Artigos de revistas: "COD"

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Zada, Muhammad, Desalegn Demise Sage, Qiuyue Zhang, Yanping Ma, Gregory A. Solan, Yang Sun e Wen-Hua Sun. "Thermally Stable and Highly Efficient N,N,N-Cobalt Olefin Polymerization Catalysts Affixed with N-2,4-Bis(Dibenzosuberyl)-6-Fluorophenyl Groups". Catalysts 12, n.º 12 (2 de dezembro de 2022): 1569. http://dx.doi.org/10.3390/catal12121569.

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The cobalt(II) chloride N,N,N-pincer complexes, [2-{(2,4-(C15H13)2-6-FC6H2)N=CMe}-6-(ArN=CMe)C5H3N]CoCl2 (Ar = 2,6-Me2C6H3) (Co1), 2,6-Et2C6H3 (Co2), 2,6-i-Pr2C6H3 (Co3), 2,4,6-Me3C6H2 (Co4), 2,6-Et2-4-MeC6H2 (Co5), and [2,6-{(2,4-(C15H13)2-6-FC6H2)N=CMe}2C5H3N]CoCl2 (Co6), each containing at least one N-2,4-bis(dibenzosuberyl)-6-fluorophenyl group, were synthesized in good yield from their corresponding unsymmetrical (L1–L5) and symmetrical bis(imino)pyridines (L6). The molecular structures of Co1 and Co2 spotlighted their distorted square pyramidal geometries (τ5 value range: 0.23–0.29) and variations in steric hindrance offered by the dissimilar N-aryl groups. On activation with either MAO or MMAO, Co1–Co6 all displayed high activities for ethylene polymerization, with levels falling in the order: Co1 > Co4 > Co5 > Co2 > Co3 > Co6. Indeed, the least sterically hindered 2,6-dimethyl Co1 in combination with MAO exhibited a very high activity of 1.15 × 107 g PE mol−1 (Co) h−1 at the operating temperature of 70 °C, which dropped by only 15% at 80 °C and 43% at 90 °C. Vinyl-terminated polyethylenes of high linearity and narrow dispersity were generated by all catalysts, with the most sterically hindered, Co3 and Co6, producing the highest molecular weight polymers [Mw range: 30.26–33.90 kg mol−1 (Co3) and 42.90–43.92 kg mol−1 (Co6)]. In comparison with structurally related cobalt catalysts, it was evident that the presence of the N-2,4-bis(dibenzosuberyl)-6-fluorophenyl groups had a limited effect on catalytic activity but a marked effect on thermal stability.

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Guo, Jingjing, Zheng Wang, Wenjuan Zhang, Ivan Oleynik, Arumugam Vignesh, Irina Oleynik, Xinquan Hu, Yang Sun e Wen-Hua Sun. "Highly Linear Polyethylenes Achieved Using Thermo-Stable and Efficient Cobalt Precatalysts Bearing Carbocyclic-Fused NNN-Pincer Ligand". Molecules 24, n.º 6 (25 de março de 2019): 1176. http://dx.doi.org/10.3390/molecules24061176.

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Six examples of 2-(1-arylimino)ethyl-9-arylimino-5,6,7,8-tetrahydrocycloheptapyridine-cobalt(II) chloride complexes, [2-(1-ArN)C2H3-9-ArN-5,6,7,8-C5H8C5H3N]CoCl2, (Ar = 2-(C5H9)-6-MeC6H3 Co1, 2-(C6H11)-6-MeC6H3 Co2, 2-(C8H15)-6-MeC6H3 Co3, 2-(C5H9)-4,6-Me2C6H2 Co4, 2-(C6H11)-4,6-Me2C6H2 Co5, and 2-(C8H15)-4,6-Me2C6H2 Co6), were synthesized by the direct reaction of the corresponding ortho-cycloalkyl substituted carbocyclic-fused bis(arylimino)pyridines (L1–L6) and cobalt(II) chloride in ethanol with good yields. All the synthesized ligands (L1–L6) and their corresponding cobalt complexes (Co1–Co6) were fully characterized by FT-IR, 1H/13C-NMR spectroscopy and elemental analysis. The crystal structure of Co2 and Co3 revealed that the ring puckering of both the ortho-cyclohexyl/cyclooctyl substituents and the one pyridine-fused seven-membered ring; a square-based pyramidal geometry is conferred around the metal center. On treatment with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all the six complexes showed high activities (up to 4.09 × 106 g of PE mol−1 (Co) h−1) toward ethylene polymerization at temperatures between 20 °C and 70 °C with the catalytic activities correlating with the type of ortho-cycloalkyl substituent: Cyclopentyl (Co1 and Co4) > cyclohexyl (Co2 and Co5) > cyclooctyl (Co3 and Co6) for either R = H or Me and afforded strictly linear polyethylene (Tm > 130 °C). The narrow unimodal distributions of the resulting polymers are consistent with single-site active species for the precatalyst. Furthermore, compared to the previously reported cobalt analogues, the titled precatalysts exhibited good thermo-stability (up to 70 °C) and possessed longer lifetime along with a higher molecular weight of PE (Mw: 9.2~25.3 kg mol−1).

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Le, Gaoyang, Huizhong Yang e Xiaodong Yu. "Improved UV/O3 method for measuring the chemical oxygen demand". Water Science and Technology 77, n.º 5 (2 de janeiro de 2018): 1271–79. http://dx.doi.org/10.2166/wst.2018.005.

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Abstract We improved the ultraviolet (UV)/O3-based method for measuring chemical oxygen demand (COD) in water. An on-line COD monitoring device was developed and the UV/O3 method was used to oxidize sample solutions. A model was established by using support vector machines (SVM) algorithm to estimate dissolved oxygen and CO2 in solutions. Based on the measured data by each sensor during the oxidation process and the estimated dissolved oxygen and CO2, the UV/O3-based COD test accuracy was improved. This approach overcomes many problems associated with the conventional COD determination techniques such as long analysis time, consumption of expensive and toxic reagents, and production of secondary toxic waste. The effect of important parameters on the measurement of COD was systematically investigated. The improved method was successfully applied to determine the COD of real samples from environmental water. Compared with the standard dichromate method, our UV/O3-based COD test method is more effective. The assay time of 10–15 min/sample can be readily achieved. A practical detection limit of 0.89 mg/L COD with a linear range of 1–300 mg/L was achieved under the normal conditions.

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M. Ibrahim, Hind, e Rasha H. salman. "Study the Optimization of Petroleum Refinery Wastewater Treatment by Successive Electrocoagulation and Electro-oxidation Systems". Iraqi Journal of Chemical and Petroleum Engineering 23, n.º 1 (30 de março de 2022): 31–41. http://dx.doi.org/10.31699/ijcpe.2022.1.5.

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In this study, successive electrocoagulation (EC) and electro-oxidation (EO) processes were used to minimize some of the major pollutants in real wastewater, such as organics (detected by chemical oxygen demand (COD)), and turbidity. The wastewater utilized in the present study was collected from the Midland Refinery Company in Baghdad-Iraq. The performance of the successive batch EC-EO processes was studied by utilizing Graphite and Aluminum (Al) as monopolar anode electrodes and stainless steel (st.st.) as the cathode. The Taguchi experimental design approach was used to attain the best experimental conditions for COD reduction as a major response. Starting from chemical oxygen demand COD of (600 ppm), the effects of current density (C.D.) (10- 20 mA/cm2), pH (4- 10), time (2– 4 h), and NaCl concentration (1.5- 2.5 g/l) on the efficiency of COD reduction were examined. The results indicated that COD reduction increased with increasing C.D., NaCl conc., and electrolysis time and increased exponentially at pH (4). The best conditions for the treatment of this wastewater were: C.D. (20 mA/cm2), pH (4), time (4 h), and NaCl conc. (2.5 g/l). At these conditions, approximately 98.12 % of COD reduction was achieved with electrical energy consumption (ENC) of about 62.04 kWh/m3. The result of analysis of variance (ANOVA) revealed that the C.D. and pH have a higher influence on the performance of organics removal, while the time and NaCl conc. have a minor impact on COD Re%.

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Jorge, Nuno, Ana R. Teixeira, Lisete Fernandes, Sílvia Afonso, Ivo Oliveira, Berta Gonçalves, Marco S. Lucas e José A. Peres. "Treatment of Winery Wastewater by Combined Almond Skin Coagulant and Sulfate Radicals: Assessment of Activators". International Journal of Environmental Research and Public Health 20, n.º 3 (30 de janeiro de 2023): 2486. http://dx.doi.org/10.3390/ijerph20032486.

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The large production of wine and almonds leads to the generation of sub-products, such as winery wastewater (WW) and almond skin. WW is characterized by its high content of recalcitrant organic matter (biodegradability index < 0.30). Therefore, the aim of this work was to (1) apply the coagulation–flocculation–decantation (CFD) process with an organic coagulant based on almond skin extract (ASE), (2) treat the organic recalcitrant matter through sulfate radical advanced oxidation processes (SR-AOPs) and (3) evaluate the efficiency of combined CFD with UV-A, UV-C and ultrasound (US) reactors. The CFD process was applied with variation in the ASE concentration vs. pH, with results showing a chemical oxygen demand (COD) removal of 61.2% (0.5 g/L ASE, pH = 3.0). After CFD, the germination index (GI) of cucumber and corn seeds was ≥80%; thus, the sludge can be recycled as fertilizer. The SR-AOP initial conditions were achieved by the application of a Box–Behnken response surface methodology, which described the relationship between three independent variables (peroxymonosulfate (PMS) concentration, cobalt (Co2+) concentration and UV-A radiation intensity). Afterwards, the SR-AOPs were optimized by varying the pH, temperature, catalyst type and reagent addition manner. With the application of CFD as a pre-treatment followed by SR-AOP under optimal conditions (pH = 6.0, [PMS] = 5.88 mM, [Co2+] = 5 mM, T = 343 K, reaction time 240 min), the COD removal increased to 85.9, 82.6 and 80.2%, respectively, for UV-A, UV-C and US reactors. All treated wastewater met the Portuguese legislation for discharge in a municipal sewage network (COD ≤ 1000 mg O2/L). As a final remark, the combination of CFD with SR-AOPs is a sustainable, safe and clean strategy for WW treatment and subproduct valorization.

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Banch, Tawfiq J. H., Marlia M. Hanafiah, Abbas F. M. Alkarkhi e Salem S. Abu Amr. "Factorial Design and Optimization of Landfill Leachate Treatment Using Tannin-Based Natural Coagulant". Polymers 11, n.º 8 (14 de agosto de 2019): 1349. http://dx.doi.org/10.3390/polym11081349.

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In this study, tannin-based natural coagulant was used to treat stabilized landfill leachate. Tannin modified with amino group was utilized for the treatment process. Central composite design (CCD) was used to investigate and optimize the effect of tannin dosage and pH on four responses. The treatment efficiency was evaluated based on the removal of four selected (responses) parameters; namely, chemical oxygen demand (COD), color, NH3–N and total suspended solids (TSS). The optimum removal efficiency for COD, TSS, NH3–N and color was obtained using a tannin dosage of 0.73 g at a pH of 6. Moreover, the removal efficiency for selected heavy metals from leachate; namely, iron (Fe2+), zinc (Zn2+), copper (Cu2+), chromium (Cr2+), cadmium (Cd2+), lead (Pb2+), arsenic (As3+), and cobalt (Co2+) was also investigated. The results for removal efficiency for COD, TSS, NH3–N, and color were 53.50%, 60.26%, and 91.39%, respectively. The removal of selected heavy metals from leachate for Fe2+, Zn2+, Cu2+, Cr2+, Cd2+, Pb2+, As3+ and cobalt Co2+ were 89.76%, 94.61%, 94.15%, 89.94%, 17.26%, 93.78%, 86.43% and 84.19%, respectively. The results demonstrate that tannin-based natural coagulant could effectively remove organic compounds and heavy metals from stabilized landfill leachate.

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Hao, X., J. J. Heijnen, Y. Qian e M. C. M. van Loosdrecht. "Contribution of P-bacteria in biological nutrient removal processes to overall effects on the environment". Water Science and Technology 44, n.º 1 (1 de julho de 2001): 67–76. http://dx.doi.org/10.2166/wst.2001.0017.

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P-bacteria can combine denitrification and P-uptake. This category of P-bacteria is abbreviated DPB. Use of DPB in BNR processes, instead of obligate aerobic PAOs, reduces oxygen consumption. Moreover, less COD is needed for the nitrogen removal. Non-required COD can be removed by presettling and used for methanation. This leads to a lower sludge production. As a result, CO2 emissions are reduced owing to less net energy consumption. Simulation for a planned WWTP with the BCFS® process indicates that DPB can save 53-59% of required COD. The optimal ratios of COD/N and COD/P for simultaneous N and P removal are determined to be 3.9~4.5 and 32.2~35.2 at 12~20°C. 80-95% of particulate COD can be removed from the influent, thereby CH4 production is increased by 154-271%, and the total volume of reactors can be reduced by about 50% compared to a minimised process design. Less net energy consumption over the whole WWTP contributes to a net reduction of the total CO2 emissions up to 16-21%. The energy production from CH4 is excessive enough to balance the energy consumption from aeration, dewatering and incineration. It is concluded that contribution of P-bacteria to saving COD has overall positive effects on the environment.

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GULDAGER, HELLE SKOV, NIELS BØKNÆS, CARSTEN ØSTERBERG, JETTE NIELSEN e PAW DALGAARD. "Thawed Cod Fillets Spoil Less Rapidly Than Unfrozen Fillets When Stored under Modified Atmosphere at 2°C". Journal of Food Protection 61, n.º 9 (1 de setembro de 1998): 1129–36. http://dx.doi.org/10.4315/0362-028x-61.9.1129.

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The effect of two months of frozen storage at −20°C on the spoilage characteristics and shelf life of thawed and modified atmosphere packed (MAP) cod fillets stored at 2°C was studied. Thawed MAP cod fillets were compared with fresh cod fillets stored in CO2-containing modified atmospheres with and without added oxygen. The shelf life of 11 to 12 days in the fresh MAP cod was extended to more than 20 days in the thawed MAP cod at 2°C. This shelf life extension was most likely due to the inactivation of the spoilage bacterium Photobacterium phosphoreum during frozen storage as reflected both in Chemical analyses and sensory evaluation. In contrast to fresh MAP cod fillets no significant production of trimethylamine occurred and almost no amine odor and taste were detected during 20 days of chill storage of thawed MAP cod fillets. The use of frozen fillets as raw material not only provides a more stable product in MAP but also allows much greater flexibility for production and distribution. However, a slightly increased concentration of dimethylamine, a larger drip loss, and detection of weak frozen storage flavor were observed in the thawed MAP cod fillets.

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Gori, Riccardo, Francesca Giaccherini, Lu-Man Jiang, Reza Sobhani e Diego Rosso. "Role of primary sedimentation on plant-wide energy recovery and carbon footprint". Water Science and Technology 68, n.º 4 (1 de agosto de 2013): 870–78. http://dx.doi.org/10.2166/wst.2013.270.

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The goal of this paper is to show the effect of primary sedimentation on the chemical oxygen demand (COD) and solids fractionation and consequently on the carbonaceous and energy footprints of wastewater treatment processes. Using a simple rational procedure for COD and solids fraction quantification, we quantify the effects of varying fractions on CO2 and CO2-equivalent mass flows, process energy demand and energy recovery. Then we analysed two treatment plants with similar biological nutrient removal processes in two different climatic regions and quantified the net benefit of gravity separation before biological treatment. In the cases analysed, primary settling increases the solid fraction of COD that is processed in anaerobic digestion, with an associated increase in biogas production and energy recovery, and a reduction in overall emissions of CO2 and CO2-equivalent from power importation.

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Tetteh, Emmanuel Kweinor, Gloria Amo-Duodu e Sudesh Rathilal. "Exploring CO2 Bio-Mitigation via a Biophotocatalytic/Biomagnetic System for Wastewater Treatment and Biogas Production". Applied Sciences 12, n.º 14 (6 de julho de 2022): 6840. http://dx.doi.org/10.3390/app12146840.

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Carbon dioxide (CO2) emissions from fossil fuels have led industries to seek cheaper carbon abatement technologies to mitigate environmental pollution. Herein, the effect of a magnetic photocatalyst (Fe-TiO2) on biogas production in anaerobic digestion (AD) of wastewater was investigated with three bioreactors coupled with UV-light (18 W). Three experimental setups defined as the control (AD system with no Fe-TiO2), biophotoreactor (BP), and biophotomagnetic (BPM) systems were operated at a mesophilic temperature (35 ± 5 °C) for a hydraulic retention time (HRT) of 30 days. The control system (ADs) had no Fe-TiO2 additives. The BPMs with 2 g Fe-TiO2 were exposed to a magnetic field, whereas the BPs were not. The removal rate of the chemical oxygen demand (COD), volatile solids (VS), and total solids (TS), together with biogas production and composition were monitored for each reactor. The degree of degradation of 75% COD was observed for the BPMs at a pH of 6.5 followed by the BPs (65% COD) and the ADs (45% COD). The results showed that the rate of degradation of COD had a direct correlation with the cumulative biogas production of the BPMs (1330 mL/d) > BPs (1125 mL/d) > AD (625 mL/d). This finding supports the use of biophotomagnetic systems (BPMs) in wastewater treatment for resource recovery and CO2 reduction (0.64 kg CO2/L) as an eco-friendly technology.

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D’Onofrio, Valentino, Elena Donders, Marie-Elena Vanden Abeele, Jasperina Dubois, Reinoud Cartuyvels, Ruth Achten, Martin Lammens et al. "The clinical value of minimal invasive autopsy in COVID-19 patients". PLOS ONE 15, n.º 11 (11 de novembro de 2020): e0242300. http://dx.doi.org/10.1371/journal.pone.0242300.

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Background Minimally invasive autopsy (MIA) is a validated and safe method to establish the cause of death (COD), mainly in low-resource settings. However, the additional clinical value of MIA in Coronavirus disease (COVID-19) patients in a high-resource setting is unknown. The objective was to assess if and how MIA changed clinical COD and contributing diagnoses in deceased COVID-19 patients. Methods and findings A prospective observational cohort from April to May 2020 in a 981-bed teaching hospital in the epicenter of the COVID-19 pandemic in Belgium was established. Patients who died with either PCR-confirmed or radiologically confirmed COVID-19 infection were consecutively included. MIA consisted of whole-body CT and CT-guided Tru-Cut® biopsies. Diagnostic modalities were clinical chart review, radiology, microbiology, and histopathology which were assessed by two independent experts per modality. MIA COD and contributing diagnoses were established during a multi-disciplinary meeting. Clinical COD (CCOD) and contributing diagnosis were abstracted from the discharge letter. The main outcomes were alterations in CCOD and contributing diagnoses after MIA, and the contribution of each diagnostic modality. We included 18 patients, of which 7 after intensive care unit hospitalization. MIA led to an alteration in 15/18 (83%) patients. The CCOD was altered in 5/18 (28%) patients. MIA found a new COD (1/5), a more specific COD (1/5), a less certain COD (1/5), or a contributing diagnosis to be the COD (2/5). Contributing diagnoses were altered in 14/18 (78%) patients: 9 new diagnoses, 5 diagnoses dismissed, 3 made more specific, and 2 made less certain. Overall, histopathology contributed in 14/15 (93%) patients with alterations, radiology and microbiology each in 6/15 (40%), and clinical review in 3/15 (20%). Histopathology was deemed the most important modality in 10 patients, radiology in two patients, and microbiology in one patient. Conclusion MIA, especially histological examination, can add valuable new clinical information regarding the cause of death in COVID-19 patients, even in a high-resource setting with wide access to premortem diagnostic modalities. MIA may provide important clinical insights and should be applied in the current ongoing pandemic. Trial registration Clinicaltrials.gov identifier: NCT04366882

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Weitzman, Jonathan B. "Cod origins". Genome Biology 2 (2001): spotlight—20010924–01. http://dx.doi.org/10.1186/gb-spotlight-20010924-01.

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Bashir, Mohammed J. K., Ong Sue Sheen, Choon Aun Ng, Mohammed Shadi S. Abujazar, Motasem Y. D. Alazaiza e Salim S. Abu Amr. "Advanced Treatment of Palm Oil Mill Effluent Using Thermally Activated Persulfate Oxidation". Separations 9, n.º 7 (8 de julho de 2022): 171. http://dx.doi.org/10.3390/separations9070171.

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Advanced treatment of biologically processed palm oil mill effluent (BIOTPOME), which possesses a potential danger to the water sources is required to meet the Malaysian discharge standard, as BIOTPOME contains high level of chemical oxygen demand (COD), suspended solids and oil and grease even after going through conventional treatment process. The significant but insufficient treatment efficiency of ponding system in Malaysia urged an alternative method to treat the recalcitrant organic compounds. Thus, post-treatment of BIOTPOME using oxidation by thermally activated persulfate process was proposed to solve this issue. In order to maximize the removal of COD and color, the central composite design (CCD) module of the response surface approach was used to optimize the interactions of the process variables temperature, S2O82−/COD ratio, and reaction time. In order to identify the significant terms of interacting process factors, CCD performed a batch study from which statistical models of responses were created. All models were confirmed by analysis of variance (ANOVA) showing significances with Prob > F less than 0.1. The optimal performance was obtained at the temperature of 67.4 °C, S2O82−/COD ratio of 9.8 and reaction time of 120 min, rendering COD removal of 85.65% and color removal of 85.74%. The total cost for the treatment process was RM0.94 per liter.

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YOSHINAGA, Tetsutaro, Toshihide NAKAMURA e Yutaka TSURU. "Comparison of Oxidizing Abilities of COD Measurement Methods. COD(Cr) and COD(Mn) Methods." NIPPON KAGAKU KAISHI, n.º 3 (1993): 278–84. http://dx.doi.org/10.1246/nikkashi.1993.278.

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Yadav, Shailendra Kumar, e R. Kalaiyarasi. "FEASIBILITY ANALYSIS ON INDUSTRIAL SYMBIOSIS BETWEEN CEMENT INDUSTRY AND TEA INDUSTRY". International Journal of Environment 4, n.º 3 (24 de agosto de 2015): 20–34. http://dx.doi.org/10.3126/ije.v4i3.13227.

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The project aims at analyzing the feasibility of utilizing cement kiln dust (CKD) in treating wastewater from tea industry with the concept of industrial symbiosis. CKD is the dust collected at the air pollution control device(s) associated with a kiln system from cement industry. A very less percent of CKD is recycled and the rest is land filled /stockpiled; disrupts groundwater through leaching of minerals. Cement Kiln Dust (CKD), rich in CaO, SiO2, behaves as a neutralizing as well as stabilizing agent for tea effluent treatment. The ability of CKD to reduce the BOD, COD, TSS, and phosphates in tea effluent was analyzed and the optimum dosage is determined. The effect of different dosages of Cement Kiln Dust ranging from (1-3) gm/l has been discussed on the bench scale tests. The results show that, for different CKD concentrations, high removal efficiencies of 94.4 and 99.0, 58.9 for BOD, TSS, phosphates and a lower efficiency for COD with 9.09 are achieved for 2.5gm/l. The persistent presence of color providing proteins theaflavins (TF) and the arubigins (TR) from the leftover tea leaves in the effluent imparts the low removal efficiencies of COD. However, the COD value is within the dischargeable limits (CPCB standards). Moreover, a considerable removal efficiency and high SVI of 0.181 makes CKD a feasible coagulant in treating tea effluent with optimum dosage of 2.5g/l. The objective of developing industrial symbiosis network was thus achieved using the CKD to treat wastewater from tea industries. International Journal of EnvironmentVolume-4, Issue-3, June-August 2015Page: 20-34

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Lin, Yen-Hui. "Modeling the performance of biodegradation of textile wastewater using polyurethane foam sponge cube as a supporting medium". Water Science and Technology 62, n.º 12 (1 de dezembro de 2010): 2801–10. http://dx.doi.org/10.2166/wst.2010.071.

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A pilot-scale fixed-biofilm reactor (FBR) was established to treat textile wastewater to evaluate the feasibility of replacing conventional treatment processes that involve activated sludge and coagulation units. A kinetic model was developed to describe the biodegradation of textile wastewater by FBR. Batch kinetic tests were performed to evaluate the biokinetic parameters that are used in the model. FBR column test was fed with a mean COD of 692 mg/L of textile wastewater from flow equalization unit. The influent flow rate was maintained at 48.4 L/h for FBR column test. Experimental data and model-predicted data for substrate effluent concentration (as COD), concentration of suspended biomass in effluent and the amount of carbon dioxide (CO2) produced in the effluent agree closely with each other. Microscopic observations demonstrated that the biofilm exhibited a uniform distribution on the surface of polyurethane foam sponge. Under a steady-state condition, the effluent COD from FBR was about 14.7 mg COD/L (0.0213 Sb0), meeting the discharge standard (COD < 100 mg/L) that has been set by the government of Taiwan for textile wastewater effluent. The amount of biofilm and suspended biomass reached a maximal value in the steady state when the substrate flux reached a constant value and remained maximal. Approximately 33% of the substrate concentration (as COD) was converted to CO2 during biodegradation in the FBR test. The experimental and modeling schemes proposed in this study could be employed to design a full-scale FBR to treat textile wastewater.

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Almeida, Antonella Araujo de, André Pereira Rosa, Izabelle de Paula Sousa, Juciara Oliveira Lopes, Silas Modesto de Melo e Alisson Carraro Borges. "Performance of two parallel covered lagoon digesters in the treatment of pig farm wastewaters". Revista Engenharia na Agricultura - Reveng 29 (21 de outubro de 2021): 286–90. http://dx.doi.org/10.13083/reveng.v29i1.11576.

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Pig farming moves a large part of the Brazilian economy. However, due to the high polluting potential, alternatives to treat and take advantage of the effluents must be developed, being the use of digesters a possible solution. This study aimed to evaluate the performance of two parallel covered lagoon digesters (CLD) in the treatment of swine wastewater. Monitoring was performed on a farm installed in Teixeiras, Minas Gerais, Brazil, in terms of COD in the period from August 2018 to July 2019. The study demonstrated that COD removal efficiency in the CLD was 40.2 and 39.5%, which did not indicate a statistical difference at a 5% significance level. The two digesters in parallel were compatible with each other in terms of COD reduction. Furthermore, individually they did not present significant changes in their performance in the summer and winter periods.

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Tomai, Fabrizio, Anna Piccoli, Fausto Castriota, Luca Weltert, Bernhard Reimers, Gabriele Pesarini, Raoul Borioni et al. "Long-Term Outcomes of Coronary and Carotid Artery Disease Revascularization in the FRIENDS Study". Journal of Interventional Cardiology 2019 (20 de junho de 2019): 1–9. http://dx.doi.org/10.1155/2019/8586927.

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Objectives. The aim of this study is to assess long-term-outcomes of patients with concomitant CAD and COD treated with different revascularization strategies. Background. Multisite artery disease is common and patients with combined disease have poor prognosis. The best therapeutic strategy for patients with concomitant carotid obstructive disease (COD) and coronary artery disease (CAD) remains controversial. Methods. This observational registry enrolled, between January 2006 and December 2012, 1022 consecutive patients from high volume institutions with concomitant CAD and COD suitable for endovascular, surgical, or hybrid revascularization in both territories selected by consensus of a multidisciplinary team. Results. The cumulative incidence of 5-year major cardiovascular events (MACCE) including cardiovascular death, myocardial infarction (MI), or stroke in the overall population was 12%. The incidence of 5-year MACCE was not statistically different in the surgical, endovascular, or hybrid patients group (10.1% vs. 13.0% vs. 13.2%, P = .257, respectively). However, the hybrid group exhibited rates of myocardial infarction, chronic kidney disease, and cumulative incidence of all clinical events higher than the surgical group. After propensity score matching, the incidence of 5-year MACCE was similar in the three groups (13.0% vs. 15.0% vs. 16.0%, p = .947, respectively). Conclusions. An individualized revascularization approach of patients with combined CAD and COD yields very good results at long-term follow-up, despite the high risk of this multilevel population even when the baseline clinical features are equalized.

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Gray, Tim, Jenny Hatchard, Tim Daw e Selina Stead. "New cod war of words: ‘Cod is God’ versus ‘sod the cod’—Two opposed discourses on the North Sea Cod Recovery Programme". Fisheries Research 93, n.º 1-2 (setembro de 2008): 1–7. http://dx.doi.org/10.1016/j.fishres.2008.04.009.

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Harada, Hideki, Kiyoshi Momonoi, Shinichi Yamazaki e Satoshi Takizawa. "Application of anaerobic-uf membrane reactor for treatment of a wastewater containing high strength particulate organics". Water Science and Technology 30, n.º 12 (1 de dezembro de 1994): 307–19. http://dx.doi.org/10.2166/wst.1994.0630.

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A cross-flow ultrafiltration (UF) membrane separation was applied to anaerobic process for treatment of a wastewater containing high proportion of particulate COD. A synthetic wastewater with the total strength of 5000 mg COD·1−1 consisting of soluble and particulate COD (cellulose) in the ratio of 1:1 was fed to the reactor. The reactor was operated for 190 days at two loading rates, i.e. 1.5 and 2.5 kg COD·m−3·d−1. More than 98% of COD removal was consistently achieved throughout the duration, and the system was furthermore likely to accommodate much higher loading. Although the permeate COD was always kept at less than 80 mg COD·1−1, soluble COD of reactor broth accumulated up to 1200 mg COD·1−1. The biomass concentration saturated around 15 000 mg ML VSS·1−1. There was no tendency for cellulose to accumulate in the reactor over the whole period, which constituted only 1-2% of the total solids retained in the reactor. The methanogenic activity of the sludge increased 3.4 times for H2/CO2 and 10 times for acetate after 40 days operation. Afterwards, however, a further cultivation caused declines to 50% of the respective peak values for both substrates, because of a low sludge loading. The methanogenic activity using cellulose as a test substrate also exhibited a similar tendency. The membrane permeate flux deteriorated significantly with the cultivation time, owing to the change in rheological properties of the reactor mixed liquor that had been caused not only by increment of MLSS but also by accumulation of soluble high molecular organics.

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Cristiani, Lorenzo, Marco Zeppilli, Cristina Porcu e Mauro Majone. "Ammonium Recovery and Biogas Upgrading in a Tubular Micro-Pilot Microbial Electrolysis Cell (MEC)". Molecules 25, n.º 12 (12 de junho de 2020): 2723. http://dx.doi.org/10.3390/molecules25122723.

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Here, a 12-liter tubular microbial electrolysis cell (MEC) was developed as a post treatment unit for simultaneous biogas upgrading and ammonium recovery from the liquid effluent of an anaerobic digestion process. The MEC configuration adopted a cation exchange membrane to separate the inner anodic chamber and the external cathodic chamber, which were filled with graphite granules. The cathodic chamber performed the CO2 removal through the bioelectromethanogenesis reaction and alkalinity generation while the anodic oxidation of a synthetic fermentate partially sustained the energy demand of the process. Three different nitrogen load rates (73, 365, and 2229 mg N/Ld) were applied to the inner anodic chamber to test the performances of the whole process in terms of COD (Chemical Oxygen Demand) removal, CO2 removal, and nitrogen recovery. By maintaining the organic load rate at 2.55 g COD/Ld and the anodic chamber polarization at +0.2 V vs. SHE (Standard Hydrogen Electrode), the increase of the nitrogen load rate promoted the ammonium migration and recovery, i.e., the percentage of current counterbalanced by the ammonium migration increased from 1% to 100% by increasing the nitrogen load rate by 30-fold. The CO2 removal slightly increased during the three periods, and permitted the removal of 65% of the influent CO2, which corresponded to an average removal of 2.2 g CO2/Ld. During the operation with the higher nitrogen load rate, the MEC energy consumption, which was simultaneously used for the different operations, was lower than the selected benchmark technologies, i.e., 0.47 kW/N·m3 for CO2 removal and 0.88 kW·h/kg COD for COD oxidation were consumed by the MEC while the ammonium nitrogen recovery consumed 2.3 kW·h/kg N.

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Stapp, Bernhard, Günther Schmidtberg e Hans Albert Brune. "Synthesen ortho-nitrosubstituierter Bis(phenyl)platin(II)-Verbindungen / Syntheses of ort/zo-Nitro-Substituted Bis(phenyl)platinum(II) Compounds". Zeitschrift für Naturforschung B 41, n.º 4 (1 de abril de 1986): 514–18. http://dx.doi.org/10.1515/znb-1986-0419.

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Syntheses of the com pounds cis-{Pt[P(C6H5)3]2(2-O2N-C6H4)(X-C6H4)}(X=4-CH3O; 4-CH3; 4-CF3; 4-O2N; 2-CH3O; 2-CH3; 2-CF3; 2-O2N), [Pt(1,2,5,6-η4-C0D)(2-O2N-C6H4)(X-C6H4)](X=4-CH3O; 4-CH3; COD= 1,5-cyclooctadiene) and [Pt(1,2,5,6-η4-COD)(X-C6H4)Cl](X= 2-CH3O; 2-CH3; 2-CF3)are reported

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23

Thayalakumaran, N., R. Bhamidimarri e P. O. Bickers. "Biological nutrient removal from meat processing wastewater using a sequencing batch reactor". Water Science and Technology 47, n.º 10 (1 de maio de 2003): 101–8. http://dx.doi.org/10.2166/wst.2003.0549.

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Meat processing effluents are rich in nutrients (nitrogen: 75-200 mg L−1 and phosphorus: 20-40 mg L−1) and COD (800-2,000 mg L−1) after primary treatment. A laboratory scale sequencing batch reactor (SBR) was operated for the treatment of a beef processing effluent from slaughtering and boning operations. An effective SBR cycle was found for removal of COD, nitrogen and phosphorus at 22°C. The solid retention time was 15 days while the hydraulic retention time (HRT) was 2.5 days. The total nitrogen in the wastewater was reduced to less than 10 mg L−1, while the total phosphorus decreased to less than 1.0 mg L−1. The residual effluent soluble COD was found to be non-biodegradable as reflected by no further soluble COD removal following prolonged aeration. Removal of biodegradable soluble COD, ammonia nitrogen and soluble phosphate phosphorus of greater than 99% was achieved in the SBR. Good prediction of ammonia and nitrate nitrogen removal was obtained using IWA Activated Sludge Model. The operating cycle is shown to be appropriate to achieve simultaneous removal of COD and nutrients from the meat processing wastewater. Alkalinity and pH have an inverse relationship during the initial anaerobic and aerobic stages due to production and stripping of CO2. Use of a low level of DO in the final aerobic stage ensured complete ammonia removal and enhanced denitrification.

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Jiao, Nianzhi, Jihua Liu, Bethanie Edwards, Zongqing Lv, Ruanhong Cai, Yongqin Liu, Xilin Xiao et al. "Correcting a major error in assessing organic carbon pollution in natural waters". Science Advances 7, n.º 16 (abril de 2021): eabc7318. http://dx.doi.org/10.1126/sciadv.abc7318.

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Microbial degradation of dissolved organic carbon (DOC) in aquatic environments can cause oxygen depletion, water acidification, and CO2 emissions. These problems are caused by labile DOC (LDOC) and not refractory DOC (RDOC) that resists degradation and is thus a carbon sink. For nearly a century, chemical oxygen demand (COD) has been widely used for assessment of organic pollution in aquatic systems. Here, we show through a multicountry survey and experimental studies that COD is not an appropriate proxy of microbial degradability of organic matter because it oxidizes both LDOC and RDOC, and the latter contributes up to 90% of DOC in high-latitude forested areas. Hence, COD measurements do not provide appropriate scientific information on organic pollution in natural waters and can mislead environmental policies. We propose the replacement of the COD method with an optode-based biological oxygen demand method to accurately and efficiently assess organic pollution in natural aquatic environments.

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Davarnejad, Reza, Masoud Pirhadi, Mohsen Mohammadi e Shahrzad Arpanahzadeh. "Numerical Analysis of Petroleum Refinery Wastewater Treatment Using Electro-Fenton Process". Chemical Product and Process Modeling 10, n.º 1 (1 de março de 2015): 11–16. http://dx.doi.org/10.1515/cppm-2014-0020.

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Abstract The important parameters in mineralization treatment of petroleum refinery wastewater by electro-Fenton process were successfully simulated by Computational Fluid Dynamics (CFD). The effects of H2O2/PRW (ratio of mole of H2O2 per petroleum refinery wastewater volume), H2O2/Fe2+ molar ratio, current density, pH and reaction time were numerically investigated. Materials distribution in the electrochemical cell was studied and CFD results demonstrated that distance between electrodes had no significant effect on the Chemical oxygen demand (COD) removal. Furthermore, the results were compared with the experimental data. The simulated data showed that maximum COD removal was around 82.55% at H2O2/PRW of 0.04, H2O2/Fe2+ molar ratio of 2.75, pH of 3.5, current density of 52.5 mA/cm2 and reaction time of 90 min while the experimental data obtained from the literature showed maximum COD removal of 77% in the same operating conditions. The simulated data showed a good agreement with the experimental ones.

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Rodríguez-Osorio, David, Oliver Gonzalo-Skok e Fernando Pareja-Blanco. "Effects of Resisted Sprints With Changes of Direction Through Several Relative Loads on Physical Performance in Soccer Players". International Journal of Sports Physiology and Performance 14, n.º 8 (1 de setembro de 2019): 1022–28. http://dx.doi.org/10.1123/ijspp.2018-0702.

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Purpose: To compare the effects of resisted change-of-direction (COD) movements, using several relative loads, on soccer players’ physical performance. Methods: Fifty-four male soccer players were randomly assigned to 1 of the following 3 groups, which differed only in the magnitude of the external load used during the COD training: COD training without external load (COD-0; n = 16), COD training with a 12.5% body-mass external load (COD-12.5; n = 19), and COD training with a 50% body-mass external load (COD-50; n = 19). Participants performed the specific COD training twice per week for 6 wk. Before and after the training period, a battery of tests was completed: countermovement jump, 30-m running sprint (time in 10 m [T10], 20 m [T20], and 30 m [T30]), L-run test, and V-cut test. Results: Within-group comparisons showed substantial improvements in countermovement jump and T10 (likely) in COD-0, whereas countermovement jump, T10, and T20 were substantially enhanced (possibly to likely) in COD-50. COD-12.5 induced substantial improvements in all analyzed variables (likely to most likely). Between-groups comparisons showed better effects on all analyzed variables for COD-12.5 than for COD-0 (possibly to very likely), whereas COD-50 only showed possibly better effects than COD-0 on T10. In addition, COD-12.5 induced a better effect on L-run and V-cut tests than COD-50 (possibly to likely). Conclusions: These results indicate that COD training, especially moderate load (12.5% body mass) resisted COD training, may have a positive effect on COD skills, running sprint performance, and jumping ability in young soccer players.

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&NA;. "Cod liver oil". Reactions Weekly &NA;, n.º 1173 (outubro de 2007): 12. http://dx.doi.org/10.2165/00128415-200711730-00035.

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Barnett, Anna. "Cod on ice". Nature Climate Change 1, n.º 801 (6 de dezembro de 2007): 2. http://dx.doi.org/10.1038/climate.2007.72.

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Rose, Jennifer. "Cape Cod Postcard". Women's Review of Books 11, n.º 4 (janeiro de 1994): 18. http://dx.doi.org/10.2307/4021731.

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Rose, George A., e Sherrylynn Rowe. "Northern cod comeback". Canadian Journal of Fisheries and Aquatic Sciences 72, n.º 12 (dezembro de 2015): 1789–98. http://dx.doi.org/10.1139/cjfas-2015-0346.

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The great “northern” cod (Gadus morhua) stock, formerly among the world’s largest and the icon for depletion and supposed nonrecovery of marine fishes, is making a major comeback after nearly two decades of attrition and fishery moratorium. Using acoustic-trawl surveys of the main prespawning and spawning components of the stock, we show that biomass has increased from tens of thousands of tonnes to >200 thousand tonnes within the last decade. The increase was signalled by massive schooling behaviour in late winter first observed in 2008 in the southern range of the stock (Bonavista Corridor) after an absence for 15 years, perhaps spurred by immigration. Increases in size composition and fish condition and apparent declines in mortality followed, leading to growth rates approaching 30% per annum. In the spring of 2015, large increases in cod abundance and size composition were observed for the first time since the moratorium in the more northerly spawning groups of this stock complex. The cod rebound has paralleled increases in the abundance of capelin (Mallotus villosus), whose abundance declined rapidly in the cold early 1990s but has recently increased during a period of warm ocean temperatures. With continued growth in the capelin stock and frugal management (low fishing mortality), this stock could rebuild, perhaps within less than a decade, to historical levels of sustainable yield. More generally, if this stock can recover, the potential exists for recovery of many other depleted stocks worldwide.

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Muir, Tom. "The Cod Hunters". Mariner's Mirror 106, n.º 3 (2 de julho de 2020): 366–67. http://dx.doi.org/10.1080/00253359.2020.1780797.

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Bjørklund, Oddrun, Morten Heide e Geir Grundvåg Ottesen. "Farmed Atlantic Cod". Journal of Food Products Marketing 14, n.º 1 (30 de outubro de 2007): 51–67. http://dx.doi.org/10.1300/j038v14n01_04.

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Williams, Nigel. "Cod all mighty". Current Biology 16, n.º 17 (setembro de 2006): R658—R659. http://dx.doi.org/10.1016/j.cub.2006.08.033.

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Drinkwater, Kenneth F. "The response of Atlantic cod (Gadus morhua) to future climate change". ICES Journal of Marine Science 62, n.º 7 (1 de janeiro de 2005): 1327–37. http://dx.doi.org/10.1016/j.icesjms.2005.05.015.

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Abstract Future CO2-induced climate change scenarios from Global Circulation Models (GCMs) indicate increasing air temperatures, with the greatest warming in the Arctic and Subarctic. Changes to the wind fields and precipitation patterns are also suggested. These will lead to changes in the hydrographic properties of the ocean, as well as the vertical stratification and circulation patterns. Of particular note is the expected increase in ocean temperature. Based upon the observed responses of cod to temperature variability, the expected responses of cod stocks throughout the North Atlantic to the future temperature scenarios are reviewed and discussed here. Stocks in the Celtic and Irish Seas are expected to disappear under predicted temperature changes by the year 2100, while those in the southern North Sea and Georges Bank will decline. Cod will likely spread northwards along the coasts of Greenland and Labrador, occupy larger areas of the Barents Sea, and may even extend onto some of the continental shelves of the Arctic Ocean. In addition, spawning sites will be established further north than currently. It is likely that spring migrations will occur earlier, and fall returns will be later. There is the distinct possibility that, where seasonal sea ice disappears altogether, cod will cease their migration. Individual growth rates for many of the cod stocks will increase, leading to an overall increase in the total production of Atlantic cod in the North Atlantic. These responses of cod to future climate changes are highly uncertain, however, as they will also depend on the changes to climate and oceanographic variables besides temperature, such as plankton production, the prey and predator fields, and industrial fishing.

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Pettersen, Ingrid K., e Øystein Myrland. "A cod is a cod, but is it a commodity?" Journal of Commodity Markets 3, n.º 1 (setembro de 2016): 70–75. http://dx.doi.org/10.1016/j.jcomm.2016.07.003.

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Asche, Frank, Andreea L. Cojocaru, Ivar Gaasland e Hans-Martin Straume. "Cod stories: Trade dynamics and duration for Norwegian cod exports". Journal of Commodity Markets 12 (dezembro de 2018): 71–79. http://dx.doi.org/10.1016/j.jcomm.2017.12.002.

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M Benaessa, Mouna, Farzana Mahomed e Sizakele P Ngwenya. "A retrospective clinico-pathologic analysis of cemento-osseous dysplasia in a South African patient population". African Health Sciences 19, n.º 4 (13 de outubro de 2020): 3154–59. http://dx.doi.org/10.4314/ahs.v19i4.38.

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Background: Cemento-osseous dysplasia (COD) is a fibro-osseous jaw bone lesion. The affected bone in COD progressively becomes sclerotic, poorly vascularized and susceptible to secondary osteomyelitis. Objective: To provide a clinico-pathologic appraisal of COD in a South African patient population. Methods: Archived records of 133 patients diagnosed with COD were reviewed for patient demographics, COD location,COD type, osteomyelitis or simple bone cyst secondary to COD. Results: The mean age was 53.4 ± 13.5 years with a 94.7% female predilection. COD mainly affected the mandible (57.1%),followed by involvement of both jaws (38.3%) and maxilla (4.5%). Florid COD was the most prevalent (69.9%), followed byfocal COD (18%) and periapical COD (12%). Florid COD showed a clear trend of increasing with age, peaking in the sixthdecade and decreasing thereafter. Osteomyelitis and simple bone cyst presented as complications of COD in 74.4% and 5.3%of cases respectively, while 21.8% of all cases of jaw osteomyelitis during the study period were secondary to COD. Conclusion: A higher frequency of jaw osteomyelitis secondary to COD was found compared to previous studies. No significantassociation was shown between any of the COD types and secondary osteomyelitis. Keywords: Cemento-osseous dysplasia; South Africa; patient population.

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Desmiarti, Reni, Maulana Yusup Rosadi, Ariadi Hazmi, Muhammad Miftahur Rahman, Nofri Naldi e Joni Aldilla Fajri. "Biogas Production from Palm Oil Mill Effluent Using Dielectric Barrier Discharge Integrated with the Aerated Condition". Water 14, n.º 22 (20 de novembro de 2022): 3774. http://dx.doi.org/10.3390/w14223774.

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In this study, the performance of dielectric barrier discharge (DBD) with the aerated condition at discharge voltages of 15, 20, and 25 kV on the production of biogas; CH4, H2, CO, and CO2 and the removal of COD and BOD from POME were investigated. The experimental results showed that the aerated condition with a rate of 2.5 L/min at a high voltage (25 kV) produced CH4, CO, and CO2 that was 9.4, 21.5, and 19.6 times higher than the non-aerated one, respectively. The maximum cumulative volume of CH4, H2, CO, and CO2 was 95.4 ± 8.92, 0.94 ± 0.71, 3.06 ± 0.73, and 2.45 ± 0.35 mL/mg COD, respectively, under the aerated condition at 25 kV and the experimental data fit well with the polynomial regression (R2 > 95) for the initial biogas production. The decrease in COD and BOD was greatly affected by the high discharge voltage under the aerated condition, resulting in a high removal rate. These findings suggest that good performance was observed when the DBD was integrated with the aerated condition under the optimum discharge voltage. The study can give information on the optimum condition in a laboratory scale to produce CH4, H2, CO, and CO2, as well as the reduction of organic pollutants from POME.

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Thomas, Maciej, Violetta Kozik, Krzysztof Barbusiński, Aleksander Sochanik, Josef Jampilek e Andrzej Bąk. "Potassium Ferrate (VI) as the Multifunctional Agent in the Treatment of Landfill Leachate". Materials 13, n.º 21 (6 de novembro de 2020): 5017. http://dx.doi.org/10.3390/ma13215017.

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Possible use of potassium ferrate (VI) (K2FeO4) for the treatment of landfill leachate (pH = 8.9, Chemical Oxygen Demand (COD) 770 mg O2/L, Total Organic Carbon (TOC) 230 mg/L, Total Nitrogen (Total N) 120 mg/L, Total Phosphorus (Total P) 12 mg/L, Total Coli Count (TCC) 6.8 log CFU/mL (Colony-Forming Unit/mL), Most Probable Number (MPN) of fecal enterococci 4.0 log/100 mL, Total Proteolytic Count (TPC) 4.4 log CFU/mL) to remove COD was investigated. Central Composite Design (CCD) and Response Surface Methodology (RSM) were applied for modelling and optimizing the purification process. Conformity of experimental and predicted data (R2 = 0.8477, Radj2 = 0.7462) were verified using Analysis of Variance (ANOVA). Application of K2FeO4 using CCD/RSM allowed to decrease COD, TOC, Total N, Total P, TCC, MPN of fecal enterococci and TPC by 76.2%, 82.6%, 68.3%, 91.6%, 99.0%, 95.8% and 99.3%, respectively, by using K2FeO4 0.390 g/L, at pH = 2.3 within 25 min. Application of equivalent amount of iron (as FeSO4 × 7H2O and FeCl3 × 6H2O) under the same conditions allowed to diminish COD, TOC, Total N, Total P, TCC, MPN of fecal enterococci and TPC only by 38.1%, 37.0%, 20.8%, 95.8%, 94.4%, 58.2%, 90.8% and 41.6%, 45.7%, 29.2%, 95.8%, 92.1%, 58.2%, 90.0%, respectively. Thus, K2FeO4 could be applied as an environmentally friendly reagent for landfill leachate treatment.

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Bundy, Alida, e L. Paul Fanning. "Can Atlantic cod (Gadus morhua) recover? Exploring trophic explanations for the non-recovery of the cod stock on the eastern Scotian Shelf, Canada". Canadian Journal of Fisheries and Aquatic Sciences 62, n.º 7 (1 de julho de 2005): 1474–89. http://dx.doi.org/10.1139/f05-086.

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The Atlantic cod (Gadus morhua) stock on the eastern Scotian Shelf collapsed in 1993. Over a decade later, in spite of a fisheries moratorium on cod fishing, this stock is at an all-time low. In parallel with the collapse of the cod stock, the abundance of large cod prey, including forage fish, shrimp, and snow crab, has greatly increased. The key question, which we explore using trophic mass-balance models, is what processes are preventing cod from recovering on the eastern Scotian Shelf? Cod were split into large and small cod. Modelling results indicate high predation pressure on small cod. In addition, small cod compete with the abundant forage fish for decreasing prey, and are in below-average condition. Large cod incur high, but unidentified, mortality that we suggest is derived from the poor condition of small cod carried through to adulthood. As a consequence of the removal of cod by fishing and an ensusing trophic cascade, eastern Scotian Shelf cod are trapped in a vicious circle: their abundance is being kept low by predation, causing an abundance so low that cod cannot compete for prey with their exceptionally abundant competitors. Furthermore, these competitors may also prey on younger stages of cod.

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Brinkhof, Jesse, Bent Herrmann, Roger B. Larsen e Tiago Veiga-Malta. "Effect of a quality-improving cod end on size selectivity and catch patterns of cod in bottom trawl fishery". Canadian Journal of Fisheries and Aquatic Sciences 76, n.º 11 (novembro de 2019): 2110–20. http://dx.doi.org/10.1139/cjfas-2018-0402.

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A new cod-end concept developed and tested exhibited significantly improved quality of caught cod (Gadus morhua) compared with that of the conventional cod end used in the Barents Sea bottom trawl fishery. However, the design of the new quality-improving cod end raised concerns about its size selectivity and the possibility that higher retention probability could negatively impact the catch pattern by increasing the proportion of undersized cod. Therefore, the goal of this study was to quantify and compare the size selectivity and catch pattern for cod when deploying, respectively, the conventional and new quality-improving cod end in the Barents Sea bottom trawl fishery. The new quality-improving cod end had significantly lower relative size selectivity than the conventional cod end, but no significant difference in the catch patterns was detected in the trawl. Further, estimation of the total size selectivity in the trawl revealed that the increased retention of small cod when using the quality-improving cod end was minor. Hence, despite the reduced selectivity, the quality-improving cod end can be used with low risk of retaining small cod.

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Mohajeri, Soraya, Hamidi Abdul Aziz, Mohamed Hasnain Isa, Mohammad Ali Zahed, Mohammed J. K. Bashir e Mohd Nordin Adlan. "Application of the central composite design for condition optimization for semi-aerobic landfill leachate treatment using electrochemical oxidation". Water Science and Technology 61, n.º 5 (1 de março de 2010): 1257–66. http://dx.doi.org/10.2166/wst.2010.018.

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In the present study, Electrochemical Oxidation was used to remove COD and color from semi-aerobic landfill leachate collected from Pulau Burung Landfill Site (PBLS), Penang, Malaysia. Experiments were conducted in a batch laboratory-scale system in the presence of NaCl as electrolyte and aluminum electrodes. Central composite design (CCD) under Response surface methodology (RSM) was applied to optimize the electrochemical oxidation process conditions using chemical oxygen demand (COD) and color removals as responses, and the electrolyte concentrations, current density and reaction time as control factors. Analysis of variance (ANOVA) showed good coefficient of determination (R2) values of >0.98, thus ensuring satisfactory fitting of the second-order regression model with the experimental data. In un-optimized condition, maximum removals for COD (48.77%) and color (58.21%) were achieved at current density 80 mA/cm2, electrolyte concentration 3,000 mg/L and reaction time 240 min. While after optimization at current density 75 mA/cm2, electrolyte concentration 2,000 mg/L and reaction time 218 min a maximum of 49.33 and 59.24% removals were observed for COD and color respectively.

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El bied, Oumaima, Mathieu Kessler, Martire Angélica Terrero, Taoufiq Fechtali, Angel Faz Cano e José A. Acosta. "Turbidity and Chemical Oxygen Demand Reduction from Pig Slurry through a Coagulation Flocculation Process". Agronomy 11, n.º 11 (27 de outubro de 2021): 2158. http://dx.doi.org/10.3390/agronomy11112158.

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Pig slurry is considered a high-risk effluent that causes several environmental problems if it is not adequately managed and treated. White Iberian pig farms in the southeast of Spain treat their slurry in situ using separation, double filtration, decantation, and constructed wetland treatments. However, the pretreatment process does not successfully reduce solids, which leads to clogging in the constructed wetlands (CWs). The main objective of this research paper is to reduce the turbidity and chemical oxygen demand (COD) from the effluent to make it appropriate for CW treatment. Optimization of the coagulation–flocculation (CF) process using iron chloride and a cationic flocculent DKFLOCC-1598 was investigated by a central composite design method (CCD). The effects of coagulant concentration, pH, and flocculent on the COD and turbidity removal were evaluated. The best results were found using 0.024 mol L−1 iron chloride and 0.164 mL L−1 flocculent at pH 7.5, which reduced COD by 96% and delivered turbidity removal of 97%. Therefore, the results indicate the high efficiency of the treatment method in reducing the COD and suspended solids.

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Dutil, Jean-Denis, Coraline Jabouin, Richard Larocque, Gaston Desrosiers e Pierre U. Blier. "Atlantic cod (Gadus morhua) from cold and warm environments differ in their maximum growth capacity at low temperatures". Canadian Journal of Fisheries and Aquatic Sciences 65, n.º 12 (dezembro de 2008): 2579–91. http://dx.doi.org/10.1139/f08-159.

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Maximum growth rate of Atlantic cod (Gadus morhua) was determined at a range of temperatures representative of cod benthic habitats (1–13 °C) using wild animals obtained from a cold environment (southern Gulf of St. Lawrence stock, SG) and a mild environment (Bay of Fundy stock, BF). SG cod performed well over a broader range of temperatures than BF cod. Growth in mass was greater for SG than BF cod at any temperature below 7 °C. SG cod consumed twice as much food as BF cod at 1 and 3 °C. At 1 °C, growth in mass was positive for SG cod but negative for BF cod, whereas growth in length did not differ from 0 for both SG and BF cod. Liver size represented a larger proportion of body mass in SG cod at both low and high temperatures, and citrate synthase activity in the intestine exhibited a strong inverse relationship to temperature. The maximum growth capacity of SG cod was comparable with that of cod of similar size in various other stocks in the Atlantic. These observations are not consistent with the view that intensive size-selective fishing practices have resulted in a significant loss of innate growth capacity in SG cod.

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Nurandani, Hardyanti, Utomo Sudarno, Oktaviana Angelica, Serafina Katrin e Junaidi Junaidi. "Effect of COD/SO42- Supply Ratio Variations of Sulfate-Reducing Bacteria of Sulphood Raise in Acid Mine Drainage". E3S Web of Conferences 73 (2018): 05009. http://dx.doi.org/10.1051/e3sconf/20187305009.

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Sulphur dioxide gas is one of most contaminating gas in the air. Sulphur gas can be produced by mining activities. Sulphur gas will be harmful if bond with CO2 to form as Sulphur Dioxide. To reduce the Sulphur Dioxide gas concentration we must inhibite the sulphur gas formation from mining activities. The inhibition of sulphur gas could be done by reduce the sulphate concentration in acid mine drainage. One of important factor that influencing the reduce of sulphate is COD/SO42- ratio. The effect of COD/SO42- ratio on bacterial growth and sulfate removal process can be investigated with anaerobic batch reactor. The laundry septic tank sediments were inoculated on an anaerobic batch reactor which were contacted with artificial coal acid mine water wastes with 1000 sulfate concentrations and 2000 mg SO42- /L. In an anaerobic batch reactor there are five reactors with variations of COD / SO42-1.0, 1.5, 2.0, 4.0, and 8.0 ratios. Efficiency ratio and the best sulfate removal rate is in reactor ratio 2.0 with value efficiency of 46.58% and a reduction rate of 29.128 mg / L.day in an anaerobic batch reactor. The efficiency of the removal rate decreased when the COD / SO42->2.0 ratio decreased. The fastest pH decline was in the COD/SO42-8.0 ratio variation in the anaerobic batch reactor and. The COD / SO42-ratio can help the sulfate reduction process in the optimum value by affecting the sulfate-reducing bacterial metabolism in the balance of the acceptor and the electron donor.

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Shahawy, Abeer El, Inas A. Ahmed, Mahmoud Nasr, Ahmed H. Ragab, Saedah R. Al-Mhyawi e Khalda M. A. Elamin. "Organic Pollutants Removal from Olive Mill Wastewater Using Electrocoagulation Process via Central Composite Design (CCD)". Water 13, n.º 24 (9 de dezembro de 2021): 3522. http://dx.doi.org/10.3390/w13243522.

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Electrocoagulation (EC) was studied in this study as a potential alternative approach for treating Olive Mill Wastewater (OMW). Aluminum plates were utilized as anode and cathode to evaluate the removal of Chemical Oxygen Demand (COD) from OMW and the aluminum electrode’s weight loss. Central Composite Experimental Design (CCD) and Response Surface Methodology were used to optimize its performance. Anodes were weighed before and after each electrocoagulation experiment, to compare the experimental and the theoretical dissolved aluminum weights calculated using Faraday’s law. We discovered the following EC conditions for CCD: current density = 15 mA/cm2, pH = 4, and electrolysis time of 30 min. Under these conditions, the maximum COD removal ratio was 41%, equating to an Al weight loss of 288.89 g/m3 at an estimated operating cost of 1.60 USD/m3. According to the response optimizer, the most economical operating settings for COD removal efficiency of 58.888% are pH 4, a current density of 18.41 mA/cm2, electrolysis time of 36.82 min, and Al weight loss of 337.33 g/m3, with a projected running cost of 2.00 USD/m3.

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Jorde, Per Erik, Alf Ring Kleiven, Marte Sodeland, Esben Moland Olsen, Keno Ferter, Sissel Jentoft e Halvor Knutsen. "Who is fishing on what stock: population-of-origin of individual cod (Gadus morhua) in commercial and recreational fisheries". ICES Journal of Marine Science 75, n.º 6 (24 de julho de 2018): 2153–62. http://dx.doi.org/10.1093/icesjms/fsy080.

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Abstract Atlantic cod (Gadus morhua) in Skagerrak are structured into distinct ecotypes or stock components that have been severely depleted over the past decades. To improve our understanding of how local commercial and recreational fisheries influence cod stocks, we investigated whether these user groups target different stock components of cod. Cod were sampled from the recreational rod and line fishery and from commercial shrimp trawlers catching cod as by-catch. Based on a large set of single nucleotide polymorphisms (SNPs), we defined a subset of 27 semi-diagnostic SNPs designed to discriminate between two cod stock components: “inner fjord” cod and “North Sea” cod, designated by their dominant habitat preferences. Genetic assignments of fishery-caught cod indicated that 4% of individuals caught by shrimp trawlers belonged to the inner fjord cod component and 96% to the North Sea, whereas among cod caught by recreational fishers, the estimated percentages were 11.8 and 88.2%, respectively. Our findings confirm the existence of two sympatric cod stock components in coastal Skagerrak, indicating that existing management units are biologically inappropriate and should be reconsidered. Furthermore, more attention should be given to recreational angling to reduce fishing mortality on the depleted inner fjord cod component.

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Mohammad Ilias, Muhammad Khalish, Md Sohrab Hossain, Rahmat Ngteni, Adel Al-Gheethi, Harlina Ahmad, Fatehah Mohd Omar, Mu Naushad e Sadanand Pandey. "Environmental Remediation Potential of Ferrous Sulfate Waste as an Eco-Friendly Coagulant for the Removal of NH3-N and COD from the Rubber Processing Effluent". International Journal of Environmental Research and Public Health 18, n.º 23 (25 de novembro de 2021): 12427. http://dx.doi.org/10.3390/ijerph182312427.

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The present study was conducted to determine the potential of utilizing the FeSO4·7H2O waste from the titanium manufacturing industry as an effective coagulant for treating industrial effluent. In this study, the secondary rubber processing effluent (SRPE) was treated using ferrous sulfate (FeSO4·7H2O) waste from the titanium oxide manufacturing industry. The FeSO4·7H2O waste coagulation efficiency was evaluated on the elimination of ammoniacal nitrogen (NH3-N) and chemical oxygen demand (COD) from SRPE. The central composite design (CCD) of experiments was employed to design the coagulation experiments with varying coagulation time, coagulant doses, and temperature. The coagulation experiments were optimized on the optimal elimination of NH3-N and COD using response surface methodology (RSM). Results showed that coagulant doses and temperature significantly influenced NH3-N and COD elimination from SRPE. The highest NH3-N and COD removal obtained were 98.19% and 93.86%, respectively, at the optimized coagulation experimental conditions of coagulation time 70 min, coagulant doses 900 mg/L, and temperature 62 °C. The residual NH3-N and COD in treated SPRE were found below the specified industrial effluent discharge limits set by DoE, Malaysia. Additionally, the sludge generated after coagulation of SRPE contains essential plant nutrients. The present study’s finding showed that FeSO4·7H2O waste generated as an industrial byproduct in a titanium oxide manufacturing industry could be utilized as an eco-friendly coagulant in treating industrial effluent.

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Quaresma, Mário, Gonçalo Pereira, Maria Leonor Nunes, Angela Jardim, Carlos Santos, Narcisa Bandarra e Cristina Roseiro. "The Effect of the Species and Harvesting Location on Dried Salted Cod Fatty Acid Signatures and Nutritional Quality". Foods 12, n.º 3 (2 de fevereiro de 2023): 654. http://dx.doi.org/10.3390/foods12030654.

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The Atlantic cod was listed as ‘vulnerable’ by the International Union for Conservation of Nature, a condition that persists today. Fishing pressure on the Atlantic cod could be partially transferred to the Pacific cod, since the two cod species share genetic and phenotypic similarities. The aim of this study is to expand knowledge of the composition of dried salted cod obtained from Atlantic and Pacific cod species, with the Atlantic cod being from two different harvesting locations. The comparison of these cod species revealed the existence of nine significant differences among individual FAs (accountable for 63.2% of total FAs), which was at a similar level to that observed between different harvesting locations for the Atlantic cod (ten significant differences among individual FAs, accountable for 61.6% of total FAs). Canonical discriminant analysis and cross-validation achieved full discrimination of the cod’s origin and 100% accuracy in the cod’s origin classification. The amount of EPA plus DHA in dried salted cod reached its higher value among the Pacific cod (302.3 mg/100 g), while the Atlantic cod averaged 284.1 g/100 g of edible portion. The Pacific cod presented a higher α-tocopherol content than its Atlantic counterpart (8.04 vs. 4.94 µg/g).

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Kristiansen, T. S., H. Otterå e T. Svåsand. "Size‐dependent mortality of juvenile Atlantic cod, estimated from recaptures of released reared cod and tagged wild cod". Journal of Fish Biology 56, n.º 3 (março de 2000): 687–712. http://dx.doi.org/10.1111/j.1095-8649.2000.tb00766.x.

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