海洋沉积磷的减少与冰期大气CO2降低的联系

从南海北部陆坡沉积物中提取的有关磷的环境与生物地球化学信息显示, 陆源磷对海洋的供应量是基本恒定的, 不同深度磷含量的变化是受气候和环境变化影响的结果. 根据沉积物中磷与碳酸钙、Cd含量随深度变化的趋势相反, 以及通过化学平衡计算得到的海水中CO₂与PO₄^3−的消长关系, 表明了海洋沉积磷的积累与大气CO₂的变化相关联, 沉积磷的积累量减少和碳酸钙含量增加, 可能是导致冰期大气CO₂浓度降低的一个关键性因素.     

渭北东部奥陶灰岩地下水硫酸盐起源的化学同位素研究

通过对渭北东部奥陶灰岩地下水中SO42-、δD、δ34S、δ18O的分析研究,认为奥陶灰岩地下水中硫酸盐起源主要为海相硫酸盐的溶解,其次为南部古沉积咸水混入.     

山东新泰太古代层状硫化物中的硫同位素非质量分馏效应

物理、化学和生物作用引起的热力学和巩俐学同位素分馏均为与质量有关的分馏。非质量同位素分馏效应应是由一些特殊的气相光化学反应引起的，它可以解释一些元素浓度，甚至单个同位素比值无法揭示的特殊的作用过程。笔者首次在山东新泰地区新太古代层状硫化物中观测到了明显的硫同位素非质量分馏效应。δ33S、δ34S呈线性排列，且与硫同位素质量分馏线平行，33S小于0。     

新疆库鲁克塔格地区早寒武世磷质岩的形成条件

根据地层层序与岩石学特征,对新疆库鲁克塔格地区下寒武统西山布拉克组磷质岩的形成环境,物质来源和形成机理进行了分析。认为本区磷质岩形成于从浪基面附近至氧化界面附近一个较宽泛的环境带中,具有热液和生物两个方面的物质来源。来自火山和生物的含磷物质由上升洋流带至沉积地点经化学沉淀形成磷质岩。而后又经历了水流与波浪的作用,以及重力产生的滑塌事件的改造。西山布拉克组沉积时期经历了三次海平面的升降变化,磷质岩是早期海平面变化的产物。沉积过程发生在高级别的海侵背景之下。     

Influence factors of phosphorus variation regularity in sediment-water system

Knowledge of phosphorus （P） variation regularity of sediment-water system has important influence on water pollution. Thus P variation regularity of top-sediment affected by some factors such as type of sediment （sandy and silty）, background value of sediment, P concentration of overlaying water, inhibiter, disinfection, was investigated. The results stated that, （1） P in the sandy sediment occurred mainly in the form of insoluble P. Silty sediment with a low background level has higher dissoluble total phosphorus （DTP） content than silty sediment with a high background level. （2） Low-P primary liquid has low TP and DTP contents, TP in the overlying water was rich in DTP. While TP in overlying water of high P primary liquid was rich in insoluble total phosphorus （ITP）. Overlying water of adding inhibitor set has high TP, dominated by ITP. TP in overlying water of no inhibitor set was dominated by DTP. Adding inhibitor set has obviously high pH value and tallish DO concentration in overlying water than in no inhibitor set. Disinfection set has high Pcontent in overlying water, DTP content is high. DO and ORP in overlying water of non-disinfection set were obviously higher than in that disinfection set.     

Eutrophication study at the Panjiakou-Daheiting Reservoir system, northern Hebei Province, People＇s Republic of China： Chlorophyll-a model and external and internal sources of phosphorus and nitrogen

Concentrations and loads of nitrate and total phosphorus and the sources of these two nutrients were investigated at the Panjiakou and Daheiting Reservoir system in northern Hebei Province, the People＇s Republic of China. The Luanhe River is the primary source of water to these reservoirs. The response of the reservoir system from the phosphorus loading, with respect to chlorophyll-a production from algae, was fitted to a model of normalized phosphorus loading which regresses the average summer-time chlorophyll-a concentration to the average annual phosphorus concentration of the reservoir. The reservoirs have a primary use for drinking water and partially supplies the city of Tianjin with its annual supply, but secondary uses include flood control and aqua culture （fish cages）. Comparison of the normalized phosphorus loading and chlorophyll-a response of this system to other reservoirs throughout the world from similar studies indicates an elevated level of eutrophication, which will require an approximate 10-fold decrease in phosphorus load reduction to bring the system to a more acceptable level of algal productivity. Isotopes of nitrogen and oxygen in dissolved nitrate were measured from the headwater streams and at various locations along the major river system that provides the majority of water to this reservoir, and within the two reservoirs.     

The treatment of wastewaters with high phosphorous and high ammonia loadings using modified bauxite refinery residues

Bauxsol（TM） is a trade marked name for a modified bauxite refining residue where Ca and Mg are used to transform carbonate and hydroxide alkalinity from soluble to insoluble forms within the bauxite refinery residue （red mud）, This leads to a pH reduction from 〉13 to ≈8.5 and reduces soluble Al and Na contents. The concentration ratios of Ca and Mg in the treatment brine can be manipulated to provide neo-formational mineral assemblages dominated by either Mg, or Ca end members; hydrotalcite and brucite （Mg-rich）, or hydrocalumite, para-aluminohydrocalcite, aragonite and portlandite （Ca-rich）. The Bauxsol（TM） raw material （BRM） has excellent metal binding capacity （〉1500 meq/kg）, good P binding capacity （〉2% by mass） and a good acid neutralising capacity （3.5-7 M/kg）, however the BRM can be further blended with other mineral additives to enhance the geochemical properties and improve specific performance. This paper reports on the use of a high-Mg Bauxsol（TM） blend to treat waters that have high P, NH4＋ and polyacrylamide （flocculant） loadings in Biological Nutrient Reduction （BNR） plant digested sewage sludge centrates. Initial analysis of the centrate indicated it contained 325 mg/L total-P （225 mg/L P as ortho-P）, 767 mg/L N as NH4^＋, suspended solids loads （TSS） of 683 mg/L and chemical oxygen demand （COD） of 480 mg/L （although the day to day variability in nutrient loadings can be as much as 25%）. This was then treated using 1.7 g/L of a high-Mg Bauxsol （TM） blend to yield a water with 〈1.8 mg/L total-P （ortho-P is 〈0.5 mg/L）, NH4^＋ 〈460 mg/L N, 〈60 mg/L TSS, and 〈300 mg/L COD. Small additions of ferric chloride post Bauxsol （TM） addition reduced the soluble ortho-P load by about 50% and about 30% of the COD, but these additions appear largely unnecessary. Analysis of the solid residue indicates it contains 11.5% P, 0.39% N, 21% Mg, and 2.44% crude protein making the solid residue a potentially useful fertilizer. It is likely that P and NH4^＋ is affected by the formation of MgHPO4 and Mg （NH4）PO4 （Struvite） within the solids. Calculations from the solids indicate that 85% of the P removal is as MgHPO4, which appears consistent with literature on the formation geochemistry of struvite around pH 8.0. Further manipulation of the geochemistry of waters and kinetics of crystal growth may allow for a greater struvite recovery, and further enhanced ammonia removal. The treated centrate is then reported back to the head of works and solids are removed with the sludge at the primary and secondary clarifier.     

Seasonal variations of adsorption/desorption equilibrium concentrations of P at water-sediment interface in the Meiliang Bay, Taihu Lake, China

Seasonal variations of adsorption/desorption equilibrium were investigated by collecting overlying water and seasonal sediment from the Meiliang Bay, Taihu Lake, China. At the same time, seasonal variations of TP and P fractions＇ concentrations in the initial and end of adsorption experiment were also carried out. In addition, the effects of temperature on the P translocation process were also conducted and discussed. The following conclusions were obtained： The sequence of adsorption/desorption equilibrium concentrations of P at water-sediment interface was spring〈winter〈autumn. In sediment the concentrations of TP decline. Concentration P decreased with temperature.     

用改进的增量方法计算硫化物中硫的同位素分馏系数

增量方法已成功地应用到硅酸盐矿物、金属氧化物、碳酸盐矿物和硫酸盐矿物氧同位素分馏系数的计算中。本文在对硫化物晶体结构与矿物学特点分析的基础上,通过详细分析前人对硅酸盐矿物和金属氧化物中氧同位素分馏的增量计算方法,将氧化物和硫化物的晶体特征加以对比,提出了计算硫化物中硫同位素分馏的增量计算方法。修正的增量方法根据硫化物的晶体化学结构特征,引入了一个重要的参数,即Madelung常数,用于指示不同结构的硫化物对~(34)S的富集能力。本文利用这一修正的增量方法计算出了0℃到1000℃温度范围内,磁黄铁矿、方铅矿、闪锌矿、黄铜矿、硫镉矿的10~3Inβ和它们之间的分馏系数10~3Inα。并给出这五种矿物间的~(34)S富集顺序：磁黄铁矿＞硫镉矿＞闪锌矿＞黄铜矿＞方铅矿。与前人的实验结果对比表明,本次计算结果与实验结果基本吻合。同时,增量计算方法成功地再现了任意硫化物中~(32)S、~(33)S、~(34)S和~(36)S这四种同位素之间确实存在一定的分馏比例关系。这说明尽管增量方法存在一定的局限性,但将其扩展到硫化物间硫同位素分馏的理论计算是可行的。