羟基乙叉二磷酸(HEDP)的中试合成、复配及现场应用

Pilot Synthesis,Compound and Field Application of 1-Hydroxyethy-lidene-1,1-diphosphonic Acid( HEDP)

以工业级乙酰氯、亚磷酸、正丁醇为原料,以"一步法"在50 L工业反应釜中合成羟基乙叉二膦酸(HEDP),并将其与硫酸锌、钼酸钠、葡萄糖酸钠复配制备一种复配型低磷水处理药剂HDW-2,通过考察其阻垢、缓蚀性能,建立了HDW-2药剂浓度与缓蚀阻垢率的线性关系模型,并于山东省某企业进行为期1个月的现场试用。结果表明:当投加量为15 mg/L,即维持PO_4^(3-)含量(质量浓度,下同)为2.02 mg/L时,对碳酸钙的阻垢率达到了96.3%;当投加量为64 mg/L,即维持PO_4^(3-)含量为8.49 mg/L时,缓蚀率达到了95.2%,腐蚀速率仅为0.028 mm/a。HDW-2在循环水系统中的吸附遵循Langmuir等温吸附模型,以此建立以阻垢为主的加药模型为η =ρ^(0.901)-2.13/ρ^(0.901)-1.13,以缓蚀为主的加药模型为η=ρ^(1.491)-26.49/ρ^(1.491)-25.49。现场试应用1个月的跟踪监测数据显示,系统运行稳定,循环水的pH保持在8.07~8.57,电导率保持在1 950~2 690μS/cm,钙硬度与总碱度之和保持在892~1 080 mg/L,氯离子保持在183~287 mg/L,总Fe保持在0.12~0.40 mg/L,腐蚀速率小于0.04 mm/a,总磷(以PO_4^(3-)计)保持在3.37~7.55 mg/L。各项水质指标均达到了甲方考核指标的要求。

1-Hydroxyethy-lidene-1,1-diphosphonic acid（ HEDP） was synthesized in medium-test（ 50L） by one-step reaction with industrial grade acetyl chloride,phosphorous acid and n-butyl alcohol.Then,a low phosphorus water treatment agent HDW-2 was obtained by combining HEDP with zinc sulfate,sodium molybdate,sodium gluconate. A linear relationship model between HDW-2 dosage,scale and corrosion inhibitor rate was set after its scale and corrosion inhibition properties were investigated,and trial on site for a period of one month in a enterprises in shandong province. The results showed that the calcium carbonate scale inhibition rate was up to 96. 3% when the dosage of HEDP was 15 mg / L（ equal to 2. 02 mg / L PO4^3-） and the corrosion inhibiting rate was 95. 2%,the corrosion rate was only 0. 028 mm / a when the dosage of HEDP was 64 mg / L（ equal to 8. 49 mg / L PO4^3-）. Adsorption law of HDW-2 followed the Langmuir isotherm adsorption model,based on it the dosing models η =ρ^0. 901-2. 13/ρ^0. 901-1.13（ for anti-scaling） and η =ρ^1.491-26. 49/ρ^1.491-25. 49（ for anti-corrosion） were set.After a month of field test application,it showed that the system run stability,p H was maintained between 8. 07 - 8. 57,electrical conductivity was maintained between 1 950 - 2 690 μS / cm,calcium hardness ＋ total alkalinity was maintained between 892 - 1 080 mg / L,chloride ion was maintained between 183 - 287 mg / L,total Fe was maintained between 0. 12 - 0. 40 mg / L,the corrosion rate 0. 04 mm / a,total phosphorus（ PO43-） was maintained between 3. 37 - 7. 55 mg /L. The water quality indicators reached the requirement of party a＇s assessment indicators.