Synthesis And Application Of The Fluorescent Trace And Carboxylate-terminated Scale Inhibitor

In the circulating cooling water system,scale deposition and pipeline corrosion are two major problems affecting production stability.Circulating cooling water due to continuous evaporation of high temperature moisture concentration,the water ion concentration doubled with the increasing of time,causing obstruction of the pipeline.Most material of pipeline used in factories is steel.The dissolved carbon dioxide and other substances in water will cause corrosion of the pipeline rust.Therefore,in order to inhibit scale formation and pipe corrosion,it is necessary to treat the water body.The most common and effective way is to add water treatment agent to the water.8-Vinylbenzyloxy-1,3,6-pyrene trisulfonic acid trisodium salt(VPTA)was synthesized from 8-Hydroxy-1,3,6-pyrene trisulfonic acid trisodium salt(PY)and 4-Vinylbenyl chloride(VBC).Oxalic acid-methallyl methoxy polyethylene glycol(HPEZ)was synthesized by methallyl methoxy polyethylene glycol(HPEG)and oxalic acid.The tracer-type green environmental Water treatment agent(HPEZ-AA-VPTA)was prepared by radical polymerization of acrylic acid(AA),HPEZ and VPTA.The structure and thermal stability of HPEZ-AA-VPTA were characterized by Fourier transform infrared spectroscopy(FT-IR),1H Nuclear magnetic resonance(1H-NMR),13C Nuclear magnetic resonance(13C-NMR).HPEZ-AA-VPTA had a great performance of inhibiting calcium carbonate,calcium sulfate and calcium phosphate.The optimum reaction conditions were as follows:reaction temperature 80?,dropping time 1.5h,reaction time 2.Oh,initiator dosage was 5%,the weight ratio of HPEZ/AA was 2:1.The inhibition ratio for CaCO3 is 89.4%at the dosage of 8 mg/L,and the results of SEM and XRD show that HPEZ-AA-VPTA can not only change the morphology of calcium carbonate scale,but also change the crystal form of calcium carbonate scale.The inhibition ratio for CaSO4 is 98.7%at the dosage of 4mg/L.The SEM and XRD results show that HPEZ-AA-VPTA can change the morphology of calcium sulfate crystals,but can not change the crystal form of calcium sulfate crystals.The inhibition ratio for Ca3(PO4)2 is 95.4%at the dosage of 4 mg/L,and the SEM and XRD showed that HPEZ-AA-VPTA could change the morphology of calcium phosphate crystals.HPEZ-AA-VPTA can be used in high hardness and high alkalinity water environment,its performance is better than the commonly used commercially available phosphorus-free scale inhibitor.The inhibition efficiency of HPEZ-AA-VPTA was 81.4%at the concentration of 5mg/L,and the corrosion inhibition performance of HPEZ-AA-VPTA was better than that of the commercially available corrosion inhibitor(EDTMP,HEDP).The excitation and emission wavelengths of HPEZ-AA-VPTA were 403nm and 427nm,respectively.The fluorescence intensity of HPEZ-AA-VPTA showed a good linear relationship with its concentration,the linear correlation coefficient R2 was 0.9971,and the detection limit of the sample was 0.68 mg/L.The effects of pH,temperature and time on the fluorescence intensity of HPEZ-AA-VPTA were investigated.HPEZ-AA-VPTA was a green and highly efficient water treatment agent,and it could meet the requirement of real-time on-line monitoring.