Research On The Synergistic Scale Inhibition Effects Of Environmently Friendly Anti-scale And Dispersing Agents With Electrostatic Water Treatment

With the increasing awareness of environment protection, research and development ongreen water treatment agents and pollution-free water treatment technology have become hotspots. The synergism between electrostatic water treatment and green anti-scale and dispersingagents can reduce the amount of anti-scale and dispersing agents,save cost, provide a theoreticalbasis for developing a static electricity - water treatment technique in circulating cooling watersystem.In this paper, the influence of time and flow rate of the water through the static waterprocessor on the synergistic inhibition was studied by the static experiments. The synergisticscale inhibition performance between electrostatical water treatment and itaconic acidhomopolymer (PLA), polyepoxysuccinic acid (PESA), polyaspartic acid (PASP) wereinvestigated under the different water hardness,temperatures and alkalinities by the staticexperiments.The results showed that time and flow rate had little effect on the synergistic scaleinhibition performance. The synergistic scale inhibition performance among electrostatical watertreatment and three kinds of inhibitors were better under high hardness or high alkalinityconditions. Under the conditions of Ca2+ 600mg.L-1, water temperature 700C, the dosage ofinhibitors 6 mg·L-1 , the scale inhibition rate of PLA in the presence of electrostatic field whichcould increase more than 20.3% was 77.3%; the scale inhibition rate of PESA in the presence ofelectrostatic field which could increase more than 13.3% was 74.4%; the scale inhibition rate ofPASP in the presence of electrostatic field which could increase more than 20.8% was 71.1%.When the scale inhibition rate was same, the dosage of PLA,PESA or PASP in the presence of electrostatic field could decrease more than 1 mg·L-1.The synergistic scale inhibition performance between electrostatic water treatment andgreen anti-scale and dispersing agent were investigated under the different flow rates, theconcentration of inhibitors by the dynamic fouling monitor equipment.The results showed thatthe scale inhibition rate of PLA,PESA or PASP in the presence of electrostatic field couldincrease more than 10% under the different flow rates.With the growth of the inhibitors'concentration, the synergistic scale inhibition performance between electrostatical watertreatment and green anti-scale and dispersing agent decreased.The calcium carbonate samples were characterized by scanning electron microscopy (SEM),infrared spectroscopy (FT-IR) and X-diffraction (XRD).The SEM results showed that thesynergism between electrostatic field and green anti-scale and dispersing agent could cause thesize of the calcium carbonate crystal particles much smaller,make scales looser, discharge fromwater easily. The XRD results showed that the crystal of calcium carbonate contained 64.6%calcite, 20.7% vaterite and 14.7% aragonite, without the electrostatic water treatment ; In thepresence of the electrostatic water treatment, the crystal of calcium carbonate contained 17.2%calcite and 82.8% of aragonite. After the synergism between electrostatic field and PLA, crystalof calcium carbonate was calcite,so was PLA alone. When using PESA , the crystal of calciumcarbonate was calcite;while the synergism between electrostatic field and PESA, the crystal ofcalcium carbonate contained 69.2% calcite and 30.8% of the Vaterite; After the synergismbetween electrostatic field and PASP, crystal of calcium carbonate was calcite,so was PASP alone.In the presence of the electrostatic water treatment , the peak intensity decreased.It showed theelectrostatic water treatment coule weak the peak intensity of calcite, diminishing the size,reducing the degree of crystal. FT-IR was basically consistent with XRD.