This study was carried out to evaluate the sorption capacity of Pb, As, Cd, Zn, and Mn by laterite from Tam Duong District (Vinh Phuc Province) and Thach That District (Hanoi City). Laterite samples were exposed to different initial concentrations of heavy metals in solutions (2.5, 5.0, 10, 20, and 50 mg/l) at pH = 5.5 during 24 hours. The results demonstrated that sorption capacity of heavy metals was in the following order: Pb> As> Cd> Zn>Mn. The highest sorption capacity of Pb, As, Cd, Zn, and Mn of laterite from Tam Duong was 1553, 756, 397, 281, and 143 mg/kg, respectively and the highest removal efficiency was 94, 76, 70, 56 and 37%. The results indicated that laterite from Tam Duong District showed lower sorption capacity than that from Thach That District. The disparity sorption capacity of Pb, As, Cd, Zn, Mn between laterite from Thach That and Tam Duong was 10.3–11.6, 11.9–17.9, 11.5–13.7, 9.5–17.6, and 11.1–14.3%, respectively. Laterites from Tam Duong and Thach That are a promising environmental material which can be used in the removal of heavy metals from wastewater. / Nghiên cứu này được thực hiện nhằm đánh giá khả năng hấp phụ Pb, As, Cd, Zn, và Mn bởi laterit đá ong khu vực huyện Tam Dương (Vĩnh Phúc) và huyện Thạch Thất (Hà Nội). Mẫu đá ong được tiến hành thí nghiệm trong các dung dịch có hàm lượng kim loại nặng ban đầu khác nhau (2,5; 5,0; 10; 20 và 50 mg/l) tại pH=5,5 trong 24 giờ. Kết quả nghiên cứu cho thấy mức độ hấp phụ kim loại nặng bởi laterit đá ong lần lượt là Pb> As> Cd> Zn>Mn. Dung lượng hấp phụ Pb, As, Cd, Zn và Mn cao nhất của laterit Tam Dương lần lượt là 1553, 756, 397, 281 và 143 mg/kg và hiệu suất hấp phụ cao nhất lần lượt là 94, 76, 70, 56 và 37%. Dung lượng hấp phụ kim loại nặng của laterit huyện Tam Dương thấp hơn khu vực huyện Thạch Thất. Sự chênh lệch về dung lượng hấp phụ Pb, As, Cd, Zn và Mn giữa laterit Thạch Thất và laterit Tam Dương lần lượt là 10,3–11,6; 11,9–17,9; 11,5– 13,7; 9,5–17,6 và 11,1–14,3%. Kết quả nghiên cứu bước đầu cho thấy đá ong khu vực huyện Tam Dương và Thạch Thất là vật liệu hấp phụ tiềm năng phục vụ ứng dụng trong xử lý nước thải bị nhiễm kim loại nặng.

Background Degloving of the sole of the foot is a rare and serious injury because the heel pad cannot be replaced by similar tissue. The management is challenging and only a few cases have been reported with different treatment regimens. - Methods Here, we report on a 46-year-old female patient with complex foot trauma consisting of complete avulsion of the heel pad at the hindfoot and a soft tissue defect at the posterior aspect of the heel accompanied by rupture of the anterior tibial tendon and fractures of the talus, calcaneus and midfoot. The sole of the foot was fixed to the calcaneus with multiple temporary Kirschner wires and moist wound dressings. The anterior tibial tendon was sutured. The soft tissue defect at the posterior heel was treated with a free anterolateral thigh flap. The fractures were fixed in staged procedures. - Results At 2-year follow-up, the patient had a durable soft tissue cover over the heel with full sensation over the sole and pliable flap over the posterior aspect of the heel. The patient was able to fully bear weight and was pain free during her daily activities in comfortable, custom shoes. All fractures had healed, the talar neck fracture after one revision and bone grafting. The foot was plantigrade and stable with preserved painless but limited range of motion at the ankle, subtalar and mid-tarsal joints. - Conclusion The unique tissue at the sole of the foot can be salvaged even in cases of full degloving at the hindfoot with the simple method of anchorage with multiple temporary K-wires. Traumatic defects of the vulnerable skin at the posterior aspect of the heel requires durable coverage with free flap coverage. With staged treatment of all bone and soft tissue injuries, a favorable result can be obtained even in case of a complex foot trauma.

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Biomasseplantagen und Aufforstung zur terrestrischen Kohlenstoffdioxid-Entfernung werden derzeit als Möglichkeit diskutiert um dem anthropogenen Treibhauseffekt entgegenzuwirken. Für die Bewertung solcher Maßnahmen ist ein umfassendes Verständnis ihrer Nachhaltigkeit und möglichen Konsequenzen erforderlich. In dieser Arbeit werden biogeochemische und hydrologische Auswirkungen von Biomasseplantagen und Aufforstung quantitativ und im Kontext der Planetarischen Grenzen (PG) analysiert. Simulationen mit einem globalen Vegetationsmodell zeigen, dass die Auswirkungen von Biomasseplantagen auf die Biosphäre nicht zu vernachlässigen sind und die der historischen landwirtschaftlichen Bodennutzung noch überschreiten können. Außerdem werden Szenarien zur räumlichen Verteilung von Biomasseplantagen unter Berücksichtigung von regionalen und globalen PG für biogeochemische Flüsse, Intaktheit der Biosphäre, Landnutzungswandel und Süßwassernutzung evaluiert. Unter Einhaltung regionaler PG können nur marginale Potentiale erzielt werden. Unter kompletter Ausnutzung des Risikobereichs könnten 1.4-6.9 GtC/a entzogen werden, abhängig von Biomasseverwertungs- und Kohlenstoffspeicherungseffizienzen. Die Relevanz von koevolutionärer Dynamik zwischen dem Kohlenstoffkreislauf und gesellschaftlichem Eingreifen wird mit einem konzeptionellen Modellierungsansatz im Kontext der PG aufgezeigt. Eine Fokussierung auf das Klimaproblem ohne die ganzheitliche Berücksichtigung von erdsystemischen Interaktionen kann ungewollte Überschreitung anderer PG zur Folge haben. Die Kombination von Bevölkerungswachstum und Nahrungsmittelbedarf mit der Minimierung von Kohlenstoff- und Biodiversitätsverlusten zeigt Möglichkeiten und Grenzen für terrestrische Kohlenstoffspeicherung auf. Räumliche Umverteilung in hochproduktive Regionen sowie substantielle landwirtschaftliche Produktivitätssteigerungen ermöglichen die Ernährung von 9 Milliarden Menschen sowie ein Kohlenstoffspeicherungspotential von bis zu 98 GtC. / Terrestrial carbon dioxide removal (tCDR) via afforestation or biomass plantations are discussed as options to counteract anthropogenic global warming. Therefore, it is important to understand sustainability limits and implications of tCDR in the context of Earth system dynamics. This thesis provides a model based assessment of biogeochemical and hydrological side-effects of biomass plantations and afforestation in the context of planetary boundaries (PBs), delimiting a safe operating space for humanity. Simulations with a global vegetation model indicate considerable biogeochemical and hydrological consequences of biomass plantations which are even larger than those of historical agricultural land use. Further, land use scenarios of biomass plantations are developed with a multi-objective optimisation model considering the PBs for biogeochemical flows, biosphere integrity, land system change and freshwater use. Respecting PBs yields almost zero tCDR potential. The transgression of PBs into a zone of increasing risk of feedbacks at the planetary scale can provide considerable tCDR potentials of 1.4-6.9 GtC/a, depending on efficiency of biomass conversion and carbon capture and storage. The importance of co-evolutionary dynamics of the Earth''s carbon cycle and societal interventions through tCDR is demonstrated with a conceptual modelling approach in the context of carbon-related PBs. A focus on climate change without an integrated trade-off assessment may lead to navigating the Earth system out of the safe operating space due to collateral transgression of other PBs. Integrating population growth and food demand while minimising carbon and biodiversity loss demonstrates opportunities and limitations for tCDR. Substantial improvements of crop and livestock productivities and the displacement of agricultural production into regions of high productivity yield sustainable terrestrial carbon sequestration potentials of up to 98 GtC while feeding 9 billion people.

In dieser Dissertation wird ein Prozess für die absorptive CO2-Abtrennung aus Gasströmen vorgestellt, der durch die Nutzung des neu entwickelten Waschmittels GenosorbN in einem Postcombustion-Prozess einen geringeren Energiebedarf als bisher bekannte Verfahren aufweist. Für die Nachrüstung bereits vorhandener Kraftwerke ist der Postcombustion-Prozess vorteilhaft, da er im Vergleich zum IGCC- oder dem Oxyfuel-Verfahren die geringsten Änderungen im Kraftwerksprozess selbst erfordert. Die bisher für die CO2-Abtrennung diskutierten Absorptionsmittel, wie z. B. MEA (Mono-Ethanol-Amin), haben allerdings vor allem in der Regeneration einen sehr hohen Energiebedarf, der vom Kraftwerk zusätzlich zur Verfügung gestellt werden muss. In Zusammenarbeit zwischen dem Institut für Verfahrenstechnik und Umwelttechnik der TU Dresden und der Clariant GmbH wurde das Absorptionsmittel GenosorbN (chemische Bezeichnung: Poly(methyldiglykol)amin) entwickelt. GenosorbN weist als Hybrid-Waschmittel gegenüber CO2 sowohl physikalische als auch chemische Bindungseigenschaften auf. Ausgehend von der Löslichkeitscharakteristik dieses Absorptionsmittels für CO2 und wichtigen Stoffwerten (z. B. Wärmekapazität und Lösungswärme von CO2) wurden mit Hilfe eines umfangreichen Versuchsprogramms an einer Technikumsanlage Betriebsparameter für einen energetisch günstigen technischen Einsatz ermittelt. Dabei hat sich herausgestellt, dass der Absorptionsprozess mit unverdünntem GenosorbN gegenüber einer MEA-Wäsche bei einem CO2-Abscheidegrad von ca. 90 % einen um ca. 20 - 27 % geringeren Energiebedarf in der Waschmittelregeneration aufweisen kann. Außerdem ist für die Desorption ein energetisch minderwertiger Heizdampf mit geringerem Temperatur- bzw. Druckniveau als bei dem MEA-Prozess ausreichend, da die Regenerationstemperatur um 40 - 50 K niedriger ist. Eine zusätzliche Druckabsenkung auf 400 mbar Absolutdruck im Desorber begünstigt die Regeneration deutlich. / This dissertation presents a process for the absorptive CO2-separation from gas streams, which shows a lower energy requirement than established methods by using the newly developed absorption liquid GenosorbN in a postcombustion-process. To retrofit an already existing power plant, the postcombustion-process is advantageous, because it needs the least changes in the power plant-process itself compared to the IGCC- or the Oxyfuel-process. The absorbents discussed for the CO2-separation up to now, for example MEA (mono-ethanol-amine), cause a high energy requirement mainly in the solvent regeneration, which has to be provided additionally from the power plant. The solvent GenosorbN (chemical notation: poly(methyldiglycol)amine) was developed in cooperation between the Institute of Process Engineering and Environmental Engineering of the Technical University of Dresden and the Clariant GmbH. GenosorbN is a hybrid-absorbent and therefore it shows both physical and chemical bonding forces. Based on the solvents characteristic of solubility for CO2 and important data on chemical media (for example heat capacity and enthalpy of solution) operating parameters for an energetic advantageous technical application were identified by a lot of test series at a pilot plant. The measurements show that the absorption process with the undiluted GenosorbN has a circa 20 - 27 % lower energy demand for the solvent regeneration compared to the MEA-process to reach a degree of separation of 90 %. Furthermore a low-value heating steam with lower temperature and therefore lower pressure level suffices because of the significant lower (40 - 50 K) regeneration temperature. An additional pressure reduction to 400 mbar absolute pressure in the regeneration column favours the solvent regeneration considerably.

Nowadays, natural polymeric materials extracted from plants are the new alternatives for synthetic chemicals in water and wastewater treatment. The aim of this study is to evaluate the ability of Cassia fistula seed gum (CFG) as a coagulant aid with PAC in the treatment of textile wastewater. Jartest experiments were carried out to identify the optimal parameters of coagulation-flocculation for removing color and COD in synthesis wastewater containing Methyl blue and RB21 dyes, including pH, settling time, PAC dose, the optimal CFG dosage in comparing with the cationic polymer. After that, actual textile wastewater was treated by using PAC, PAC plus cationic polymer, and PAC plus CFG for evaluating the role of CFG. CFG supplementation has assisted the process effects at nearly 98% color, 85% COD for RB21 and 90% color, 70% COD for MB at the best dose of CFG 0.15 mL and 0.1 mL, respectively. The optimized parameters for the coagulation of real textile wastewater using PAC were pH = 6 and dose = 0.6 mL can removal 66% of color. By adding CFG to PAC, the efficient of treatment was increased about 70% even at the lower dosage of PAC and CFG (0.5 mL for each reagent). The yield of combining PAC and polymer was a little bit lower than PAC and CFG, for instant 68% color was decreased at the same condition. These achievements demonstrated a workable substitute of natural products such as Cassis fistula seed gum for synthetic chemical products in coagulation-flocculation process. / Hiện nay các loại vật liệu sinh học chiết xuất từ thực vật đang được nghiên cứu ứng dụng trong xử lý nước và nước thải thay cho các chất hóa học. Mục tiêu của nghiên cứu này là đánh giá hiệu quả của việc sử dụng gum được chiết xuất từ hạt cây Muồng Hoàng Yến (MHY) làm chất trợ keo tụ trong xử lý nước thải dệt nhuộm. Thí nghiệm Jartest được tiến hành nhằm xác định các điều kiện tối ưu cho quá trình xử lý nước thải tổng hợp chứa thuốc nhuộm Methyle Blue (MB) và RB21 bao gồm pH, thời gian lắng, liều PAC, liều gum MHY và liều polymer. Sau đó tiến hành xử lý nước thải thật với các điều kiện thích hợp đã xác định nhằm đánh giá vai trò của gum MHY. Gum MHY làm tăng hiệu quả của quá trình xử lý, đạt gần 98% đối với độ màu, 85% COD đối với RB21, 90% độ màu và 70% COD đối với MB với liều lượng tương ứng là 0,15 mL và 0,1 mL. Các thông số tối ưu cho quá trình xử lý trên mẫu nước thải thật là pH = 6, liều PAC = 0.6 mL có thể làm giảm 66% độ màu. Bổ sung gum MHY làm chất trợ keo tụ giúp gia tăng hiệu quả xử lý màu lên 70% dù với liều lượng rất thấp là 0,5 mL. Hiệu suất xử lý khi sử dụng kết hợp PAC và polymer thấp hơn trong trường hợp sử dụng PAC và gum MHY, cụ thể khoảng 68% độ màu được xử lý ở cùng một điều kiện. Những kết quả này cho thấy tiềm năng của việc sử dụng các vật liệu gum tự nhiên nhằm thay thế cho các hợp chất hóa học trong các quá trình keo tụ tạo bông để xử lý nước thải.

In dieser Dissertation wird ein Prozess für die absorptive CO2-Abtrennung aus Gasströmen vorgestellt, der durch die Nutzung des neu entwickelten Waschmittels GenosorbN in einem Postcombustion-Prozess einen geringeren Energiebedarf als bisher bekannte Verfahren aufweist. Für die Nachrüstung bereits vorhandener Kraftwerke ist der Postcombustion-Prozess vorteilhaft, da er im Vergleich zum IGCC- oder dem Oxyfuel-Verfahren die geringsten Änderungen im Kraftwerksprozess selbst erfordert. Die bisher für die CO2-Abtrennung diskutierten Absorptionsmittel, wie z. B. MEA (Mono-Ethanol-Amin), haben allerdings vor allem in der Regeneration einen sehr hohen Energiebedarf, der vom Kraftwerk zusätzlich zur Verfügung gestellt werden muss. In Zusammenarbeit zwischen dem Institut für Verfahrenstechnik und Umwelttechnik der TU Dresden und der Clariant GmbH wurde das Absorptionsmittel GenosorbN (chemische Bezeichnung: Poly(methyldiglykol)amin) entwickelt. GenosorbN weist als Hybrid-Waschmittel gegenüber CO2 sowohl physikalische als auch chemische Bindungseigenschaften auf. Ausgehend von der Löslichkeitscharakteristik dieses Absorptionsmittels für CO2 und wichtigen Stoffwerten (z. B. Wärmekapazität und Lösungswärme von CO2) wurden mit Hilfe eines umfangreichen Versuchsprogramms an einer Technikumsanlage Betriebsparameter für einen energetisch günstigen technischen Einsatz ermittelt. Dabei hat sich herausgestellt, dass der Absorptionsprozess mit unverdünntem GenosorbN gegenüber einer MEA-Wäsche bei einem CO2-Abscheidegrad von ca. 90 % einen um ca. 20 - 27 % geringeren Energiebedarf in der Waschmittelregeneration aufweisen kann. Außerdem ist für die Desorption ein energetisch minderwertiger Heizdampf mit geringerem Temperatur- bzw. Druckniveau als bei dem MEA-Prozess ausreichend, da die Regenerationstemperatur um 40 - 50 K niedriger ist. Eine zusätzliche Druckabsenkung auf 400 mbar Absolutdruck im Desorber begünstigt die Regeneration deutlich. / This dissertation presents a process for the absorptive CO2-separation from gas streams, which shows a lower energy requirement than established methods by using the newly developed absorption liquid GenosorbN in a postcombustion-process. To retrofit an already existing power plant, the postcombustion-process is advantageous, because it needs the least changes in the power plant-process itself compared to the IGCC- or the Oxyfuel-process. The absorbents discussed for the CO2-separation up to now, for example MEA (mono-ethanol-amine), cause a high energy requirement mainly in the solvent regeneration, which has to be provided additionally from the power plant. The solvent GenosorbN (chemical notation: poly(methyldiglycol)amine) was developed in cooperation between the Institute of Process Engineering and Environmental Engineering of the Technical University of Dresden and the Clariant GmbH. GenosorbN is a hybrid-absorbent and therefore it shows both physical and chemical bonding forces. Based on the solvents characteristic of solubility for CO2 and important data on chemical media (for example heat capacity and enthalpy of solution) operating parameters for an energetic advantageous technical application were identified by a lot of test series at a pilot plant. The measurements show that the absorption process with the undiluted GenosorbN has a circa 20 - 27 % lower energy demand for the solvent regeneration compared to the MEA-process to reach a degree of separation of 90 %. Furthermore a low-value heating steam with lower temperature and therefore lower pressure level suffices because of the significant lower (40 - 50 K) regeneration temperature. An additional pressure reduction to 400 mbar absolute pressure in the regeneration column favours the solvent regeneration considerably.

Produced water is the largest waste product by volume in the oil industry and its treatment in onshore or offshore fields poses bigger and different challenges than what water engineers are used to encounter. Process to achieve reuse quality of this water is very expensive with many technical hurdles to overcome making the optimization of the treatment steps necessary. Electrocoagulation (EC) generates coagulants in-situ responsible for destabilizing oil droplets, suspended particles, and common pollutant in produced water. Furthermore, EC is a very efficient technology compared with traditional primary treatments used in the oil & gas industry and has several advantages such as: no hazardous chemical handling (which diminishes the risk of accident and logistic costs), high efficiency potential concerning boron removal, potential small footprint and less sludge generation. In this research, the treatment of produced water using EC was investigated in a practical manner for the oilfield to aim for a cleaner effluent for further processing and help to achieve a reuse quality. For this, an EC cell was designed using different parameters normally used in the literature to fit this scenario. After preliminary tests, the treatment time was set to 3 seconds. Response surface method (RSM) was employed to optimize the operating conditions for TOC removal on a broad quality of synthetic produced water while varying: salinity, initial oil concentration and initial pH. TOC was chosen to be the main response because of its importance in legislation and sensibility on the method. Furthermore, turbidity removal, change of pH value after EC in water with lack of buffer capacity, aluminum concentration and preliminary tests involving boron removal and influence of hydrogen carbonate were also studied. Real produced water was treated with EC to assess the optimum conditions obtained by the RSM showing the results were closely related. Finally, an estimation of volume required and operating cost for EC in the different types of produced water was made to assess how realistic it is for onshore and offshore applications.:ERKLÄRUNG DES PROMOVENDEN I ACKNOLEDGEMENT III ABSTRACT V TABLE OF CONTENT VII LIST OF FIGURES IX LIST OF TABLES X LIST OF EQUATIONS XII ABBREVIATIONS XIV 1. INTRODUCTION 1 2. PRODUCED WATER 6 2.1 Characterization of Oilfield Produced Water 6 2.2 Produced Water Management 10 2.2.1 Discharge and Regulations 10 2.2.2 Efforts on Reuse 11 2.2.3 Cost 14 3. PRODUCED WATER TREATMENT 17 3.1 Most Common Primary Treatment 17 3.1.1 Hydrocyclones 17 3.1.2 Flotation unit 18 3.2 Further Water Treatment Technologies 19 3.2.1 Membrane Process 19 3.2.1.1 Microfiltration 19 3.2.1.2 Ultrafiltration 21 3.2.1.3 Nanofiltration 23 3.2.1.4 Reverse Osmosis 24 3.2.1.5 Forward osmosis 24 3.2.2 Electrodialysis 25 3.2.3 Biological treatment 28 3.2.3.1 Aerobic and anaerobic process 28 3.2.3.2 Combining membrane and bio-reactor 29 3.2.4 Oxidative process 30 3.2.4.1 Oxidation process 30 3.2.4.2 Anodic oxidation 32 3.2.5 Thermal technology 34 3.2.5.1 Evaporation 34 3.2.5.2 Eutectic freeze crystallization 35 3.2.6 Adsorption and ion-exchange 36 3.3 Electrocoagulation 39 3.3.1 Colloidal Stability Theory 39 3.3.2 Theory of Electrocoagulation 40 3.3.3 Mechanism of Abatement of Impurities 44 3.3.4 Operational parameters and efficiency 49 4. MATERIALS AND METHODS 51 4.1 Analytical Techniques and Synthetic Solutions 51 4.1.1 Analytical Techniques 51 4.1.2 Synthetic Produced Water 51 4.2 Design of Experiment and Models 54 4.3 Experimental Protocol for EC 56 4 .4 Development of the new Electrocoagulation cell 57 4.5 Real Produced water 58 5. RESULTS AND DISCUSSION 59 5.1 Designing EC Cell Process 59 5.1.1 Computational Fluid Dynamics for EC manufacturing 59 5.2 Preliminary Experiments 61 5.2.1 TOC Removal and Residence Time Determination 61 5.2.2 Aluminum Concentration 64 5.3 Models Quality and Range of Validity 66 5.3.1 TOC Removal 66 5.3.2 Turbidity Removal 69 5.3.3 Final pH value 71 5.3.4 Ionic Strength and Interpolation for Different Salinities 73 5.3.5 Partial Conclusions 76 5.4 Evolution of the Final pH Value 78 5.5 Operation Region for Effective Treatment of Produced Water with EC 80 5.5.1 Produced Water with Low Salinity 80 Organic Compounds Removal 80 Turbidity Removal 83 5.5.2 Produced Water with Medium Salinity 84 Organic Compounds Removal 84 Turbidity Removal 86 5.5.3 Produced Water with High Salinity 87 Organic Compounds Removal 87 5.6 Influence of Hydrogen Carbonate 90 5.7 Real Produced water 91 5.8 Boron Removal 93 5.9 Estimation of the Size for EC in Full scale 94 5.10 Produced Water with Very Low Salinity and EC 95 5.11 Estimation of Operation Cost 96 6. CONCLUSION AND RECOMMENDATIONS 98 6.1 Conclusion 98 6.2 Recommendations for Future Work 101 Scale up on EC for upstream 101 Further processing and reuse 101 Online optimization for EC 101 Recommendations for any research related to upstream produced water 101 BIBLIOGRAPHY 102 APPENDIX A 117 APPENDIX B 120