The effect of drastic temperature changes on the performance of MBR treating municipal wastewater

2011 ◽  
Vol 64 (7) ◽  
pp. 1398-1405 ◽  
Author(s):  
Abdullah Al-Amri ◽  
Mohd Razman Salim ◽  
Azmi Aris
Keyword(s):  
Membrane Fouling ◽  
Temperature Increase ◽  
Municipal Wastewater ◽  
Hollow Fibre ◽  
Critical Conditions ◽  
Temperature Changes ◽  
Sludge Properties ◽  
Removal Efficiencies ◽  
Final Effluent ◽  
Biomass Reduction

A study has been carried out to define the effect of drastic temperature changes on the performance of lab-scale hollow-fibre MBR in treating municipal wastewater at a flux of 10 L m−2 h−1 (LMH). The objectives of the study were to estimate the activated sludge properties, the removal efficiencies of COD and NH3-N and the membrane fouling tendency under critical conditions of drastic temperature changes (23, 33, 42 & 33 °C) and MLSS concentration ranged between 6,382 and 8,680 mg/L. The study exhibited that the biomass reduction, the low sludge settleability and the supernatant turbidity were results of temperature increase. The temperature increase led to increase in SMP carbohydrate and protein, and to decrease in EPS carbohydrate and protein. The BRE of COD dropped from 80% at 23 °C to 47% at 42 °C, while the FRE was relatively constant at about 90%. Both removal efficiencies of NH3-N trended from about 100% at 33 °C to less than 50% at 42 °C. TMP and BWP ascended critically with temperature increase up to 336 and 304 mbar respectively by the end of the experiment. The values of suspended solids (SS) and the turbidity in the final effluent were negligible. The DO in the mixed liquor was varying with temperature change, while the pH was within the range of 6.7–8.3.

Copper removal from sludge permeate with ultrafiltration membranes using zeolite, bentonite and vermiculite as adsorbents

2010 ◽  
Vol 61 (3) ◽  
pp. 581-589 ◽  
Author(s):  
S. Malamis ◽  
E. Katsou ◽  
M. Stylianou ◽  
K. J. Haralambous ◽  
M. Loizidou
Keyword(s):  
Membrane Fouling ◽  
Ph Value ◽  
Low Cost ◽  
Exchange Capacity ◽  
Copper Removal ◽  
Ultrafiltration Membranes ◽  
Ion Exchange Capacity ◽  
Mineral Addition ◽  
Removal Efficiencies ◽  
Final Effluent

The aim of this work is to examine copper removal from sludge permeate with the use of low-cost minerals of Mediterranean origin combined with ultrafiltration membranes. The minerals used were zeolite (clinoptilolite), bentonite and vermiculite. Activated sludge was enriched with 0.01 N (317.7 ppm) of Cu(II). Fixed concentrations of minerals were added to sludge and the pH value was adjusted at 5.5. The mixture was agitated for 2 hours at 800 rpm at room temperature and was then filtered through a batch ultrafiltration system for 1 hour. This experiment was repeated, for comparison purposes, with sludge enriched with 0.01 N of Cu(II) with no mineral addition. The results showed that ultrafiltration membranes with no mineral addition were able to remove a significant amount of copper with removal efficiencies ranging from 59.4–78.3%. The addition of 10 g/l and 20 g/l of bentonite combined with ultrafiltration membranes resulted in removal efficiencies of 94.9% and 99.4% respectively and that of 10 g/l and 20 g/l of vermiculite in removal efficiencies of 93.8% and 96.8%, respectively. The ion exchange capacity of minerals followed the order bentonite > vermiculite > zeolite. Furthermore, membrane fouling was investigated. The addition of zeolite and bentonite reduced membrane fouling, while the addition of vermiculite did not impact on fouling. The use of low-cost minerals in combination with ultrafiltration membranes can be employed to treat industrial wastewater, resulting in a final effluent with very low copper concentrations.

Optimising the operation of a MBR pilot plant by quantitative analysis of the membrane fouling mechanism

2005 ◽  
Vol 51 (6-7) ◽  
pp. 19-25 ◽  
Author(s):  
T. Jiang ◽  
M.D. Kennedy ◽  
B.F. Guinzbourg ◽  
P.A. Vanrolleghem ◽  
J.C. Schippers
Keyword(s):  
Membrane Fouling ◽  
Pilot Plant ◽  
Filter Cake ◽  
Municipal Wastewater ◽  
Hollow Fibre ◽  
Critical Flux ◽  
Membrane Pore ◽  
Operational Conditions ◽  
Temperature Conditions ◽  
Filtration Flux

In order to optimize some operational conditions of MBR systems, a MBR pilot plant equipped with a submerged hollow fibre membrane module was employed in this study. The pilot MBR was fed with real municipal wastewater and the filtration flux, backwashing interval, aeration frequency and temperature were varied. A filtration flux below 25 l/m2h is generally recommended, at below this flux, the MBR operated at sub-critical flux conditions, the filter cake was minimized and membrane fouling was mainly attributed to the membrane pore blocking. Moreover, the membrane fouling, at below 25 l/m2h, was more reversible to backwashing; above this value, backwashing became less efficient to clean the membrane. Less frequent backwashing (e.g. 600 s filtration/45 s backwashing) decreased the amount of fouling irreversible to backwashing and its performance was superior to that of frequent backwashing (e.g. 200 s filtration/15 s backwashing). The MBR suffered more fouling at low temperature conditions (e.g. at 13–14 °C) than at high temperature conditions (e.g. at 17–18 °C). A conceptual model was built up and successfully interpreted this temperature effect.

scholarly journals MEMBRANE FOULING IN ANOXIC-OXIC MBR SYSTEM OPERATED AT LOW DISSOLVED OXYGEN

2018 ◽  
Vol 55 (4C) ◽  
pp. 258
Author(s):  
Khac Uan Do
Keyword(s):  
Dissolved Oxygen ◽  
Pore Size ◽  
Membrane Fouling ◽  
Hollow Fibre ◽  
Membrane Module ◽  
Hollow Fibre Membrane ◽  
Low Dissolved Oxygen ◽  
Removal Efficiencies ◽  
Filter Area ◽  
Low Do

Membrane fouling in a lab-scale anoxic-oxic MBR operated at low dissolved oxygen (DO) was investigated in this study. The system includes an anoxic, an oxic and a membrane basin with the working volumes of 73 L, 124 L, and 68 L, respectively. A hollow fibre membrane module with a pore size of 0.2 µm and with total filter area of 1.44 m2 was submerged in the membrane basin. The system was operated at various low DO concentrations of 2.0; 1.5; 1.0; and 0.5 mg/L. The results shown that at DO higher than 1.0 mg/L, COD and TN removal efficiencies were higher than 90 % and 60 %, respectively. However, low DO (less than 1.0 mg/L) lead to poor sludge flocculation which deteriorate the membrane filterability. The TMP increased dramatically at different DO levels. There was a significant increase of TMP during first 15-days experiment at DO 2.0 mg/L. After that the TMP was increased slowly and lower than 16 kPa to until 30-days. In contrast, when DO was reduced to 1.5, 1.0, and 0.5, the TMP was increased sharply almost from 1 to over 20 kPa within about 15 days.

Experience from 10 Years Advanced Wastewater Treatment – Technology and Results

1982 ◽  
Vol 14 (1-2) ◽  
pp. 121-133
Author(s):  
C Forsberg ◽  
B Hawerman ◽  
B Hultman
Keyword(s):  
Wastewater Treatment ◽  
Urban Population ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Municipal Wastewater Treatment ◽  
Treatment Technology ◽  
Removal Efficiencies ◽  
Municipal Wastewater Treatment Plants ◽  
Operational Modes ◽  
Polluted Waters

Experience from advanced municipal wastewater treatment plants and recovery of polluted waters are described for the last ten years in Sweden. Except in municipalities with large recipients, the urban population is served by treatment plants with combined biological and chemical treatment. Most of these plants are post-precipitation plants. Several modified operational modes have been developed in order to improve the removal efficiencies of pollutants and to reduce the costs. Results are presented on the recovery of specially investigated lakes with a lowered supply of total phosphorus and organic matter.

scholarly journals Engineered Nanoparticles with Decoupled Photocatalysis and Wettability for Membrane-Based Desalination and Separation of Oil-Saline Water Mixtures

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1397
Author(s):  
Bishwash Shrestha ◽  
Mohammadamin Ezazi ◽  
Gibum Kwon
Keyword(s):  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Uv Light ◽  
Saline Water ◽  
Membrane Surface ◽  
Sio2 Nanoparticles ◽  
Engineered Nanoparticles ◽  
Water Mixture ◽  
Organic Substances ◽  
Suspended Substances

Membrane-based separation technologies are the cornerstone of remediating unconventional water sources, including brackish and industrial or municipal wastewater, as they are relatively energy-efficient and versatile. However, membrane fouling by dissolved and suspended substances in the feed stream remains a primary challenge that currently prevents these membranes from being used in real practices. Thus, we directly address this challenge by applying a superhydrophilic and oleophobic coating to a commercial membrane surface which can be utilized to separate and desalinate an oil and saline water mixture, in addition to photocatalytically degrading the organic substances. We fabricated the photocatalytic membrane by coating a commercial membrane with an ultraviolet (UV) light-curable adhesive. Then, we sprayed it with a mixture of photocatalytic nitrogen-doped titania (N-TiO2) and perfluoro silane-grafted silica (F-SiO2) nanoparticles. The membrane was placed under a UV light, which resulted in a chemically heterogeneous surface with intercalating high and low surface energy regions (i.e., N-TiO2 and F-SiO2, respectively) that were securely bound to the commercial membrane surface. We demonstrated that the coated membrane could be utilized for continuous separation and desalination of an oil–saline water mixture and for simultaneous photocatalytic degradation of the organic substances adsorbed on the membrane surface upon visible light irradiation.

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

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.

Enantioselective analysis and fate of polycyclic musks in a water recycling plant in Sydney (Australia)

2014 ◽  
Vol 69 (10) ◽  
pp. 1996-2003 ◽  
Author(s):  
L. Wang ◽  
S. J. Khan
Keyword(s):  
Municipal Wastewater ◽  
High Sensitivity ◽  
Environmental Chemicals ◽  
Water Recycling ◽  
Environmental Persistence ◽  
Enantioselective Analysis ◽  
Treatment Processes ◽  
Polycyclic Musks ◽  
Household Products ◽  
Final Effluent

Synthetic polycyclic musks (PCMs) Galaxolide (HHCB), Tonalide (AHTN), Phantolide (AHDI), Traseolide (ATII) and Cashmeran (DPMI) are chiral chemicals that are commonly used in washing product industries as racemic mixtures. The major source of PCMs in municipal wastewater is from personal care and household products. Recent studies have shown that PCMs may enhance the relative toxicity of other environmental chemicals by inhibiting cellular xenobiotic defence systems. High sensitivity enantioselective analysis of these compounds enables improved characterisation of the environmental persistence and fate of PCMs, distinguishing between individual enantiomers so that a more complete understanding of environmental risks tributed by individual enantiomers may be obtained. Concentrations of PCMs through the various treatment stages of an advanced water recycling plant in Sydney were investigated to assess the removal of these chemicals. Average concentrations of HHCB, AHTN, AHDI, ATII and DPMI in influent were: 2,545, 301, 2, 5 and 33 ng L−1, respectively. In the final effluent, AHDI, ATII and DPMI were not detected, while HHCB and AHTN were still measured at concentrations of 21 and 2 ng L−1. No significant enantioselective transformation was detected during biological or advanced treatment processes.

Design and operation of an eco-system for municipal wastewater treatment and utilization

2006 ◽  
Vol 54 (11-12) ◽  
pp. 429-436 ◽  
Author(s):  
L. Wang ◽  
J. Peng ◽  
B. Wang ◽  
L. Yang
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetland ◽  
Municipal Wastewater ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Annual Average ◽  
Total Capital ◽  
Dongying City ◽  
Final Effluent ◽  
Better Than

An eco-system consisting of integrated ponds and constructed wetland systems is employed in Dongying City, Shandong Province for the treatment and utilization of municipal wastewater with design capacity of 100,000 m3/d. The total capital cost of this system is 680 Yuan (RMB) or US$82/m3/d, or about half that of the conventional system based on activated sludge process, and the O/M cost is 0.1 Yuan (RMB) or US$ 0.012/m3, only one fifth that of conventional treatment systems. The performance of the wastewater treatment and utilization eco-system is quite good with a final effluent COD, BOD, SS, NH3-N and TP of 45–65 mg/l, 7–32 mg/l, 12–35 mg/l, 2–13 mg/l and 0.2–1.8 mg/l respectively and the annual average removals of COD, BOD, SS, NH3-N and TP are 69.1%, 78.3%, 76.4%, 62.1% and 52.9% respectively, which is much better than that of conventional pond system or constructed wetland used separately and illustrates that the artificial and integrated eco-system is more effective and efficient than the simple natural eco-system.

The importance of measuring the sludge filterability at an MBR – introduction of a new method

2012 ◽  
Vol 66 (1) ◽  
pp. 9-14 ◽  
Author(s):  
C. Thiemig
Keyword(s):  
Membrane Fouling ◽  
Reliable Method ◽  
Membrane Bioreactors ◽  
New Method ◽  
Strong Impact ◽  
Laboratory Equipment ◽  
Filtration Performance ◽  
Sludge Properties ◽  
Operational Aspects ◽  
General Method

Sludge properties have a strong impact on the operational aspects of membrane bioreactors (MBRs). Poor sludge properties cause stronger membrane fouling and reduce the filtration performance of MBRs. Up to now there is no general method used to measure the fouling or filtration relevant sludge properties in MBRs. The aim of this work was to develop a simple but reliable method to supply operators a tool to monitor the important sludge properties for their application and to compare this method with existing techniques. Through extensive research a new method called the sludge filtration index (SFI) has been developed to indicate the appropriate sludge parameters for MBR systems in a cheap and easy manner. The SFI can be measured with simple laboratory equipment and offers operators a powerful tool to monitor the conditions of their sludge, independent of the membrane conditions.

Sign in / Sign up

Export Citation Format

Share Document