磷酸钙盐法回收剩余污泥超声波处理上清液中磷的研究

在污泥减量化处理中,细胞微生物中的碳氮磷等会释放到上清液中。为了对上清液中的磷进行有效回收,在前期研究的基础上,以生物厌氧好氧除磷(An/O)工艺的剩余污泥超声波处理上清液为研究对象,考察了磷酸钙盐(HAP)法的磷回收效果。结果表明:HAP法反应较快,5 min时反应基本完成;初始pH值在8.5～10.0时,回收率均可保持在较高水平;最佳钙磷比(Ca2+/PO34--P)为3.87。在以上最佳工艺条件下,总磷(TP)、正磷酸盐(PO34--P)的回收率分别达到88.4%、94.0%,同时对上清液中的有机物、氮也有一定的去除。     

有机物料与~(32)P标记过磷酸钙混合施用对磷有效性的影响

本试验利用~(32)P示踪法研究赤红壤上两种有机物料与过磷酸钙混合施用对磷有效性的影响。盆栽试验表明,纸厂废料蔗渣或猪粪与磷肥混合施用比磷肥单独施用更有利于提高格拉姆柱花草的含磷量和总吸磷量。单位施磷量引起的土壤有效磷和植株吸磷量的增加量也是有机物料单施或与磷肥混施高于磷肥单施。在前39d,~(32)P标记过磷酸钙的利用率在单独施用时为2.14％,比混合施用高一倍左右;在80d时,混合施用的磷利用率较快提高,蔗渣与磷肥混施处理超过单独施用,达22.88％。     

Concentrations of inorganic elements in bottled waters on the Swedish market

This study presents the concentrations of about 50 metals and ions in 33 different brands of bottled waters on the Swedish market. Ten of the brands showed calcium (Ca) concentrations ≤10 mg L⁻¹ and magnesium (Mg) levels <3 mg L⁻¹, implying very soft waters. Three of these waters had in addition low concentrations of sodium (Na; <7 mg L⁻¹), potassium (K; <3 mg L⁻¹) and bicarbonate (HCO₃ ≤31 mg L⁻¹). These brands were collected from barren districts. Nine of the brands were collected from limestone regions. They showed increased Ca-levels exceeding 50 mg L⁻¹ with a maximum of 289 mg L⁻¹. Corresponding Mg-levels were also raised in two brands exceeding 90 mg L⁻¹. Two soft and carbonated waters were supplemented with Na₂CO₃ and NaCl, resulting in high concentrations of Na (644 and 648 mg L⁻¹) and chloride (Cl; 204 and 219 mg L⁻¹). Such waters may make a substantial contribution to the daily intake of NaCl in high water consumers. The storage of carbonated drinking water in aluminum (Al) cans increased the Al-concentration to about 70 μg L⁻¹. Conclusion As there was a large variation in the material as regards concentrations of macro-elements such as Ca, Mg, Na, K and Cl. Supplementation with salts, e.g., Na₂CO₃, K₂ CO₃ and NaCl, can lead to increased concentrations of Na, K and Cl, as well as decreased ratios of Ca/Na and larger ratios of Na/K. Water with high concentrations of e.g., Ca and Mg, may make a substantial contribution to the daily intake of these elements in high water consumers. Al cans are less suited for storage of carbonated waters, as the lowered pH-values may dissolve Al. The levels of potentially toxic metals in the studied brands were generally low.     

土壤钙的生物有效性及与其它元素的相互作用

根据国内有关土壤钙素的研究文献、总结了土壤钙的生物有效性.土壤钙与其它元素的相互作用,以及钙在土壤中的固定、移动的研究进展,提出了钙肥的施用原则.其施用原则应该是平衡且适量。     

原子吸收分光光度法测定植株中钙、镁的几种样品前处理方法的比较

本文比较了原子吸收分光光度法测定植株中钙、镁的三种样品前处理方法：干友化法、１ｍｏｌ／ＬＨＣｌ振荡提取法（振荡法）和１ｍｏｌ／ＬＨＣｌ静止浸泡提取法（浸泡法）．结果表明，振荡法和浸泡法对钙的测定结果平均分别为干灰化法的１０１％和９２．０％，对镁的测定结果平均分别为１０３％和９７．６％．振荡法和浸泡法与干灰化法之间不存在显著性差异（α＝０．０５），它们之间有极显著的正相关性（相关系数在０．９９以上）．因此，在大批量样品的常规分析中，１ｍｏｌ／ＬＨＣｌ提取法可代替干灰化法．     

Degradation of Starch–Calcium Carbonate Disposable Packaging in a Solid Waste Composting Facility

The compostability of starch–CaCO₃ disposable packaging was examined in a source-separated municipal solid waste (MSW) composting facility located in East Hampton, NY. Source-separated MSW:starch–CaCO₃ container mixtures of 0 (control), 5, and 20% (by volume) were prepared as feedstock for composting. Compost samples were collected weekly or biweekly during the composting process and examined for fragments of the starch–CaCO₃ containers. Changes in compost quality due to the presence of starch–CaCO₃ containers were assessed by measuring the nutrient and metal content of the three resultant MSW:starch–CaCO₃ composts. Finally, plant growth studies were conducted to examine the composts for possible plant growth inhibition due to the deterioration of the starch–CaCO₃ containers. Results showed that portions of the starch–CaCO₃ containers were not identified in any of the 5 and 20% sieved and characterized compost fractions > 1.3 cm following 1–3 weeks of composting. Mechanical agitation of the waste along with optimum composting conditions were sufficient to initiate the rapid degradation of the starch–CaCO₃ composites. Degradation of starch–CaCO₃ containers did not affect compost nutrient and trace element content. Grass biomass measurements were performed once weekly over 28 days for grass grown in control (0%), 5%, and 20% starch–CaCO₃-containing compost:soil mixtures. Significant differences in grass biomass for these compost:soil mixtures were measured only for the 0 and 20% starch–CaCO₃-containing compost:soil mixtures at 28 days (9.07 vs 11.05 g, respectively; P = 0.046).     

烟气脱硫过程锰催化氧化亚硫酸钙的研究

利用直径280 mm、高320 mm的间歇式搅拌槽,在MnSO4加入浓度为0～0.05 mol/L的情况下,对亚硫酸钙悬浮液进行了催化氧化实验研究.实验结果表明,锰离子的加入会改变亚硫酸钙的氧化机理及氧化过程,表现为终点氧化率和氧化速率的变化.当Mn2 浓度为0.05 mol/L时,亚硫酸钙的终点氧化率比未加入Mn2 时高30%;此外,与非催化反应过程相比,Mn2 的加入能使亚硫酸钙在一个更宽的浓度范围内(0.02～0.073 mol/L)和一个更宽的时间范围内(20～100 min)均保持较高的氧化速率水平.     

机械工业废水中重金属离子的处理工艺研究

研究了过氧化钙处理剂对机械工业废水中重金属离子锰、铜、锌、铬的处理工艺，以及过滤方法对重金属离子去除率的影响。处理的最佳条件为：过氧化钙用量0．1％～0．2％，处理时间30min，处理温度为室温，处理过程中不需调整pH。     

薄膜级碳酸钙可焚烧母料的环保性能的探讨

采用 12 5 0目以上的碳酸钙填充料、铝酸酯偶联剂、焚烧热氧降解剂、生物活性剂等助剂制备的可焚烧PE母料 ,吹制成购物袋和垃圾袋。经人工加速老化实验、户外曝晒实验后 ,用红外光谱、高效液相色谱、热 红联用仪等对其综合环保性能进行表征 ,实验结果表明 ,该薄膜适应于垃圾的焚烧处理 ,特别是对促进塑料的快速完全燃烧和降低尾气中有害气体的含量 ,具有积极的意义 ,可用于装盛焚烧发电垃圾     

制浆废液降低普钙水分的应用研究

针对我国采用高临界流动水分的磷矿进行湿法生产普钙普遍存在产品水分达不到部颁标准的难题,直接采用制浆废液（利用其主要对环境有害成分之一——MNA作减水剂）进行降低普钙水分的研究和应用.实验结果表明,添加少量的减水剂MNA可显著降低国内朝阳、昆阳、浏阳和国外摩洛哥等单种磷矿以及昆阳-朝阳混矿的矿浆粘度和水分.采用国产昆阳-朝阳混矿进行工业生产试验结果表明,添加0.35%～0.4%干矿粉重量的减水剂MNA,不仅可使球磨添加水量从145 kg降至103 kg,矿浆含水量从30.5%降至27%,成品肥含水量从16.24%降至13.77%,而且可使有效磷从10.67%升至12.24%,转化率由86.57%提高到90.45%,矿浆细度由90.18%提高到93.12%.实验和工业生产试验表明,直接用造纸制浆废液降低普钙水分,既确保和改善了普钙的产品质量,又治理了环境污染,取得了较好的经济、环境和社会效益.