超声波/Fenton联用对对硝基苯酚的处理

采用超声/Fenton联用技术对水中对硝基苯酚(P-NP)进行处理,探讨了单纯超声(US)、Fenton试剂法、US/Fenton试剂法联用对P-NP的处理效果和影响因素,结果表明,对于浓度为10mg/L的P-NP, 当pH=3、H2O2与Fe2 投加量之比为10:1、H2O2投加量为40mg/L时降解效果最好,通过动力学分析发现US/Fenton试剂法对P-NP的降解具有明显的协同效应.     

Prenatal diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency by steroid analysis in the amniotic fluid of mid-pregnancy: Comparison with HLA typing in 17 pregnancies at risk for CAH

Amniotic fluid (AF) levels of 17-hydroxyprogesterone (17OHP) and testosterone (T) were determined at 16–17 weeks in 17 pregnancies at risk for CAH and results compared to 75 normal controls. The fetus was predicted to be unaffected in 12 cases on the findings of normal AF levels of both 17OHP and T and the latter allowed a correct prediction of fetal sex in all instances. HLA typing confirmed normality in 12 cases revealing 5 carriers, 5 homozygous normal and 2 indeterminate. Steroid levels of the 2 groups were similar. Three fetuses were predicted to be CAH affected on unambiguously high levels of 17OHP and T (in female only). HLA typing was in agreement, and the diagnosis was confirmed in 2 abortuses and a female newborn by physical and hormonal studies. In the last 2 cases AF levels of OHP and T were normal but HLA (A/B/C) genotypes were identical to the CAH affected siblings. Normal physical and hormonal findings in the 2 aborted fetuses would exclude the possibility of an in utero virilizing form of CAH. The discrepancy could be explained on the basis that the fetuses had an allelic form of 21-hydroxylase deficiency or on the basis of recombination (not fully tested). It is concluded that a fully informative prenatal diagnosis of CAH should not rely entirely on HLA typing but on hormonal studies.     

Insights into the mechanism of the deterioration of mainstream partial nitritation/anammox under low residual ammonium

Residual ammonium is a critical parameter affecting the stability of mainstream partial nitritation/anammox (PN/A), but the underlying mechanism remains unclear. In this study, mainstream PN/A was established and operated with progressively decreasing residual ammonium. PN/A deteriorated as the residual ammonium decreased to below 5 mg/L, and this was paralleled by a significant loss in anammox activity in situ and an increasing nitrite oxidation rate. Further analysis revealed that the low-ammonium condition directly decreased anammox activity in situ via two distinct mechanisms. First, anammox bacteria were located in the inner layer of the granular sludge, and thus were disadvantageous when competing for ammonium with ammonium-oxidizing bacteria (AOB) in the outer layer. Second, the complete ammonia oxidizer (comammox) was enriched at low residual ammonium concentrations because of its high ammonium affinity. Both AOB and comammox presented kinetic advantages over anammox bacteria. At high residual ammonium concentrations, nitrite-oxidizing bacteria (NOB) were effectively suppressed, even when their maximum activity was high due to competition for nitrite with anammox bacteria. At low residual ammonium concentrations, the decrease in anammox activity in situ led to an increase in nitrite availability for nitrite oxidation, facilitating the activation of NOB despite the dissolved oxygen limitation (0.15–0.35 mg/L) for NOB persisting throughout the operation. Therefore, the deterioration of mainstream PN/A at low residual ammonium was primarily triggered by a decline in anammox activity in situ. This study provides novel insights into the optimized design of mainstream PN/As in engineering applications.     

分光光度法测定水样中铬

在ｐＨ４．４ＨＡＣ－ＮａＡｃ缓冲介质及乳化剂ＯＰ存在下，Ｃｒ６＋与二溴羟基苯基荧光酮（ＤＢＨＰＦ）显色反应生成桔红色络合物．该络合物最大吸收位于４８２ｎｍ波长处，表现摩尔吸光系数εｍａｘ＝３．４７×１０４．络合物配位比为Ｃｒ６＋：ＤＢＨＰＦ＝２：３，Ｃｒ６＋在０－１６μｇ／２５ｍＬ范围内遵守比耳定律．方法已用于水样中微量铬的测定，结果满意．     

江宁开发区污水处理厂二期调试运行

江宁开发区污水处理厂建设规模为4万m^3／d，分两期建成，采用氧化沟处理工艺，污泥处理采用不经消化的带式脱水工艺。在此主要叙述了各工艺构筑物的设备配置、功能、设计参数及二期工程的试运行情况。     

金堆城超大型钼矿床水-岩δD-δ~(18)O同位素交换体系理论模型及成矿流体来源

基于水-岩δD-δ18O同位素交换体系理论模型的建立和计算，对金堆城超大型斑岩钼矿四个不同成矿期中成矿流体的演化和来源进行了研究，发现在成矿前期和早期，成矿流体为岩浆水与围岩在较低水／岩比值（0．1W／R＞0．001）和中、高温（t=250～500℃）条件下反应后的残余流体，而主成矿期和成矿晚期的成矿流作为大气降水在相对较高水／岩比值（0．5＞W／R0．1）和中、低温（t＝150～310℃）条件下与围岩反应后的残留流体。大气降水在金堆城钼矿成矿过程中起了重要作用。在主成矿期水／岩比值达到最高。     

南太平洋社会群岛塔希提岛(TAHITI)火山岩——一种典型的大洋岛屿玄武岩

塔希提岛火山岩属典型的大洋岛屿玄武岩(OIB)。该岛是法属波利尼西亚群岛中社会群岛链之一部分,火山活动可分三期:早期(1.7—1.3Ma),中期(1.3—0.6Ma)和晚期(0.6—0.3Ma)。早期火山岩兼有碱性和拉斑系列岩石,包括苦橄玄武岩、碱性玄武岩、拉斑玄武岩及少量玄武安山岩;中期火山岩主要有粗面玄武岩—粗面岩、碱性玄武岩和少量碧玄岩;晚期则以碧玄岩为主,并有部分碱玄岩出现。火山岩的这种岩性变化表明其岩浆由早到晚从富镁、硅弱不饱和向富碱和硅强烈不饱和演化。 社会群岛火山链的火山活动以平均11cm/a的速率从西北向东南迁移,与MORB相比,所有塔希提的岩石皆富大离子亲石元素并有较高的~(87)Sr/~(66)Sr比值,这一特征可能与其特殊的源区成分有关,即富集的地幔热柱或大洋岩石圈。早期岩石是地幔热柱和少量洋壳的部分熔融产物的混合体,故既有拉斑系列又有碱性系列。随着火山活动远离存在热柱的热点区域,洋壳部分熔融的程度逐渐降低,因而其产生的熔融体也越来越富碱,~(87)Sr/~(66)Sr比值也相应有所降低。     

几种重金属对紫背萍过氧化氢酶活性的影响

通过测定被暴露植物分解过氧化氢后放出氧气的体积，确定紫背萍过氧化氢酶（ＣＡＴ）的活性。结果表明，紫背萍暴露在Ｈｇ、Ｐｂ、Ｃｒ、Ｎｉ、Ｆｅ的溶液中，其ＣＡＴ活性除在Ｐｂ作用下明显降低外，在其它４种重金属的作用下都有不同程度的升高。这表明Ｐｂ对紫背萍 ＣＡＴ活性有抑制作用，而其它４种重金属对紫背萍ＣＡＴ均有刺激作用。紫背萍对５种重金属所表现出来的这种生态效应，是重金属水污染的植物潜在效应，植物的ＣＡＴ     

磺酰脲类除草剂的残留分析

磺酰脲类除草剂是一类新型超高效除草剂，大约包括２Ｖ化合物，已被广泛用于禾谷作物防除阔叶杂草以及某些禾本科杂草，该类除草剂在环境中的残留浓度〈１μｇ．ｋｇ＾－１水平。常规的分析方法包括生物鉴定，酶免疫分析，气相色谱法和高效液相色谱法（ＨＰＬＣ）、ＨＰＬＣ／ＭＳ联用后，可以准确测定复杂环境样中磺酰脲类除草剂的痕量残留。     

县级生态农业建设的人工神经网络模型

引入人工神经网络的评价识别方法，建立了ＢＰ模型，以前人建立的县级生态农业建设评价指标体系评价标准，和某县生态农业综合评价指标数据为实例，比较ＢＰ模型的有效性，得到的评价分类结果和指标优先发展顺序决策与实际情况相吻合。