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.

scholarly journals Low-dissolved-oxygen nitrification in tropical sewage: an investigation on potential, performance and functional microbial community

2018 ◽  
Vol 77 (9) ◽  
pp. 2274-2283 ◽  
Author(s):  
S. W. How ◽  
S. Y. Lim ◽  
P. B. Lim ◽  
A. M. Aris ◽  
G. C. Ngoh ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Batch Reactor ◽  
In Situ Hybridisation ◽  
Sewage Treatment ◽  
Oxygen Affinity ◽  
Amplicon Sequencing ◽  
Fluorescence In Situ Hybridisation ◽  
Low Dissolved Oxygen ◽  
16S Rrna Amplicon Sequencing ◽  
Low Do

Abstract Intensive aeration for nitrification is a major energy consumer in sewage treatment plants (STPs). Low-dissolved-oxygen (low-DO) nitrification has the potential to lower the aeration demand. However, the applicability of low-DO nitrification in the tropical climate is not well-understood. In this study, the potential of low-DO nitrification in tropical setting was first examined using batch kinetic experiments. Subsequently, the performance of low-DO nitrification was investigated in a laboratory-scale sequential batch reactor (SBR) for 42 days using real tropical sewage. The batch kinetic experiments showed that the seed sludge has a relatively high oxygen affinity. Thus, the rate of nitrification was not significantly reduced at low DO concentrations (0.5 mg/L). During the operation of the low-DO nitrification SBR, 90% of NH4-N was removed. The active low-DO nitrification was mainly attributed to the limited biodegradable organics in the sewage. Fluorescence in-situ hybridisation and 16S rRNA amplicon sequencing revealed the nitrifiers were related to Nitrospira genus and Nitrosomonadaceae family. Phylogenetic analysis suggests 47% of the operational taxonomic units in Nitrospira genus are closely related to a comammox bacteria. This study has demonstrated active low-DO nitrification in tropical setting, which is a more sustainable process that could significantly reduce the energy footprint of STPs.

Real role of an ultrafiltration hollow-fibre membrane module in a submerged membrane bioreactor

Desalination ◽  
2005 ◽  
Vol 181 (1-3) ◽  
pp. 185-191 ◽  
Author(s):  
Ayhan Ünlü ◽  
Halil Hasar ◽  
Cumali Kınacı ◽  
Mehmet Çakmakcı ◽  
Nilüfer Nacar Koçer
Keyword(s):  
Membrane Bioreactor ◽  
Hollow Fibre ◽  
Membrane Module ◽  
Hollow Fibre Membrane ◽  
Submerged Membrane Bioreactor ◽  
Fibre Membrane

Life Cycle Costing Model for Hollow Fibre Membrane Module: A Review and Further Research

2014 ◽  
Vol 660 ◽  
pp. 1020-1025 ◽  
Author(s):  
Nur Syamimi Jiran ◽  
Muhamad Zameri Mat Saman ◽  
Noordin Mohd Yusof ◽  
Norhayati Zakuan
Keyword(s):  
Life Cycle ◽  
Initial Step ◽  
Membrane System ◽  
Hollow Fibre ◽  
Life Cycle Costing ◽  
Membrane Module ◽  
Hollow Fibre Membrane ◽  
Traditional System ◽  
Fibre Membrane ◽  
Fresh Water Supply

Increasing human population increases the demand for fresh water supply. Membrane technology has been identified as one of the solutions to reduce water pollution due to industrial activities, especially the chemical industry. In order to promote this technology and shift from the traditional system, economic aspect is an important attraction. The total cost for owning, operating, using and post-using the technology will influence the industry to invest this technology in their workplace. Therefore, a life cycle costing (LCC) analysis should be performed to estimate the complete overall cost of the membrane system from cradle-to-grave. This paper aimed to review some economic analysis of the membrane system, previous LCC model and highlight the initial step in performing LCC analysis of hollow fibre membrane module, which is to identify all primary and secondary activities and all possible costs related to the module.

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.

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