磷石膏中有效磷的测定方法比较

分别用EDTA、中性柠檬酸铵两种萃取剂萃取并测定磷石膏中有效磷含量,通过比较,选择能够完全萃取磷石膏中有效磷的萃取剂——中性柠檬酸铵,用于磷石膏中有效磷的分析测定。     

重过磷酸钙中有效磷的直接提取

现行标准ＨＧ２２２０－９１〔１〕中重过磷酸钙有效磷的提取分水溶性磷和中性柠檬酸铵溶性磷两次提取，操作繁琐，耗时均在２．５ｈ以上，从而使整个分析过程的时间超过６ｈ。因此，研究快捷的提取方法对于工业生产控制有重大的实际意义。１实验方法称取重过磷酸钙样品１...     

复合肥料中有效磷、水溶性磷检测的方法研究

在社会快速发展的同时,粮食短缺成为了我国发展过程中的一大难题。虽然袁隆平院士发明了杂交水稻,并且还有其他的科研人员在不断研究高产、高质量的品种,但是现阶段的土地肥力正在不断的下降,为了保证农作物更好的生长,现阶段需要复合肥料来催熟。对于复合肥料来说,有效磷和水溶性磷是两种重要的物质,一种是可以帮助作物成长的,另一种对作物没有太大的作用。通过有效的方法进行检测,可以帮助农民朋友更好的劳作,在采用有效复合肥料的情况下,获得更大的收获。     

过磷酸钙中有效磷测定方法的比较

现行化工行业标准过磷酸钙 ( HG 2 740 95)有效磷的测定提取剂选用碱性柠檬酸铵 ,分为水溶性磷和柠檬酸铵性磷两步提取 ,操作繁琐耗时 ,试剂消耗量大。有文献介绍用草酸铵一步提取法进行有效磷的测定 ,但提取不够完全 ,结果偏低。本文探讨用EDTA一步直接提取有效磷 ,较之现行化工行业标准规定的方法用时减少 2 h以上 ,分析结果与标准法结果的绝对差值≤ 0 .2 %。1　碱性柠檬酸铵二步提取法 (标准法 )水溶性磷以水为提取剂提取 ,枸溶性磷以碱性柠檬酸铵溶液为提取剂进行提取 ,吸取部分两种溶液 ,加合后以硝酸酸化 ,用磷钼酸喹啉重量法或容…     

磷肥中有效磷的分析方法研究

根据Ｐｂ＾２＋能与ＰＯ４＾３－定量形成沉淀，过量的Ｐｂ＾２＋在示波图上有敏锐的切工可指示示波滴定终点的性质，了用Ｐｂ＾３＋标准溶液直接滴定磷肥中有效磷的新方法。该方法不用外加指示剂，终点直观，结果准确，适用于多种磷有效磷的测定     

不同波长流动分析仪法检测中性石灰性土壤中的有效磷含量

为探究连续流动分析法,采用660 nm、880 nm波长检测中性、石灰性土壤有效磷含量差异。通过选择本地30个中性、石灰性土壤样品,采用农业行业标准(NY/T 1121.25-2012)连续流动分析法,利用660 nm、880nm波长检测有效磷含量,与常规紫外分光光度法对比。1)当有效磷含量较低时(小于10mg/kg),传统分光光度法比色检测的有效磷浓度高于660 nm与880 nm波长连续流动分析仪法的检测值;2)880 nm波长比660 nm波长增益值低,连续流动仪880 nm波长比660 nm波长的有效磷含量检测值低;3)当有效磷含量大于10 mg/kg时,应用流动分析仪660 nm、880 nm与常规检测880 nm三种结果无显著差异。研究发现有效磷质量分数大于10mg/kg时,应用流动分析仪660nm、880nm与常规检测880nm三种结果无显著差异。当有效磷质量分数小于10mg/kg时,常规分光光度检测建议使用无磷的活性炭粉震荡吸附后再比色。     

肥料中有效磷测定方法的探讨

各种形态肥料以适当弱酸或碱中和至ｐＨ７．０，并以０．１ｍｏｌ／Ｌ柠檬酸溶液振荡提取有效磷，再在０．７５ｍｏｌ／Ｌ（１２Ｈ２ＳＯ４）介质中，以１，２，４—氨基萘酚磺酸还原钼蓝法测定。该法不但简便快速，准确可靠，而且使各种形态肥料中有效磷含量具有较好的可比性。     

复混肥中有效磷含量测定方法探讨

用水和C（EDTA）=0.2mol/L的EDTA溶液两步提取复混肥中的有效磷，以磷钼酸喹啉重量法测定提取液中的磷含量，实验结果与标准方法对比相一致，达到简化分析步骤的目的。     

复合肥中有效磷测定方法的改进

我公司复合肥以磷酸-铵为主要原料，其有效磷测定按GB／T8573方法需分两步进行，即先提取水溶性磷，再提取枸溶性磷，操作繁琐，且浪费时间。经过多次试验，我们采用一步法提取复合肥中的有效磷，大大缩短了分析时间，操作也十分简便。     

钒钼酸铵分光光度示差法测定过磷酸钙中有效磷

介绍了用钒钼酸铵显色剂与正磷酸根离子结合生成黄色配合物溶液，分光光度示差法测定吸光度，计算出过磷酸钙中有效磷含量的方法。对不同波长的吸光度、显色时间与温度、硝酸浓度及柠檬酸用量进行了试验。结果表明，该法适用于不同磷矿生产的过磷酸钙中有效磷含量的测定，且快速、准确、回收率高。     

徐州市城区表层土壤的理化性质研究

采用野外调查与室内分析相结合的方法,对徐州市城区表层土壤(0～10 cm)的理化性质进行研究。结果表明,城区土壤有酸化的趋势;土壤有机质及全量氮磷钾含量均低于该地区自然褐土;受人为作用方式与强度不同的影响,土壤有效氮磷钾含量表现出较大的差异性。     

快速测定重过磷酸钙中水溶磷和有效磷的超声波法

介绍了采用超声波清洗器提取粒状三料重过磷酸钙中的水溶性磷和有效磷的测定方法及提取条件对测定结果的影响,该方法与HG/T 2219~2224-91相比较,具有快速、简便的优点。水溶性磷的测定值与标准方法的绝对偏差<0.3,RSD=0.38%;有效磷的测定值与标准方法的绝对偏差<0.3,RSD=0.26%。     

磷酸化技术及其在皮革加脂剂中的应用

综述了在制备磷酸酯皮革加脂剂中使用的磷酸化试剂如三氯氧磷、三氯化磷、磷酸、多聚磷酸及五氧化二磷各自的优缺点，指出P2O5是皮革工业中应用最广泛、最重要的磷酸化试剂；简述了磷酸酯的组成分析方法及其注意的问题；介绍了合成磷酸酯在皮革加脂中的研究进展，并强调为了更好地提高磷酸酯加脂剂的加脂性能，要从皮革工业对于加脂剂的多功能和绿色化的要求来对磷酸酯的分子进行设计。     

Change in soil available phosphorus in relation to the phosphorus budget in China

Limited information on soil available phosphorous (P) status has restricted rational P-management strategies, which are necessary to develop, budget, and control P fertilizer inputs. This study was conducted to quantify the relationship between the P budget (P input minus output) and soil available P content (Olsen-P) and its variation from seven long-term experiments that covered subtropical and temperate zones with seven crop systems and six soil types. Across all years and experiments, soil available P content increased linearly with increasing P budget (P?<?0.01), and the increase in soil available P content in the 0?C20 cm topsoil layer by each 100?kg P budget was 1.44?C5.74?mg kg^?1 for the seven sites. This large variation can be explained by the different environments, crop systems, and soil physico-chemical properties. These results will help to predict long-term changes in soil available P using the annual P budget and provide useful information for proper management of P fertilizer.     

Controlling soil water content in fertiliser dissolution experiments

Phosphorus lost in runoff from agricultural land leads to the enrichment of surface waters and contributes to algal blooms. Fertilisers are one source of this P. To compare the water available P of different fertiliser formulations in the laboratory it is necessary to control environmental conditions, temperature, relative humidity and soil water content, prior to simulating rainfall. Two chambers were designed in which relative humidity and soil water content were controlled using salt solutions. An initial design comprising a sealed chamber with three layers of soil samples over a salt bath was found to be inferior to a single layer design. The changes in water content of soil samples were used to test the single layer chamber in a constant temperature environment (15 °C) using a saturated KCl solution (90% relative humidity). Based on the final soil water content of the samples, the spatial variation within the chamber was within tolerable limits. The single layer chamber was used for a simulation experiment comparing the water available P of two commercial fertilisers. Using a saturated resorcinol solution (95% relative humidity) soil samples were equilibrated at 15 °C for 21 days, fertiliser added, and the water available P measured up to 600 h after fertiliser application. The results indicate that the amount of water available P was related to the fertiliser compound and exponentially related to the time since fertiliser application. It was concluded that the single layer chamber is suitable for controlling relative humidity and soil water content in trials such as these where the water available P of fertilisers are being compared.     

利用亚磷酸二甲酯蒸馏残液副产亚磷酸生产工艺述评

亚磷酸二甲酯是合成草甘膦的一个主要中间体,其蒸馏残液主要用于回收亚磷酸.文章分别阐述了用水解和酸解两种方法副产亚磷酸的生产方法,副产出含量在98%以上的亚磷酸,具有回收率高、产品质量好等优点,并减少了三废排放.     

Vegetable cultivation under greenhouse conditions leads to rapid accumulation of nutrients,acidification and salinity of soils and groundwater contamination in South-Eastern China

Vegetable cultivation during winter season is economically profitable, but the impact of the intensive production on soil and water quality remains to be studied. The objectives of this study were to investigate the seasonal dynamics of soil nutrients, acidification and salt accumulation in vegetable fields in South-Eastern China. Various vegetables were grown either under open-field conditions or under two different alternating open-field and greenhouse conditions with three replications. Soil samples were collected periodically and analyzed for pH, plant available nitrogen (N), phosphorous (P), potassium (K), electrical conductivity (EC), and urease activity. Water samples from wells located in or near the plots were collected and analyzed for nitrate. Soil nitrate, available phosphate and salt concentrations declined in summer under open-field conditions and significantly increased from December to May under greenhouse conditions. Exchangeable K also decreased in summer season, but did not increase in the spring. Under alternating open-field and greenhouse conditions, nutrient accumulation, soil salinity and acidification were significantly higher for soil used for vegetable cultivation for 2 years (2-y-plot) than that for only half year (0.5-y-plot). The accumulation of nitrate significantly correlated with soil EC and soil acidification. Thirty-two percent of groundwater samples from the 2-y-plot showed a nitrate concentration higher than 50 mg NO₃ l⁻¹. Conversely, no groundwater sample of 0.5-y-plot showed such high nitrate concentration. It can be concluded that the nitrate accumulation in soil used for vegetable cultivation under alternating open-field and greenhouse conditions not only causes soil salinization and soil acidification but also presents a high pollution potential for groundwater.     

化学辅助除磷药剂比选及试验研究

为保障深圳市观澜污水处理厂出水水质达标排放，对该厂的化学除磷进行药剂比选研究。试验过程采用污水厂实际进水，分别投加液体铝盐、液体铁盐、两种固体聚合氯化铝，进行药剂比选。结果表明，铝盐效果要比铁盐好，且液体铝盐（浓度10％）具有效果好、运行费用低、操作方便等特点，推荐作为试运行期使用的药剂。     

测土配方施肥与复混肥料

阐述20年来我国土壤养分变化的特点,提出用肥应坚持稳氮、磷,增钾肥、微肥、有机肥。测土配方施肥中,还应注意:土壤障碍因子、某种元素临界法与供应强度,肥料利用率等问题。对专用肥配方、复混肥的浓度、复混肥标准的一些规定从农艺角度提出一些意见。最后介绍几种常见作物的复混肥配方及施肥量、施肥方法。     

Compost mulch effects on soil fertility, nutritional status and performance of grapevine

Two composts were tested as mulching materials in a vineyard: one was a sewage sludge and bark compost with a low heavy metal content, the other was a municipal solid waste compost with a higher concentration of metals. Both compost mulches increased organic matter content, available phosphorous and exchangeable potassium of soil and improved the porosity and water retention capacity of the soil. They also reduced soil temperature fluctuations, reduced evaporation of soil water, and influenced the levels of some nutrients measured in leaf samples. The data obtained show that the nutrients uptake was more influenced by the physical conditions of the soil (temperature, moisture) than by the availability of nutrients in the soil. The sewage sludge and bark compost did not cause any significant increase in heavy metal levels in soil and plants. In contrast, the municipal solid waste compost led to a notable accumulation of metals in the soil, in the vegetation and in the musts. Both the compost mulch materials had considerable advantages for the soil management on the grapevine rows, by reducing chemical weed control and allowing for the substitution of chemical fertilisers with no loss in vigour, yield or quality of musts.