scholarly journals A Performance Comparison of Pilot-Scale Sand Filtration and Membrane Filtration of Glafkos River Water

2021 ◽  
Vol 9 (2) ◽  
pp. 203
Author(s):  
Fotios K. Katrivesis ◽  
Varvara Sygouni ◽  
Christakis A. Paraskeva ◽  
Vagelis G. Papadakis
Keyword(s):  
Water Treatment ◽  
River Water ◽  
Flow Rate ◽  
Membrane Filtration ◽  
Particle Concentration ◽  
Pilot Scale ◽  
Precipitation Method ◽  
Permeate Flux ◽  
Operational Parameters ◽  
Membrane Unit

Surface-water treatment plants use the flocculation–precipitation method followed by gravity filters to remove suspended solids. In the present work, the replacement of gravity filters with ultrafiltration membrane units is suggested to improve the efficiency of water treatment and to reduce fixed and operational costs. A parametric pilot-scale study was conducted to compare the filtration efficiency of a deep bed and a membrane module for water-simulating river water of various turbidity degrees. Suspensions of kaolinite were prepared to simulate turbidity of the Glafkos River, Achaia Region of Greece and were filtered using a laboratory sand-bed column and a pilot ultrafiltration (UF) membrane unit. Operational parameters such as the particle concentration ratio, the flow rate, and the filter head loss were studied in the case of the granular bed. In the case of membrane filtration, the permeate flux, turbidity, and membrane permeability loss due to fouling were tested. A discussion in terms of the operational cost and environmental impacts was performed. Filtration capacity of the sand filter is a decreasing function of the flow rate and it was found less efficient than membrane ultrafiltration for increased turbidity or increased particle concentration values. Membrane ultrafiltration could achieve long-term economic profit while it is characterized by minimum environmental impact since the use of chemical reagents and the production of waste sludge are limited.

Long-term studies on hybrid ceramic microfiltration for treatment of surface water containing high dissolved organic matter

2013 ◽  
Vol 14 (2) ◽  
pp. 246-254 ◽  
Author(s):  
A. Abeynayaka ◽  
C. Visvanathan ◽  
S. Khandarith ◽  
T. Hashimoto ◽  
H. Katayama ◽  
...  
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Pilot Scale ◽  
Transmembrane Pressure ◽  
Raw Water ◽  
Operational Parameters ◽  
Polyaluminum Chloride ◽  
Filtration Cycle

This long-term pilot-scale study on the performance of ceramic microfiltration (CMF) was conducted at the Bangkhen water treatment plant (BWTP), with the raw water from Chaophraya River, Thailand. Raw water turbidity and dissolved organic carbon (DOC) were varied in the ranges of 20–210 NTU and 3.0–8.5 mg/L respectively. The hybrid pilot-scale CMF (Pilot-CMF) operational parameters were optimized with the aid of jar-tests and laboratory-scale CMF (Lab-CMF) operations. The systems were operated with various polyaluminum chloride dosages and filtration cycle times. Pilot-CMF provided excellent steady turbidity removal compared to the conventional water treatment process. DOC removal percentages of Pilot-CMF and the conventional process at the BWTP were 49% and 30% respectively. With different coagulant dosages, unique patterns in transmembrane pressure (TMP) variations were observed. The daily TMP increment under low turbidity conditions was 0.08 kPa/day. During rainy periods (turbidity over 100 NTU) the TMP increment reached 0.79 kPa/day. However, once the turbidity of raw water reaches normal conditions (30–60 NTU at the BWTP) the Pilot-CMF system recovers the TMP increment due to efficient backwashing.

scholarly journals Application of Coagulation–Membrane Rotation to Improve Ultrafiltration Performance in Drinking Water Treatment

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 643
Author(s):  
Hongjian Yu ◽  
Weipeng Huang ◽  
Huachen Liu ◽  
Tian Li ◽  
Nianping Chi ◽  
...  
Keyword(s):  
Shear Stress ◽  
Drinking Water ◽  
Water Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Drinking Water Treatment ◽  
Permeate Flux ◽  
Organic Removal ◽  
Cake Layer ◽  
The Impact

The combination of conventional and advanced water treatment is now widely used in drinking water treatment. However, membrane fouling is still the main obstacle to extend its application. In this study, the impact of the combination of coagulation and ultrafiltration (UF) membrane rotation on both fouling control and organic removal of macro (sodium alginate, SA) and micro organic matters (tannic acid, TA) was studied comprehensively to evaluate its applicability in drinking water treatment. The results indicated that membrane rotation could generate shear stress and vortex, thus effectively reducing membrane fouling of both SA and TA solutions, especially for macro SA organics. With additional coagulation, the membrane fouling could be further reduced through the aggregation of mediate and macro organic substances into flocs and elimination by membrane retention. For example, with the membrane rotation speed of 60 r/min, the permeate flux increased by 90% and the organic removal by 35% in SA solution, with 40 mg/L coagulant dosage, with an additional 70% increase of flux and 5% increment of organic removal to 80% obtained. However, too much shear stress could intensify the potential of fiber breakage at the potting, destroying the flocs and resulting in the reduction of permeate flux and deterioration of effluent quality. Finally, the combination of coagulation and membrane rotation would lead to the shaking of the cake layer, which is beneficial for fouling mitigation and prolongation of membrane filtration lifetime. This study provides useful information on applying the combined process of conventional coagulation and the hydrodynamic shear force for drinking water treatment, which can be further explored in the future.

scholarly journals The efficiency of a membrane bioreactor in drinking water denitrification

2015 ◽  
Vol 21 (2) ◽  
pp. 269-275
Author(s):  
Aleksandra Petrovic ◽  
Marjana Simonic
Keyword(s):  
Drinking Water ◽  
Flow Rate ◽  
Membrane Bioreactor ◽  
Nitrate Removal ◽  
Maximum Flow ◽  
Pilot Scale ◽  
Operational Parameters ◽  
Flow Rates ◽  
Removal Capacity ◽  
Removal Efficiencies

The membrane bioreactor (MBR) system was investigated regarding its nitrate removal capacity from drinking water. The performance of a pilot-scale MBR was tested, depending on the operational parameters, using sucrose as a carbon source. Drinking water from the source was introduced into the reactor in order to study the influence of flow-rate on the nitrate removal and denitrification efficiency of drinking water. The content of the nitrate was around 70 mg/L and the C/N ratio was 3:1. Nitrate removal efficiencies above 90% were obtained by flow-rates lower than 4.8 L/h. The specific denitrification rates varied between 0.02 and 0.16 g/L NO3/ (g/L MLSS?d). The efficiencies and nitrate removal were noticeably affected by the flow-rate and hydraulic retention times. At the maximum flow-rate of 10.2 L/h still 68% of the nitrate had been removed, whilst the highest specific denitrification rate was achieved at 0.2738 g/L NO3/ (g/L) MLSS?d). The maximum reactor removal capacity was calculated at 8.75 g NO3/m3?h.

Ceramic membranes for direct river water treatment applying coagulation and microfiltration

2006 ◽  
Vol 6 (4) ◽  
pp. 89-98 ◽  
Author(s):  
A. Loi-Brügger ◽  
S. Panglisch ◽  
P. Buchta ◽  
K. Hattori ◽  
H. Yonekawa ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Pilot Study ◽  
River Water ◽  
Membrane Filtration ◽  
Ceramic Membrane ◽  
Drinking Water Treatment ◽  
Ceramic Membranes ◽  
Operating Conditions ◽  
Optimum Operating

A new ceramic membrane has been designed by NGK Insulators Ltd., Japan, to compete in the drinking water treatment market. The IWW Water Centre, Germany, investigated the operational performance and economical feasibility of this ceramic membrane in a one year pilot study of direct river water treatment with the hybrid process of coagulation and microfiltration. The aim of this study was to investigate flux, recovery, and DOC retention performance and to determine optimum operating conditions of NGK's ceramic membrane filtration system with special regards to economical aspects. Temporarily, the performance of the ceramic membrane was challenged under adverse conditions. During pilot plant operation river water with turbidities between 3 and 100 FNU was treated. Membrane flux was increased stepwise from 80–300 l/m2h resulting in recoveries between 95.9 and 98.9%. A DOC removal between about 20–35% was achieved. The pilot study and the subsequent economical evaluation showed the potential to provide a reliable and cost competitive process option for water treatment. The robustness of the ceramic membrane filtration process makes it attractive for a broad range of water treatment applications and, due to low maintenance requirements, also suitable for drinking water treatment in developing countries.

Pilot scale evaluation of biofiltration as an innovative pre-treatment for ultrafiltration membranes for drinking water treatment

2011 ◽  
Vol 11 (1) ◽  
pp. 23-29 ◽  
Author(s):  
P. M. Huck ◽  
S. Peldszus ◽  
C. Hallé ◽  
H. Ruiz ◽  
X. Jin ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Membrane Fouling ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Membrane Unit ◽  
Ozone Addition ◽  
Pre Treatment ◽  
Uf Membranes

Fouling remains one of the major constraints on the use of low pressure membranes in drinking water treatment. Work over the last few years has shown the importance of biopolymers (carbohydrates and protein-like material) as foulants for ultrafiltration (UF) membranes. The purpose of this study was to investigate at pilot scale the use of rapid biofiltration (without prior coagulation or ozone addition) as an innovative pretreatment to reduce fouling of UF membranes. The investigation was carried out on a water with a higher than average DOC and significant temperature variation. The biofilters, each operated at a hydraulic loading of 5 m/h, had empty bed contact times of 5, 10 and 15 minutes. The membrane unit was operated at a flux equivalent to 60 LMH at 20°C. The investigation confirmed the encouraging results obtained in an earlier smaller scale study with essentially the same water. Increased biofiltration contact time (i.e. increased bed depth) led to lower rates of hydraulically irreversible fouling. The initial biofiltration backwash procedure, involving air scour as is common in chemically assisted filtration, led in some cases to an increased rate of membrane fouling immediately after the backwash. An alternative backwashing strategy was developed, however the feasibility of operating with this approach over very long periods of time needs to be confirmed. To assist in full-scale implementation of this “green” and simple pretreatment, the design and operating conditions for the biofilters should be optimized for various types of waters. It is expected that biofiltration pretreatment will be of particular interest for small and/or isolated systems where a higher initial capital cost may be acceptable because of operational simplicity and reduced chemical requirements.

Pilot scale evaluation on ferric floc sludge concentration with pelleting flocculation blanket process

2010 ◽  
Vol 62 (9) ◽  
pp. 2021-2027
Author(s):  
Huang Ting-lin ◽  
Zhang Gang ◽  
Guo Ning ◽  
He Wen-jie ◽  
Han Hong-da ◽  
...  
Keyword(s):  
Flow Rate ◽  
Pilot Scale ◽  
Operational Parameters ◽  
Experimental Conditions ◽  
High Efficient ◽  
High Turbidity ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
The Relationship ◽  
Sludge Concentration

Pelleting flocculation blanket (PFB) process has been successfully applied to high turbidity suspensions for high efficient solid/liquid separation. In this paper, by using the PFB process, a dynamic experimental study was carried out on concentrating ferric flocs sludge with a scale of 1.3–5.4 m3/h. The pilot experiment aimed to optimize the conditioning system and determine the operational parameters. Under the raw sludge concentrations of 103–1,154 mg/L, the system could achieve ideal conditioning effect with polyacrylamide (PAM) dosages of 0.3–2.7 mg/L, agitation speed of 10 rpm, and water up-flow rates of 18–48 m/h. Under the experimental conditions, the increase of polymer dosage would improve effluent turbidity and pellets settling behaviour, the moderate up-flow rate had no marked effect on treatment results, while too large surface loading could worsen effluent turbidity. The experimental results also revealed that there existed an approximately linear relationship between the raw sludge concentration and optimum PAM dosage, that is, the optimum dosage of PAM increased synchronously as the raw sludge concentration increased. While the relationship between the raw sludge concentration and maximum up-flow rate reflected another linear dependence, namely, the maximum up-flow rate would decreased linearly as the raw sludge concentration increased.

scholarly journals REJECTION CHARACTERISTICS OF ORGANOCHLORINE PESTICIDES BY LOW PRESSURE REVERSE OSMOSIS MEMBRANE

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Woro Nastiti Utami ◽  
Rofiq Iqbal ◽  
I Gede Wenten
Keyword(s):  
River Water ◽  
Reverse Osmosis ◽  
Organochlorine Pesticides ◽  
Low Pressure ◽  
Permeate Flux ◽  
Operational Parameters ◽  
Feed Concentration ◽  
Ph Variation ◽  
Artificial Water ◽  
Reverse Osmosis Unit

The  increased  use  of  pesticides  has  led  to many  benefits  such  as  advanced  productivity and lower maintenance costs  in agriculture. On the other hand, their  adverse  effects  have  also  grown : an increase of  the risks to the ecosystem and human health. Pressure driven technique such as reverse osmosis and nanofiltration have the potentiality to remove hazardous organic micropollutants such as pesticides. The rejection characteristic of artificial water with 10 ppb concentration of endosulfan and organochlorine pesticides from upper Citarum water shed sample were investigated with a commercial low pressure reverse osmosis unit on laboratory scale. Rejection and flux were measured with a varied operational parameters ; pH, pressure, and feed concentration. Endosulfan rejection was achieved 80% with all varied operational parameters. There was a little dependence permeate flux and percent of rejection on pH. An increasing pressure caused a higher permeate flux while there was no effect of an increasing pressure to higher percentage of endosulfan rejection. An increasing feed concentration caused a lower permeate flux due to an increasing osmotic pressure.  An increasing feed concentration also result in an increasing percent of endosulfan rejection. Organochlorine pesticides found in river water sample which are lindane, aldrin, and heptachlor were all rejected 100%. This may be caused by natural organic matter present in river water and hydrophobicity. Percent rejection was constant to pressure and pH variation. Keywords : Low Pressure Reverse Osmosis, Organochlorine Pesticides, Pressure, pH, Feed Concentration

Experimental evaluations of water treatment systems using a pilot-scale plant for adaptations to a sharp increase in raw-water turbidity caused by climate change

2013 ◽  
Vol 13 (1) ◽  
pp. 139-146
Author(s):  
Y. Kobayashi ◽  
M. Itoh ◽  
T. Yamada ◽  
M. Akiba ◽  
Y. Matsui
Keyword(s):  
Climate Change ◽  
Water Treatment ◽  
Sharp Increase ◽  
Membrane Filtration ◽  
Pilot Scale ◽  
Transmembrane Pressure ◽  
Water Supply Systems ◽  
Raw Water ◽  
Sand Filtration ◽  
Water Turbidity

One effect of climate change on the water supply systems in Japan may be a sharp increase in the raw-water turbidity following heavy rain. The objective of this study was to evaluate water treatment performance with a sharp increase in raw-water turbidity. This evaluation was carried out from the perspective of turbidity response by a pilot-scale plant using sand filtration and membrane filtration with coagulation–sedimentation pretreatment. Two coagulants were used; namely, polyaluminum chloride with a basicity of either 72% (PACl-72%) or 51% (PACl-51%). Raw-water turbidity was increased from 5 to 300 TU by adding kaolin suspension. In the case of sand filtration, the filtered-water turbidity increased during the filter stabilization period. An increase in the coagulant dosage produced a more rapid decrease in the filtered-water turbidity and shortened the filter stabilizing period. Filtered-water turbidity decreased more rapidly for PACl-72% than for PACl-51%. In the case of membrane filtration, an increase in raw-water turbidity caused no significant increase in filtered-water turbidity or transmembrane pressure. These results demonstrated that, although neither filtration technique completely failed, membrane filtration was more robust than sand filtration against a sharp increase in raw-water turbidity.

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