitet. Es bezieht sich dabei hauptsächlich auf einen Prozess, wobei das Oberflächenwasser in das Flussbett eindringt, durch den Grundwasserleiter fließt und schließlich durch ufernahe Brunnen gewonnen wird. Beim Einströmen in den unterirdischen Aquifer verbessert sich die Wasserqualität durch eine Reihe von vorteilhaften Reaktionen, die jedoch langfristig zum Auftreten von Kolmation des Flussbetts führen. Aufgrund der Anreicherung von Mikroben und organischen Substanzen bildet sich die Kolmationsschicht einerseits als bioaktive Zone für zahlreiche biochemische Reaktionen; andererseits kann ihre geringe Permeabilität die Infiltration von Oberflächenwasser behindern, welches zur Produktivitätseinschränkung von Brunnen führt. Daher ist das Entfernen der Kolmationsschicht immer ein Kompromiss zwischen Behandlungskapazität und Effizienz. Diese Doktorarbeit zielt darauf ab, die zeitlichen und räumlichen Veränderungen der Wasserqualität und -menge entlang des Fließwegs eines hydrogeologisch heterogenen Uferfiltrat-Standorts nahe einem baulich vertieften Kanal (Ausbaggerung und Ufersanierung) in Potsdam zu untersuchen. Zur Quantifizierung der durch die Kanalvertiefung hervorgerufenen Änderung auf die Infiltrationsrate, die Laufzeitverteilung und das thermische Feld wurde ein dreidimensionales Strömungs- und Wärmetransportmodell mit zwei Modellszenarien (mit und ohne Baumaßnahmen) erstellt. Insgesamt stimmten die Kalibrierungsergebnisse der Wasserstände und der Temperaturen mit den Beobachtungen überein. Die Modellierungsergebnisse zweier Szenarien zeigten, dass durch die Vertiefung durchschnittlich 521 m3/d, was etwa 9% der Gesamtpumprate entspricht, mehr Wasser in den Grundwasserleiter geflossen ist. Die unterirdische Fliesszeit verkürzte sich. Die Anzahl der Fliesswege mit Fliesszeiten <200 Tage erhöhten sich um ca. 10% und jene mit <300 Tage um 15%. Darüber hinaus breitete sich die Wärme im Grundwasserleiter tiefer und weiter im Modell mit Baumaßnahmen aus. Mittels Streudiagrammen von d18O und d2H konnte das infiltrierte Flusswasser vom landseitigen Grundwasser unterschieden werden, während eine dekolmationsbedingte Erhöhung des Flusswasseranteils in Brunnen durch Piper-Diagramme nachgewiesen werden konnte. Die geologische Heterogenität verursachte erhebliche horizontale und vertikale Unterschiede in der Redox-Zonierung zwischen verschiedenen Strömungsbahnen. Das Redoxniveau verändert sich in verschiedenen Brunnen durch die Baumaßnahme. Die Behandlungseffizienz für organische und anorganische Stoffe blieb unabhänig von der Baumaßnahme erhalten, mit Ausnahme von Ammonium. Dies ist wohl auf die Änderung der Kationenaustauschkapazität im neu ausgebaggerten Flussbett zurückzuführen, das noch nicht in der Lage war, neu entstehendes Ammonium zu absorbieren, was zu einem Fortschreiten der Ammonium-Fahne führt. Schätzungsweise erreicht das Maximum der Ammonium-Fahne den entferntesten Brunnen vor Februar 2024, wobei sich die Konzentration durch Sorption und Vermischung mit nachströmendem Wassser verringern sollte. Das gleichbleibende DOC- und SUVA-Niveau deutete darauf hin, dass es keine Bevorzugung beim Abbau organischer Substanzen entlang des Fließwegs gab. KW - Bank filtration KW - Groundwater modelling KW - Heat transport KW - Geological heterogeneity KW - Decolmation KW - Wärmetransport KW - Uferfiltration KW - Grundwassermodellierung KW - Geologische Heterogenität KW - Dekolmation Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-490234 ER -