不同条件下高炉渣吸附水中无机磷的研究

高炉渣(BFS)是在冶炼生铁过程中产生的固体废弃物,开展高炉渣的资源化研究具有重要意义.为了对水淬高炉渣净化含磷污水的应用提供理论依据,采取等温吸附的实验方法,比较了不同水淬炉渣的吸附磷效果,研究了不同pH和不同温度下水淬炉渣吸附磷的特点,结果如下:利用Langmuir等温吸附方程炉渣吸附磷的过程进行拟合,其相关系数均能达到显著水平.炉渣的碱度越高,吸附磷的效果越好;炉渣对磷的吸附能力随溶液pH的增加而降低,且初始为酸性(pH=2、4)的溶液在吸附达到平衡后pH有所上升,而初始为碱性的溶液(pH=10、12)在吸附达到平衡后pH有所下降;炉渣对磷的吸附是一个自发放热过程.     

太湖地区“禁磷”措施的效果及在富营养化控制中的作用

通过太湖地区采取“禁磷”措施前后城市生活污水、主要入湖河水和湖体水域中磷浓度与富营养化指数变化的分析 ,证实“禁磷”措施对降低居民生活污水中磷浓度的作用较为明显 ,降幅为 2 4 %左右 ,但对入湖河道和湖体水域中磷浓度与水体富营养化的影响则不明显。表明太湖富营养化的改善 ,除了实施“禁磷”措施外 ,尚需结合流域内其它污染治理措施 ,进行综合治理 ,才能取得较好的效果。     

Assessing stress response of Stylophora pistillata towards oil and phosphate pollution in the Gulf of Aqaba,using molecular and biochemical markers

Crude oil (from oil terminal) and raw phosphate (from phosphate port) pollution are responsible for the lowered health conditions of coral reefs at their vicinity in the Jordanian coast of the Gulf of Aqaba. Both in situ incubations and ex situ laboratory exposure experiments were used to study the effects of those pollutants on corals, by using molecular and biochemical biomarkers in the coral Stylophora pistillata. For ex situ part of the experiment, crude oil and raw phosphate were added to a final concentration of 500?ppm for both pollutants. The DNA damage was assessed by Comet assay, while biochemical stress markers were reassessed by lipid peroxidation (LPO) test. Although the corals looked healthy from outside, the use of stress biomarkers indicated that they are under high pressure at the cellular level. The corals incubated with oil and phosphate had more DNA damage and LPO in comparison with the control samples. The results obtained suggest that the use of stress biomarkers can be used as important prognostic tools for examining the sub-lethal stress on corals before their death.     

解磷微生物肥料的研究与进展

磷是植物生长必需的矿物质元素之一,在土壤中易被固定降低其有效性,目前,研究和生产含有解磷功能的微生物有机肥料是转化土壤中无效磷、提高磷肥利用率的有效途径之一。叙述了解磷微生物犯料中微生物的种类、生态分布规律和影响高效解磷微生物选育的外部因素,概述了解磷微生物菌肥的应用和研究进展,探讨了解磷微生物肥料的应用价值。为解磷微生物未来的研究重点提出理论依据。．     

碳酸根对磷酸钙沉淀反应回收磷的影响简

以模拟的厌氧消化液为处理对象,通过小试实验,考察不同初始磷浓度C_P、Ca/P物质的量比、pH和温度下,碳酸根（CO₃^2-）对磷酸钙沉淀反应回收磷的影响;利用扫描电镜（SEM）、X射线衍射仪（XRD）和傅里叶变换红外光谱（FTIR）对沉淀产物进行表征。结果表明,高浓度的CO₃^2-对以磷酸钙沉淀反应去除和回收磷的效率影响较大;C_P相同时,CO₃^2-浓度（C_CO3^2-）越大,P的去除率越低,低C_P（20 mg/L）时尤为显著;当C_CO3^2-相同时,随着C_P的增大,反应速率加快,P的去除率逐渐升高,但升高幅度越来越小;增大Ca/P比和pH能提高P的去除率,降低CO₃^2-对磷酸钙沉淀反应的抑制作用,综合考虑实际效果,应选择Ca/P比为3.33,pH为9.0作为适宜的反应条件;升高温度对降低CO₃^2-对磷酸钙沉淀反应的抑制作用贡献不大。在C_P为60 mg/L,Ca/P比为1.67,pH为9.0,温度为20℃的条件下,当C _CO3^2-为0时,得到的沉淀产物主要为羟基磷灰石HAP;当C _CO3^2-为30 mmol/L时,得到的沉淀产物为磷酸钙和碳酸合磷灰石的混合物。     

利用白云石石灰去除与回收污泥厌氧消化液中氮和磷

以白云石石灰为实验材料去除与回收污泥厌氧消化液中的氮磷,通过小试实验研究不同投药固液比S/L、初始pH值、反应温度、搅拌速度及反应时间对去除与回收氮磷效果的影响。实验结果表明,在最佳投药固液比S/L为300mg/L,最佳初始pH值范围为8.5~9.5,反应温度为25.0℃,搅拌速度为150 r/min,反应时间为24 h条件下,氨氮(NH+4-N)和磷(PO3-4-P)的去除率分别为37.26%和89.60%。利用X射线衍射仪(XRD)、扫描电镜(SEM)对沉淀产物进行了表征,通过分析可知沉淀产物中含有磷酸铵镁(MAP),可实现废水中氮磷经济有效的回收。     

不同载体对淀粉酶固定化的比较研究

采用海藻酸钠微胶囊法和壳聚糖交联法对淀粉酶进行固定化,比较两种淀粉酶固定化方法的优劣。结果表明,两种固定化酶的活力回收分别为33．2％、26．6％,比活力分别为27．1U／mg蛋白、24．2U／mg蛋白,最适pH分别为5．0、8．0。海藻酸钠微胶囊法热稳定性、pH稳定性、操作稳定性、贮存稳定性明显高于壳聚糖交联法,因此海藻酸钠微胶囊法较佳,具有一定应用价值。     

Subcellular distribution and toxicity of cadmium in Potamogeton crispus L

The submerged macrophyte Potamogeton crispus L. was subjected to varying doses of cadmium (0, 20, 40, 60 and 80 μM) for 7 d, and the plants were analyzed for subcellular distribution of Cd, accumulation of mineral nutrients, photosynthesis, oxidative stress, protein content, and ultrastructural distribution of calcium (Ca). Leaf fractionation by differential centrifugation indicated that 48-69% of Cd was accumulated in the cell wall. At all doses of Cd, the levels of Ca and B rose and the level of Mn fell; the levels of Fe, Mg, Zn, Cu, Mo, and P rose initially only to decline later. Exposure to Cd caused oxidative stress as evident by increased content of malondialdehyde and decreased contents of chlorophyll and protein. Photosynthetic efficiency, as indicated by the quenching of chlorophyll a fluorescence (Fv/Fm, Fo and Fm), decreased significantly, the extent of decrease being directly proportional to the concentration of Cd. Increased amounts of precipitates of calcium were noticed in the treated plants, located either outside the cell membrane or in chloroplasts, mitochondria, the nucleus, and the cytoplasm whereas control plants showed small deposits of the precipitates around surface of the vacuole membrane and in the intercellular space but rarely in the cytoplasm. Photosynthetic efficiency and oxidative stress could be used as indicators of physiological end-points in determining the extent of Cd phytotoxicity.     

Extraction of raw sewage sludge containing iron phosphate for phosphorus recovery

The objective of the present study was to establish an alkali extraction technology for FePO₄-containing sewage sludge obtained from a wastewater treatment system that includes phosphorous removal by iron electrolysis. By clarifying the extraction properties of phosphorous, organic matter, and inorganic matter, conditions for alkali extraction were optimized. As a result, it was suggested that unheated phosphorous extraction would be superior for FePO₄-containing sewage sludge. And, extraction methods and sewage sludge properties were also compared, and the noteworthy result that extraction of metals can be suppressed to extremely low amounts with alkali extraction as compared with acid extraction was obtained. A new insight was also gained that, as compared with the use of incinerated ash reported in previous studies, alkali extraction was more efficient when raw sewage sludge was used.     

磷酸铵镁沉淀法预处理垃圾渗滤液

探讨了用磷酸铵镁沉淀法预处理垃圾渗滤液时,沉淀剂种类、pH值、物质摩尔配比和反应时间等因素对氨氮去除效果的影响。得出了处理氨氮浓度为2 677.34 mg/L的垃圾渗滤液时,在兼顾所用镁盐量尽量低和处理出水氨氮或磷酸盐的残留量都比较低的较佳实验条件为:沉淀剂种类为:MgSO4.7H2O和Na2HPO4.12H2O,反应时间为20 min,pH=9.5,n(Mg)∶n(P)∶n(N)=1.3∶1.15∶1.0。在较佳实验条件下,垃圾渗滤液的NH3-N去除率为97.05%,处理出水PO34--P含量为8.35 mg/L,NH3-N含量为75.86 mg/L。对所得沉淀物进行了成分分析和X-衍射光谱、扫描电镜表征,表明大部分沉淀物为磷酸铵镁物质。