Polishing of municipal secondary effluent using native microalgae consortia

This work evaluates the use of native microalgae consortia for a dual role: polishing treatment of municipal wastewater effluents and microalgae biomass feedstock potential for biodiesel or biofertilizer production. An initial screening was undertaken to test N and P removal from secondary effluents and biomass production by 12 consortia. A subsequent treatment was performed by selected consortia (01 and 12) under three operational conditions: stirring (S), S + 12 h of daily aeration (S + A) and S + A enriched with CO2 (S + AC). All treatments resulted in compliance with environmental regulations (e.g. Directive 91/271/EEC) and high removal efficiency of nutrients: 64–79% and 80–94% of total N and PO43−-P respectively. During the experiments it was shown that pH alkalinization due to microalgae growth benefits the chemical removal of ammonia and phosphorus. Moreover, advantages of pH increase could be accomplished by intermittent CO2 addition which in this research (treatment S + AC) promoted higher yield and lipid concentration. The resulting dry biomass analysis showed a low lipid content (0.5–4.3%) not ideal for biodiesel production. Moreover, the high rate of ash (29.3–53.0%) suggests that biomass could be readily recycled as a biofertilizer due to mineral supply and organic constituents formed by C, N and P (e.g. carbohydrate, protein, and lipids).

Download Full-text

Primitive techno-economic study of bio-diesel and bio-active compound production from microalgae

Bulletin of the National Research Centre ◽

10.1186/s42269-020-00383-z ◽

2020 ◽

Vol 44 (1) ◽

Author(s):

Sayeda M. Abdo ◽

Guzine I. El Diwani ◽

Kamel M. El-Khatib ◽

Sanaa A. Abo El-Enin ◽

Mohammed I. El-Galad ◽

...

Keyword(s):

Active Compound ◽

Municipal Wastewater ◽

Scenedesmus Obliquus ◽

Cetane Number ◽

Treatment Plant ◽

Acid Methyl Ester ◽

Biodiesel Production ◽

High Rate ◽

Total Phenolic ◽

Microscopical Examination

Abstract Background Microalgae cells can be identified as a potential source for new and renewable energy. The economic investigation for biodiesel and bio-active compound production from the microalgae community (Bloom), which are collected from the high rate algal pond (HRAP) constructed to treat municipal wastewater at Zenin wastewater treatment plant, Giza, was the main target of study. Results The microscopical examination showed that Scenedesmus obliquus is the dominant species. The total carotenoids were extracted using jojoba oil and determined by high-performance liquid chromatography (HPLC) to reach 81.44 μg/g. The biodiesel production through acid transesterification reaction recorded 70.6% of fatty acid methyl ester content with high cetane number (44) and low acid value. Such results prove that the obtained biodiesel has better ignition quality. The total phenolic and flavonoid compounds have been derived from the remaining biomass to give 5.36 ± 0.03 and 1.50 ± 0.19 mg/g respectively. Finally, total proteins and carbohydrates content in algal cells were recorded 54.3 and 1.5 mg/g successively Conclusion The preliminary economic evaluation showed that the production of biodiesel and carotenoids from the microalgae growing in municipal wastewater can be considered, as a techno-economic feasible process.

Download Full-text

Effects on Soil and Crops of Irrigation with Primary and Secondary Effluents

Water Science & Technology ◽

10.2166/wst.1989.0245 ◽

1989 ◽

Vol 21 (6-7) ◽

pp. 427-434 ◽

Cited By ~ 7

Author(s):

H. Marecos do Monte ◽

M. Silva e Sousa ◽

A. Silva Neves

Keyword(s):

Soil Contamination ◽

Nitrogen Content ◽

Potable Water ◽

Municipal Wastewater ◽

Crop Yields ◽

High Rate ◽

Secondary Effluents ◽

Composition Changes

The results of two years of experiments about irrigation of sorghum, maize and sunflower with municipal wastewater treated by primary sedimentation and high-rate biofiltration are described. Control plots were irrigated with potable water and given commercial fertilizers. Identical crop yields were obtained for the three treatments,which leads to the conclusion that the nitrogen content of wastewater can replace the nitrogen from commercial fertilizers; subsequent fertilizer savings ranged from US$67/ha up to US$184/ha. No significant crop composition changes were noticed. Soil contamination was negligible at harvest.

Download Full-text

A study about the use of chemicals in conventional tertiary treatment. Performances comparison of three municipal wastewater treatment plants and pilot plant experiences

Water Practice & Technology ◽

10.2166/wpt.2011.005 ◽

2011 ◽

Vol 6 (1) ◽

Author(s):

A. Iborra-Clar ◽

J.A. Mendoza-Roca ◽

A. Bes-Pií ◽

J.J. Morenilla-Martínez ◽

I. Bernácer-Bonora ◽

...

Keyword(s):

Water Quality ◽

Wastewater Treatment ◽

Pilot Plant ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Secondary Effluent ◽

Municipal Wastewater Treatment ◽

Wastewater Reclamation ◽

Valencian Region ◽

Municipal Wastewater Treatment Plants

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.

Download Full-text

WASTEWATER DISINFECTION BY UV AT TRANI MUNICIPAL PLANT

Water Science & Technology ◽

10.2166/wst.1994.0173 ◽

1994 ◽

Vol 30 (4) ◽

pp. 125-132 ◽

Cited By ~ 2

Author(s):

D. Carnimeo ◽

E. Contini ◽

R. Di Marino ◽

F. Donadio ◽

L. Liberti ◽

...

Keyword(s):

Wastewater Treatment ◽

Municipal Wastewater ◽

Treatment Plant ◽

Continuous Operation ◽

Secondary Effluent ◽

Municipal Wastewater Treatment ◽

South Italy ◽

Wastewater Disinfection ◽

Pilot Investigation ◽

Effluent Characteristics

The pilot investigation on the use of UV as an alternative disinfectant to NaOCI was started in 1992 at Trani (South Italy) municipal wastewater treatment plant (335 m3/h). The results collected after six months continuous operation enabled us to compare UV and NaOCl disinfection effectiveness on the basis of secondary effluent characteristics, quantify photoreactivation effects, evidence possible DBP formation and assess costs.

Download Full-text

Occurrence of SARS-CoV-2 RNA in Six Municipal Wastewater Treatment Plants at the Early Stage of COVID-19 Pandemic in The United States

Pathogens ◽

10.3390/pathogens10070798 ◽

2021 ◽

Vol 10 (7) ◽

pp. 798

Author(s):

Samendra P. Sherchan ◽

Shalina Shahin ◽

Jeenal Patel ◽

Lauren M. Ward ◽

Sarmila Tandukar ◽

...

Keyword(s):

United States ◽

Wastewater Treatment ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Quantitative Polymerase Chain Reaction ◽

The United States ◽

Secondary Effluent ◽

Untreated Wastewater ◽

Treatment Processes ◽

Wastewater Samples

In this study, we investigated the occurrence of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) RNA in primary influent (n = 42), secondary effluent (n = 24) and tertiary treated effluent (n = 34) collected from six wastewater treatment plants (WWTPs A–F) in Virginia (WWTP A), Florida (WWTPs B, C, and D), and Georgia (WWTPs E and F) in the United States during April–July 2020. Of the 100 wastewater samples analyzed, eight (19%) untreated wastewater samples collected from the primary influents contained SARS-CoV-2 RNA as measured by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays. SARS-CoV-2 RNA were detected in influent wastewater samples collected from WWTP A (Virginia), WWTPs E and F (Georgia) and WWTP D (Florida). Secondary and tertiary effluent samples were not positive for SARS-CoV-2 RNA indicating the treatment processes in these WWTPs potentially removed SARS-CoV-2 RNA during the secondary and tertiary treatment processes. However, further studies are needed to understand the log removal values (LRVs) and transmission risks of SARS-CoV-2 RNA through analyzing wastewater samples from a wider range of WWTPs.

Download Full-text

PARAMETERS FOR DYNAMIC SIMULATION OF W ASTEW ATER TREATMENT PLANTS WITH HIGH-RATE AND LOW-RATE ACTIVATED SLUDGE TANKS

Water Science & Technology ◽

10.2166/wst.1994.0194 ◽

1994 ◽

Vol 30 (4) ◽

pp. 211-214 ◽

Cited By ~ 11

Author(s):

E. Brands ◽

M. Liebeskind ◽

M. Dohmann

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Dynamic Simulation ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

High Rate ◽

Yield Coefficient ◽

Municipal Wastewater Treatment ◽

Municipal Wastewater Treatment Plants ◽

Low Rate

This study shows a comparison of important parameters for dynamic simulation concerning the highrate and low-rate activated sludge tanks of several municipal wastewater treatment plants. The parameters for the dynamic simulation of the single-stage process are quite well known, but parameters for the high-ratellow-rate activated sludge process are still missi ng, although a considerable number of wastewater treatment plants are designed and operated that way. At present any attempt to simulate their operation is restricted to the second stage due to missing data concerning growth rate, decay rate, yield coefficient and others.

Download Full-text

Expenditure on the operation of municipal wastewater treatment plants for nutrient removal

Water Science & Technology ◽

10.2166/wst.2000.0225 ◽

2000 ◽

Vol 41 (9) ◽

pp. 281-289 ◽

Cited By ~ 2

Author(s):

O. Nowak

Keyword(s):

Nutrient Removal ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

General Scheme ◽

Operating Costs ◽

Municipal Wastewater Treatment ◽

Wastewater Purification ◽

Labour Costs ◽

Municipal Wastewater Treatment Plants ◽

P Removal

Operating costs of Austrian municipal treatment plants are evaluated for 1989/90 and for 1997, respectively. The results indicate that presently the expenses which can be directly connected to wastewater purification, i.e. energy and chemicals for P removal, comprise only about 20% of the total operating costs. Today, in Austria like in other EU countries, the predominating factor is “labour costs”, even at nutrient removal plants. A general scheme for estimating operating costs is presented that can be applied to WWTPs in other parts of the world. In this scheme the important factors relevant to the operating costs are integrated.

Download Full-text

Enhanced Performance of Ultrafiltration Membrane with Powdered Zeolite Addition for Secondary Effluent Treatment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.838-841.2712 ◽

2013 ◽

Vol 838-841 ◽

pp. 2712-2716

Author(s):

Yong Tu ◽

Yong Gang Bai ◽

Yong Chen ◽

Wei Jing Liu ◽

Jun Xu ◽

...

Keyword(s):

Membrane Fouling ◽

Fluorescence Spectra ◽

Municipal Wastewater ◽

Three Dimensional ◽

Treatment Plant ◽

Ultrafiltration Membrane ◽

Effluent Treatment ◽

Secondary Effluent ◽

Municipal Wastewater Treatment ◽

Sem Images

The research on ultrafiltration membrane assisted by powdered zeolite for the treatment of secondary effluent from a municipal wastewater treatment plant was studied. The results show that membrane fouling rate is reduced by pre-coating the ultrafiltration membrane with powdered zeolite, and the treatment performance of secondary effluent is enhanced. UV-vis, three-dimensional excitation emission matrix (3D-EEM) fluorescence spectra and scanning electron microscopy (SEM) images for ultrafiltration were also discussed.

Download Full-text