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1
Ma, Juan, Chengyao Peng, Akio Takigawa, Shuying Wang, Li Wang, Ningping Ma, Yang Liu, and Yongzhen Peng. "Effect of influent nutrient ratios and temperature on simultaneous phosphorus and nitrogen removal in a step-feed CAST." Water Science and Technology 62, no. 9 (November 1, 2010): 2028–36. http://dx.doi.org/10.2166/wst.2010.518.
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A step-feed cyclic activated sludge technology (CAST) with a working volume of 72 L treating real municipal wastewater was operated to examine the effect of varying ratios of influent COD/TN and COD/P on the nutrient removal. With the increased COD/P and COD/TN, the phosphorus and nitrogen removals exhibited an upward trend. The TN removals had a positive linear correlation with the phosphorus removal efficiencies, mainly because the presence of nitrate in the anaerobic zone negatively affected the phosphorus release thus the nitrogen removal process took priority over the phosphorus removal process to utilize the limited carbon source in the influent in step-feed CAST where simultaneous removals of nitrogen and phosphorus were achieved. By employing the effective step-feed strategy with alternating anoxic/oxic operation, efficient phosphorus and nitrogen removals of 95.8 and 89.3% were obtained with lower influent COD/P and COD/TN ratios of 61.9 and 5.2, respectively. It was also found that lower temperature, e.g. 13 ∼ 16°C, did not deteriorate the phosphorus removal, though the nitrogen removal decreased significantly due to incomplete nitrification. As the temperature increased further, TN removal efficiency increased gradually and nitrogen removal via nitrite pathway was successfully achieved with average nitrite accumulation rate above 90% in the system.
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Bissinger, Oliver, Luisa Biermann, Andreas Kolk, Klaus-Dietrich Wolff, and Carolin Götz. "Osteosynthesis Plate Removal: Patient Benefits and Burdens." Applied Sciences 10, no. 5 (March 6, 2020): 1810. http://dx.doi.org/10.3390/app10051810.
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Maxillofacial fractures are lege artis treated via open reduction and internal fixation in cases of dislocation of the fracture. Plate removal is indicated for various reasons. Whereas symptomatic plate removals are justified, elective removals are questionable. This retrospective monocenter study examined the individual benefit of plate removal from the patient’s point of view and involved 233 patients undergoing plate removal. The data of 233 patients undergoing plate removal were first collected, and then, an individual follow-up questionnaire was created that assessed the personal reasons of patients requesting removal and addressed whether the patient gained any benefit from removal surgery. A total of 43 patients agreed to complete the survey. The complication rate was lower after plate removal (13.3%) than after osteosynthesis (31.8%). The most common indication for removal was surgeon recommendation (51.9%), followed by ongoing symptoms (31.3%) and request by the patient (16.7%). Significantly, more patients underwent symptomatic plate removal after mandibular fractures (46.8%, n = 37, p = 0.001) than fractures elsewhere. According to the survey, 86% (n = 37) of the patients benefitted from plate removal. Although elective plate removal is nowadays controversial, our data provide evidence for a high level of patient satisfaction after removal surgery.
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Michaelowa, Axel, Matthias Honegger, Matthias Poralla, Malte Winkler, Sandra Dalfiume, and Ankita Nayak. "International carbon markets for carbon dioxide removal." PLOS Climate 2, no. 5 (May 8, 2023): e0000118. http://dx.doi.org/10.1371/journal.pclm.0000118.
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International carbon markets are potentially a very powerful tool for mobilizing carbon dioxide removal in line with Paris Agreement ambitions to limit global warming to well below 2°C. This requires reaching global net-zero emissions between 2050 and 2070. Yet, carbon market regulators have not approached removals in a systematic manner. This review assesses the highly fragmented treatment of removals under compliance and voluntary carbon markets, including baseline, credit and cap-and-trade systems. The Kyoto mechanisms and the large voluntary carbon market standards have long focussed on biological removals without inherent storage permanence and only recently started to develop methodologies for removals with geological storage, mineralization or biochar. Driven by high prices for credits from emerging removal technologies and advance market commitment initiatives targeting high permanence removals, various newcomers in voluntary markets are currently establishing their own approaches for generating removal credits. However, they disregard key concepts safeguarding market quality such as additionality, which risks triggering scandals and tainting the entire market for removal credits. Given the diversity of credit prices spanning three orders of magnitude from 1 to 1000, as well as of volumes ranging from a few hundred to tens of millions of credits, the current “gold rush” atmosphere of removal markets needs to quickly be replaced by a coordinated approach, ensuring credibility, and enabling removals to play the required role in reaching global net zero.
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Peiffer, Friederike, Sonia Bejarano, Giacomo Palavicini de Witte, and Christian Wild. "Ongoing removals of invasive lionfish in Honduras and their effect on native Caribbean prey fishes." PeerJ 5 (October 18, 2017): e3818. http://dx.doi.org/10.7717/peerj.3818.
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The invasion of Indo-Pacific lionfish is one of the most pressing concerns in the context of coral reef conservation throughout the Caribbean. Invasive lionfish threaten Caribbean fish communities by feeding on a wide range of native prey species, some of which have high ecological and economic value. In Roatan (Honduras) a local non-governmental organisation (i.e. Roatan Marine Park) trains residents and tourists in the use of spears to remove invasive lionfish. Here, we assess the effectiveness of local removal efforts in reducing lionfish populations. We ask whether reefs subject to relatively frequent removals support more diverse and abundant native fish assemblages compared to sites were no removals take place. Lionfish biomass, as well as density and diversity of native prey species were quantified on reefs subject to regular and no removal efforts. Reefs subject to regular lionfish removals (two to three removals month−1) with a mean catch per unit effort of 2.76 ± 1.72 lionfish fisher−1 h−1 had 95% lower lionfish biomass compared to non-removal sites. Sites subject to lionfish removals supported 30% higher densities of native prey-sized fishes compared to sites subject to no removal efforts. We found no evidence that species richness and diversity of native fish communities differ between removal and non-removal sites. We conclude that opportunistic voluntary removals are an effective management intervention to reduce lionfish populations locally and might alleviate negative impacts of lionfish predation. We recommend that local management and the diving industry cooperate to cost-effectively extend the spatial scale at which removal regimes are currently sustained.
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Basu, O. D., and P. M. Huck. "Removal of humic acid by biofiltration." Water Supply 4, no. 4 (December 1, 2004): 147–54. http://dx.doi.org/10.2166/ws.2004.0072.
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Biofiltration was found to be a possible process for humic acid removal once filters had been acclimated to a synthetic feedwater for 12–16 months. The biofilters were exposed to a synthetic feedwater with influent TOC concentrations ranging from 1.6–4.5 mg L‒1 and a composition of 65% humic acid, 15% formate, 10% acetate and 10% formaldehyde on a carbon mass basis. TOC removals improved from 19 ± 13% (n = 15) to 49 ± 10% (n = 20) in one biofilter and from −11 ± 25% (15) to 51 ± 7% (n = 20) in another biofilter. These increases were found to be statistically significant at the 5% level. The increase in removal was due to an increase in removal of both the readily biodegradable carbons and humics in the biofilters. The humic removal increased from 10 to 36% in biofilter #1 and from 0 to 35% in biofilter #2. At the end of the experiments, formate removals were between 91–94%, acetate removals ranged from 83–87%, and formaldehyde was completely removed in the biofilters. SUVA was not found to be a good indicator of humic removal in the biofilters.
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Lacey, Marcia. "Forget Location, It's all About Removal, Removal, Removal." Journal - American Water Works Association 104, no. 12 (December 2012): 2. http://dx.doi.org/10.1002/j.1551-8833.2012.tb08849.x.
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Ignatius, Dr Gary, Dr Shruti D. Nayak, and Dr Amarnath Shenoy. "Chemomechnical Caries Removal-CMCR." International Journal of Scientific Research 3, no. 4 (June 1, 2012): 1–2. http://dx.doi.org/10.15373/22778179/apr2014/180.
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정, 영환. "미국의 소송이송 간주제도(Removal)." Korea Association of the Law of Civil Procedure 27, no. 1 (February 28, 2023): 149–84. http://dx.doi.org/10.30639/cp.2023.2.27.1.149.
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Comparative civil procedure scholars often encounter foreign civil procedure different from their own. To understand and translate terminology of the foreign civil procedure have been challenges. For such work, analyzing functions and roles of the specific procedure is crucial. ‘Removal’ in U.S. civil procedure is one example of such foreign procedure. This article examines procedural aspects of the removal. Part II of this article reviews concept, definition, and grounds of removal by comparing it with transfer and remand that have similar functions. Part III examines i) party-related requirements of removal; ii) claim-related requirements; and iii) timing of filing notice of removal. Part IV looks into the procedure of removal with more details; and Part V describes effects of removal. In Part VI, based on functions and roles of removal in U.S. civil procedure, this article provides suggestions for Korean civil procedure with regard to enhancing defendants’ defenses in choice of jurisdiction. Such recommendations include i) recognition of the parties’ right to move for transfer when the litigation is filed at a court that does not have a jurisdiction; and ii) ways to use transfer of civil litigations more actively in intellectual property cases. This article provides an opportunity to contemplate on what to learn from foreign civil procedure to improve Korean counterpart.
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Gaspard, Scott F., and Donald J. Gaspard. "Retrievable Inferior Vena Cava Filters Are Rarely Removed." American Surgeon 75, no. 5 (May 2009): 426–28. http://dx.doi.org/10.1177/000313480907500515.
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There has been an increasing nationwide trend of inferior vena cava (IVC) filter placement over the past 3 years. Most of these have been the newer, removable variety. Although these are marketed as retrievable, few are removed. The purpose of this study was to examine the practice pattern of IVC filter placement at Huntington Hospital. This study is a retrospective chart review of all IVC filter placements and removals between January 1, 2004, and December 31, 2006. The primary data points include indication for placement, major complications (migration, caval thrombosis, pulmonary embolus [PE]), attempted removal, and successful removal. Three hundred ten patients received IVC filters at our institution during this period. Eighty-four were placed in 2004, 95 in 2005, and 131 in 2006. Of those, only 12 (3.9%) were documented permanent filters, whereas the remainder (298) were removable. Of the retrievable filters placed, only 11 (3.7%) underwent successful removal. There were four (1.3%) instances in which the filter could not be removed as a result of thrombus present within the filter and two (0.67%) in which removal was aborted as a result of technical difficulty. Our use of IVC filters has increased steadily over the last 3 years. Despite the rise in use of “removable” filter devices, few are ever retrieved. Although IVC filter insertion appears an effective method of PE prevention, it comes at a cost, both physiological and monetary. It would be wise to devise more stringent criteria to identify those patients in the various populations who truly require filter placement and to be cautious in altering our indications for placement.
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Sruthi, Gudla, M. Mansoor Ahammed, and Abhipsa R. Makwana. "Effect of source water/wastewater quality on bacterial removal during electrocoagulation." Water Science and Technology 77, no. 5 (January 17, 2018): 1460–68. http://dx.doi.org/10.2166/wst.2018.024.
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Abstract Bacterial removal during electrocoagulation (EC) was investigated employing samples from four different water/wastewater sources, namely, greywater, river water, secondary treated sewage and tap water spiked with Escherichia coli. Effects of current density and electrolysis time on the bacterial removal with aluminium electrodes were evaluated. For greywater, river water and secondary treated sewage, total coliform and E. coli removal efficiencies were not significantly different for the tested samples and varied in the range of 2.22–2.53 log10 units at a current density of 1 mA/cm2 and electrolysis time of 30 min. Higher removals up to 3.80 log10 units could be obtained at higher current density of 5 mA/cm2. Heterotrophic bacterial removals were higher compared with coliforms for the tested samples. Further, higher removal was obtained with spiked E. coli in tap water compared with naturally occurring coliforms in other samples. A comparison of bacterial removal by chemical coagulation (CC) employing alum at optimum dose with that by EC with 1 mA/cm2 current density and 30 min electrolysis time showed significantly higher removal by EC (2.22–2.53 log10 removal) compared with CC (1.40–1.80 log10 removal) for the three tested samples. Upon storage up to 48 h, no significant regrowth/decay of organisms was observed in the EC-treated samples.
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Ruchiraset, Apaporn, and Sopa Chinwetkitvanich. "Estrogens Removal by Sludge from Enhance Biological Phosphorus Removal System." Advanced Materials Research 931-932 (May 2014): 246–50. http://dx.doi.org/10.4028/www.scientific.net/amr.931-932.246.
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This study was to investigate the removal of four estrogens in enhance biological phosphorus removal (EBPR) system. Sludge from four EBPRs were used to investigate both of anaerobic and aerobic conditions. Results showed that EBPR could remove estrogen both under anaerobic and aerobic conditions. In anaerobic condition, estrogens removals were in the range of 7692% for E1 (estrone), 5890% for E2 (17β-estradiol), 4363% for E3 (estrol), and 6288% for EE2 (17α-ethinylestradiol). In aerobic phase, removal of estrogens were ranging from 7996% for E1, 7696% for E2, 3664% for E3, and 5796% of EE2. Sorption onto sludge was the main mechanism of estrogens removal in comparison with biodegradation, which their sorption:biodegradation ratios were around 0.9:0.1 and 0.8:0.2 in anaerobic and aerobic conditions, respectively. Moreover, biotransformation of E2 to E1 was found in every E2-batch experiments that used active sludge.
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Shammay, A., I. Evanson, and R. M. Stuetz. "A comparison of removal performance of volatile organic and sulfurous compounds between odour abatement systems." Water Science and Technology 77, no. 11 (May 17, 2018): 2657–67. http://dx.doi.org/10.2166/wst.2018.223.
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Abstract Three types of odour abatement systems in sewer networks in Australia were studied for 18 months to determine the removals of different compounds. Six volatile sulfurous compounds and seven volatile organic compounds (VOCs) were further investigated. All types of odour abatement systems exhibited good removal of hydrogen sulfide with the biotrickling filters (BTFs) showing the highest consistent removal. Biofilters outperformed BTFs and activated carbon (AC) filters in the removal of dimethyl mono-, di- and tri-sulfide species at the low inlet concentrations typically found. AC filters exhibited little VOC removal with no compound consistently identified as having a removal greater than 0%. Biofilters outperformed BTFs in VOC removal, yet both had high removal variability.
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Yu, Lian. "Effect of SRT on Nitrogen and Phosphorus Removal in Modified Carrousel Oxidation Ditch Process." Advanced Materials Research 396-398 (November 2011): 1995–2001. http://dx.doi.org/10.4028/www.scientific.net/amr.396-398.1995.
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Based on a modified Carrousel oxidation ditch process acclimated with synthetic wastewater，effect of SRT on nitrogen and phosphorus removal occurred in the system was investigated. The results indicated that SRT was prominent to nitrogen and phosphorus removal. The removal efficiency of nitrogen was better with SRT extension and that the removal efficiency of phosphorus was better with SRT shortness. With the operation conditions of water temperature 30°C, SRT 11days, the removal efficiency of TN and TP reached 85.4% and 74.9%, which indicated that nitrogen and phosphorus removals were best.
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Ferguson, John F. "Anaerobic and Aerobic Treatment for AOX Removal." Water Science and Technology 29, no. 5-6 (March 1, 1994): 149–62. http://dx.doi.org/10.2166/wst.1994.0710.
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A two-year study has focused on AOX removal from bleaching wastewaters in anaerobic and aerobic biological treatment, using bench scale bioreactors operated in parallel and in series. Significantly higher removals have been found in anaerobic than in aerobic treatment. Earlier work with dilute kraft bleaching wastes has been extended in additional laboratory tests and at a nearby kraft mill. 50-75% fractions of bleaching wastes were treated. Toxicity in the anaerobic process was encountered at 85% bleach waste fractions. Total AOX removal experienced in aerobic treatment is 30-35%, in anaerobic treatment 40-45%, and in an anaerobic/aerobic sequence 50-55%. Percentage removals were not sensitive to the fraction of bleaching wastewater. Several process modifications were attempted to try to obtain higher removals with only marginal success. Studies at a kraft mill confirmed the AOX removals that had been found in lab studies. AOX removal occurs by several mechanisms. There is a very significant chemical or abiotic degradation that occurs after neutralization, perhaps enhanced by reductants or other inorganic salts. Biological processes are much more significant in anaerobic than in aerobic treatment. Anaerobic reductive dehalogenation affects specific chlorinated compounds and catalyzed AOX degradation is facilitated by reduced coenzymes that are produced by bacteria. Removal by sorption or insolubilization is relatively minor in aerobic and anaerobic processes.
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Ribeiro, Jefferson P., Juliene T. Oliveira, André G. Oliveira, Francisco W. Sousa, Eliezer F. Abdala Neto, Carla B. Vidal, Denis de Keukeleire, André B. dos Santos, and Ronaldo F. Nascimento. "Treatment of Sulfonated Azo Dye Reactive Red 198 by UV/H2O2." Journal of Chemistry 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/619815.
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UV/H2O2system was tested on the color removal of sulfonated azo dye Reactive Red 198 (RR), which is widely used in textile process. The effects of hydrogen peroxide concentration, temperature, pH, and the in-line addition of hydrogen peroxide on high color and chemical oxygen demand (COD) removals were investigated. The kinetic of dye decolorization was also determined. The results showed that 2% H2O2decreased the process efficiency, while 1% H2O2solution led to a better performance of the system. Despite the fact that the pH increase had small effect on color removal, it affects positively COD removals. The same behavior was found for temperature increase. A high temperature resulted in a slight decrease in color removal and a sharp decrease for COD removal. In addition the H2O2in-line provided a small improvement in both color and COD removals. UV/1% H2O2treatment was the most efficient, the good performance was linked to higher amount of hydroxyl radicals formed.
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Lu, Ping, James E. Amburgey, Vincent R. Hill, Jennifer L. Murphy, Chandra L. Schneeberger, Michael J. Arrowood, and Tao Yuan. "Removals of cryptosporidium parvum oocysts and cryptosporidium-sized polystyrene microspheres from swimming pool water by diatomaceous earth filtration and perlite-sand filtration." Journal of Water and Health 15, no. 3 (February 24, 2017): 374–84. http://dx.doi.org/10.2166/wh.2017.221.
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Removal of Cryptosporidium-sized microspheres and Cryptosporidium parvum oocysts from swimming pools was investigated using diatomaceous earth (DE) precoat filtration and perlite-sand filtration. In pilot-scale experiments, microsphere removals of up to 2 log were obtained with 0.7 kg·DE/m2 at a filtration rate of 5 m/h. A slightly higher microsphere removal (2.3 log) was obtained for these DE-precoated filters when the filtration rate was 3.6 m/h. Additionally, pilot-scale perlite-sand filters achieved greater than 2 log removal when at least 0.37 kg/m2 of perlite was used compared to 0.1–0.4 log removal without perlite both at a surface loading rate of 37 m/h. Full-scale testing achieved 2.7 log of microspheres and oocysts removal when 0.7 kg·DE/m2 was used at 3.6 m/h. Removals were significantly decreased by a 15-minute interruption of the flow (without any mechanical agitation) to the DE filter in pilot-scale studies, which was not observed in full-scale filters. Microsphere removals were 2.7 log by perlite-sand filtration in a full-scale swimming pool filter operated at 34 m/h with 0.5 kg/m2 of perlite. The results demonstrate that either a DE precoat filter or a perlite-sand filter can improve the efficiency of removal of microspheres and oocysts from swimming pools over a standard sand filter under the conditions studied.
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Green, M. B., P. Griffin, J. K. Seabridge, and D. Dhobie. "Removal of bacteria in subsurface flow wetlands." Water Science and Technology 35, no. 5 (March 1, 1997): 109–16. http://dx.doi.org/10.2166/wst.1997.0176.
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Removal of E. coli and total coliforms in subsurface flow constructed wetlands is investigated in field surveys and pilot experiments. Both systems use reed beds with 5-10 mm gravel medium receiving secondary effluents. A diurnal pattern of numbers was indicated in the survey of an operational tertiary reed bed at Leek Wootton. Removals of E. coli and total coliforms were compared in dry and wet periods in surveys on two successive years. Removals of about 1.5 to 2.1 log were found in dry weather. Removals fell in wet weather although no change was detected in removal of BOD5, TSS and amm N. The effect of different flow rates was compared using a pilot reed bed. A trend of increasing removal was seen between retention times of 12, 24, 48 and 120 hrs but variation between samples implied caution. All effluent samples from the pilot had less than 1000 cfu E. coli/100 ml at retention times of 24 hrs or more.
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Siwila, Stephen, and Isobel C. Brink. "Low cost drinking water treatment using nonwoven engineered and woven cloth fabrics." Journal of Water and Health 17, no. 1 (December 14, 2018): 98–112. http://dx.doi.org/10.2166/wh.2018.226.
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Abstract The study investigated two engineered fabrics and five cloth fabrics for low cost drinking water treatment. An optimized fabric filtration method has been developed and tested. Numerical models for predicting particulate removal efficiency have been developed for each fabric as support tools for selecting optimal process configuration. Both engineered fabrics showed better performance and achieved the most effective particulate removal for the highest number of layers used. Sequential filtration was done on eight layers for representative fabrics of each type and recorded higher contaminant removal than one filtration run. Geotextile 1 was better than geotextile 2 in particulate removal and recorded Escherichia coli removals of up to 1.4 log removal value (LRV) for eight-layer normal filtration and 3.0 LRV for four-pot sequential filtration. Brushed cotton was best among the cloth fabrics in particulate removal but performed below expectation in bacterial removal. It recorded E. coli removals of only 0.04 LRV and 0.2 LRV for eight-layer normal filtration and four-pot sequential filtration, respectively. Effluent turbidity decreased exponentially with number of fabric layers, in line with porous media filtration theory. The optimized filtration method produced very clear drinking water of relatively safe quality using geotextile 1. Appropriate disinfection is still recommended to ensure continued water safety.
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Silva, S. A., R. de Oliveira, J. Soares, D. D. Mara, and H. W. Pearson. "Nitrogen removal in pond systems with different configurations and geometries." Water Science and Technology 31, no. 12 (June 1, 1995): 321–30. http://dx.doi.org/10.2166/wst.1995.0501.
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Nitrogen removal in its various chemical forms was evaluated in a complex of waste stabilisation ponds comprising ponds of different depths and geometries. TKN and ammonia removal reached 78.5% and >90%, respectively, in the 5-pond systems with overall retention times of only 19 days. Removals were highest in the maturation ponds, and shallow maturation ponds were the most efficient. In terms of optimum pond geometry, high nitrogen and ammonia removal was compatible with optimal BOD5 removal and faecal coliform die-off. TKN and ammonia removal in these ponds could be modelled using conventional first-order equations.
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Ataberk, Selale, and Celal F. Gökçay. "Treatment of chlorinated organics in bleached kraft mill effluents by activated sludge process." Water Science and Technology 36, no. 2-3 (July 1, 1997): 147–50. http://dx.doi.org/10.2166/wst.1997.0505.
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Combined effluents from a bleached Kraft pulp mill using annual plants were treated in a lab-scale activated sludge (AS) system. The effects of operating solids retention time (SRT) and concentration of additional carbon source on AOX removal were investigated. Higher AOX removals (30%) were observed with long SRTs, 99% of which was pure metabolization. As SRT was decreased AOX removal efficiency also decreased (4%) and principal AOX removal mechanism changed to adsorption onto wasted biomass. The AOX removal efficiency was lower (10%) on a 20% decrease in the supplemental carbon source, with no apparent effect on the removal mechanism.
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Ouzoulias, Fanny, Nicolas Bousquet, Mathieu Genu, Anita Gilles, Jérôme Spitz, and Matthieu Authier. "Development of a new control rule for managing anthropogenic removals of protected, endangered or threatened species in marine ecosystems." PeerJ 12 (January 5, 2024): e16688. http://dx.doi.org/10.7717/peerj.16688.
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Human activities in the oceans are increasing and can result in additional mortality on many marine Protected, Endangered or Threatened Species (PETS). It is necessary to implement ambitious measures that aim to restore biodiversity at all nodes of marine food webs and to manage removals resulting from anthropogenic activities. We developed a stochastic surplus production model (SPM) linking abundance and removal processes under the assumption that variations in removals reflect variations in abundance. We then consider several ‘harvest’ control rules, included two candidate ones derived from this SPM (which we called ‘Anthropogenic Removals Threshold’, or ART), to manage removals of PETS. The two candidate rules hinge on the estimation of a stationary removal rate. We compared these candidate rules to other existing control rules (e.g. potential biological removal or a fixed percentage rule) in three scenarios: (i) a base scenario whereby unbiased but noisy data are available, (ii) scenario whereby abundance estimates are overestimated and (iii) scenario whereby abundance estimates are underestimated. The different rules were tested on a simulated set of data with life-history parameters close to a small-sized cetacean species of conservation interest in the North-East Atlantic, the harbour porpoise (Phocoena phocoena), and in a management strategy evaluation framework. The effectiveness of the rules were assessed by looking at performance metrics, such as time to reach the conservation objectives, the removal limits obtained with the rules or temporal autocorrelation in removal limits. Most control rules were robust against biases in data and allowed to reach conservation objectives with removal limits of similar magnitude when averaged over time. However, one of the candidate rule (ART) displayed greater alignment with policy requirements for PETS such as minimizing removals over time.
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Altinbaş, Ufuk, and Izzet Öztürk. "Comparison of intermittently aerated continuous and batch biofilm reactor in nutrient removal." Water Science and Technology 48, no. 11-12 (December 1, 2004): 371–76. http://dx.doi.org/10.2166/wst.2004.0883.
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Removal efficiency of TOC ranged between 86–89% in an intermittently aerated reactor. High efficiency in TKN removal and nitrification was found at lower applied load or longer retention time such as 2 days. TKN removal and nitrification efficiency was found to be 17–96% and 35–99% respectively. Through examination and comparison of the removal efficiencies, the stability of nitrification/denitrification and the biological phosphorus removal it was found that the sequencing batch feeding system gave a higher performance in total nitrogen and phosphorus removals. In the SBR reactor, nitrogen removal efficiency was mainly controlled by organic loading. Nitrification efficiency ranged between 31–56%. Nearly complete denitrification was observed in the sequencing batch reactor.
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Guo, Gai Mei. "Effect of the Ratio of CODCr to Total Nitrogen on Enhanced Treatment of Sewage from Discharging Points of Rivers by Enzyme-Biofilm Process." Advanced Materials Research 243-249 (May 2011): 3751–54. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.3751.
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The research studied enhanced treatment of sewage from discharging points of rivers by biofilm process dosing with enzyme and promotion effect of enzyme on treatment of sewage by biofilm process, and investigated the effect of the ratio of CODCr to total nitrogen (C/N) on removals of pollution indexes. The research results indicated that with the decrease of C/N, the removal rates of CODCrwere stable and the removal rates of NH3-N increased, but the removal rates of TN obviously decreased in the three reactors. When C/N=5, the average removal rate of TN was higher than 30% in reactor B and C. When C/N=3, it decreased and maintained about 30%. When C/N=2, it was low and approximately 20%. When C/N=5, 3 or 2，the removal rates of CODCr, NH3-N and TN greatly increased in reactor B and C than in reactor A, which indicated that the promotion effects of the composite enzyme and the compounded enzyme on the removals of the target pollutants were favorable.
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Ramakrishna, Konduru R., and T. Viraraghavan. "Dye removal using low cost adsorbents." Water Science and Technology 36, no. 2-3 (July 1, 1997): 189–96. http://dx.doi.org/10.2166/wst.1997.0516.
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Dyestuff production units and dyeing units have always had a pressing need for techniques that allow economical pretreatment for color in the effluent. The effectiveness of adsorption for dye removal from wastewaters has made it an ideal alternative to other expensive treatment options. The current paper deals with an investigation on four low-cost adsorbents locally available in Saskatchewan, Canada for dye removal. Peat, steel plant slag, bentonite clay and fly ash were utilized for this study and their performance evaluated against that of granular activated carbon. Batch kinetic and isotherm studies, and column studies were undertaken, and the data evaluated for compliance with the Langmuir, Freundlich and BET isotherm models. Synthetic dye wastewaters prepared from commercial grade acid, basic and disperse dyes were used in this study and the results showed high removals of acid dyes by fly ash and slag while peat and bentonite exhibited high basic dye removals. For the acid and basic dyes, the removals were comparable with that of granular activated carbon, while for the disperse dyes, the performance was much better than that of granular activated carbon. The results obtained point towards viable adsorbents which are both effective as well as economically attractive for color removal from wastewaters.
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Zhang, Huining, Xin Yuan, Hanqing Wang, Shuoqi Ma, and Bixiao Ji. "Performance and Microbial Community of Different Biofilm Membrane Bioreactors Treating Antibiotic-Containing Synthetic Mariculture Wastewater." Membranes 10, no. 10 (October 14, 2020): 282. http://dx.doi.org/10.3390/membranes10100282.
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The performance of pollutant removals, tetracycline (TC) and norfloxacin (NOR) removals, membrane fouling mitigation and the microbial community of three Anoxic/Oxic membrane bioreactors (AO-MBRs), including a moving bed biofilm MBR (MBRa), a fixed biofilm MBR (MBRb) and an AO-MBR (MBRc) for control, were compared in treating antibiotic-containing synthetic mariculture wastewater. The results showed that MBRb had the best effect on antibiotic removal and membrane fouling mitigation compared to the other two bioreactors. The maximum removal rate of TC reached 91.65% and the maximum removal rate of NOR reached 45.46% in MBRb. The addition of antibiotics had little effect on the removal of chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N)—both maintained more than 90% removal rate during the entire operation. High-throughput sequencing demonstrated that TC and NOR resulted in a significant decrease in the microbial diversity and the microbial richness MBRs. Flavobacteriia, Firmicutes and Azoarcus, regarded as drug-resistant bacteria, might play a crucial part in the removal of antibiotics. In addition, the dynamics of microbial community had a great change, which included the accumulation of resistant microorganisms and the gradual reduction or disappearance of other microorganisms under antibiotic pressure. The research provides an insight into the antibiotic-containing mariculture wastewater treatment and has certain reference value.
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Balaji, Prof P. "Laparoscopic Removal of Mesenteric Cyst." Journal of Medical Science And clinical Research 05, no. 01 (January 5, 2017): 15384–86. http://dx.doi.org/10.18535/jmscr/v5i1.30.
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Shafiquzzaman, Md, Saad Mohammed A. Alqarawi, Husnain Haider, Md Rafiquzzaman, Meshal Almoshaogeh, Fawaz Alharbi, and Yassine El-Ghoul. "Evaluating Permeable Clay Brick Pavement for Pollutant Removal from Varying Strength Stormwaters in Arid Regions." Water 14, no. 3 (February 7, 2022): 491. http://dx.doi.org/10.3390/w14030491.
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Permeable pavement is a low impact development technology for stormwater (SW) runoff control and pollutant removal. The strength of SW depends on land use of the catchment, e.g., semi-urban vs. industrial. The performance (in terms of pollutants removal) of permeable clay bricks (PCB) has not been adequately assessed for SW of varying strengths. For using the permeable clay bricks as a pavement surface layer, the present research investigates its pollutant removal capacity through SW infiltration using a laboratory setup. SW samples of two different strengths, i.e., high polluted stormwater (HPSW) and less polluted stormwater (LPSW), were tested for a pavement system consisting of the clay brick layer on top of a coarse gravel support layer. The tests were performed at a rainfall intensity of 12.5 mm/h (for a 10-year return period in Buraidah, Qassim) to evaluate the suitability of PCB for the arid and semi-arid regions. The experiments revealed that PCB became fully saturated and achieved a steady-state outflow condition after 10 min of rainfall. Irrespective of contamination level, the pollutant removal efficiency was found to be similar for both HPSW and LPSW. High TSS (>98%) and turbidity (>99%) removals were achieved for both strengths, while BOD5 (78.4%) and COD (76.1%) removals were moderate. Poor to moderate nutrient removal, 30.5% and 39.1% for total nitrogen (TN) and 34.7% and 31.3% for total phosphorus (TP), respectively for HPSW and LPSW, indicates an adsorptive removal of nutrients in the system. Heavy metal removal efficiency ranged from 6.7% to 94%, with higher removals archived for Fe, Mn, Se, and Pb. The study provides insights into the role of PCB as a surface layer in the permeable pavement for pollutant removal. The study also establishes the guidelines for the optimal permeable pavement design to deal with SW of varying contamination levels. Permeable clay bricks showed the potential to be used as a sustainable LID technology for arid regions.
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Han, Ying, Zhong Lin Chen, Ji Min Shen, and Yue Liu. "Effect of Liquid Properties on the Reduction of N-Nitrosodimethylamine with Zinc(0)." Advanced Materials Research 243-249 (May 2011): 4757–60. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.4757.
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The effect of the common cations, anions and humic acid on the reduction of NDMA with zinc(0) was investigated. The NDMA removals were not the influenced greatly by the cations. All the anions depressed the NDMA final removal in the order of SO42-＜Cl-＜HCO3-=NO3-＜S2-. The humic acid of the varied concentrations inhibited the NDMA final removal. The initial NDMA removals were enhanced by several ions and the humic acid. The enhancements could be due to the promotion of the passive film breakage, the generation of reactive sites or the inhibition of the passive film formation. The final removal decrease may be caused by the diminishing reactive sites or the competing effects from the ions.
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Shi, X. L., X. B. Hu, Z. Wang, L. L. Ding, and H. Q. Ren. "Effect of reflux ratio on COD and nitrogen removals from coke plant wastewaters." Water Science and Technology 61, no. 12 (June 1, 2010): 3017–25. http://dx.doi.org/10.2166/wst.2010.266.
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A laboratory-scale anaerobic-anoxic-aerobic-moving bed biofilm reactor (A1-A2-O-MBBR) system was undertaken to treat coke plant wastewaters from two different factories (wastewater A and B). Wastewater B had higher BOD5/COD ratio and COD/TN ratio than wastewater A. The effects of reflux ratios on COD, TN and NH3-N removals were studied. Results indicated that, with the reflux ratio increased from 2 to 5, COD removals of wastewater A and wastewater B increased from 57.4% to 72.6% and 78.2% to 88.6%, respectively. Meanwhile, TN removals were also increased accompanying reflux ratio rise, from 53.1% to 74.4% for wastewater A and 64.2% to 83.5% for wastewater B. At the same reflux ratio, compared with wastewater A, higher COD and TN removal efficiencies were observed in wastewater B, which had higher BOD5/COD and COD/TN ratio. Reflux ratio had no significant influence on NH3-N removal; 99.0% of the overall NH3-N removal efficiency was achieved by the system for both coke plant wastewaters at any tested reflux ratio. MBBR was effective in NH3-N removal, and about 95% of the NH3-N was removed in the MBBR.
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Mäntyniemi, Samu, Atso Romakkaniemi, and Elja Arjas. "Bayesian removal estimation of a population size under unequal catchability." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 2 (February 1, 2005): 291–300. http://dx.doi.org/10.1139/f04-195.
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We introduce a Bayesian probability model for the estimation of the size of an animal population from removal data. The model is based on the assumption that in the removal sampling, catchability may vary between individuals, which appears to be necessary for a realistic description of many biological populations. Heterogeneous catchability among individuals leads to a situation where the mean catchability in the population gradually decreases as the number of removals increases. Under this assumption, the model can be fitted to any removal data, i.e., there are no limitations regarding the total catch, the number of removals, or the decline of the catch. Using a published data set from removal experiments of a known population size, the model is shown to be able to estimate the population size appropriately in all cases considered. It is also shown that regardless of the statistical approach, a model that assumes equal catchability of individuals generally leads to an underestimation of the population. The example indicates that if there is only vague prior information about the variation of catchability among individuals, a very high number of successive removals may be needed to correctly estimate the population size.
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Van Buren, M. A., W. E. Watt, and J. Marsalek. "Enhancing the removal of pollutants by an on-stream pond." Water Science and Technology 33, no. 4-5 (February 1, 1996): 325–32. http://dx.doi.org/10.2166/wst.1996.0522.
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A methodology is presented for assessing the pollution control performance of an on-stream pond located in Kingston, Ontario, Canada, and enhancing the removal of pollutants by remediation techniques., Descriptions are provided of the instrumentation used to measure continuously rainfall and water levels, and the sampling program to collect stormwater samples., The assessment is based on examining contaminant removals for both baseflow and event conditions and applying in-pond remedial measures to improve pond performance., Results on removal rates are provided for selected dissolved constituents (total dissolved solids, sulphate and chloride), nutrients, suspended solids, metals and organic contaminants., In summary, dissolved constituents exhibit zero removal for baseflow periods and positive removal for events; nutrients and suspended solids exhibit negative removal for baseflow periods and positive removal for events; and metals and organics exhibit positive removal for both baseflow periods and events. Remediation techniques are discussed and preliminary results of one technique — internal pond baffles — indicate that extended hydraulic residence times and prevention of flow short-circuiting result in increased particulate settling and associated contaminant removal.
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Acuna-Askar, K., M. A. de la Torre-Torres, M. J. Guerrero-Munoz, M. T. Garza-Gonzalez, B. Chavez-Gomez, I. P. Rodriguez-Sanchez, and H. A. Barrera-Saldana. "Biodegradation kinetics of BTE-OX and MTBE by a diesel-grown biomass." Water Science and Technology 53, no. 11 (May 1, 2006): 197–204. http://dx.doi.org/10.2166/wst.2006.353.
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The biodegradation kinetics of BTE-oX and MTBE, mixed all together in the presence of diesel-grown bioaugmented bacterial populations as high as 885 mg/L VSS, was evaluated. The effect of soil in aqueous samples and the effect of Tergitol NP-10 on substrate biodegradation rates were also evaluated. Biodegradation kinetics was evaluated for 54 h, every 6 h. All BTE-oX chemicals followed a first-order two-phase biodegradation kinetic model, whereas MTBE followed a zero-order removal kinetic model in all samples. BTE-oX removal rates were much higher than those of MTBE in all samples. The presence of soil in aqueous samples retarded BTE-oX and MTBE removal rates. The addition of Tergitol NP-10 to aqueous samples containing soil had a positive effect on substrate removal rate in all samples. Substrate percent removals ranged between 64.8–98.9% for benzene, toluene and ethylbenzene. O-xylene and MTBE percent removals ranged between 18.7–40.8% and 7.2–10.3%, respectively.
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Xue, Juan Qin, Ni Na Liu, Guo Ping Li, and Long Tao Dang. "Optimization of cyanide extraction from wastewater using emulsion liquid membrane system by response surface methodology." Water Science and Technology 74, no. 4 (July 14, 2016): 779–86. http://dx.doi.org/10.2166/wst.2016.220.
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To solve the disposal problem of cyanide wastewater, removal of cyanide from wastewater using a water-in-oil emulsion type of emulsion liquid membrane (ELM) was studied in this work. Specifically, the effects of surfactant Span-80, carrier trioctylamine (TOA), stripping agent NaOH solution and the emulsion-to-external-phase-volume ratio on removal of cyanide were investigated. Removal of total cyanide was determined using the silver nitrate titration method. Regression analysis and optimization of the conditions were conducted using the Design-Expert software and response surface methodology (RSM). The actual cyanide removals and the removals predicted using RSM analysis were in close agreement, and the optimal conditions were determined to be as follows: the volume fraction of Span-80, 4% (v/v); the volume fraction of TOA, 4% (v/v); the concentration of NaOH, 1% (w/v); and the emulsion-to-external-phase volume ratio, 1:7. Under the optimum conditions, the removal of total cyanide was 95.07%, and the RSM predicted removal was 94.90%, with a small exception. The treatment of cyanide wastewater using an ELM is an effective technique for application in industry.
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Park, Jeong-Ann, Jae-Hyun Kim, Chang-Gu Lee, and Song-Bae Kim. "Pyrophyllite clay for bacteriophage MS2 removal in the presence of fluoride." Water Supply 14, no. 3 (December 27, 2013): 485–92. http://dx.doi.org/10.2166/ws.2013.224.
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The aim of this study was to investigate the removal of the bacteriophage MS2 from aqueous solution using pyrophyllite. Batch experiments were conducted to examine MS2 sorption to pyrophyllite. The influence of fluoride, a groundwater contaminant, on the removal of MS2 was also observed. Column experiments were performed with pyrophyllite to examine MS2 removal in the absence and presence of fluoride. Batch results demonstrated that pyrophyllite was effective in MS2 removal. The percentage removal of MS2 increased from 5.26% to 99.99% (4.0 log removal) with increasing pyrophyllite concentrations from 0.2 to 20 g/L. At fluoride concentrations of 5 and 10 mg/L, the log removals of MS2 by pyrophyllite were 3.05 and 2.54, respectively, which were lower than that with no fluoride present. The results suggested that the removal of MS2 by pyrophyllite was influenced by fluoride ions because fluoride ions could compete with MS2 for sorption sites on the pyrophyllite surfaces. Column results showed that pyrophyllite was effective in MS2 removal under flow-through conditions, with a removal capacity of 8.17 × 106pfu/g with no fluoride present and 4.70 × 106pfu/g with 5 mg/L fluoride present.
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Chak, Solomon T. C., Clement P. Dumont, Kee-Alfian Abd Adzis, and Katie Yewdall. "Effectiveness of the removal of coral-eating predator Acanthaster planci in Pulau Tioman Marine Park, Malaysia." Journal of the Marine Biological Association of the United Kingdom 98, no. 1 (September 9, 2016): 183–89. http://dx.doi.org/10.1017/s002531541600117x.
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Population outbreaks of the coral-eating predator crown of thorns starfish (COTS), Acanthaster planci are responsible for large-scale disturbance of coral reefs throughout the Indo-Pacific. In response, attempts are often made to control COTS outbreaks in protected areas. For instance, volunteers remove thousands of sea stars every year in Malaysia. This study reports the status of the COTS population in the Pulau Tioman Marine Park and examines the effectiveness of the seasonal sea star removal programme. After the 2009 removal season, we monitored COTS densities and coral assemblages before and after a 6-month no-removal season at sites with and without COTS removal efforts. We recorded high COTS densities up to 330 ind. ha−1 at a few sites independent of removal effort. In fact, removal only temporarily reduced large individuals from local populations. Moreover, after the no-removal season, sites with COTS removal had increased live coral cover, but sites without COTS removal had a drastic decrease in live coral cover, with Acropora spp. being most affected. Therefore, this study suggests that the current seasonal removals could promote coral health, despite the high density of COTS.
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Joab, Malanda, Péter Balogh, and Gabriella Novotni Dankó. "Sow removal patterns in commercial breed-wean herds of Midwest, USA." Acta Agraria Debreceniensis, no. 2 (December 15, 2019): 9–14. http://dx.doi.org/10.34101/actaagrar/2/3671.
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An observational retrospective study was done to provide up-to-date information on recent sow removal patterns from 9 breed-wean herds of Midwest USA. The study comprised of sow’s removal reasons and removal types of F1 Landrace x Yorkshire gilts entered in the herds between 1st Jan 2014 and 31st July 2016. Data was extracted from existing database on Dec 2018 and 15% of the sows were still active in the herds hence not included in the study. Descriptive statistics showed that out of the 20,009 removed sows, planned removals comprised of farrowing productivity (FP) 3,523 (17.6%) and old age (OA) 1,785 (8.9%) while unplanned removals consisted of reproductive failure (RF) 7,786 (38.9%), health problems (HP) 2,629 (13.1%), locomotion problems (LP) 1,473 (7.4%) and conformation issues (CI) 1,350 (6.8%).‘Did not conceive’ and “No heat” were observed as the main contributing factors accounting for 37.6% and 32.9% respectively for gilts & sows removed by RF.13.5% of the gilts (Parity 0) were removed from the herds before attaining their first litter of which 64.1% of their removals was due to RF. Removal type consisted of slaughter (S) 85.0%, found dead on the farm (DoF) 10.8% and euthanized (E) 4.2%. The research findings depict an upward trend of sow RF removals in the US swine herds posing a serious concern for US swine producers. Characterization and quantification of sow removals gives a revelation on the deeper intrigues about the vulnerability of the various parity in respect to common causes of RF. This helps swine producers to decisively improve on gilt replacement selection, reproductive efficiency, health and nutrition management all aimed at increasing overall swine productivity and efficiency in management. Swine farmers in the US can now focus their efforts towards curbing unnecessary RF removal within parity specifics.
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Mena, J., R. Gómez, J. Villaseñor, and A. de Lucas. "Influence of polyphenols on low-loaded synthetic winery wastewater constructed wetland treatment with different plant speciesA paper submitted to the Journal of Environmental Engineering and Science." Canadian Journal of Civil Engineering 36, no. 4 (April 2009): 690–700. http://dx.doi.org/10.1139/l09-004.
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Synthetic wastewaters simulating physically pre-treated low-loaded winery effluents were treated for four months with five pilot-scale horizontal subsurface flow constructed wetlands (HSSF-CWs) using different plants. Species under study were Phragmites australis (HSSF-CW2), Lythrum salicaria (HSSF-CW3), Cladium mariscus (HSSF-CW4), and Iris pseudacorus (HSSF-CW5). The designation HSSF-CW1 was not planted, and was used as a control. The mean dissolved oxygen and oxidation–reduction potential values in all HSSF-CWs indicated anaerobic conditions in the bulk liquid. High pollutant-removal efficiencies were obtained. Apparently, the species with higher growth (Phragmites, Lythrum, and particularly Iris) improved total nitrogen (TN) and nitrogen as ammonium (N-NH4+) removals, but adversely affected sulphate (SO42–) anaerobic reduction. Chemical oxygen demand (COD) removal efficiencies were high, although there were no clear indications how the kinds of plants might have influenced this parameter. A statistical analysis of variance indicated that only N-NH4+ removal efficiencies were statistically different owing to the influence of the different plants. In a second 6 month experimental period, polyphenols (13 mg L–1) were added to the synthetic wastewater to study possible inhibition effects. The addition of polyphenols did not seem to cause inhibition effects on COD, TN, and N-NH4+ removals, but clearly negatively affected SO42– removal. A new two-way analysis of variance confirmed that only SO42– removal was negatively affected by polyphenols, while the effects of the different plants were only significant for N-NH4+ removal. Polyphenols were nearly completely removed. First order rate constants obtained for COD, TN, SO42–, and polyphenol removals were similar to those reported by other authors.
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Gutierrez-Macias, Tania, and Petia Mijaylova Nacheva. "Clofibric acid and gemfibrozil removal in membrane bioreactors." Water Science and Technology 71, no. 8 (February 20, 2015): 1143–50. http://dx.doi.org/10.2166/wst.2015.079.
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The removal of two blood lipid regulators, clofibric acid (CLA) and gemfibrozil (GFZ), was evaluated using two identical aerobic membrane bioreactors with 6.5 L effective volume each. Polysulfone ultrafiltration hollow fiber membranes were submerged in the reactors. Different operating conditions were tested varying the organic load (F/M), hydraulic residence time (HRT), biomass concentration measured as total suspended solids in the mixed liquor (MLTSS) and the sludge retention time (SRT). Complete GFZ removal was obtained with F/M of 0.21–0.48 kg COD kgTSS−1 d−1, HRT of 4–10 hours, SRT of 10–32 d and MLTSS of 6–10 g L−1. The GFZ removal can be attributed to biodegradation and there was no accumulation of the compound in the biomass. The CLA removals improved with the SRT and HRT increase and F/M decrease. Average removals of 78–79% were obtained with SRT 16–32 d, F/M of 0.21–0.34 kgCOD kgTSS−1 d−1, HRT of 7–10 hours and MLTSS of 6–10 g L−1. Biodegradation was found to be the main removal pathway.
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Lambert, S. D., N. J. D. Graham, C. J. Sollars, and G. D. Fowler. "Evaluation of inorganic adsorbents for the removal of problematic textile dyes and pesticides." Water Science and Technology 36, no. 2-3 (July 1, 1997): 173–80. http://dx.doi.org/10.2166/wst.1997.0512.
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This paper evaluates three inorganic adsorbents (activated bauxite, fullers earth and a synthetic clay), relative to activated carbon, for the removal of several representative contaminants of major concern and frequent occurrence in UK textile industry effluents; reactive dyes, pentachlorophenol and Propetamphos. The results indicate that, for the removal of reactive dyes, the synthetic clay was the most effective adsorbent over the pH range from pH 5.5 to pH 8.5 and temperature range from 20 to 40°C, although comparable dye removals were exhibited by activated carbon under neutral and alkaline conditions. Under acidic conditions activated bauxite was as effective as activated carbon. Fullers Earth was largely ineffective. With regard to the removal of pesticides activated carbon was highly effective, whereas the three inorganic adsorbents showed negligible removals.
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Zhang, Min, and Shi Bin Xia. "PCBs Removing in Aged Landfill Leachate by an Innovative Biofilm Reactor with Biomass Carriers - Luffa Sponges." Applied Mechanics and Materials 670-671 (October 2014): 253–57. http://dx.doi.org/10.4028/www.scientific.net/amm.670-671.253.
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PCBs removal in the aged leachate by a new combination process based on an innovative biofilm reactor with natural fiber media, combined coagulation with a two-staged sequencing batch biofilm reactor with Luffa Sponges (LS) as the biomass carriers (LS-SBBR), was studied in this paper. The results indicated that the total PCBs removal in the aged leachate was 51.97%, and the PCBs removals are mainly achieved by the removal of trichlorobiphenyls, the PCBs contents in sludge in the two-staged LS-SBBR were consistent with the conclusion that the PCBs removal in liquid phase of the second LS-SBBR was higher than that of the first LS-SBBR.
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ANDERSSON, MATTIAS, JOACHIM GUDMUNDSSON, and CHRISTOS LEVCOPOULOS. "RESTRICTED MESH SIMPLIFICATION USING EDGE CONTRACTIONS." International Journal of Computational Geometry & Applications 19, no. 03 (June 2009): 247–65. http://dx.doi.org/10.1142/s0218195909002940.
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We consider the problem of simplifying a planar triangle mesh using edge contractions, under the restriction that the resulting vertices must be a subset of the input set. That is, contraction of an edge must be made onto one of its adjacent vertices, which results in removing the other adjacent vertex. We show that if the perimeter of the mesh consists of at most five vertices, then we can always find a vertex not on the perimeter which can be removed in this way. If the perimeter consists of more than five vertices such a vertex may not exist. In order to maintain a higher number of removable vertices under the above restriction, we study edge flips which can be performed in a visually smooth way. A removal of a vertex which is preceded by one such smooth operation is called a 2-step removal. Moreover, we introduce the possibility that the user defines "important" vertices (or edges) which have to remain intact. Given m such important vertices, or edges, we show that a simplification hierarchy of size O(n) and depth O( log (n/m)) can be constructed by 2-step removals in O(n) time, such that the simplified graph contains the m important vertices and edges, and at most O(m) other vertices from the input graph. In some triangulations, many vertices may not even be 2-step removable. In order to provide the option to remove such vertices, we also define and examine k-step removals. This increases the lower bound on the number of removable vertices.
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Huck, P. M., B. M. Coffey, W. B. Anderson, M. B. Emelko, D. D. Maurizio, R. M. Slawson, I. P. Douglas, S. Y. Jasim, and C. R. O'Melia. "Using turbidity and particle counts to monitor Cryptosporidium removals by filters." Water Supply 2, no. 3 (July 1, 2002): 65–71. http://dx.doi.org/10.2166/ws.2002.0086.
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Physicochemical removal of protozoan pathogens is receiving increased attention because of the difficulty of chemically inactivating these organisms, particularly Cryptosporidium parvum. Most studies that have examined the removal of these and other pathogens by filtration have been conducted under steady-state conditions with optimized pre-treatment. The research on which this paper is based evaluated the removal of Cryptosporidium and surrogates at various points in the filter cycle and under non-optimal conditions, at several pilot plants. The focus of this paper is on the relationship between removals of Cryptosporidium, and turbidity and particle counts. Under stable or optimal operating conditions all pilot plants produced similar low filter effluent turbidity and particle counts. Average Cryptosporidium removal varied among locations, however, by more than two log units. Cryptosporidium removal was impaired under all of the non-optimal conditions. Particle and turbidity performance was also worse, but the relationship of these parameters to Cryptosporidium removal varied. Particle counts show greater promise than turbidity as a tool to monitor filter performance in real time for possible deterioration in Cryptosporidium removal capability.
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Chen, Ming, Orion Dollar, Karen Shafer-Peltier, Stephen Randtke, Saad Waseem, and Edward Peltier. "Boron removal by electrocoagulation: Removal mechanism, adsorption models and factors influencing removal." Water Research 170 (March 2020): 115362. http://dx.doi.org/10.1016/j.watres.2019.115362.
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Yang, Hou-Yun, Pei Xu, Hua-Yuan Wang, Wei-Hua Li, and Shu-Guang Zhu. "Removal of Nitrogen and Phosphorus from Wastewater by Modified Pyrite in a Sequencing Batch Reactor (SBR)." E3S Web of Conferences 136 (2019): 06027. http://dx.doi.org/10.1051/e3sconf/201913606027.
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The removal efficiency of nitrogen and phosphorus is challenging in the conventional biological nitrogen and phosphorus removal processes. In this study, the modified pyrite was used as the fillings of se-quencing batch reactor (SBR) in order to improve the efficiencies of nitrogen and phosphorus removal from wastewater. The results showed that SBR with the modified pyrite could significantly improve the removal efficiencies of nitrogen and phosphorus when compared with that in SBR without fillings (control SBR). The average influent ammonia nitrogen (NH4+-N) and total phosphorus (TP) were 6.96±0.17 mg L-1 and 6.94±0.01 mg L-1, respectively. The average NH4+-N and TP removals of modified pyrite constructed SBR were 49.65±19.49% with 3.54±1.31 mg L-1 of average effluent NH4+-N and 76.20±6.55% with 1.84±0.46 mg L-1 of average effluent TP, respectively. While the average NH4+-N and TP removal efficiencies of con-trol SBR were only 34.76±11.28% and 56.28±0.11%. The mechanisms of the SBR with enhanced simulta-neous nitrogen and phosphorus removals might be anaerobic and aerobic oxidations of modified pyrite, and phosphorus retained in the SBR of modified pyrite was mostly in the form of Fe-bound-P.
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Edzwald, J. K., J. E. Tobiason, H. Dunn, G. Kaminski, and P. Galant. "Removal and fate of Cryptosporidium in dissolved air drinking water treatment plants." Water Science and Technology 43, no. 8 (April 1, 2001): 51–57. http://dx.doi.org/10.2166/wst.2001.0463.
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In the first part of the paper, data from pilot plant studies are used to evaluate Cryptosporidium removal by dissolved air flotation (DAF) clarification and dual media filters under challenge conditions. Oocyst removals were investigated for design detention times and hydraulic loadings for winter and spring seasons. Coagulation was optimized for turbidity and removal of natural organic matter. DAF performance was better for spring water temperatures achieving 2.5 ± 0.3 log removal of oocysts compared to 1.7 ± 0.3 log removal in the winter. Cumulative log removal across DAF and filtration exceeded 5.4, and was not affected by water temperature. Low turbidities and particle counts are indicators of good treatment and good removals of Cryptosporidium. The second part of the paper uses a mathematical model to predict the fate of Cryptosporidium through a DAF plant and the impact of filter backwash recycle on oocyst build-up in the plant influent. Model predictions show that the fate of Cryptosporidium and the build-up of oocysts in the plant influent depend on: DAF performance, the percent of filtered water production used for backwashing, and the percent of filter backwash recycle flow. A DAF plant with 2.5% filtered water production for backwashing and that achieves 1.6 log removal or greater of oocysts by DAF clarification will not have a build-up of oocysts in the plant influent regardless of the recycle rate. This is because the oocysts are concentrated in the DAF floated sludge and not within granular filters.
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Tran, Van L., Joy Greenberg, and Andrew Nuibe. "Evaluating the Incidence of Sepsis Post–Central Catheter Removal When Using Prophylactic Vancomycin in the Neonatal Intensive Care Unit." Journal of Pediatric Pharmacology and Therapeutics 26, no. 7 (September 24, 2021): 728–33. http://dx.doi.org/10.5863/1551-6776-26.7.728.
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OBJECTIVE With no consensus, the practice of using prophylactic antibiotics prior to central venous catheter (CVC) removal in NICU patients remains controversial. The objective of this study was to compare the incidence of sepsis post–CVC removal in those who received a dose of vancomycin prophylactically with those who did not. METHODS This single-center, retrospective chart review included NICU patients who had CVCs removed. Patients were excluded if they had a confirmed or suspected infection at the time of CVC removal or if the indwelling CVC was removed prior to 30 days from insertion. Primary outcome was the occurrence of a sepsis evaluation within 72 hours from CVC removal. Secondary outcomes included the development of acute kidney injury, source and identification of positive cultures, time to onset of suspected or confirmed sepsis, and the appropriate administration of intravenous vancomycin. RESULTS Eighty-two CVC removals received prophylactic vancomycin (P-VAN), and 22 CVCs did not receive prophylactic vancomycin (NP-VAN) prior to CVC removal. There were no significant differences in patient demographics between groups and median duration of indwelling CVC. Two clinical sepsis evaluations occurred in the P-VAN group compared with none in the NP-VAN group. Of all the P-VAN CVC removals, 45 (55%) received vancomycin appropriately. There were no statistical differences in all evaluated secondary outcomes. CONCLUSIONS Vancomycin administered prophylactically prior to CVC removal did not reduce the number of subsequent clinical sepsis evaluations or infections in NICU patients.
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Acuna-Askar, K., J. F. Villarreal-Chiu, M. V. Gracia-Lozano, M. T. Garza-Gonzalez, B. Chavez-Gomez, I. P. Rodriguez-Sanchez, and H. A. Barrera-Saldana. "BTE-OX biodegradation kinetics with MTBE through bioaugmentation." Water Science and Technology 50, no. 5 (September 1, 2004): 85–92. http://dx.doi.org/10.2166/wst.2004.0313.
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The biodegradation kinetics of BTE-oX and MTBE, mixed all together, in the presence of bioaugmented bacterial populations as high as 880 mg/L VSS was evaluated. The effect of soil in aqueous samples and the effect of Tergitol NP-10 on substrate biodegradation rates were also evaluated. Biodegradation kinetics was evaluated for 36 hours, every 6 hours. Benzene and o-xylene biodegradation followed a first-order one-phase kinetic model, whereas toluene and ethylbenzene biodegradation was well described by a first-order two-phase kinetic model in all samples. MTBE followed a zero-order removal kinetic model in all samples. The presence of soil in aqueous samples retarded BTE-oX removal rates, with the highest negative effect on o-xylene. The presence of soil enhanced MTBE removal rate. The addition of Tergitol NP-10 to aqueous samples containing soil had a positive effect on substrate removal rate in all samples. Substrate percent removals ranged from 95.4-99.7% for benzene, toluene and ethylbenzene. O-xylene and MTBE percent removals ranged from 55.9-90.1% and 15.6-30.1%, respectively.
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John P. Bowes. "American Indian Removal beyond the Removal Act." Wicazo Sa Review 1, no. 1 (2014): 65. http://dx.doi.org/10.5749/natiindistudj.1.1.0065.
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Holm, Thomas R., Walton R. Kelly, Steven D. Wilson, and Jonathan L. Talbott. "Arsenic removal at llinois iron removal plants." Journal - American Water Works Association 100, no. 9 (September 2008): 139–50. http://dx.doi.org/10.1002/j.1551-8833.2008.tb09727.x.
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Bowes, John P. "American Indian Removal beyond the Removal Act." Native American and Indigenous Studies 1, no. 1 (March 2014): 65–87. http://dx.doi.org/10.1353/nai.2014.a843652.
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