Membrane filtration retentate thickening efficiency using electrolytic ion products instead of chemical coagulants

2003 ◽  
Vol 3 (3) ◽  
pp. 43-48
Author(s):  
J.Y. Huang ◽  
T. Uchiburi ◽  
K. Fujita
Keyword(s):  
Membrane Filtration ◽  
Wash Water ◽  
Aluminum Anode ◽  
Alkaline Agent ◽  
Iron Anode

Electrolytic coagulation has advantages compared with conventional chemicals coagulation treatment. First of all, the addition of alkaline agent is necessary in chemicals coagulation treatment as the addition of acid agents in coagulation of dense wash water makes pH decline. While not much change of pH is observed with electrolytic coagulation, where alkaline agent is not demanded. Secondly, it is easy to control the dose of additional coagulants. In this study, electrolytic coagulation sedimentation treatment is adopted for membrane retentate from membrane filtration treatment without using coagulants. As electricity can control the addition of coagulation, an automation method is applied in the experiment. The lower the iron as well as aluminum dissolved, the higher the sludge density becomes; especially aluminum has this tendency. It is possible to achieve 400 kg/m3 of condensed sludge density with artificial wash water and more than 80 kg/m3 for real retentate, in terms of electrolytic coagulation of iron anode. The sludge density of aluminum anode is higher, but its filtrate density is lower than iron anode.

scholarly journals Microbial wash water quality on dairy farms from Galicia (NW Spain)

2019 ◽  
Vol 19 (8) ◽  
pp. 2214-2221
Author(s):  
F. J. Saavedra ◽  
E. Yus ◽  
F. J. Diéguez
Keyword(s):  
Water Samples ◽  
Membrane Filtration ◽  
Dairy Farms ◽  
Total Coliform ◽  
Faecal Coliform ◽  
Wash Water ◽  
Nw Spain ◽  
Filtration Method ◽  
Bacterial Groups ◽  
Faecal Streptococci

Abstract This study evaluated the microbiological quality of wash water used in dairy farms from Galicia (NW Spain) based on the total coliform, faecal coliform and faecal streptococci counts. The paper aimed to identify geographical areas that are at a high risk for bacterial contamination of wash water and to study the temporal distribution of positive samples. Water samples from 120 farms, whose water supply came from a private well, were tested for the presence of the three mentioned bacterial groups by the membrane filtration method. To investigate whether the presence of positive herds for a particular bacterial group in water samples was higher in some areas or during a specific time period, data were tested using the Bernoulli model. In farms without a purification system, the prevalence of positive samples for total coliform, faecal coliform and faecal streptococci was 36.7%, 13.3% and 24.5%, respectively. In farms using hydrogen peroxide, these figures were 15.4%, 7.7% and 7.7%, respectively. In farms using chlorine or ultraviolet radiation all the samples were negative for the three bacterial groups. The spatial analysis identified one statistically significant spatial cluster of herds with positive samples of faecal streptococci in an area characterized by a high cattle density. Moreover, one most likely temporal cluster was identified for each of the three groups between July and August 2017, which were the driest months in the studied area.

Impact of Organic Load on Escherichia coli O157:H7 Survival during Pilot-Scale Processing of Iceberg Lettuce with Acidified Sodium Hypochlorite

2014 ◽  
Vol 77 (10) ◽  
pp. 1669-1681 ◽  
Author(s):  
GORDON R. DAVIDSON ◽  
CHELSEA N. KAMINSKI ◽  
ELLIOT T. RYSER
Keyword(s):  
Escherichia Coli ◽  
Citric Acid ◽  
Membrane Filtration ◽  
Fluorescent Protein ◽  
Pilot Scale ◽  
Wash Water ◽  
Organic Load ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Iceberg Lettuce

Chemical sanitizers are routinely used during commercial flume washing of fresh-cut leafy greens to minimize cross-contamination from the water. This study assessed the efficacy of three chlorine treatments against Escherichia coli O157:H7 on iceberg lettuce, in wash water, and on surfaces of a pilot-scale processing line using flume water containing various organic loads. Iceberg lettuce (5.4 kg) was inoculated to contain 106 CFU/g of a 4-strain cocktail of nontoxigenic, green fluorescent protein–labeled, ampicillin-resistant E. coli O157:H7 and held for 24 h at 4°C before processing. Lettuce was shredded using a Urschel TransSlicer, step conveyed to a flume tank, washed for 90 s using water alone or one of three different sanitizing treatments (50 ppm of total chlorine either alone or acidified to pH 6.5 with citric acid or T-128) in water containing organic loads of 0, 2.5, 5, or 10% (wt/vol) blended iceberg lettuce, and then dried using a shaker table and centrifugal dryer. Next, three 5.4-kg batches of uninoculated iceberg lettuce were processed identically. Various product (25 g), water (50 ml), and equipment surface swab (100 cm2) samples were homogenized in neutralizing buffer, diluted appropriately, and plated on tryptic soy agar containing 0.6% (wt/vol) yeast extract and 100 ppm of ampicillin without prior 0.45-μm membrane filtration to quantify E. coli O157:H7. Organic load negatively impacted the efficacy of all three chlorine treatments (P < 0.05) at the end of processing, with typical E. coli O157:H7 reductions of >5 and 0.9 to 3.7 log CFU/ml for organic loads of 0 and 10%, respectively. Organic load rarely had a significant impact (P < 0.05) on the efficacy of chlorine, chlorine plus citric acid, or chlorine plus T-128 against E. coli O157:H7 on iceberg lettuce. Reduced sanitizer efficacy generally corresponded to changes in total solids, chemical oxygen demand, turbidity, and maximum filterable volume, indicating that these tests may be effective alternatives to the industry standard of oxygen/reduction potential.

Salmonella Transfer during Pilot Plant Scale Washing and Roller Conveying of Tomatoes

2014 ◽  
Vol 77 (3) ◽  
pp. 380-387 ◽  
Author(s):  
HAIQIANG WANG ◽  
ELLIOT T. RYSER
Keyword(s):  
Membrane Filtration ◽  
Free Water ◽  
Pilot Scale ◽  
Wash Water ◽  
Cross Contamination ◽  
Plastic Foam ◽  
Surface Samples ◽  
Serovar Typhimurium ◽  
Before And After ◽  
Pilot Plant Scale

Salmonella transfer during washing and roller conveying of inoculated tomatoes was quantified using a pilot scale tomato packing line equipped with plastic, foam, or brush rollers. Red round tomatoes (2.3 kg) were dip inoculated with Salmonella enterica serovar Typhimurium LT2 (avirulent) (4 log CFU/g), air dried for 2 h, and then washed in sanitizer-free water for 2 min. Inoculated tomatoes were then passed single file over a 1.5-m conveyor equipped with plastic, foam, or brush rollers followed by 25 previously washed uninoculated tomatoes. Tomato samples were collected after 2 min of both washing and roller conveying, with all 25 uninoculated tomatoes collected individually after conveying. Roller surface samples were collected before and after conveying the uninoculated tomatoes. Both tomato and surface samples were quantitatively examined for Salmonella by direct plating or membrane filtration using xylose lysine Tergitol 4 agar. Regardless of the roller type, Salmonella populations on inoculated tomatoes did not significantly (P < 0.05) decrease during contact with the roller conveyors. After conveying uninoculated tomatoes over contaminated foam rollers, 96% of the 25 tomatoes were cross-contaminated with Salmonella at >100 CFU per tomato. With plastic rollers, 24 and 76% of tomatoes were cross-contaminated with Salmonella at 10 to 100 and 1 to 10 CFU per tomato, respectively. In contrast, only 8% of 25 tomatoes were cross-contaminated with brush rollers with Salmonella populations of 1 to 10 CFU per tomato. Overall, cross-contamination was greatest with foam, followed by plastic and brush rollers (P < 0.05). Adding peroxyacetic acid or chlorine to the wash water significantly decreased cross-contamination during tomato conveying, with chlorine less effective in controlling Salmonella on foam compared with plastic and brush rollers.

Brownstock washing: A review of the literature

TAPPI Journal ◽  
2014 ◽  
Vol 13 (1) ◽  
pp. 9-19 ◽  
Author(s):  
RICARDO B. SANTOS ◽  
PETER W. HART
Keyword(s):  
High Efficiency ◽  
Black Liquor ◽  
Material Balance ◽  
Kraft Pulping ◽  
Wash Water ◽  
Pulp Fibers ◽  
Kraft Process ◽  
Cooking Process ◽  
Materials Used ◽  
Entrapped Air

Brownstock washing is a complex, dynamic process in which dirty wash water or weak black liquor (dissolved organic and inorganic material obtained from the pulp cooking process) is separated from pulp fibers. The use of material balance techniques is of great importance to identify potential problems and determine how well the system is operating. The kraft pulping industry was the first known to combine pulp washing with the recovery of materials used and produced in the wood cooking process. The motivation behind materials recovery is economic, and more recently, environmentally driven. The chemicals used in the kraft process are expensive as compared to those used in the sulfite process. For the kraft process to be economically viable, it is imperative that a very high percentage of the cooking chemicals be recovered. To reach such high efficiency, a variety of washing systems and monitoring parameters have been developed. Antifoam additives and processing aids have also played an important role in increasing washing effectiveness. Antifoam materials help attain washing effectiveness by preventing entrapped air from forming in the system, which allows for an easier, unimpeded flow of filtrate through the screens and washers.

EFFECTS OF USING CONCRETE WASH WATER ON A FEW CHARACTERISTICS OF NEW CONCRETE

2017 ◽  
Vol 16 (7) ◽  
pp. 1569-1575 ◽  
Author(s):  
Gholamreza Asadollahfardi ◽  
Gholamreza Tahmasabi ◽  
Saviz Mohammad Nabi ◽  
Homa Pouresfandyani ◽  
Seyed Ali Asghar Hossieni
Keyword(s):  
Wash Water

Prospects of using dynamic membrane filtration module UF-RDM for concentrating cheese whey proteins

2019 ◽  
Vol 56 (6) ◽  
pp. 54-56
Author(s):  
E.Yu. Agarkova ◽  
◽  
A.G. Kruchinin ◽  
A.A. Agarkov ◽  
V.D. Haritonov
Keyword(s):  
Membrane Filtration ◽  
Cheese Whey ◽  
Whey Proteins ◽  
Dynamic Membrane

Leading the City of Baltimore into the 21st Century: Flexible Treatment Solutions and Integrated Raw Water Management

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
J. L. Manuszak ◽  
M. MacPhee ◽  
S. Liskovich ◽  
L. Feldsher
Keyword(s):  
Water Management ◽  
Water Quality ◽  
Water Supply ◽  
Conceptual Design ◽  
Membrane Filtration ◽  
Treatment Plant ◽  
Low Pressure ◽  
Management Tool ◽  
Raw Water ◽  
The City

The City of Baltimore, Maryland is one of many US cities faced with challenges related to increasing potable water demands, diminishing fresh water supplies, and aging infrastructure. To address these challenges, the City recently undertook a $7M study to evaluate water supply and treatment alternatives and develop the conceptual design for a new 120 million gallon per day (MGD) water treatment plant. As part of this study, an innovative raw water management tool was constructed to help model source water availability and predicted water quality based on integration of a new and more challenging surface water supply. A rigorous decision-making approach was then used to screen and select appropriate treatment processes. Short-listed treatment strategies were demonstrated through a year-long pilot study, and process design criteria were collected in order to assess capital and operational costs for the full-scale plant. Ultimately the City chose a treatment scheme that includes low-pressure membrane filtration and post-filter GAC adsorption, allowing for consistent finished water quality irrespective of which raw water supply is being used. The conceptual design includes several progressive concepts, which will: 1) alleviate treatment limitations at the City's existing plants by providing additional pre-clarification facilities at the new plant; and 2) take advantage of site conditions to design and operate the submerged membrane system by gravity-induced siphon, saving the City significant capital and operations and maintenance (O&M) costs. Once completed, the new Fullerton Water Filtration Plant (WFP) will be the largest low-pressure membrane plant in North America, and the largest gravity-siphon design in the world.

Sign in / Sign up

Export Citation Format

Share Document