Effect of Microalgae/Activated Sludge Ratio on Cooperative Treatment of Anaerobic Effluent of Municipal Wastewater

Roudsari, Fatemeh Pourasgharian; Mehrnia, Mohammad Reza; Asadi, Akram; Moayedi, Zohreh; Ranjbar, Reza

doi:10.1007/s12010-013-0480-z

Cited by 23 publications

(8 citation statements)

References 23 publications

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“…Obviously, it was also efficient in removing aliphatic acids, ending up as the second most efficient method after activated charcoal (Table 1). Compared to anion exchanger, cation exchanger treatments were much less efficient in removing fermentation inhibitors, which agrees well with previous results [17,18]. Overliming of hydrolysate led to 35-45% removal of furans and 14% removal of phenolics, but did not cause any change of the levels of aliphatic acids.…”

Section: Resultssupporting

confidence: 91%

“…Detoxification with anion-exchange resins at pH 10 has been reported as a very efficient method to decrease the concentrations of furan derivatives and total phenols in spruce hydrolysates [16,17]. Obviously, it was also efficient in removing aliphatic acids, ending up as the second most efficient method after activated charcoal (Table 1).…”

Section: Resultsmentioning

confidence: 99%

“…The different resins were carefully washed with Milli-Q water several times and then the water was removed by filtration before use. In accordance with a previously described procedure [17], the ion exchangers were used in two different quantities. To 120 mL of the spruce hydrolysate, 6.2 g of the anion exchanger was added to reach pH 10.0, and 3.8 g was added to reach pH 5.5.…”

Section: Methodsmentioning

confidence: 99%

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Comparison of methods for detoxification of spruce hydrolysate for bacterial cellulose production

et al. 2013

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BackgroundBacterial cellulose (BC) is a nanostructured material with unique properties and wide applicability. In order to decrease the production cost of bacterial cellulose, lignocellulose-based media have considerable potential as alternative cost-effective feedstocks. However, pretreatment and enzymatic hydrolysis of lignocellulose to sugars also generate fermentation inhibitors. Detoxification of lignocellulosic hydrolysates is needed to achieve efficient production of BC. In this investigation, different methods for detoxification of spruce hydrolysate prior to production of BC were compared with respect to effects on potential inhibitors and fermentable sugars, sugar consumption, BC yield, and cell viability. The objectives were to identify efficient detoxification methods and to achieve a better understanding of the role played by different inhibitors in lignocellulosic hydrolysates.ResultsIn a first series of experiments, the detoxification methods investigated included treatments with activated charcoal, alkali [sodium hydroxide, calcium hydroxide (overliming), and ammonium hydroxide], anion and cation ion-exchange resins, and reducing agents (sodium sulfite and sodium dithionite). A second series of detoxification experiments included enzymatic treatments (laccase and peroxidase). The potential inhibitors studied included aliphatic acids, furan aldehydes, and phenolic compounds. The best effects in the first series of detoxification experiments were achieved with activated charcoal and anion exchanger. After detoxification with activated charcoal the BC yield was 8.2 g/L, while it was 7.5 g/L in a reference medium without inhibitors. Treatments with anion exchanger at pH 10 and pH 5.5 gave a BC yield of 7.9 g/L and 6.3 g/L, respectively. The first series of experiments suggested that there was a relationship between the BC yield and phenolic inhibitors. Therefore, the second series of detoxification experiments focused on treatments with phenol-oxidizing enzymes. The BC yield in the laccase-detoxified hydrolysate reached 5.0-5.5 g/L after 14 days cultivation, which demonstrated the important inhibitory role played by phenolic compounds.ConclusionsThe investigation shows that detoxification methods that efficiently remove phenolics benefit bacterial growth and BC production. Negative effects of salts could not be excluded and the osmotolerance of Gluconacetobacter xylinus needs to be further investigated in the future. Combinations of detoxification methods that efficiently decrease the concentration of inhibitors remain as an interesting option.

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Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Comparison of methods for detoxification of spruce hydrolysate for bacterial cellulose production

et al. 2013

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“…In a study carried out on this strain, unlike ammonium, variations of nitrate concentration were low in the first 7 days (17). In another study, no significant changes were observed in nitrate concentration during the first 5 days (18). In the present study, nitrate concentration had also little changes after 8 days.…”

Section: Discussioncontrasting

confidence: 53%

Optimization of nitrogen and phosphorus removal from meat processing wastewaters using microalgal biofilms

Danaee

Ofoghi

Heydarian

et al. 2018

Environ Health Eng Manag

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Background: The conventional activated sludge processes are not able to completely treat the nitrogen and phosphorus compounds of meat processing wastewaters. Microalgal biofilm, which has the advantages of easiness and inexpensiveness, can be applied as a post-treatment method. Methods: The optimal levels of micronutrients and N/P ratio were aimed in the cultivation of Scenedesmus quadricauda as a biofilm formed on the two types of commercially available bed packing. For this purpose, the Factorial design was run to maximize the removal of ammonium, nitrate and phosphate concentration in the synthetic meat processing wastewater. Results: Experimental data showed better results for the removal of biofilm formed on the sponge filter. In addition, a maximum removal efficiency of 55.6%, 47% and 48.% was respectively achieved for ammonium, nitrate and phosphate at optimal N/P ratio of 10.5 and volumetric percentage of 50% of micronutrients. Conclusion: The results demonstrated that microalgal biofilm of Scenedesmus is able to remove the nutritional components of meat processing wastewaters. The process is needed to be optimized for the effective treatment.

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“…Microalgae have also been used for advanced wastewater treatment because they can effectively remove nitrogen and phosphorus. Microalgae/bacteria-based waste-water treatment has been investigated widely [7][8][9][10][11]. Bacteria in the activated sludge mainly remove organic carbon compounds in wastewater and microalgae reduce inorganic nitrogen and phosphorus compounds more effectively [7].…”

Section: Introductionmentioning

confidence: 99%

Enhanced and Balanced Microalgal Wastewater Treatment (COD, N, and P) by Interval Inoculation of Activated Sludge

Lee¹,

Lee²,

Oh³

et al. 2019

Journal of Microbiology and Biotechnology

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Although chemical oxygen demand (COD) is an important issue for wastewater treatment, COD reduction with microalgae has been less studied compared to nitrogen or phosphorus removal. COD removal is not efficient in conventional wastewater treatment using microalgae, because the algae release organic compounds, thereby finally increasing the COD level. This study focused on enhancing COD removal and meeting the effluent standard for discharge by optimizing sludge inoculation timing, which was an important factor in forming a desirable algae/bacteria consortium for more efficient COD removal and higher biomass productivity. Activated sludge has been added to reduce COD in many studies, but its inoculation was done at the start of cultivation. However, when the sludge was added after 3 days of cultivation, at which point the COD concentration started to increase again, the algal growth and biomass productivity were higher than those of the initial sludge inoculation and control (without sludge). Algal and bacterial cell numbers measured by qPCR were also higher with sludge inoculation at 3 days later. In a semi-continuous cultivation system, a hydraulic retention time of 5 days with sludge inoculation resulted in the highest biomass productivity and N/P removal. This study achieved a further improved COD removal than the conventional microalgal wastewater treatment, by introducing bacteria in activated sludge at optimized timing.

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Effect of Microalgae/Activated Sludge Ratio on Cooperative Treatment of Anaerobic Effluent of Municipal Wastewater

Cited by 23 publications

References 23 publications

Comparison of methods for detoxification of spruce hydrolysate for bacterial cellulose production

Comparison of methods for detoxification of spruce hydrolysate for bacterial cellulose production

Optimization of nitrogen and phosphorus removal from meat processing wastewaters using microalgal biofilms

Enhanced and Balanced Microalgal Wastewater Treatment (COD, N, and P) by Interval Inoculation of Activated Sludge

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