Evaluation of biologic and non-biologic methods for assessing virus removal by and integrity of high pressure membrane systems

2003 ◽  
Vol 3 (5-6) ◽  
pp. 81-92 ◽  
Author(s):  
M. Kitis ◽  
J.C. Lozier ◽  
J.H. Kim ◽  
B. Mi ◽  
B.J. Mariñas
Keyword(s):  
River Water ◽  
Granular Media ◽  
Pilot Scale ◽  
Test Methods ◽  
Single Element ◽  
Secondary Effluent ◽  
Membrane Systems ◽  
Integrity Test ◽  
Virus Removal ◽  
Membrane Processing

This paper describes pilot-scale studies that examined three integrity test methods for: (1) quantifying virus removal by nanofiltration (NF) and reverse osmosis (RO) membrane systems when arranged in single element unit and two-stage system configurations, and (2) determining change in virus removal capability of such systems when subject to different types of membrane/o-ring compromisation and fouling. The three methods evaluated included one biologic type (MS-2 phage), that has been employed previously; and two, new non-biologic types (24-nanometre polystyrene fluorescent dyed microspheres and fluorescent Rhodamine WT [R-WT] dye, molecular mass 496 daltons). All three surrogates were employed in a manner intended to show a minimum of 4-logs removal by the NF and RO membranes selected for test. Methods of compromisation included a pinhole induced through one membrane leaf in the spiral wound NF/RO element, and both cracking of and removal of sections from one of the permeate tube o-rings. Testing was conducted on two source waters, representing brackish surface water and effluent categories: a microfiltered secondary effluent and a river water. The river water is characterized by low to moderate TDS and high TOC and was treated with conventional alum coagulation, flocculation, sedimentation and granular media filtration for subsequent membrane processing.

Advanced wastewater disinfection technologies: short and long term efficiency

1998 ◽  
Vol 38 (12) ◽  
pp. 109-117 ◽  
Author(s):  
V. Lazarova ◽  
M. L. Janex ◽  
L. Fiksdal ◽  
C. Oberg ◽  
I. Barcina ◽  
...  
Keyword(s):  
Peracetic Acid ◽  
Contact Time ◽  
Pilot Scale ◽  
Coli Strain ◽  
Plate Count ◽  
Galactosidase Activity ◽  
Virus Removal ◽  
E Coli ◽  
Bacteriophage Ms2 ◽  
Short And Long Term

Advanced disinfection processes (peracetic acid, UV irradiation and ozonation) have been tested and evaluated through bench and pilot scale studies. 3 log removals of total coliforms, faecal coliforms and faecal streptococci were achieved by 10mg/L peracetic acid at a 10min contact time, by UV radiation at 35mW.s/cm2 and by ozone at 5mg/L for 10min contact time. Higher doses are required for virus removal by UV and PAA and especially for highly resistant viruses such as F-specific bacteriophage MS2. Ozonation has the advantage of having a strong effect on all types of bacteriophages and protozoa cysts even when low treatment doses and short contact times are applied. The results of this study demonstrated that evaluation of disinfection efficiency of ozone, UV and PAA depends on the criteria and methods employed. Standard method (plate count) results showed an important disinfection effect on culturability, while results from non-standard methods (respiratory activity and β-galactosidase activity assay) indicated less reduction of viable cells. Moreover, the results confirm that disinfectants act on bacteria in different ways. It has been clearly demonstrated that b-galactosidase activity is affected by PAA while UV treatment has no or very limited effect on the enzyme activity. Even without sunlight reactivation, bacterial regrowth in seawater was observed after disinfection of sewage effluents. This study also shows that the biodegradability of sewage effluent for an E coli strain was affected differently by the oxidative disinfectants ozone and PAA. Biodegradability should therefore be considered when evaluating the total disinfection efficiency.

Antimicrobial resistance of fecal indicators in disinfected wastewater

2011 ◽  
Vol 64 (12) ◽  
pp. 2352-2361 ◽  
Author(s):  
A. Luczkiewicz ◽  
K. Jankowska ◽  
R. Bray ◽  
E. Kulbat ◽  
B. Quant ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Treatment Plant ◽  
Tetracycline Resistance ◽  
Pilot Scale ◽  
Resistant Bacteria ◽  
Secondary Effluent ◽  
Fecal Indicators ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Operation Conditions

The main objective of the study was to assess the potential of three systems (UV irradiation, ozonation, and micro/ultrafiltration) operated in a pilot scale in removal of antimicrobial-resistant fecal bacteria from secondary effluent of the local wastewater treatment plant (700,000 population equivalent). The effectiveness of the processes was analysed using the removal ratio of fecal indicators (Escherichia coli and Enterococcus spp.). The susceptibility of fecal indicators to antimicrobial agents important in human therapy was examined. Resistance to nitrofurantoin and erythromycin was common among enterococci and followed by resistance to fluoroquinolones and tetracycline. Resistance to high-level aminoglycosides and glycopeptides was also observed. E. coli isolates were most frequently resistant to penicillins and tetracycline. The extended-spectrum beta-lactamase-producing E. coli was detected once, after ozonation. Substantial attention should be paid to the E. coli and enterococci resistant to three or more chemical classes of antimicrobials (MAR), which in general constituted up to 15 and 49% of the tested isolates, respectively. Although the applied methods were effective in elimination of fecal indicators (removal efficiency up to 99.99%), special attention has to be paid to the application of sufficient disinfection and operation conditions to avoid selection of antimicrobial resistant bacteria.

scholarly journals Removal Characteristics of N-Nitrosamines and Their Precursors by Pilot-Scale Integrated Membrane Systems for Water Reuse

2018 ◽  
Vol 15 (9) ◽  
pp. 1960 ◽  
Author(s):  
Haruka Takeuchi ◽  
Naoyuki Yamashita ◽  
Norihide Nakada ◽  
Hiroaki Tanaka
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Pilot Scale ◽  
Feed Water ◽  
Water Reclamation ◽  
Size Distributions ◽  
Membrane Systems ◽  
Chemical Cleaning ◽  
Ro Membrane ◽  
Feed Water Temperature

This study investigated the removal characteristics of N-Nitrosamines and their precursors at three pilot-scale water reclamation plants. These plants applies different integrated membrane systems: (1) microfiltration (MF)/nanofiltration (NF)/reverse osmosis (RO) membrane; (2) sand filtration/three-stage RO; and (3) ultrafiltration (UF)/NF and UF/RO. Variable removal of N-Nitrosodimethylamine (NDMA) by the RO processes could be attributed to membrane fouling and the feed water temperature. The effect of membrane fouling on N-Nitrosamine removal was extensively evaluated at one of the plants by conducting one month of operation and chemical cleaning of the RO element. Membrane fouling enhanced N-Nitrosamine removal by the pilot-scale RO process. This finding contributes to better understanding of the variable removal of NDMA by RO processes. This study also investigated the removal characteristics of N-Nitrosamine precursors. The NF and RO processes greatly reduced NDMA formation potential (FP), but the UF process had little effect. The contributions of MF, NF, and RO processes for reducing FPs of NDMA, N-Nitrosopyrrolidine and N-Nitrosodiethylamine were different, suggesting different size distributions of their precursors.

In-process tests of river water conditioning for domestic and drinking water supply in the city of Kurgan

2021 ◽  
pp. 52-59
Author(s):  
А.В. Селюков ◽  
М.Ю. Семенов ◽  
И.С. Байкова
Keyword(s):  
River Water ◽  
Pilot Plant ◽  
Pilot Scale ◽  
Manganese Concentration ◽  
Winter Period ◽  
Initial Water ◽  
Sand Filter ◽  
Polyaluminum Chloride ◽  
Water Composition ◽  
Ozone Dose

Рассматривается опыт применения озонирования речной воды в лабораторных и пилотных масштабах. Вода реки Тобол – жесткая минерализованная со средними значениями цветности 24 град, содержанием марганца в зимний период более 0,8 мг/дм3. После определения рабочих доз реагентов (коагулянт гидроксохлорид алюминия, флокулянт Praestol 650TR) проводилось пробное озонирование с последующей реагентной обработкой на лабораторном флокуляторе. Для достижения норматива по содержанию марганца в речной воде 0,1 мг/дм3 потребовались высокие дозы озона – от 35 мг/дм3. Подщелачивание исходной воды до рН 9 позволило снизить дозу озона до 23 мг/дм3. Снижение цветности до 15 град происходит при дозах озона 6–7 мг/дм3. Очистка речной воды на пилотной установке производительностью 50 л/ч проводилась по полной технологической схеме (озонирование, обработка коагулянтом и флокулянтом, отстаивание, фильтрование через песчаный фильтр, фильтрование через угольный фильтр, опреснение-умягчение обратным осмосом). Доза коагулянта составляла 5 мг/дм3, флокулянта – 0,3 мг/дм3. В стационарном режиме работы пилотной установки при дозе озона 25 мг/дм3 были достигнуты следующие показатели качества фильтрата песчаного фильтра: цветность 5–7 град; марганец 0,05–0,15 мг/дм3; железо общее 0,02–0,03 мг/дм3; алюминий 0,05–0,08 мг/дм3; перманганатная окисляемость 3–4 мг/дм3. Исходя из расчетных показателей состава воды р. Тобол, для концентрации марганца в воде 0,8 мг/дм3теоретическая доза озона составляет ≈ 8 мг/дм3, проектная доза озона может быть принята 10 мг/дм3 (г/м3). The experience of using ozonation of river water on a laboratory and pilot scale is considered. The water of the Tobol River is hard and mineralized with an average color value of 24 degrees, a manganese concentration in the winter period of more than 0.8 mg/dm3. After determining the operational doses of the chemicals (polyaluminum chloride coagulant, Praestol 650TR flocculant), test ozonation was carried out followed by the chemical treatment in a laboratory flocculator. To achieve the standard for manganese concentration in river water of 0.1 mg/dm3, high doses of ozone were required – from 35 mg/dm3. Alkalinization of the initial water to pH 9 provided for reducing the ozone dose to 23 mg/dm3. A decrease in color to 15 degrees occurred at ozone doses of 6–7 mg/dm3. River water purification at a pilot plant with a capacity of 50 l/h was carried out according to the complete process flow scheme (ozonation, treatment with coagulant and flocculant, sedimentation, filtration in a sand filter, filtration in a carbon filter, desalination-softening by reverse osmosis). The coagulant dose was 5 mg/dm3, and that of the flocculant – 0.3 mg/dm3. In the steady run of the pilot plant at an ozone dose of 25 mg/dm3, the following quality indicators of the sand filter filtrate were achieved: color 5–7 degrees; manganese 0.05–0.15 mg/dm3; total iron 0.02–0.03 mg/dm3; aluminum 0.05–0.08 mg/dm3; permanganate index 3–4 mg/dm3. Based on the estimate indicators of the Tobol River water composition related to the manganese concentration in water of 0.8 mg/dm3, the theoretic dose of ozone is ≈ 8 mg/dm3, the design dose of ozone can be assumed as 10 mg/dm3 (g/m3).

scholarly journals Microplastics Removal from Treated Wastewater by a Biofilter

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1085 ◽  
Author(s):  
Fan Liu ◽  
Nadia Nord ◽  
Kai Bester ◽  
Jes Vollertsen
Keyword(s):  
Particle Number ◽  
Treatment Plant ◽  
Complete Removal ◽  
Pilot Scale ◽  
Particle Mass ◽  
Treated Wastewater ◽  
Secondary Effluent ◽  
Global Environmental Issue ◽  
Wwtp Effluent ◽  
Global Environmental

Microplastic (MP) pollution is a global environmental issue, and traditionally treated wastewater has been identified as a source of land-based microplastics into the aquatic environment. This study evaluated the performance of a pilot-scale biofilter to polish wastewater treatment plant (WWTP) effluent before it enters the environment. The filter was divided into four zones, allowing the concentration of microplastics to be followed through the filter. It was fed with secondary effluent from a conventional WWTP in Denmark. The raw effluent from the WWTP contained 917 items m−3 which corresponded to a mass concentration of 24.8 µg m−3. After the top layer of the biofilter, the concentration had decreased to a median value of 197 item m−3 and 2.8 µg m−3, indicating an overall removal efficiency of 79% in terms of particle number and 89% in terms of particle mass. We also observed a tendency that MP of larger size and higher particle mass were more likely to be retained. After the last filtration zone, all MP larger than 100 µm had been removed. The results of this study demonstrate that biofilters are able to lower the MP abundance in treated wastewater significantly, but a complete removal is not ensured, hence some MP, particularly small-sized ones, can still be discharged into the receiving environment.

Characterization of Fouling Potential for Pressure-Driven Membrane Processes: A New Simulated Flow Cell

1982 ◽  
Vol 14 (6-7) ◽  
pp. 499-522 ◽  
Author(s):  
R H Reed ◽  
G Belfort
Keyword(s):  
Water Quality ◽  
Flow Cell ◽  
Feed Water ◽  
Secondary Effluent ◽  
Membrane Systems ◽  
Membrane Processes ◽  
Wide Range ◽  
New Apparatus ◽  
Simulated Flow

Membrane systems are unit processes that are becoming widely accepted for the demineralization of saline and other waste waters. Dissolved and particulate material, specifically colloidal matter, present in the feed stream to membrane systems are considered the principal causes of membrane fouling and reduced efficiency. Conventional water analysis do not yield the information needed to determine the amount of fouling that will occur. Therefore, some rapid indication of the water quality and its potential to foul is needed. Presently there are five tests available to evaluate feed-water quality for membrane processes. However, in each of these tests the apparatuses used do not model tangential (shear) flow across the membrane surface. Therefore, a new apparatus was designed and constructed to predict how the feed water foulants would behave in a flow field. A new apparatus, named the Simulated Flow Cell (SFC), was developed and tested in the laboratory with feed waters containing polystyrene latex spheres (PSL) as foulants and in the field with well-water and precholorinated secondary effluent. The SFC reproduced essentially the same results as the standard non-flow cell when operated under the same conditions. However, the SFC was also able to model flow regimes to membrane systems. The Simulated Flow Cell was tested using irradiated polycarbonate membranes with pore diameters ranging from 0.1 µm to 1.0 µm. The feed water turbidity was varied during the testing by the addition of PSL spheres. Varying these parameters permitted data collection under a wide range of conditions. For laboratory feed water with the addition of PSL spheres, a theoretically expected threshold velocity was observed with the SFC using 0.1 µm pore diameter membranes. The threshold axial velocity was directly proportional to the square root of the initial flux through the 0.1 µm Nuclepore membranes, which is in agreement with data collected from actual hyperfiltration plant operations. The Simulated Flow Cell is a low cost apparatus for the rapid characterization of permeator feed waters. The Simulated Flow Cell promises to become an important tool in the ever widening use of membrane processes in water and wastewater applications.

scholarly journals Performance Evaluation of Tight Ultrafiltration Membrane Systems at Pilot Scale for Agave Fructans Fractionation and Purification

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 261
Author(s):  
Noe Luiz-Santos ◽  
Rogelio Prado-Ramírez ◽  
Enrique Arriola-Guevara ◽  
Rosa-María Camacho-Ruiz ◽  
Lorena Moreno-Vilet
Keyword(s):  
Molecular Weight ◽  
Ceramic Membranes ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Polymeric Membrane ◽  
Transmembrane Pressure ◽  
Hydraulic Permeability ◽  
Distribution Analysis ◽  
Permeate Flux ◽  
Membrane Systems

Ceramic and polymeric membrane systems were compared at the pilot scale for separating agave fructans into different molecular weight fractions that help to diversify them into more specific industrial applications. The effect of the transmembrane pressure of ultrafiltration performance was evaluated through hydraulic permeability, permeate flux and rejection coefficients, using the same operating conditions such as temperature, feed concentration and the molecular weight cut-off (MWCO) of membranes. The fouling phenomenon and the global yield of the process were evaluated in concentration mode. A size distribution analysis of agave fructans is presented and grouped by molecular weight in different fractions. Great differences were found between both systems, since rejection coefficients of 68.6% and 100% for fructans with degrees of polymerization (DP) > 10, 36.3% and 99.3% for fructooligosaccharides (FOS) and 21.4% and 34.2% for mono-disaccharides were obtained for ceramic and polymeric membrane systems, respectively. Thus, ceramic membranes are better for use in the fractionation process since they reached a purity of 42.2% of FOS with a yield of 40.1% in the permeate and 78.23% for fructans with DP > 10 and a yield of 70% in the retentate. Polymeric membranes make for an efficient fructan purification process, eliminating only mono-disaccharides, and reaching a 97.7% purity (considering both fructan fractions) with a yield of 64.3% in the retentate.

Rejection of organic micropollutants by high pressure membranes: comparison of bench-scale versus single element tests

2006 ◽  
Vol 6 (4) ◽  
pp. 107-116
Author(s):  
T.U. Kim ◽  
C. Bellona ◽  
P. Xu ◽  
J. Drewe ◽  
G. Amy
Keyword(s):  
High Pressure ◽  
Scale Up ◽  
Pilot Scale ◽  
Membrane Properties ◽  
Single Element ◽  
Organic Micropollutants ◽  
Trace Organic Compounds ◽  
Operational Conditions ◽  
Bench Scale ◽  
Trace Organic

There has been considerable information reported on rejection of trace organic compounds from pilot-scale and full-scale experiments with reverse osmosis (RO) and nanofiltration (NF), but this information has limited value in predicting the rejection of these compounds by high-pressure membranes. The goal of this research is to define relationships between compound properties, membrane properties, and operational conditions, e.g. pressure, recovery, affecting trace organic compound rejection, comparing bench-scale recirculation tests and bench-scale single-pass tests. In addition, bench-scale results are compared against single element tests to ascertain scale-up effects.

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