【正文】
ess on the scale inhibition performance were studied. The 2+Ca concentration of the solutions was 600 mg/L (as CaCO3) and the pH was about . The experiments were carried out under different solution temperatures and PASP concentrations with 10 h running for 26 each test. The scale inhibition ratios versus PASP concentrations were calculated under different solution temperature conditions. To validate the scale inhibition performance under a higher hardness condition, the solution was confected at a 2+Ca concentration of 800 mg/L and pH . Then it was put into water baths of 30 and 60℃ for 10 h, respectively. The curves of the scale inhibition ratio versus the PASP concentration were obtained under different solution hardness conditions. Experimental results and discussion Effect of solution temperature on scale inhibition performance. Figure 1 shows the effect of the solution temperature on scale inhibition performance. When the solution temperatures are 30 and 60℃ , the scale inhibition ratios exceed 90% with only 3 mg/L PASP used and the scale inhibition performance was excellent. When the solution temperature reaches 80℃ , the scale inhibition rate decreases and 9 mg/L PASP is needed to get a scale inhibition ratio of 50%. From the figures, it is shown that the solution temperature has an effect on the scale inhibition performance of PASP. Thus, PASP as a scale inhibitor fits to application in industrial cooling water systems。上海:華東理工大學(xué)出版社, 24 外文資料 Experimental study on scale inhibition performance of a green scale inhibitor polyaspartic acid QUAN ZhenHua?, CHEN YongChang, WANG XiuRong , SHI Cheng, LIU YunJie amp。工業(yè)水處理, 20xx, 21( 3):2325 [3]徐菊春 ,王慧龍等。 溫度變化時 ,PESA 影響碳酸鈣結(jié)垢過程的控制過程發(fā)生改變。 改變 溫度 ( 30℃ 、 35℃ 、 40℃ 、 45℃ 、 50℃ )重復(fù)以上實驗。 14 2 試 驗 試驗 試劑 表 藥劑名稱 化學(xué)純度 生產(chǎn)廠家 無水氯化鈣 分析純 天津市北方天醫(yī)化學(xué)試劑廠 無水碳酸鈉 分析純 天津市光復(fù)科技發(fā)展有限公司 馬來酸酐 分析純 天津市永大化學(xué)試劑有限公司 鎢酸鈉 分析純 天津市永大化學(xué)試劑有限公司 雙氧水 30% 天津市福晨化學(xué)試劑廠 氫氧化鈉 分析純 天津市永大化學(xué)試劑有限公司 無水甲醇 分析純 天津市永大化學(xué)試劑有限公司 氫氧化鈣 分析純 天津市巨星圣源化學(xué)試劑有限公司 試驗 儀器 表 儀器名稱 型號 生產(chǎn)廠家 數(shù)字恒溫水浴鍋 HH2 型 江蘇省金壇市原華儀器制造有限公司 精密定時電動攪拌器 JJ1 型 常州市華普達(dá)教學(xué)儀器有限公司 電導(dǎo)率儀 DDS11A 型 上海雷磁儀器廠 循環(huán)水式真空泵 SHZD(III) 型 鞏義市予華儀器責(zé)任有限公司 電熱恒溫鼓風(fēng)干燥箱 DHG9203 型 上海一恒科技有限公司 電子 天平 TG328B 型 上海精密科學(xué)儀器有限公司 精密酸度計 PHS2C 型 上海精科雷磁有限公司 試驗方法 聚環(huán)氧琥珀酸的合成 及紅外表征 由馬來酸酐在氫氧化鈉堿性條件下水解得馬來酸鹽,在鎢酸鈉作為催化劑條件下,用雙氧水進(jìn)行環(huán)氧化,得到環(huán)氧琥珀酸鹽,再以氫氧化鈣復(fù)配物為引發(fā)劑引發(fā)聚合反應(yīng),得到聚環(huán)氧琥珀酸鹽。這種方法具有零排放的特點,因此工廠不想或者 不能向下水道系統(tǒng)排放污水時常采用這種設(shè)備。而且,通過形成不同的氧濃差電池,垢會引起嚴(yán)重的局部腐蝕而造成金屬表面穿孔。同濟(jì)大學(xué)的張冰如、李鳳亭,南京理工大學(xué)的夏明珠、雷武、呂志芳等人也對聚環(huán)氧琥珀酸做了一些研究。 因此低磷、無磷 且 可生物降解性能好的阻垢劑已成為近年來國內(nèi)外水處理劑研制方面的熱點課題。保留在水中不析出的鈣離子濃度越大,該阻垢劑的阻垢性能越好。 阻垢性能的評定方法 目前國內(nèi)評定阻垢劑性能常用的方法是靜態(tài)阻 垢 法 、 動態(tài)模擬法、 鼓泡法 、電導(dǎo)率法 。由于吸附于晶體表面上的官能團(tuán)只是阻垢劑分子中的部分官能團(tuán),未參與吸附的官能團(tuán)就會對晶體呈現(xiàn)離子性,因電荷的排斥力增大而使晶體處于分散狀態(tài)。 [3]丙烯酸類共聚物 美國 Chemed公司提出以丙烯酸與苯乙烯磺酸的水溶性共聚物作為水系統(tǒng)阻垢劑。目前市場上的阻垢劑主要有天然聚合物阻垢劑、含磷 (膦) 共聚物阻垢劑、磺酸類共聚物阻垢劑 、 綠色聚合物阻垢劑 等。以馬來酸酐為原料,鎢酸鈉作催化劑,過氧化氫作氧化劑, Ca(OH)2 復(fù)配物為引發(fā)劑,得到聚環(huán)氧琥珀酸鹽,經(jīng)酸化甲醇洗滌、干燥得到目標(biāo)產(chǎn)物聚環(huán)氧琥珀酸。 高溫時分散起主要作用 , 從動力學(xué)上影響碳酸鈣結(jié)垢過程。這類聚合物的特點是分子中含有許多酚經(jīng)基 ,因而對鈣離子等鹽垢晶體生長有一定的抑制作用。該藥劑適用于冷卻水系統(tǒng) ,共聚物濃度為 20mg/L 左右。加入阻垢劑后,阻垢劑吸附在晶體上并摻雜在晶格的點陣中,對無機(jī)垢 的結(jié)晶形成 8 了干擾,使晶體發(fā)生畸變,或使大晶體內(nèi)部的應(yīng)力增大,從而使晶體易于破裂,阻礙了垢的生長。然后 ,用己知濃度的 EDTA 溶液測定水中的剩余硬度,得到用作比較的空白試驗值。測定溶液中的電導(dǎo)率是間接地表示溶液中溶解鹽類的最簡便的方法。 聚環(huán)氧琥珀酸的發(fā)現(xiàn) 綠色化學(xué)的概念重新塑造了水處理技術(shù)的發(fā)展方向。 美國 Prectoramp。美國專利 5147555 和日本專利 4166298 中,采用了聚環(huán)氧琥珀酸或者其鹽來防止水系統(tǒng)中金屬的腐蝕和結(jié)垢。 (4)聚環(huán)氧琥珀酸在地下蓄水系統(tǒng)中的應(yīng)用 在地下蓄水池子中碳?xì)浠衔锏纳a(chǎn)過程中,固體鹽的沉積和設(shè)備表面成垢是生產(chǎn)過程中面臨的嚴(yán)重問題。 ( 3)在四口燒瓶中加入 順丁烯二酸酐,加約 100ml 去離子水,并開動攪拌器。 ( 5) PESA 濃度對碳酸鈣結(jié)垢的影響 在裝有溫度計、冷凝管、滴液漏斗和磁力攪拌裝置的 250mL四口燒瓶內(nèi)加 200ml去 離子水,將其放入恒溫水浴之中,調(diào)節(jié)恒溫水浴使水溫保持在 25℃ ,向其中加入 ,恒速攪拌。 (2) PESA影響碳酸鈣結(jié)垢過程的原因:低溫時 晶格畸變起主要作用;高溫時分散起作用從動力學(xué)上影響碳酸鈣結(jié)垢過程。聚環(huán)氧琥珀酸的多元阻垢性能 [J]。 Effect of 2+Ca concentration on scale inhibition performance. Figure 2 shows the effect of the 2+Ca concentration (solution hardness) on scale inhibition performance. It indicates that the scale inhibition ratios decrease with the increasing of the Ca2+ concentration. However, the scale inhibition performance bees better by 27 increasing the PASP concentration. The scale inhibition ratios can also reach 90% even for 800 mg/L hardness solution with 6 and 12 mg/L PASP under solution temperatures of 30 and 60℃ , respectively. Accordingly PASP may control scale formation effectively even under conditions of a high solution hardness. Analysis of scale inhibition mechanism Solutions in two conical flasks were confected, of which the 2+Ca concentrations were both 600 mg/L. For the purpose of parison, PASP was added into the solution in one conical flask for the scale inhibition test. They were both put into a water tank 28 with the water temperature at 60℃ . After 10 h the conical flasks were taken out and the solutions were filtered. The filtered scale was dried in a drying box for 48 h at room temperature. Samples of crystals were observed by using a scan electron microscope (SEM). The contrastive SEM photographs of the CaCO3 crystals are shown in Figure 3 for experiments with and without PASP treatment. In the experiment without PASP treatment, CaCO3 crystals are normally poleshaped and very hard, and they grow in strict orders. It is difficult to wipe them off from the heat transfer surface. However, in the experiment with PASP treatment, the scale inhibitor can be adsorbed to crystal nuclei of inanic salt. The formation of CaCO3crystals is influenced by the inhibitor and the crystal structure changes to a great extent. The crystal lattice twists to form some bigger and anomalistic noncrystal particulates, which are loose a