Influence of Redox Mediators and Electron Donors on the Anaerobic Removal of Color and Chemical Oxygen Demand from Textile Effluent

2013 ◽  
Vol 41 (9) ◽  
pp. 928-933 ◽  
Author(s):  
Sandra M. Amorim ◽  
Mario T. Kato ◽  
Lourdinha Florencio ◽  
Sávia Gavazza
2014 ◽  
Vol 69 (8) ◽  
pp. 1669-1675 ◽  
Author(s):  
Rogerio Silveira Vilela ◽  
Márcia Helena Rissato Zamariolli Damianovic ◽  
Eugenio Foresti

The simultaneous organic matter removal and sulfate reduction in synthetic sulfate-rich wastewater was evaluated for various chemical oxygen demand (COD)/sulfate ratios applied in a horizontal-flow anaerobic immobilized sludge (HAIS) reactor. At higher COD/sulfate ratios (12.5 and 7.5), the removal of organic matter was stable, likely due to methanogenesis. A combination of sulfate reduction and methanogenesis was clearly established at COD/sulfate ratios of 3.0 and 1.9. At a COD/sulfate ratio of 1.0, the organic matter removal was likely influenced by methanogenesis inhibition. The quantity of sulfate removed at a COD/sulfate ratio of 1.0 was identical to that obtained at a ratio of 1.9, indicating a lack of available electron donors for sulfidogenesis. The sulfate reduction and organic matter removal were not maximized at the same COD/sulfate ratio; therefore, competitive inhibition must be the predominant mechanism in establishing an electron flow.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Geetanjali Rajhans ◽  
Adyasa Barik ◽  
Sudip Kumar Sen ◽  
Amrita Masanta ◽  
Naresh Kumar Sahoo ◽  
...  

AbstractGlobally, textile industries are one of the major sectors releasing dye pollutants. This is the first report on the positive correlation between toxicity and chemical oxygen demand (COD) of textile effluent along with the proposed pathway for enzymatic degradation of acid orange 10 using Geotrichum candidum within a very short stretch of time (18 h). Removal efficiency of this mycoremedial approach after 18 h in terms of chemical oxygen demand, biological oxygen demand, total suspended solids, salinity, color and dye concentration in the treated effluent reached to 98.5%, 56.3%,73.2%, 64%, 89% and 87% respectively. Also there was a decrease in pH of the treated effluent. FTIR analysis of the treated effluent confirmed biodegradation. The LCMS analysis showed the degradation of acid orange 10, which was confirmed by the formation of two biodegradation products, 7-oxo-8-iminonapthalene-1,3-disulfonate and nitrosobenzene, which subsequently undergoes stepwise hydrogenation and dehydration to form aniline via phenyl hydroxyl amine as intermediate. The X-ray diffraction studies showed that heavy metal content in the treated effluent has reduced along with decrease in % crystallinity, indicating biodegradation. The connection between toxicity and COD was also inveterated using Pearson’s correlation coefficient. Further the toxicological studies indicated the toxicity of raw textile effluent and relatively lower toxic nature of metabolites generated after biodegradation by G. candidum.


2017 ◽  
Vol 113 (11) ◽  
pp. 2112 ◽  
Author(s):  
K. Ramesh ◽  
M. Balakrishnan ◽  
B. Vigneshkumar ◽  
A. Manju ◽  
S. Dhanakumar ◽  
...  

2014 ◽  
Vol 13 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Ghasem Najafpour Darzi ◽  
Reza Katal ◽  
Hossein Zare ◽  
Seyed Omid Rastegar ◽  
Poorya Mavaddat

2018 ◽  
Vol 69 (10) ◽  
pp. 2940-2952 ◽  
Author(s):  
Martina Zelenakova ◽  
Pavol Purcz ◽  
Radu Daniel Pintilii ◽  
Peter Blistan ◽  
Petr Hlustik ◽  
...  

Evaluating trends in water quality indicators is a crucial issue in integrated water resource management in any country. In this study eight chemical and physical water quality indicators were analysed in seven river profiles in the River Laborec in eastern Slovakia. The analysed water quality parameters were biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), pH, temperature (t), ammonium nitrogen (NH4+-N), nitrite nitrogen (NO2--N), nitrate nitrogen (NO3--N), and total phosphorus (TP). Data from the monitored indicators were provided by the Ko�ice branch of the Slovakian Water Management Company, over a period of 15 years from 1999 to 2013. Mann�Kendall non-parametric statistical test was used for the trend analysis. Biochemical and chemical oxygen demand, ammonium and nitrite nitrogen content exhibit decreasing trends in the River Laborec. Decreasing agricultural activity in the area has had a significant impact on the trends in these parameters. However, NO2--N was the significant parameter of water quality because it mostly exceeds the limit value set in Slovak legislation, Regulation No. 269/2010 Coll. In addition, water temperature revealed an increasing trend which could be caused by global increase in air temperature. These results indicate that human activity significantly impacts the water quality.


1978 ◽  
Vol 5 (1) ◽  
pp. 83-97 ◽  
Author(s):  
Robert D. Cameron

The use of cheap, locally available peat as a treatment method for landfill leachate was investigated by passing leachate through plexiglass columns filled with an amorphous-granular peat. Preliminary adjustment of pH showed that reducing pH to 4.8 dramatically reduced adsorption. Increasing the pH to 8.4, metal removal was increased owing to filtration of precipitated metals. The best adsorption of metals occurred at the 'natural' pH of 7.1. Manganese was found to be the limiting pollutant. At the 0.05 mg/ℓ maximum acceptable manganese concentration 94% of the total metals were removed, requiring 159 kg of peat per 1000 ℓ of leachate.Resting the peat for 1 month did significantly increase removal capacity.Desorption of some contaminants occurred when water was percolated through the peat. The desorption test effluent was not toxic to fish although iron, lead and COD (chemical oxygen demand) exceeded acceptable values.Chemical pretreatment using lime and ferric chloride achieved significant iron, manganese and calcium removals. Chemical pretreatment followed by peat adsorption offered no advantage other than reducing toxicity to fish.Peat treatment alone was effective in reducing concentrations to a level that was non-toxic to fish.


2019 ◽  
Vol 17 (1) ◽  
pp. 1017-1025
Author(s):  
Mohamed Réda Arhoutane ◽  
Muna Shueai Yahya ◽  
Miloud El Karbane ◽  
Kacem El Kacemi

AbstractIn the context of environmental protection, where there is a need to develop effective operations for carrying out appropriate treatment of polluted water by pharmaceuticals. Therefore, the present study aims at evaluating the degradation for gentamicin through electro-Fenton (EF) operation, through taking into consideration the effect of several parameters of experimental in the process, namely, the concentration of initial gentamicin, the applied current and the Fe+2 (II) quantities. The (EF) operation employed involves a carbon-felt as cathode and platinum as anode at pH 3. Studies for the gentamicin kinetics is monitored by HPLC giving a pseudo-first order reaction following by a chemical oxygen demand, with a reached degree of mineralization 96% after of four hours of treatment through current 100 mA/cm2 with 0.1 mM of Fe+2. We find that the degradation for molecule of gentamicin is accompanied by an augmentation of the biodegradability, assesse through the Biochemical Oxygen Demand (BOD5) on chemical oxygen demand (COD) ratio, that augmentation from 0 to 0.41 before treatment after 30 min for EF treatment, showing that there is potential for conjugation of the EF process and the biological process. Furthermore, the by-products have been identified on the basis of HPLC-MS/MS results.


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