循环冷却水中聚合物的分析研究

发布时间：2018-08-12 10:46

【摘要】：阻垢分散剂是工业循环水中常用的水处理药剂。水溶性聚合物阻垢剂因阻垢性能良好、低使用量、少(无)公害以及较好的协同与溶限效应,被广泛用于循环冷却水系统。循环水中聚合物阻垢剂浓度的高低对于系统的正常运行具有重要意义。因此需要及时准确监测循环水中聚合物阻垢剂的浓度,达到阻垢且经济的目的。建立浊度法测定聚合物阻垢剂的浓度,其理论依据是聚合物能与十二烷基二甲基苄基氯化铵(1227)形成缔合物浑浊。利用分光光度计测定溶液吸光度并通过标准曲线得到聚合物浓度。研究了影响反应进度的因素,如1227投加量、稳定时间、pH等对吸光度的影响,然后确定最佳测定条件。同时还讨论了循环水中其他物质的存在对聚合物阻垢剂测定的影响及其干扰的消除。得出主要结论如下：(1)在一定浓度内,各种聚合物阻垢剂浓度与生成的缔合物浑浊液吸光度呈较强的线性关系。(2)各种聚合物的最佳测定条件：聚丙烯酸(PAA)最佳测定条件：1227浓度250 mg/L,pH为8-9,放置30 min后于410 nm处测吸光度；聚环氧琥珀酸(PESA)最佳测定条件：1227浓度250 mg/L,pH为9-10,放置30min后于420 nm处测吸光度；羧酸盐-磺酸盐-非离子三元共聚物TH-3100最佳测定条件：1227浓度211 mg/L,调节溶液pH≈5,稳定35min后于520 nm处测吸光度；改性聚羧酸盐TH-2000最佳测定条件：1227浓度280 mg/L,调节溶液pH≈5,稳定35 min后于570nm处测吸光度；聚马来酸酐(HPMA)最佳测定条件：1227浓度105 mg/L,调节溶液pH≈4,稳定35 min后于410 nm处测吸光度。(3)当苯骈三氮唑(BTA)、巯基苯骈噻唑(MBT)、Zn2+4 mg/L,SO42-、 Cl-1000 mg/L,氨基三甲叉膦酸(ATMP)20 mg/L,羟基乙叉二膦酸(HEDP)、 PO43-50 mg/L时,它们的存在对于PESA、TH-3100、TH-2000和HPMA的测定几乎不产生影响；SO42-、Cl-1000 mg/L,ATMP20mg/L,HEDP、PO43-50mg/L, Zn2+、BTA4mg/L时对PAA的测定没有影响；Ca2+、Mg2+对PAA和HPMA的测定不产生影响,然而它们对PESA、TH-3100、TH-2000的影响,可通过添加EDTA二钠消除,物质的量之比至少为1:1(EDTA二钠：Ca2+或Mg2+)；通过加酸蒸煮将聚磷酸盐解聚来消除六偏磷酸钠(SHMP)对这5种聚合物阻垢剂测定的影响。(4)实际电厂循环水样的加标回收实验表明浊度法的现实可行性,该方法检测限低,操作简单且费用低,具有很强的应用实际应用价值。
[Abstract]:Scale inhibitor and dispersant is a commonly used water treatment agent in industrial circulating water. The water-soluble polymer scale inhibitor is widely used in circulating cooling water system because of its good scale inhibition performance, low usage, little (no) pollution and good synergistic and dissolving effect. The concentration of polymer scale inhibitor in circulating water is very important for the normal operation of the system. Therefore, it is necessary to monitor the concentration of polymer scale inhibitor in circulating water timely and accurately to achieve the purpose of scale inhibition and economy. A turbidimetric method was established for the determination of the concentration of polymer scale inhibitor. The theoretical basis is that the polymer can form turbidity with dodecyl dimethyl benzyl ammonium chloride (1227). The absorbance of solution was determined by spectrophotometer and the concentration of polymer was obtained by standard curve. The factors influencing the reaction progress, such as the dosage of 1227, the time of stabilization and the pH value, were studied, and the optimum conditions were determined. The influence of other substances in circulating water on the determination of polymer scale inhibitor and the elimination of interference are also discussed. The main conclusions are as follows: (1) within a certain concentration, There was a strong linear relationship between the concentration of various polymer scale inhibitors and the absorbance of the turbid liquid. (2) the optimum conditions for the determination of polyacrylic acid (PAA) were as follows: the pH value of 250mg 路L ~ (-1) O ~ (2 +) was 8-9, and the pH value was 8 ~ 9 at the concentration of min mg 路L ~ (-1). Absorbance at 410 nm; The optimum conditions for the determination of (PESA) were as follows: (1) the concentration of 1: 1227 was 250mg / L ~ (-1) pH was 9-10, and the absorbance was measured at 420nm after 30min was placed. The optimum conditions for the determination of carboxylate sulfonate-nonionic terpolymer TH-3100 were as follows: (1) the concentration of 1: 1227 was 211 mg / L, the pH of the solution was about 5, and the absorbance was measured at 520nm after stabilizing the 35min. The optimum conditions for the determination of modified polycarboxylate TH-2000 were as follows: 1: 1227, 280mg / L, adjusted solution pH 鈮，

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