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采用碳酸钙沉积法对QD-681A、QD-632A、QD-631-5A、QD-655四种药剂的阻垢性能进行了评价。实验结果表明,药剂单一作用时,QD-655阻垢率最高;复配使用时,QD-632A与QD-631-5A在4:1的比例下阻垢率最高;药剂的浓度增大时,QD-681A的阻垢率升高,QD-655的阻垢率略有降低;随着温度的升高,药剂的阻垢率降低;Ca2+浓度增大时,QD-681A的阻垢率先升高后降低,QD-655的阻垢率逐渐降低;随着HCO3-浓度的增大,药剂的阻垢性能降低。 相似文献
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使用 QD- 6 31、QD- 70 2、QD- 70 1水处理剂具有显著的阻垢、杀菌、灭藻效果 ,不仅可提高换热设备的传热效率 ,降低设备的腐蚀率 ,而且更为经济有效。 相似文献
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为缓解循环水换热器结垢趋势及降低循环水系统总磷含量,公司将循环水配方由聚磷酸盐配方改为低磷配方,使用9个月以来效果明显。 相似文献
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本文介绍了LS101型全有机磷系配方在我公司4~#凉水塔循环冷却水系统中的应用情况。 相似文献
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There is incomplete understanding, based on a single comprehensive study, of the relationship between empirical extractants of soil-test P (STP) and fundamental measurements of soil-P status such as inorganic (Pi) and organic (Po) fractions, P adsorption and relevant ancillary soil attributes. Consequently, we assessed these relationships for the extractants Morgan, Mehlich-3, Olsen, Bray-1, lactate–acetate, CaCl2 (1:2 and 1:10 soil:solution) and resin. Multiple regression analysis indicated that STP extracted with Morgan and CaCl2 related dominantly with the most labile resin Pi fraction, Mehlich-3 and Olsen with labile NaHCO3 Pi, Bray-1 with moderately labile NaOH Pi and lactate-acetate with relatively stable Ca-bound HCl Pi, for example. Especially for Morgan and CaCl2 (1:2), and except for Bray-1, the best relationship of STP with adsorption characteristics was with equilibrium P concentration in solution (EPC). Buffering capacity (EBC) and binding energy (k) did not have significant effects, as indicated by regression, whereas the effects of clay and oxalate-extractable Fe (Feox) were generally negative and Alox and organic carbon (OC) positive. Principal component analysis (PCA) highlighted many similarities in the extractants. However, regression of STP against soil-P pools, integrated as principal component scores, inadequately revealed relationships, which were better facilitated by PCA ordinations. For ordinations of STP with P fractions, eigenvalues for the first two axes explained 88.6% of the variance. Closest associations were residual Pi with HCl Pi, CaCl2 (1:10) and to a lesser extent Morgan with OC and clay, and Mehlich-3 and Olsen with NaHCO3 Pi and resin Pi. For ordinations of STP with P adsorption, eigenvalues for the first two axes explained 97.8% of the variance. The STP extractants grouped in specific, but distinctly different, combinations. For example, strongest inverse relationships were EBC to EPC and Morgan, and k to resin and Olsen, and to OC and clay, indicative of weak P bonding on these surfaces. These distinctions are consistent with, and provide a rationale for, the relevance of Morgan as an environmental P test vis-a-vis other extractants of STP. 相似文献
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Annika Svanbäck Barbro Ulén Ararso Etana Lars Bergström Peter J. A. Kleinman Lennart Mattsson 《Nutrient Cycling in Agroecosystems》2013,96(2-3):133-147
In Sweden, subsurface transport of phosphorus (P) from agricultural soils represents the primary pathway of concern for surface water quality. However, there are mixed findings linking P in leachate with soil P and limited understanding of the interactive effects of applied P sources and soil test P on P leaching potential. Identifying soils that are susceptible to P leaching when manure is applied is critical to management strategies that reduce P loadings to water bodies. Intact soil columns (20 cm deep) from five long-term fertilization trials across Sweden were used in leaching experiments with simulated rainfall to explore the interactive effects of dairy cow (Bos taurus L.) manure application, soil test P and cropping system. Strong relationships were observed between ammonium lactate-extractable P in soil and dissolved reactive P (DRP) concentrations in leachate, although regression slopes varied across soils. For three soils, application of manure (equal to 21–30 kg P ha?1) to the soil columns significantly increased DRP leaching losses. The increase in DRP concentration was correlated to soil test P, but with wide variations between the three soils. For two soils leachate P concentrations after manure addition were independent of soil P status. Despite variable trends in P leaching across the different soils, P concentrations in leachate were always moderate from soils at fertilization rates equivalent to P removal with harvest. Results clearly stress the importance of long-term P balance to limit P leaching losses from Swedish agricultural soils. 相似文献
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Phosphorus (P) runoff from agricultural land contributes to elevated P concentrations in surface water. Although P concentrations in runoff are often higher when soil P is increased, attempts to quantify this relationship in field studies have been inconclusive, either because of confounding within experiments or methodological differences between experiments. The present study attempted to address these issues using simulated rainfall at 15 pastoral locations with varied lithology, land-use intensity, plant cover and soil-P properties in SE Australia, at a total of 38 on-farm sites, each with paired plots. At 27 sites, one of each pair was covered with 70?% shade-cloth to reduce rainfall energy. Although these were uncultivated pastoral sites and surface soil erosion rates were all relatively low, eroded surface soil had sufficiently high concentrations of P to make a major contribution to total P in runoff from some sites, even when plant-available soil P was low. We conclude that greater vegetative cover is required to manage P in runoff than to manage soil erosion. When soil was adequately protected against erosion by either high vegetative cover or shade-cloth, greater than 90?% of the variation in both dissolved reactive P and total P was explained by two commonly measured soil variables: soil-test P (bicarbonate extract) and P-buffering index (where P was in the range where plants may respond to fertiliser). It appears that available soil P can be raised with fertiliser to improve agronomic production without fear of significantly increasing P losses in runoff provided soil test P remains below the agronomic critical concentration defined by the soil P-buffering index. These findings have broad relevance for environmental risk assessment and management where the data required for more complex procedures are unavailable. 相似文献
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磷缓释复混肥的制备及其氮、磷缓释性评价 总被引:1,自引:0,他引:1
在实验室条件下制得不同程度磷缓释的复混肥(磷缓释肥),分别测定以水为淋洗剂和以2%柠檬酸溶液为淋洗剂时在特定淋洗装置下水溶性氮、磷及有效磷随时间的溶出率,采用双曲线方程Xt=b a/t对肥料的累计养分溶出率进行分段拟合,在此基础上引入缓释指数评价各养分缓释特性。结果表明:磷缓释肥对磷的缓释作用强于氮,对有效性磷的缓释作用强于水溶性磷;其水溶性氮、磷缓释指数(SR IWN、SR IW P)和有效磷缓释指数(SR IAP)与肥料中加入的缓释剂硫酸镁相对含量(X)具有很好的正相关,其直线相关系数为0.7414、0.8958和0.9829,后两者分别达到显著和极显著水平;2%柠檬酸溶液几乎能溶出肥料中全部有效磷,从而证明了自制磷缓释肥的有效性。 相似文献
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利用多段式接触氧化法工艺的中试装置(有12级反应槽)处理北京某污水处理厂的污水,以污泥减量为目的研究不同水力停留时间和曝气量下装置的除磷效果及12格沿程的磷变化情况,探究污泥灰分磷回收。结果表明,水力停留时间24 h相对于12 h,装置抗冲击负荷能力较好,且磷去除率高达91. 92%,优于传统生物除磷工艺,腐殖污泥磷含量74. 5 mg P/g DS,其灰分磷含量高达167 mg P/g SA,相当于高品位磷矿,采用盐酸作为浸出剂时,可快速从腐殖污泥灰分中提取90%的磷。 相似文献
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黄磷产品中除了主含量磷以外,还含有其他杂质,如:有机杂质、砷、铅、硫等。为了解决目前工业黄磷国家标准中磷含量的测定方法中的有机物的干扰问题,通过探索,可以采用磷钼酸喹啉重量法测定黄磷中的磷含量。该方法是利用混合酸来溶解黄磷样品,通过进一步的水解,使黄磷样品中的磷完全转化成正磷酸,根据分析测定后得到的磷钼酸喹啉的质量求出单质磷的含量。由所获得的分析数据来看,该方法的可靠程度较高,可以应用于黄磷中磷含量的测定。利用附加的分析方法,还可以同时解决黄磷样品中其他微量杂质的分析检测工作。 相似文献