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Effects of Rainfall and Polysilicon Industrial Pretreated Effluent on Biological Nitrogen RemovalLu, Yi-chieh 04 September 2012 (has links)
The biological treatment is one of the commonly methods of wastewater treatment plant in wastewater treatment processes. The biological treatment can meet water quality standards required by the plant in response to different sewage conditions and qualities. It can purify high pollution loading sewage through the use of microbial metabolic transformation. Through effectively protecting and using water resources, the ecological balance of ocean and river can be maintained and environmental quality can be improved in consequence.
This study analyzes the operations of a wastewater treatment plant, which is part of an urban sewage system. The major sources of inflow to the plant are domestic sewage, followed by rainfall runoff and industrial wastewater. The biological treatment system adopted in the plant is "Biological Nutrient Removal (BNR)". The reason for using BNR is to prevent eutrophication of downstream water bodies due to untreated nitrogen, phosphorus and other nutrient substances in discharged sewages. The design of BNR, which is called "A2O activated sludge method", would increase the anaerobic-anaerobic mixing process for simultaneous removal of the sewage of organic carbon, nitrogen, phosphorus and BOD.
The study collected the data to analyze the impacts of extreme weather event, i.e. Typhoon Morakot, and the effects of newly developed industrial, i.e. polysilicon industry. Water quality data of inflow and outflow sewages starting from January 2009 to December 2011 were compiled to perform statistical analyses. By plotting various time series figures, the study can effectively explore the variations of pollutant removal under the two designated situations in the biological treatment system.
The results show the abnormal increase in conductivity of effluent which has decreased pollutant removal since August 2010. Besides, the confluence of rainwater and sewage has severely affected the efficiency and quality of the biological treatment process during a typhoon or heavy rain event. This study has identified the potential impacts on a BNR plant which can provide the administration to enhance the effectiveness of the biological treatment plant and the function of sewage purification stability control.
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Selenium as paleo-oceanographic proxy: a first assessmenMitchell, Kristen Ann 05 April 2011 (has links)
Selenium (Se) is an essential trace element, which, with multiple oxidation states and six stable isotopes, has the potential to be a powerful paleo-environmental proxy. In this study, Se concentrations and isotopic compositions were analyzed in a suite of about 120 samples of fine-grained marine sedimentary rocks and sediments spanning the entire Phanerozoic. While the selenium concentrations vary greatly (0.22 to 72 ppm), the δ82/76Se values fall in a fairly narrow range from -1 to +1 , with the exception of laminated black shales from the New Albany Shale formation (Devonian), which have δ82/76Se values of up to +2.20 . Black Sea sediments (Holocene) and sedimentary rocks from the Alum Shale formation (Late Cambrian) have Se/TOC ratios and δ82/76Se values close to those found in modern marine plankton (1.72x10-6±1.55x10-7 mol/mol and 0.42±0.22 ). (Note: TOC = total organic carbon.) For the other sedimentary sequences, the Se/TOC ratios indicate enrichment in selenium relative to marine plankton. Additional input of isotopically light terrigenous Se (δ82/76Se ≈ -0.42 ) may explain the Se data measured in recent Arabian Sea sediments (Pleistocene). The very high Se concentrations in sedimentary sequences that include the Cenomanian-Turonian Ocean Anoxic Event (OAE) 2 possibly reflect a significantly enhanced input of volcanogenic Se to the oceans. As the latter has an isotopic composition (δ82/76Se ≈ 0 ) not greatly different from marine plankton, the volcanogenic source does not impart a distinct signature to the sedimentary Se isotope record. The lowest δ82/76Se values are observed in the OAE2 samples from Demerara Rise and Cape Verde Basin cores (δ82/76Se = -0.95 to 1.16 ) and are likely due to fractionation associated with microbial or chemical reduction of Se oxyanions in the euxinic water column. In contrast, a limiting availability of seawater Se during periods of increased organic matter burial is thought to be responsible for the elevated δ82/76Se values and low Se/TOC ratios in the black shales of the New Albany Shale formation. Overall, our results suggest that Se data may provide useful information on paleodepositional conditions, when included in a multi-proxy approach.
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Integrating Methods for Characterizing the Passive Treatment of Mercury and Selenium in Groundwater and SedimentGibson, Blair Donald January 2011 (has links)
Standard geochemical analysis methods, such as aqueous geochemistry analysis and mineralogical analysis, frequently are utilized to evaluate the effectiveness of passive treatment systems, though they do not necessarily provide information regarding the mechanism of removal. Two emerging analytical techniques have shown promise by providing additional information to improve characterization of treatment systems: X-ray absorption spectroscopy (XAS) and stable isotope analysis. In this thesis, these novel analytical techniques were integrated with standard geochemical measurements to better characterize contaminated sites as well as potential treatment technologies used to mitigate aqueous contaminant mobility. Laboratory experiments were used to evaluate the removal of Se(VI) form simulated groundwater using granular Fe0 (GI) and organic carbon (OC). Greater than 90 % removal of Se(VI) was observed for systems containing GI after 5 days of reaction time and only 15 % removal was observed in systems containing OC. Synchrotron radiation-based XAS analysis of the treatment materials indicated the presence of both Se(IV) and Se(0) on the edges of GI grains after 6 hours reaction time, with no evidence of oxidized Se after 5 days of reaction. Several analytical techniques were integrated to characterize sediment contaminated with Hg and other contaminants through previous industrial practices. Analysis of the sediment by XAS indicated the possible presence of mercury selenide and copper sulfide. Resuspension tests were performed in oxic and anoxic conditions to simulate the effects of changing geochemical conditions of Hg release from sediments during dredging operations. The results indicated a higher release of Hg under oxic conditions in some sediment locations, suggesting that oxidative degradation of organic carbon or oxidative dissolution of Hg sulfides contributed to Hg release. The treatment of aqueous Hg(II) was evaluated with a variety of treatment media, including clay and GI. Treatment with GI was rapid, with 90 % removal observed after 2 hours reaction time. Extended X-ray absorption fine structure (EXAFS) analysis indicated the presence of Hg-O bonding on GI, suggesting that Hg was bound to Fe oxides formed on the surface of corroded GI. A new conceptual model for tracking the stable isotope fractionation of sulfur was coupled to the reactive transport model MIN3P to determine the effects of secondary transformations on sulfur cycling in passive treatment systems. Minor differences were noted when comparing the transport model-derived fractionation factor to calculations using a simplified Rayleigh distillation model, possibly indicating the effect of SO4 precipitation. The incorporation of stable isotope modeling provides a framework for the modeling of other isotope systems in treatment technologies.
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Submarine plateau volcanism and Cretaceous Ocean Anoxic Event 1a : geochemical evidence from Aptian sedimentary sections /Walczak, Paul S. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 73-79). Also available on the World Wide Web.
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Effects of Calcium Depletion and Loading on Injury During Metabolic Inhibition of Isolated Adult Rat MyocytesRim, Dianne S., Altschuld, Ruth A., Ganote, Charles E. 01 January 1990 (has links)
The hypothesis that calcium influxes from the extracellular space play an important role in the pathogenesis of irreversible anoxic injury was tested using isolated adult rat myocytes. Myocytes treated with 6 mm amytal and 3 mm iodoacetate and subsequently incubated in either calcium-containing (1.12 mm) or calcium-free media (with or without 1 mm EGTA) developed rigor contracture (cell squaring) and cell death (trypan blue permeability) at the same rate. The rates of cell death in both calcium-containing and calcium-free media were increased by incubation in hypotonic media even though the rates of contracture development remained unaltered. Cells developed osmotic fragility prior to membrane permeability increases. The calcium ionophore, A23187 (10 μm), induced rapid rounding of rod-shaped cells subjected only to mitochondrial inhibition in calcium containing media, confirming its ability to cause an increase in cellular permeability to calcium. However, A23187 did not alter the rates of cell death of totally metabolically inhibited myocytes in either calcium-containing or calcium-free media with EGTA. The results indicate that influxes of calcium are not necessary for the development of irreversible injury in metabolically inhibited, isolated myocytes.
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Biological Treatment of Nitrophenol Containing Wastewater Using Ethanol and Acetic Acid as SubstratesSurendran, Suvid 06 August 2010 (has links)
No description available.
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Characterization of a highly acid watershed located mainly in Perry County, OhioEberhart, Ryan J. January 1998 (has links)
No description available.
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Evaluating redox cycling across the Toarcian Oceanic Anoxic Event with implications for paleo-environmental reconstructions and organic matter sulfurizationMarroquin, Selva Mariana 09 December 2020 (has links)
Understanding oxygenation throughout Earth history, particularly intervals where marine deoxygenation occurred, are crucial to investigating the changes in habitability on Earth. Marine deoxygenation events, in particular, can result in changes in the carbon, sulfur, and iron cycles on our planet. Changes in these elemental cycles lead to distinctive variation in the chemical composition of seawater that is recorded in marine sediments that are preserved into the sedimentary record. Our modern ocean is experiencing rapid deoxygenation, thus understanding the duration and extent of ancient deoxygenation events is vital to predicting future climate scenarios. Here I investigated the record of environmental change during the Early Jurassic Toarcian Oceanic Anoxic Event or T-OAE (~183 Ma).
The first chapter of this dissertation investigates the record of marine anoxia across the Pliensbachian to Toarcian transition. Specifically, I investigate the temporal and geographic development of anoxia across three basins from the European Epicontinental Seaway. Through utilization of iron speciation, a local redox proxy, I identify anoxia developing before and persisting well after the negative carbon isotope excursion (NCIE) conventionally used to define the T-OAE. These data indicate an increase in the occurrence of anoxia at the Pliensbachian – Toarcian boundary, coincident with the initial phase of volcanism associated with the Karoo-Ferrar Large Igneous Province and an interval of heightened marine invertebrate extinction. Ultimately, our data support a greater temporal extent of anoxic conditions around the T-OAE, which support the greater sensitivity of marine oxygen levels to climatic change outside of the NCIE interval.
The second chapter of this dissertation assesses the occurrence and extent of organic matter sulfurization (OMS), a biogeochemical feedback known to enhance the preservation and burial of OM. Because this process is accelerated when euxinic conditions develop in the water column, I investigated it as a mechanism promoting OM burial across two oceanic anoxic events of the Mesozoic. Importantly, I find that sulfurization does not occur uniformly across both events and propose a conceptual model of the depositional settings most favorable for sulfurization to occur and when throughout geologic time OMS is most likely to influence the global cycles of carbon and sulfur. / Doctor of Philosophy / Understanding past time intervals where there was widespread loss of oxygen in the oceans is crucial to understanding habitability on Earth. Since our modern oceans are experiencing a rapid loss of oxygen, understanding the duration and extent of ancient marine oxygen loss events is vital to predicting future habitability of the oceans. These ancient events can result in distinctive changes in the carbon, sulfur, and iron cycles on our planet. Variation in these elemental cycles lead to distinctive shifts in the chemical composition of seawater that is recorded in marine sediments that get preserved as rocks in the geologic record. Here, I investigated the record of environmental change during the Early Jurassic Toarcian Oceanic Anoxic Event or T-OAE (~183 Ma).
The first chapter of this dissertation investigates the record of marine oxygen loss across the T-OAE. Specifically, I investigate the temporal and geographic development of oxygen loss across three ancient marine basins. Through utilization of a local tracer of water column oxygen loss (e.g. iron speciation) I identify oxygen loss developing before and persisting well after the conventional timeframe associated with the event. These data indicate oxygen loss first occurred before the T-OAE, coincident with the initial phase of volcanic eruptions from the Karoo-Ferrar Large Igneous Province and an interval of heightened marine extinction. Ultimately, these data support a longer time interval of oxygen loss around the T-OAE and the greater sensitivity of marine oxygen levels to climatic change.
The second chapter of this dissertation assesses the occurrence and extent of organic matter sulfurization (OMS), a feedback known to enhance the preservation and burial of organic matter (OM). Because this process is accelerated when oxygen is lost and free sulfur builds up in the water column, I investigated its occurrence across two oceanic oxygen loss events of the Mesozoic Era. Importantly, I find that sulfurization does not occur uniformly across both events and propose a conceptual model of the settings most favorable for sulfurization to occur and also when in geologic time it is most likely to influence the global cycling of carbon and sulfur.
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The Investigation of Nitrite Accumulation and Biological Phosphorus Removal in an Intermittently Aerated Process Combining Shortcut Nitrogen Removal and Sidestream Biological Phosphorus RemovalPrintz, Kathryn Elizabeth 22 November 2019 (has links)
The research in this thesis was conducted at the Hampton Road Sanitation District's biological nutrient removal pilot, located at the Chesapeake-Elizabeth WWTP in Virginia Beach, VA. The pilot is operated in an A/B process with a high-rate, carbon-diverting A-stage, followed by a biological nitrogen removal B-stage containing four intermittently aerated CSTRs, followed by an anammox polishing MBBR. The goal of this research was to successfully combine short-cut nitrogen removal with sidestream enhanced biological nutrient removal (EBPR) in the most efficient way possible, specifically aiming to decrease cost and energy requirements, divert the most amount of carbon possible before B-stage, and to achieve low effluent nitrogen and phosphorus concentrations.
A RAS fermenter (SBPR) and an A-stage WAS fermenter that feeds VFA into the SBPR (the supernatant of the fermenter is called fermentate) were implemented in order to enhance biological phosphorus removal. About 8 months after the RAS and WAS fermenter implementation, there was a 28 day consecutive period of low B-stage effluent OP <1 mg/L, with an average of 0.5 ± 0.1 mg/L OP. Following this low effluent OP period, bio-P became more unstable and there was high nitrite accumulation in the B-stage effluent for 106 days with concentrations ranging from 1.1-5.9 mg/L NO2. The nitrite accumulation was not due to NOB out-selection, confirmed by AOB and NOB maximum activity tests. It was determined that the nitrite accumulation was due to partial denitrification of nitrate to nitrite by bacteria using internally stored carbon, because profiles and activity tests showed anoxic nitrite accumulation at the end of the aerobic process. Post-anoxic denitrification using internally stored carbon compounds has been observed in other EBPR systems (Vocks, Adam, Lesjean, Gnirss, and Kraume, 2005).
Fermentate addition was then halted, and nitrite accumulation and bio-P activity ceased all together, linking the fermentate addition to both bio-P activity and nitrite accumulation. Fermentate was then controlled to dose at 60% of the sCOD/OP (fermentate sCOD g/day / total OP- fermentate + influent - g/day) of the first low effluent OP period. During this fermentate dosing period where the average sCOD/OP was 15.6 ± 3.0 g/g, no nitrite accumulation was observed, but another consecutive low effluent OP period was observed with an average of 0.6 ± 0.2 mg/L OP.
Linear correlation analysis shows that the highest r2 values relating the low effluent OP periods and the COD loads to the SBPR for both periods were between VFA g/day vs OP effluent mg/L, at r2=0.18 for the first low effluent OP period and r2=0.65 for the second. There were also high tCOD r2 values for the second low effluent OP period showing that COD hydrolysis in the SBPR could have impacted bio-P activity. However, the VFA r2 value was higher than any tCOD r2 value, concluding that the fermentate dosing mainly worked to enhance biological phosphorus removal by increasing the VFA load in g VFA as acetate/day. Since no nitrite was observed in a period with a lower VFA/OP dose, then the probable VFA load needed to provide enough internal storage to produce nitrite accumulation by partial denitrification is between 5-9 (g VFA as acetate/ g total OP). If sidestream EBPR systems could be studied further to promote nitrite accumulation and bio-P activity to produce low effluent OP, then short-cut nitrogen removal and EBPR could be successfully combined in an efficient way. / Master of Science / It is important to reduce nitrogen and phosphorus concentrations in wastewater treatment effluent in order to both protect the environment from eutrophication and to meet the increasingly stringent nutrient effluent discharge limits imposed by the EPA. Conventional biological nitrogen removal is achieved through nitrification and denitrification converting ammonia to nitrogen gas, where nitrogen gas is volatile and leaves the system naturally. Phosphorus removal can be achieved through either chemical addition or through biological phosphorus removal, where phosphorus is taken up in cells and removed from the system by the subsequent solids wasting of these cells. The combination of biological nitrogen and phosphorus removal can be improved to increase energy efficiency, reduce costs including aeration and chemical addition costs, increase system capacity and reduce tank sizes, and reduce biomass production, all while achieving low effluent N and P concentrations.
Short-cut nitrogen removal can increase the efficiency of biological nitrogen removal. Deammonification, the combination of partial nitritation and anammox, has the potential to reduce wastewater treatment plant (WWTP) aeration costs by 63%, carbon requirements by 100%, and biomass production by 80% (Nifong, Nelson, Johnson, and B. Bott, 2013). Deammonification is the combination of partial nitritation and anammox. Anaerobic ammonia oxidation (anammox) is a useful class of bacteria that converts ammonia and nitrite straight to nitrogen gas in anaerobic conditions, which is a more direct pathway than the conventional nitrification-denitrification pathway. Anammox requires a nitrite supply, which can supplied by partial nitratation of ammonia to nitrite, performed by ammonia oxidizing bacteria (AOB) aerobically in the deammonification process. In order for partial nitratation to work, there needs to be nitrite oxidizing bacteria (NOB) out-selection so that the nitrite produced by AOB does not get oxidized to nitrate.
Enhanced biological phosphorus removal (EBPR) is accomplished by the taking up and storing of orthophosphate (OP) by phosphorus accumulating organisms (PAOs). These organisms require an anaerobic carbon-storage phase followed by an aerobic growth phase where the internally stored carbon is used for growth. During the cell growth phase of PAOs in aerobic conditions, PAOs are able to take up more OP than they previously released in anaerobic conditions, creating a net OP removal from the system. There has been recent success in recycle activated sludge (McIlroy et al.) fermentation to enhance biological phosphorus removal, which works to promote hydrolysis, fermentation, and EBPR enhancement (Houweling, Dold, and Barnard, 2010). A portion of the RAS is introduced to an anaerobic zone before returning to the main process, allowing for extra VFA production and adsorption by PAOs. RAS fermentation solves the issue of carbon needed for EBPR in VFA/carbon limited systems without having to add too much additional carbon, creating a carbon efficient EBPR system.
The research outlined in this study was done at the Hampton Road Sanitation District's (HRSD) pilot plant located within HRSD's Chesapeake-Elizabeth WWTP in Virginia Beach VA. The pilot is run in an A/B process that works in two separate steps: the A-stage is the first step that works to remove carbon by oxidation, and by adsorption so it can potentially be diverted, and the B-stage is the second step where biological nitrogen removal (BNR) is done. The BNR phase consists of an anaerobic selector followed by four completely stirred tank reactors (CSTRs) that are intermittently aerated to provide aerobic and anoxic phases. The pilot also has an anammox polishing step following B-stage. The nitrogen removal goal for this research was short-cut nitrogen removal via deammonification, by producing partial nitritation in B-stage and polishing with anammox. A B-stage RAS fermenter, along with an A-stage waste activated sludge (WAS) fermenter that feeds VFA into the RAS fermenter, was implemented to the existing pilot to enhance biological phosphorus removal. The overall goal of this study was to successfully combine short-cut nitrogen removal with sidestream EBPR to achieve low effluent N and P concentrations in the most energy and carbon efficient way possible.
EBPR was achieved about eight months after the implementation of the RAS and WAS fermenter to the pilot. A period of B-stage effluent OP that was consistently below 1 mg/L OP was observed right before an unexpected period of high nitrite in the B-stage effluent. The high effluent nitrite lasted for 106 days and ranged from 1.1-5.9 mg/L of effluent nitrite during this time. The nitrite accumulation was unexpected because weekly maximum activity tests for AOB and NOB showed that NOB out-selection was not occurring. The first phase of this research investigates the cause of the nitrite accumulation. Based on profiles taken in the reactors in the aerobic and anoxic phases, and based on denitrification activity tests, it was determined that the nitrite accumulation was due to partial denitrification of nitrate to nitrite. Because this partial denitrification was happening in the reactor anoxic times where external should have been used up, it was determined that the source of the partial denitrification was from a bacteria using internally stored carbon during anoxic periods as the electron supply for partial denitrification. Research has showed that EBPR systems promote bacteria that are capable of storing carbon internally and keeping that carbon stored through an aerobic phase and then using that stored carbon for denitrification following an aerobic phase (Vocks et al., 2005), like observed in this research.
The second phase of this research sought to link the nitrite accumulation and bio-P activity to the VFA added to the RAS fermenter. The VFA addition was decreased in phases, and with that a decrease in nitrite in the effluent was observed. The bio-P activity became more unstable after the nitrite accumulation occurred, but all bio-P activity ceased after VFA addition to the RAS fermenter ceased. It was concluded, unsurprisingly, that the VFA added to the RAS fermenter was the source of the internally stored carbon that caused the nitrite accumulation, and necessary for bio-P enhancement.
The third phase of this research sought to recreate the low effluent OP period and the nitrite accumulation by controlling the VFA dose to the RAS fermenter. The average soluble chemical oxygen demand (sCOD) per OP (fermenter sCOD g/day / total OP-fermenter + influent- g/day) of the period of low effluent OP was calculated, and the dose from the WAS fermenter was controlled to meet 60% of the calculated value. The calculated dose was 13.6 gC/gP, but the actual average dose from controlling the load during this period was 15.6 ± 3.0 gC/gP. The average VFA/OP (g VFA as acetate/ g total OP) dose for the first low effluent OP period was 9.4 ± 3.6 g/g, and the average dose for the third phase of research was 5.5 ± 1.3 g/g. No nitrite accumulation occurred in this phase, but another consistent low effluent OP period did occur. From linear correlation analysis, the highest r2 values relating the low effluent OP periods and the COD loads to the RAS fermenter for both periods were between VFA g/day vs OP mg/L, at r2=0.18 for the first period and r2=0.65 for the second. This shows that effluent OP < 1 mg/L can be achieve at 5.5 or 9.4 (g VFA as acetate/ g total OP). Since no nitrite was observed in phase 3, than the probable VFA load needed to provide enough internal storage to produce nitrite accumulation by partial denitrification is probably between 5.5-9.4 (g VFA as acetate/ g total OP).
This research was significant because the link between nitrite accumulation and bio-P enhancement with sidestream RAS and WAS fermentation was confirmed. Partial denitrification of nitrate to nitrite could be used as an alternative source of nitrite for anammox, instead of NOB out-selection and partial nitritation of ammonia to nitrite by AOB, in combined EBPR and short-cut nitrogen removal systems. If sidestream EBPR systems could be used to promote nitrite accumulation and bio-P activity to produce low effluent OP and nitrogen removal efficiently than short-cut nitrogen removal and EBPR could be successfully combined in an efficient way. Future work needs to be done on the organism that is capable of nitrite accumulation and if that organism can be enhanced in conjunction with EBPR organisms to promote both nitrite accumulation and low effluent OP simultaneously.
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Biostratigraphy and microfacies of the cretaceous sediments in the Indus Basin, PakistanKhan, Suleman January 2013 (has links)
In this thesis I document the biostratigraphy of two Cretaceous sections in Pakistan, the Chichali Nala Section and the Moghal Kot Section. Furthermore, I document the stratigraphy of the so-called Oceanic Anoxic Events (OAEs) in the Moghal Kot Section. In addition, I establish potential links between the planktonic foraminiferal evolution and these OAEs in the Moghal Kot Section. Sea Surface Temperatures (SSTs) are established for the Valanginian time by using the TEX86 and δ18O proxies in the Chichali Nala Section. The new biostratigraphy of the Chichali Nala Section shows that the ages of the sediments are mainly Valanginian. The biostratigraphy of the Moghal Kot Section show ranges in age from the Early Aptian to Early Maastrichtian. Seven OAEs were recorded in the Moghal Kot Section based on the combined study of biostratigraphy, microfacies, and δ13C analysis. These OAEs correlate well with previously documented OAEs elsewhere, therefore the new record of the OAEs in the Moghal Kot Section confirms the widespread occurrence of these events, possibly all global in nature. A quantitative review of the planktonic foraminiferal evolution in the Moghal Kot Section indicates that the environmental changes along the OAE2 have strongly forced the evolution of the planktonic foraminifera. Conversely, no clear relationship is observed between other OAEs and planktonic foraminiferal evolution in the same section. The SST results based on the TEX86 in the Chichali Nala Section show that the surface ocean was consistently much warmer (10-12 oC) than today at the paleolatitude of ~-35o during the Valanginian time. Such warm conditions are also supported by the spore and pollen assemblages of the Chichali Nala Section. Collectively the two datasets indicate strongly that the Valanginian world was overall extremely warm. Such warming during the Valanginian is incompatible with previously suggested cooler conditions during this time period.
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