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The two fluorescent monomers N‐allyl‐4‐methoxy‐1,8‐naphtalimide (F1) and N‐allyl‐2‐(6‐hydroxy‐3‐oxo‐3H‐xanthen‐9‐yl)benzamide (N‐allylamidefluorescein, F2) have been synthesized and then conjugated to either polyacrylate (PAA) or to a co‐polymer of fumaric and acrylic acids (MA‐AA) to give four novel fluorescent‐tagged antiscalants: nonbiodegradable PAA‐F1, PAA‐F2 and biodegradable MA‐AA‐F1, MA‐AA‐F2. All four reagents demonstrate the fluorescence intensity suitable for inhibitors monitoring with a detection limit within 0.40 mg dm−3. A good linear relationship between antiscalant fluorescent intensity and its dosage is detected. PAA‐F1, PAA‐F2, MA‐AA‐F1, and MA‐AA‐F2 can be used for corresponding scale inhibitor content on‐line measurement. For some antiscalants, the fluorescence is found to be dependent on the background heavy metal ions normally present in the cooling water. This effect is explained by the corresponding complexes formation. PAA‐F1, PAA‐F2, MA‐AA‐F1, and MA‐AA‐F2 revealed a good antiscaling activity toward CaCO3 and CaSO4 deposition, comparable with that one of commercial polyacrylates. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45017.

A relative ability of industrial samples of four phosphorus-free polymers (polyaspartate (PASP); polyepoxysuccinate (PESA); polyacrylic acid sodium salt (PAAS); copolymer of maleic and acrylic acid (MA-AA)) and of three phosphonates (aminotris(methylenephosphonic acid), ATMP; 1-hydroxyethane-1,1-bis(phosphonic acid), HEDP; phosphonobutane-1,2,4-tricarboxylic acid, PBTC) to inhibit calcium sulfate precipitation is studied following the NACE Standard along with dynamic light scattering (DLS), scanning electron microscopy (SEM), and X-ray diffraction (XRD) technique. For the 0.5 mg·dm−3dosage, the following efficiency ranking was found:MA-AA~ATMP>PESA (400–1500 Da)>PASP (1000–5000 Da)≫PAAS (3000–5000 Da)~PBTC~HEDP. The isolated crystals are identified as gypsum. SEM images for PESA, PASP, PAAS, and HEDP and for a blank sample indicated the needle-like crystal morphology. Surprisingly, the least effective reagent PBTC revealed quite a different behavior, changing the morphology of gypsum crystals to an irregular shape. The DLS experiments exhibited a formation of 300 to 700 nm diameter particles with negativeζ-potential around −2 mV for all reagents.Although suchζ-potential values are not capable of providing colloidal stability, all three phosphonates demonstrate significant gypsum particles stabilization relative to a blank experiment.

a b s t r a c tDesalination of seawater and brackish water by reverse osmosis to produce potable and process water has been widely used. But the precipitation of low soluble salts is one of the major problems in RO plants operation. Several well-known techniques are used to protect membranes and antiscalant dosing is one of the most widespread. A wide range of reliable and efficient inhibitors have been developed but the trend of the last decade is creation environmentally friendly ("green") chemicals: phosphorus-free and biodegradable. A relative ability of industrial samples of four phosphorus-free polymers (polyaspartate (PASP); polyepoxysuccinate (PESA); polyacrylic acid sodium salt (PAAS); copolymer of maleic and acrylic acid (MA/AA)) and of three phosphonates (aminotris (methylenephosphonic acid), ATMP; phosphonobutane-1,2,4-tricarboxylic acid, PBTC; and AMINAT) to inhibit carbonate membrane fouling in the simulated Black Sea water under reverse osmosis (RO) conditions for the dosages ranging from 1 to 25 ppm is tested. The following ranking ATMP > HEDP > PESA (400 ÷ 1500 Da) ~ PASP (1000 ÷ 5000 Da) > PAAS (3000-5000 Da) ~ MA-AA is found. A comparison of this ranking with that one performed following the NACE Standard TM0374-2007 under static conditions confirmed results provided by NACE Protocol.

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