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Complex Innovative Design
Published in Wei Zhang, Fangrong Yan, Feng Chen, Shein-Chung Chow, Advanced Statistics in Regulatory Critical Clinical Initiatives, 2022
Let denote the toxicity rate and denote the response rate of SD/PR/CR. Let denote the upper limit of the toxicity rate, and denote the lower limit of the response rate, specified by physicians. We define the BOD as the dose with the highest utility while satisfying and .
Wastewater Phycoremediation by Microalgae for Sustainable Bioproduct Production
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
Najeeha Mohd. Apandi, Radin Maya Saphira Radin Mohamed, Adel Ali Saeed Al-Gheethi, Amir Hashim Mohd. Kassim
In a wastewater treatment system, the elimination or reduction of unnecessary contaminants such as biochemical oxygen demand (BOD), toxins, bacteria, suspended solids, nutrients and coliform is necessary and must therefore comply with international standards. Wastewater treatment consists of physical, chemical and biological processes. The process applied in conventional wastewater treatments is summarized in Figure 1.1.
Water quality and standards
Published in Sandy Cairncross, Richard Feachem, Environmental Health Engineering in the Tropics, 2018
Sandy Cairncross, Richard Feachem
The oxygen demand of sewage is roughly the amount of oxygen required to oxidise the various organic chemicals within it. A raw sewage having an oxygen demand of 300 mg/l requires 300 mg of oxygen to oxidise the organics and any reduced inorganics in one litre. The inorganics normally require only a small proportion of the total, so that the oxygen demand is a gross and indirect measure of the total organic load contained in the sewage. It is a most important measure because the organic content of sewage is highly complex and defies easy analysis in other ways. Oxygen demands are usually expressed either as a chemical oxygen demand (COD) or a biochemical oxygen demand (BOD). The COD is measured by boiling the sewage with an acid dichromate solution which converts almost all the organics to carbon dioxide and water. The BOD is usually measured by allowing a sample of sewage to stand at 20°C for five days and calculating the amount of oxygen used up during the oxidation of the organics by bacteria. This measure is called the BOD5 and is related to the amount of biodegradable organic matter contained in the sewage. Very approximately:
Determination and seasonal analysis of physicochemical characterization and metal(oid)s of landfill leachate in Bushehr port along the Persian Gulf
Published in Toxin Reviews, 2023
Azam Mohammadi, Mohammad Malakootian, Sina Dobaradaran, Majid Hashemi, Neemat Jaafarzadeh, Nasrin Parniani
The age of the landfill can be determined by the values of COD and BOD5/COD (Naveen et al. 2017). The annual mean concentrations of BOD5 and COD of fresh leachate samples were 16,123.83 and 35,581.50 mg/L, respectively (Table 1). High amounts of these parameters can be due to the type of the leachate samples that were fresh. The high BOD5 and COD concentrations in fresh leachate is due to higher degradability of organic compounds (acid phase) (Słomczyńska and Słomczyński 2004, Bhalla et al. 2012). As seen in Table 3, there were no significant differences (p-values >0.05) between the BOD5 levels in different seasons, but significant differences (p-values <0.05) in different seasons were detected for COD. In spring, COD had the highest level (Figure 3(c)). Also, COD levels in all samples were higher than the leachate discharge standards (Table 1 and Figure 3(c)). The results of this study for BOD5 and COD were in accordance with a study in Egypt with the values of 28,833 and COD 45,240 mg/L, respectively (Hassan and Ramadan 2005). Furthermore, an increase of COD levels and as a result decrease of BOD5/COD ratio can detect the release of a significant biologically inert material amount into the leachate (Kurniawan et al. 2006, Pablos et al. 2011), which can be due to the low rainfall amount that can influence biodegradability process (Tsarpali et al. 2012).
Optimization of an integrated system for refinery wastewater treatment
Published in Toxin Reviews, 2020
Ali Almasi, Leila Yavari, Mitra Mohammadi, Seyyed Alireza Mousavi
The improvement of BOD5/COD ratio as an indicator of wastewater degradability has been considered by researchers during previous studies using Fenton process (Gomez-Herrero et al. 2018, Grisales et al. 2018). Mendoza-Marín et al. (2010), investigated the effect of photo-Fenton process to increase the degradability of sugar cane wastewater, that results showed that BOD5/COD ratio increased from 0.22 to 0.58 after 13 min. Padoley et al. (2011) studied biodegradability of wastewaters containing Pyridine using Fenton process that degradability of pyridine and pyridines have increased from 0.037 to 0.79, and 0.12 to 0.94, respectively. These results were obtained at a concentration of hydrogen peroxide of 699 mg/L and ferrous ions of 2.4 g/L (Padoley et al. 2011).
Emulgel based on amphotericin B and bacuri butter (Platonia insignis Mart.) for the treatment of cutaneous leishmaniasis: characterization and in vitro assays
Published in Drug Development and Industrial Pharmacy, 2018
Elvilene de Sousa Coêlho, Gláucia Laís Nunes Lopes, Iluska Martins Pinheiro, Josefa Natália Policarpo de Holanda, Michel Muálem de Moraes Alves, Naiane Carvalho Nogueira, Fernando Aécio de Amorim Carvalho, André Luis Menezes Carvalho
The assay was performed with promastigote forms of L. major in log phase of growth. The parasites were seeded in 96-well cell culture plates containing Schneider's medium supplemented in the amount of 1 × 106 Leishmania/100 μL of medium already containing the formulations previously added to the wells, in triplicate. Serial dilutions were performed, reaching eight final concentration ranges desired [800–6.25 μg/mL]. The plate was incubated in biochemical oxygen demand (BOD) at 26 °C for 48 h. After 42 h of this period, 20 μL of resazurin 1 × 10−3 mol/l was added, and the plate was incubated again. The plate reading was performed on absorbance plate reader, Biotek 31(model ELx800), at a wavelength of 550 nm, and the results were expressed concerning growth inhibition (%) [4,35].