【正文】 阻垢性能及良好的水溶性并且利用后可被微生物、真菌降解為對環(huán)境無害的終產(chǎn)物，被認為是一種環(huán)境友好型的綠色水處理劑。早在 60 年代，人們就認識到世界江河、湖泊、海洋營養(yǎng)源的逐年增高會影響這些地區(qū)的經(jīng)濟發(fā)展，破壞這些地區(qū)的生態(tài)平衡 。它的阻垢性能和緩蝕性能都明顯優(yōu)于聚丙烯酸鈉、聚馬來酸和酒石酸等。遺憾的是，國內(nèi)對其研究還 很少，和美國、日本等發(fā)達國家在這一領(lǐng)域還存在很大的差距，但是令人慶幸的是，國外的研究大部分還停留在實驗室階段。 聚環(huán)氧琥珀酸合成 ： （ 1）一步法合成聚環(huán)氧琥珀酸 聚環(huán)氧琥珀酸作為一種新型的水處理劑最先是 11 由美國 Prectoramp。 20 世紀 90 年代末，熊蓉春教授改用釩系催化劑進行馬來酸酐的環(huán)氧化反應(yīng)，然后以稀土催化劑催化使之聚合，得聚環(huán)氧琥珀酸。 聚環(huán)氧琥珀酸 的 應(yīng)用 聚環(huán)氧琥珀酸作為一種綠色水處理劑，在高硬度、高堿度和高 PH 條件下不 會像傳統(tǒng)的阻垢劑那樣因形成阻垢劑一鈣化合物而失效。因此被廣泛的應(yīng)用的到工業(yè)水處理的各個領(lǐng)域。金屬表面的大量 腐蝕將會導(dǎo)致加工設(shè)備過早的損壞，縮短設(shè)備的更換周期或維修周期。美國專利 5256332 中，通過向水溶液中加入有效劑量的正磷酸鹽、聚環(huán)氧琥珀酸、溶于水的一氮二烯五元化合物和丙烯酸 /烯丙基磺酸醚單體的共聚物來有 效的緩蝕阻垢。這將減緩水的流動性、破壞噴射狀態(tài)的穩(wěn)定性、增加破裂的可能性和延長故障的停工期。傳統(tǒng)的水垢抑制劑如聚磷酸鹽和聚丙烯酸鹽，需要頻繁的中斷生產(chǎn)來實施，周期大約是 3 一 6 月，使用化學(xué)藥品和蒸汽氣流除去蒸發(fā)器表面的水垢。美國專利 5886011 中，在鹽濃縮和蒸發(fā)系統(tǒng)中加入低于化學(xué)計量用量的聚環(huán)氧琥珀酸，不但有效地控制了礦物垢如碳酸鈣、硫酸鈣和磷酸鈣的生成，而且對于濃縮固化的工業(yè)過程沒有任何影響。聚環(huán)氧琥珀酸是一種有 效的地下蓄水池流體的阻垢劑。目前水處理藥劑的研究向綠色化發(fā)展，聚環(huán)氧琥珀酸是目前世界公認的綠色水處理劑，它兼具阻垢、緩蝕雙重作用。 13 本題目擬研究 聚環(huán)氧琥珀酸（ PESA）對碳酸鈣結(jié)垢過程的影響 。 實驗步驟 15 （ 1）配制 50%氫氧化鈉溶液。 （ 5）使溫度控制在 60℃左右，加入 催化劑鎢酸鈉。 （ 8）反應(yīng)后，升高溫度到 85℃，分 兩 批加入 引發(fā)劑 (氫氧化鈣 )。 （ 2） 氯化鈣溶液的配制 用 電子 天平稱取氯化鈣 ，加入燒杯 中，并向其中加入少許蒸餾水，攪拌溶解后，移至 100ml 容量瓶，加蒸餾水至刻度線處。測定不同溫度下電導(dǎo)率隨時間的變化值。加入 PESA（ 、 ?? ） ，重復(fù)上面試驗，測定其電導(dǎo)率隨時間的變化值。推斷 PESA 起阻垢作用的主要原因應(yīng)該是晶格畸變作用。即加入 PESA ,在減緩 CaCO3聚集速度的同時將大量的CaCO3微粒穩(wěn)定在溶液中 ,從而從動力學(xué)上阻止碳酸鈣結(jié)垢過程。 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15時間溶液電導(dǎo)率25℃30℃35℃40℃45℃50℃ 20 PESA 濃度對碳酸鈣結(jié)垢的影響 圖 5 不同濃度 PESA碳酸鈣結(jié)垢時間與溶液電導(dǎo)率關(guān)系 由圖可見 , 25℃無晶種存在下 ,試樣中加入 1mg/mL 阻垢劑 效果達到最佳 ,說明 PESA的低劑量效應(yīng) 。 (3) PESA有低劑量效應(yīng) 。其次要感謝和我一組的康靜偉同學(xué)，和其他各組同學(xué)的配合，使得畢業(yè)論文得以完成。綠色阻垢劑聚環(huán)氧琥珀酸的合成 [J].工業(yè)水處理， 1999， 19（ 3）：1311。綠色水處理劑聚環(huán)氧琥珀酸的研究進展 [J]。 20xx， 27（ 2）：9295 [5]李繼友?；みM展 20xx，24（ 5）： 2628 [7]白樺萍，趙志仁，雷武，等。循環(huán)冷卻水用阻垢劑性能的評定方法 [J]。 MA ChongFang Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China Abstract Static and dynamic experiments were carried out to validate scale inhibition performance of a greenscale inhibitorpolyaspartic acid (PASP). From the static experiment, it was shown that below 60℃ , polyaspartic acid is very effective in scale inhibition, with the scale inhibition ratio exceeding 90% with only 3 mg/L PASP for the 600 mg/L hardness solution. For a higher hardness solution of 800 mg/L, the scale inhibition ratio can also reach 90% with 6 and 12 mg/L PASP at 30 and 60℃ respectively. The SEM photographs of CaCO3 crystals indicate that the crystal structure transforms from a pact stickshape to a loose shape so that the scale can be washed away easily instead of being deposited on the heat transfer surface. The dynamic experimental results show that almost no scales formed on the heat transfer surface and the fouling thermal resistance decreases extraordinarily if PASP is added in the solution. Key words : polyaspartic acid scale inhibition fouling resistance In cooling water systems of industry, mineralions in water, such as bicarbonate and calcium, may concentrate to form scale in heat transfer equipment, for example heat exchangers, evaporators, condensers etc. The scale not only degrades performance of heat exchangers by increasing the resistance to heat transfer, but also wastes energy due to increasing power of pumps, resulting in tremendous economic loss. In order to control scale, numerous chemicals have been used widely in the cooling water systems. With the 25 increase of environmental awareness, people pay much more attention to the study of new green scale inhibitors all over the world. A green scale inhibitor named polyaspartic acid (PASP) without phosphorus was developed in the niies. It is produced without any environmental pollution and can be degraded pletely by microbes and epiphytes after being used. In China, people have performed relevant researches and published many papers, in which PASP was reported as a good substitute of other conventional scale inhibitors and a kind of valuable green scale inhibitor . However, most of the studies focusedon the chemical syntheses of PASP rather than its scale inhibition performance. Experimental data of the scale inhibitor are not enough to validate its performance of scale inhibition. In addition, the static method is usually used to estimate the scale inhibition behavior, but it does not involve dynamic influence. The dynamic method is regarded as a credible evaluating method because of its simulating actual fouling processes of heat exchangers more factually. In this paper, static and dynamic experiments were conducted to study the scale inhibition performance of PASP for the further application of PASP in industrial circulating water systems. 1 Static experiment Experimental method In the present study, artificial hard water was used as the test solution, which was made by dissolving a certain quantity of calcium chloride (CaCl2) and sodium bicarbonate (NaHCO3) (the molar ratio of CaCl2 to NaHCO3 was 1:2) in the conical flask with deionized water. The solution was confected with and without PASP for the scale inhibition experiment and the scale experiment, respectively. Then the conical flask was put into a water bath at a constant temperature for a certain time。 the solution temperature was ℃ 。℃ during 1 h. Then certain amounts of CaCl2 and NaHCO3 were put into the water storage tank, respectively, to confect 100 L of a test solution of 600 mg/L hardness. The experiments lasted 12 h. During the experiments, all the temperatures and flow rates were recorded by a puter through a data acquisition system. Then the fouling resistance can be calculated by eq. (2). where t means a certain operational period, and