A Time-Saving Filtration System For Nutrient Analysis

1987 ◽  
Vol 44 (11) ◽  
pp. 2018-2021
Author(s):  
G. T. Bowman ◽  
B. A. Schuknecht ◽  
J. E. Wilken ◽  
W. C. Sonzogni
Keyword(s):  
Hydrochloric Acid ◽  
Membrane Filtration ◽  
Dilute Hydrochloric Acid ◽  
Particulate Material ◽  
Nitrogen And Phosphorus ◽  
Time Saving ◽  
Nutrient Analysis ◽  
Dissolved Nitrogen ◽  
Filtration System ◽  
Validation Tests

Conventional membrane filtration to separate particulate material from water samples, such as in the analysis of dissolved nitrogen and phosphorus, is time consuming and subject to contamination. To minimize this problem, a device is presented that allows filtration of up to 80 samples per hour without introducing contamination or affecting the sample integrity. The device requires only partial dismantling and minimal cleaning with dilute hydrochloric acid between samples. Validation tests show that the device does not alter dissolved constituents in filtered samples. Unlike conventional membrane filtering apparatus, a cumbersome vacuum flask is not required. The system is compact and easily adapted to mobile and shipboard laboratories.

scholarly journals Wastewater treatment facility upgrade uses combination of technologies to solve nutrient removal challenges

2017 ◽  
Vol 12 (2) ◽  
pp. 251-259
Author(s):  
Thor Young
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Membrane Filtration ◽  
Treatment Facility ◽  
Nitrogen And Phosphorus ◽  
North East ◽  
Performance Requirements ◽  
East River ◽  
Wastewater Treatment Facility ◽  
Filtration System

New regulations required the 7.5 ML/d North East River Advanced Wastewater Treatment Facility to upgrade to meet lower annual average effluent nitrogen and phosphorus limits. At the same time, facility planning was underway to expand the facility to 17.0 ML/d to accommodate planned growth in the service area. Following a pilot study to establish the performance capabilities of the existing process and a technology alternatives evaluation, a combination of a Carrousel® 5-stage oxidation ditches followed by a membrane filtration system was used to convert the facility to a membrane bioreactor. This combination of technologies is unique among the more than 300 facilities recently upgraded for nutrient removal in the Chesapeake Bay region. The new process went into service in late 2015 and has demonstrated the ability to meet effluent performance requirements for total nitrogen and total phosphorus.

Low-pressure membrane filtration with unconventional coagulation regimes

2005 ◽  
Vol 5 (5) ◽  
pp. 1-8 ◽  
Author(s):  
K.Y. Choi ◽  
B.A. Dempsey
Keyword(s):  
Activated Carbon ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Cross Flow ◽  
Chemical Cleaning ◽  
Sand Filters ◽  
Charge Neutralization ◽  
Floc Size ◽  
Filtration System ◽  
Pre Treatment

The objective of the research was to evaluate in-line coagulation to improve performance during ultrafiltration (UF). In-line coagulation means use of coagulants without removal of coagulated solids prior to UF. Performance was evaluated by removal of contaminants (water quality) and by resistance to filtration and recovery of flux after hydraulic or chemical cleaning (water production). We hypothesized that coagulation conditions inappropriate for conventional treatment, in particular under-dosing conditions that produce particles that neither settle nor are removed in rapid sand filters, would be effective for in-line coagulation prior to UF. A variety of pre-treatment processes for UF have been investigated including coagulation, powdered activated carbon (PAC) or granular activated carbon (GAC), adsorption on iron oxides or other pre-formed settleable solid phases, or ozonation. Coagulation pre-treatment is often used for removal of fouling substances prior to NF or RO. It has been reported that effective conventional coagulation conditions produced larger particles and this reduced fouling during membrane filtration by reducing adsorption in membrane pores, increasing cake porosity, and increasing transport of foulants away from the membrane surface. However, aggregates produced under sweep floc conditions were more compressible than for charge neutralization conditions, resulting in compaction when the membrane filtration system was pressurized. It was known that the coagulated suspension under either charge-neutralization or sweep floc condition showed similar steady-state flux under the cross-flow microfiltration mode. Another report on the concept of critical floc size suggested that flocs need to reach a certain critical size before MF, otherwise membranes can be irreversibly clogged by the coagulant solids. The authors were motivated to study the effect of various coagulation conditions on the performance of a membrane filtration system.

Kinetics of cyclization of S-ethoxycarbonylmethylisothiouronium chloride to 2-imino-4-thiazolidone

1979 ◽  
Vol 44 (3) ◽  
pp. 912-917 ◽  
Author(s):  
Vladimír Macháček ◽  
Said A. El-bahai ◽  
Vojeslav Štěrba
Keyword(s):  
Hydrochloric Acid ◽  
Dilute Hydrochloric Acid ◽  
Base Catalysis ◽  
General Base ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Kinetics Of Formation ◽  
Acid Catalyzed ◽  
Rate Limiting ◽  
Kinetics Of

Kinetics of formation of 2-imino-4-thiazolidone from S-ethoxycarbonylmethylisothiouronium chloride has been studied in aqueous buffers and dilute hydrochloric acid. The reaction is subject to general base catalysis, the β value being 0.65. Its rate limiting step consists in acid-catalyzed splitting off of ethoxide ion from dipolar tetrahedral intermediate. At pH < 2 formation of this intermediate becomes rate-limiting; rate constant of its formation is 2 . 104 s-1.

Synthesis of the semi-rigid analogues of prothiadene and dithiadene as potential antidepressant and antihistamine agents: 11-[2-(Dimethylaminomethyl)cyclohexylidene]-6,11-dihydrodibenzo[b,e]thiepins and 4-[2-(dimethylaminomethyl)cyclohexylidene]-4,9-dihydrothieno-[2,3-c]-2-benzothiepins

1985 ◽  
Vol 50 (5) ◽  
pp. 1078-1088 ◽  
Author(s):  
Zdeněk Polívka ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
Jan Metyš ◽  
Miroslav Protiva
Keyword(s):  
Hydrochloric Acid ◽  
Ir Spectrum ◽  
Title Compound ◽  
Dilute Hydrochloric Acid ◽  
Amino Alcohols ◽  
Geometric Isomers ◽  
Pharmacological Testing

Reaction of dibenzo[b,e]thiepin-11(6H)-one with 2-(dimethylaminomethyl)cyclohexylmagnesium chloride gave a mixture of stereoisomeric amino alcohols IX from which four homogeneous bases (IXa to IXd) were separated by chromatography. Dehydration of these compounds with boiling dilute hydrochloric acid afforded mixtures of racemic geometric isomers of the title compound VII, which were separated by crystallization. To the prevailing less polar base VIIa (E)-configuration was assigned on the basis of the IR spectrum. Using a similar procedure, thieno[2,3-c]-2-benzothiepin-4(9H)-one gave mixture of amino alcohols X from which three homogeneous stereoisomers X-A to X-C were isolated. Their dehydration resulted in both expected racemic geometric isomers VIII-A and VIII-B. Pharmacological testing proved the character of an antidepressant for the semi-rigid analogue of dithiadene VIII.

Carbon–titanium dioxide (C/TiO2) nanofiber composites for chemical oxidation of emerging organic contaminants in reactive filtration applications

2021 ◽  
Vol 8 (3) ◽  
pp. 711-722
Author(s):  
Katherine E. Greenstein ◽  
Matthew R. Nagorzanski ◽  
Bailey Kelsay ◽  
Edgard M. Verdugo ◽  
Nosang V. Myung ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Water Treatment ◽  
Organic Contaminants ◽  
Membrane Filtration ◽  
Titanium Dioxide Nanoparticles ◽  
Chemical Oxidation ◽  
Tio2 Nanofiber ◽  
System P ◽  
Filtration System ◽  
Emerging Organic Contaminants

Electrospun carbon nanofibers with integrated titanium dioxide nanoparticles are used for water treatment in a photoactive membrane filtration system.

An alternative method for assaying cerebrospinal fluid protein in the presence of methotrexate.

1988 ◽  
Vol 34 (10) ◽  
pp. 2091-2092 ◽  
Author(s):  
L M Kasper ◽  
W R Moorehead ◽  
T O Oei ◽  
M Markanich
Keyword(s):  
Cerebrospinal Fluid ◽  
Hydrochloric Acid ◽  
Trichloroacetic Acid ◽  
Dilute Hydrochloric Acid ◽  
Constant Amount ◽  
Manual Method ◽  
Turbidimetric Method ◽  
Methotrexate Concentration ◽  
Cerebrospinal Fluid Protein ◽  
Positive Interference

Abstract Therapeutic concentrations of methotrexate can cause significant positive interference in cerebrospinal fluid (CSF) protein values when assayed in the Du Pont aca. Conversely, our modified turbidimetric method, in which trichloroacetic acid (TCA) plus a sample blank containing dilute hydrochloric acid is used in place of TCA, exhibits little or no interference from methotrexate. This was verified by assaying solutions that contained a constant amount of protein (approximately 430 mg/L) and various amounts of methotrexate (0.0-2.3 x 10(-4) mol/L) by both the Du Pont aca and the manual turbidimetric method. As expected, the aca results showed increasing protein values with increasing methotrexate, whereas the manual method gave results approximating the expected protein value irrespective of the methotrexate concentration.

scholarly journals Effect of Pre-Oxidation on Coagulation/Ceramic Membrane Treatment of Yangtze River Water

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 369
Author(s):  
Shengji Xia ◽  
Xinran Zhang ◽  
Yuanchen Zhao ◽  
Fibor J. Tan ◽  
Pan Li ◽  
...  
Keyword(s):  
Water Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Ceramic Membrane ◽  
Membrane Separation ◽  
Membrane System ◽  
Coagulation System ◽  
Fouling Control ◽  
Filtration System ◽  
Membrane Treatment

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.

scholarly journals Comparative environmental impact evaluation using life cycle assessment approach: a case study of integrated membrane-filtration system for the treatment of aerobically-digested palm oil mill effluent

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Yeit Haan Teow ◽  
Meng Teck Chong ◽  
Kah Chun Ho ◽  
Abdul Wahab Mohammad
Keyword(s):  
Activated Carbon ◽  
Life Cycle ◽  
Palm Oil ◽  
Membrane Filtration ◽  
Electricity Consumption ◽  
Sand Filters ◽  
Unit Operations ◽  
Filtration System ◽  
Pre Treatment ◽  
Aerobically Digested

AbstractAiming to mitigate wastewater pollution arising from the palm oil industry, this university-industry research-and-development project focused on the integration of serial treatment processes, including the use of moving bed biofilm reactor (MBBR), pre-treatment with sand filters and activated carbon filters, and membrane technology for aerobically-digested palm oil mill effluent (POME) treatment. To assess the potential of this sustainable alternative practice in the industry, the developed technology was demonstrated in a pilot-scale facility: four combinations (Combinations I to IV) of unit operations were developed in an integrated membrane-filtration system. Combination I includes a MBBR, pre-treatment unit comprising sand filters and activated carbon filters, ultrafiltration (UF) membrane, and reverse osmosis (RO) membrane, while Combination II excludes MBBR, Combination III excludes UF membrane, and Combination IV excludes both MBBR and UF membrane. Life cycle assessment (LCA) was performed to evaluate potential environmental impacts arising from each combination while achieving the goal of obtaining recycled and reusable water from the aerobically-digested POME treatment. It is reported that electricity consumption is the predominant factor contributing to most of those categories (50–77%) as the emissions of carbon dioxide (CO2), sulfur dioxide (SO2), nitrogen oxides, and volatile mercury during the combustion of fossil fuels. Combination I in the integrated membrane-filtration system with all unit operations incurring high electricity consumption (52 MJ) contributed to the greatest environmental impact. Electricity consumption registers the highest impact towards all life cycle impact categories: 73% on climate change, 80% on terrestrial acidification, 51% on eutrophication, and 43% on human toxicity. Conversely, Combination IV is the most environmentally-friendly process, since it involves only two-unit operations – pre-treatment unit (comprising sand filters and activated carbon filters) and RO membrane unit – and thus incurs the least electricity consumption (41.6 MJ). The LCA offers insights into each combination of the operating process and facilitates both researchers and the industry towards sustainable production.

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