A new disinfection system for wastewater treatment: performic acid full-scale trial evaluations

2013 ◽  
Vol 67 (11) ◽  
pp. 2476-2487 ◽  
Author(s):  
P. Ragazzo ◽  
N. Chiucchini ◽  
V. Piccolo ◽  
M. Ostoich
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Vibrio Fischeri ◽  
Product Formation ◽  
Full Scale ◽  
Performic Acid ◽  
Municipal Wastewater Treatment ◽  
Faecal Coliforms ◽  
E Coli

To evaluate the efficiency and effect of a new disinfection technology in wastewater treatment, batch and full-scale experiments were performed between winter 2005 and summer 2011. The system, developed by Kemira Oyj, produces a disinfection solution containing performic acid (PFA) by mixing hydrogen peroxide and formic acid. A preliminary study in batch reactors established the suitability for wastewater disinfection; three subsequent full-scale plant experiments conducted at two municipal wastewater treatment plants (120,000 and 32,000 equivalent inhabitants) discharging in sensitive areas demonstrated its effectiveness and reliability in this application field. The disinfection power of the system was measured using faecal coliforms, Escherichia coli and faecal enterococci; additional water quality parameters included total organic carbon, suspended solids, eco-toxicity and disinfection by-products. Full-scale experiments indicated that PFA has a high disinfection power, always ensuring over 3 log of faecal coliforms and E. coli reductions at CT over 60 mg/L min (CT: disinfectant initial Concentration (mg/L) × contact Time (min)). The final production system yielded even better performance, with E. coli and faecal enterococci reductions ranging from 2 to 4.2 and from 0.7 to 3.2 log, respectively, at CT conditions lower than 23 mg/L min. There were no eco-toxicological effects measured by Vibrio fischeri or by-product formation.

Population dynamics of filamentous bacteria identified in Polish full-scale wastewater treatment plants with nutrients removal

2014 ◽  
Vol 71 (5) ◽  
pp. 675-684 ◽  
Author(s):  
A. Miłobędzka ◽  
A. Muszyński
Keyword(s):  
Population Dynamics ◽  
Wastewater Treatment ◽  
Correlation Coefficient ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Volume Index ◽  
Nutrients Removal ◽  
Filamentous Bacteria ◽  
Municipal Wastewater Treatment

A comprehensive study of the identity and population dynamics of filamentous bacteria in five Polish full-scale municipal wastewater treatment plants (WWTPs) with nutrients removal had been carried out for 2 years. A quantitative culture-independent, molecular method – fluorescence in situ hybridization – was applied to evaluate the structure of different filamentous bacteria populations and their temporal variations. Activated sludge was examined for the abundance of 11 groups of filamentous bacteria. On average, filaments constituted 28% of all bacteria. All samples presented a low diversity of probe-defined filamentous bacteria, usually with significant domination of Chloroflexi (with distinction to types 1851, 0803 and others) and/or Microthrix (14% and 7% of EUBmix, respectively). Haliscomenobacter hydrossis, Mycolata, Skermania piniformis and TM7 were less abundant, whereas Curvibacter, Thiothrix/021N and family Gordonia have not been detected in any of the samples. The tested WWTPs showed similarity among species found and differences in their abundance. The composition of filamentous populations was rather stable in each plant and similar to those found in other European countries. Little differences between plants were shown by multivariate analysis of variance in terms of Chloroflexi and Microthrix. No significant general correlations have been found with Pearson product-moment correlation coefficient and Spearman's rank correlation coefficient. Medium correlation strength between the presence of different filaments was recorded only for Microthrix and Skermania piniformis. Deleterious effect on settling properties of sludge (measured as sludge volume index) was found only for abundance of Microthrix; a strong linear correlation was recorded between them. However, no other correlations with wastewater and operational data were revealed.

Kinetic assessment and modeling of an ozonation step for full-scale municipal wastewater treatment: Micropollutant oxidation, by-product formation and disinfection

2011 ◽  
Vol 45 (2) ◽  
pp. 605-617 ◽  
Author(s):  
Saskia G. Zimmermann ◽  
Mathias Wittenwiler ◽  
Juliane Hollender ◽  
Martin Krauss ◽  
Christoph Ort ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Product Formation ◽  
Full Scale ◽  
Municipal Wastewater Treatment ◽  
Kinetic Assessment

scholarly journals Effect of COD:N ratio on biological nitrogen removal using full-scale step-feed in municipal wastewater treatment plants

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Supaporn Phanwilai ◽  
Pongsak Noophan ◽  
Chi-Wang Li ◽  
Kwang-Ho Choo
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Biological Nitrogen Removal ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plants ◽  
Scale Step ◽  
Biological Nitrogen

Abstract This study investigated the effect of low and high chemical oxygen demand (COD):N ratios on biological nitrogen removal and microbial distributions in full-scale step-feed (SF) municipal wastewater treatment plants (WWTPs) in Thailand (SF1) and Taiwan (SF2). The SF1 WWTP had a low COD:N (4:1) ratio, a long solids retention time (SRT) (> 60 d), and low dissolved oxygen (DO) conditions (0.2 mg L− 1 in anoxic tank and 0.9 mg L− 1 in aerobic tank). The total nitrogen (TN) removal efficiency was 48%. The SF2 WWTP had a high COD:N (10:1) ratio, a short SRT (7 d), and high DO (0.6 mg L− 1 in anoxic tank and 1.8 mg L− 1 in aerobic tank). The TN removal efficiency was 61%. The nitrification and denitrification rates from these two plants were inadequate. Using a quantitative polymerase chain reaction (qPCR) technique, the populations of ammonium oxidizing bacteria (AOB) and ammonium oxidizing archaea were quantified. Measurement of ammonia monooxygenase (amoA) gene abundances identified these AOB: Nitrosomonas sp., Nitrosospira sp., Nitrosoccus sp. and Zoogloea sp. Higher amounts of the archaeal-amoA gene were found with long SRT, lower DO and COD:N ratios. Abundance of Nitrobacter sp. was slightly higher than Nitrospira sp. at the SF1, while abundance of Nitrobacter sp. was two orders of magnitude greater than Nitrospira sp. at the SF2. More denitrifying bacteria were of the nirS-type than the nirK-type, especially at higher COD:N ratio. Most bacteria belong to the phyla Acidobacteria, Actinobacteria Bacteroidetes, Chloroflexi, Proteobacteria. The results from this work showed that insufficient carbon sources at the SF1 and high DO concentration in anoxic tank of SF2 adversely affected nitrogen removal efficiencies. In further research work, advanced techniques on the next generation sequencing with different variable regions should be recommended in full-scale WWTPs.

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