Effects of chemical cleaning on RO membrane inorganic, organic and microbial foulant removal in a full-scale plant for municipal wastewater reclamation

The combination of simultaneous nitrification-denitrification (SND) with enhanced biological phosphorus removal (EBPR) provides a more efficient and economically viable option for nutrient removal from municipal wastewater compared to conventional two-step nitrification-denitrification. This study analyzed the nutrients (N and P) profiles in a full-scale municipal wastewater reclamation plant (WRP) located in the tropical region, in which more than 90% of nitrogen was removed. Interestingly, average SND efficiency in aerobic zones was found to be up to 50%, whereas phosphorus profile displayed a clear cyclic release and uptake pattern with a phosphorus removal efficiency of up to 76%. The capability of sludge to perform SND and EBPR was further confirmed through a series of batch experiments. Microbial analysis revealed the presence of Accumulibacter and Tetrasphaera phosphate accumulating organisms in the plant, while few glycogen accumulating organisms (GAO) was observed. This study showed the significant occurrence of combined SND and EBPR, known as simultaneous nitrification, denitrification and phosphorus removal (SNDPR), in the studied WRP under warm climate. The possible causes behind the observed SNDPR were also discussed.

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Elimination and fate of selected micro-organic pollutants in a full-scale anaerobic/anoxic/aerobic process combined with membrane bioreactor for municipal wastewater reclamation

Water Research ◽

10.1016/j.watres.2010.07.052 ◽

2010 ◽

Vol 44 (20) ◽

pp. 5999-6010 ◽

Cited By ~ 138

Author(s):

Wenchao Xue ◽

Chunying Wu ◽

Kang Xiao ◽

Xia Huang ◽

Haidong Zhou ◽

...

Keyword(s):

Organic Pollutants ◽

Membrane Bioreactor ◽

Municipal Wastewater ◽

Full Scale ◽

Wastewater Reclamation ◽

Aerobic Process

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Fouling of reverse osmosis membrane for municipal wastewater reclamation: Autopsy results from a full-scale plant

Desalination ◽

10.1016/j.desal.2014.06.018 ◽

2014 ◽

Vol 349 ◽

pp. 73-79 ◽

Cited By ~ 44

Author(s):

Fang Tang ◽

Hong-Ying Hu ◽

Li-Juan Sun ◽

Qian-Yuan Wu ◽

Yan-Mei Jiang ◽

...

Keyword(s):

Reverse Osmosis ◽

Municipal Wastewater ◽

Full Scale ◽

Reverse Osmosis Membrane ◽

Wastewater Reclamation

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Fouling and cleaning of microfiltration membrane in municipal wastewater reclamation

Water Science & Technology ◽

10.2166/wst.2003.0065 ◽

2003 ◽

Vol 47 (1) ◽

pp. 263-270 ◽

Cited By ~ 12

Author(s):

C.-H. Xing ◽

X.-H. Wen ◽

Y. Qian ◽

D. Sun ◽

P.S. Klose ◽

...

Keyword(s):

Municipal Wastewater ◽

Fold Increase ◽

Complex Model ◽

Wastewater Reclamation ◽

Chemical Cleaning ◽

Microfiltration Membrane ◽

Fouling Mechanism ◽

Operation Period ◽

Preventive Method ◽

Pore Plugging

This paper presents an investigation on fouling and cleaning of a tubular microfiltration membrane for municipal wastewater reclamation. A bi-level complex model, namely channel clogging and pore plugging, was introduced to elucidate the fouling mechanism. Based on 135 days of microfiltration of activated sludge, a preventive method for channel clogging was reasonably proposed and proven to be effective. Without channel clogging, the operation period was observed a five-fold increase on average, reaching 3-4 weeks. To remove pore plugging, a multi-step chemical cleaning was employed and further optimized in terms of temperature and alkaline concentration. Generally, the chemical cleaning could restore the membrane permeability to higher than 90%.

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Application of immersed MF (IMF) followed by reverse osmosis (RO) membrane for wastewater reclamation: A case study in Malaysia

Water Science & Technology ◽

10.2166/wst.2007.700 ◽

2007 ◽

Vol 56 (9) ◽

pp. 103-108 ◽

Cited By ~ 5

Author(s):

Z. Ujang ◽

K.S. Ng ◽

Tg Hazmin Tg Hamzah ◽

P. Roger ◽

M.R. Ismail ◽

...

Keyword(s):

Reverse Osmosis ◽

Municipal Wastewater ◽

Wastewater Reuse ◽

Membrane System ◽

Pilot Scale ◽

Hydraulic Performance ◽

Feed Water ◽

Wastewater Reclamation ◽

Chemical Cleaning ◽

Local Conditions

A pilot scale membrane plant was constructed and monitored in Shah Alam, Malaysia for municipal wastewater reclamation for industrial application purposes. The aim of this study was to verify its suitability under the local conditions and environmental constraints for secondary wastewater reclamation. Immersed-type crossflow microfiltration (IMF) was selected as the pretreatment step before reverse osmosis filtration. Secondary wastewater after chlorine contact tank was selected as feed water. The results indicated that the membrane system is capable of producing a filtrate meeting the requirements of both WHO drinking water standards and Malaysian Effluent Standard A. With the application of an automatic backwash process, IMF performed well in hydraulic performance with low fouling rate being achieved. The investigations showed also that chemical cleaning is still needed because of some irreversible fouling by microorganisms always remains. RO treatment with IMF pretreatment process was significantly applicable for wastewater reuse purposes and promised good hydraulic performance.

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Permeability decline in nanofiltration/reverse osmosis membranes fed with municipal wastewater treated by a membrane bioreactor

Water Science & Technology ◽

10.2166/wst.2013.080 ◽

2013 ◽

Vol 67 (9) ◽

pp. 1994-1999 ◽

Cited By ~ 4

Author(s):

Katsuki Kimura ◽

Naoko Ogawa ◽

Yoshimasa Watanabe

Keyword(s):

Organic Matter ◽

Reverse Osmosis ◽

Membrane Bioreactor ◽

Municipal Wastewater ◽

Membrane Surface ◽

Chemical Cleaning ◽

Filtration Resistance ◽

Cake Layer ◽

Total Filtration ◽

Ro Membrane

Decline in the permeability in nanofiltration (NF)/reverse osmosis (RO) membranes that filtered effluents from a membrane bioreactor (MBR) treating municipal wastewater was investigated in this study. Four different 2-inch spiral-wound NF/RO membrane elements were continuously operated for 40 days. The results showed that the amount of deposits on the membrane surface did not affect the degree of permeability decline. Laboratory-scale filtration tests with coupons obtained from the fouled membranes also revealed that the contribution of the gel/cake layer to total filtration resistance was minor. Rather, constituents that were strongly bound to the membranes were mainly responsible for permeability decline. Chemical cleaning of the fouled membranes carried out after removal of the cake showed that silica played an important role in the decline in permeability. A considerable amount of organic matter which was mainly composed of carbohydrates and proteins was also desorbed from the fouled membranes.

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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.

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