Ammonium removal from waste solutions by precipitation of MgNH4PO4 I. Ammonium removal with use of commercial reagents

The method of ammonium ion removal from industrial waste solutions was investigated and parameters for MgNH₄PO₄ precipitation were determined. A solution laden with NH₄⁺ ions was brought to pH 1–2 by the use of H₃PO₄; MgO was then added and the pH adjusted to 9–10 with the use of NaOH solution. Stirring of the suspension was carried out during a prolonged period of time ( 3 hours), with final filtration or sedimentation. By this method the ammonium ion content in the filtrate may be reduced to concentrations below 1 mg/l. The MgNH₄PO₄·6H₂O sediment produced is considered to be a long-term fertilizer, suitable for agricultural use.     

芳烃联合装置地下管线测漏处理过程的风险分析

运用预先危险性分析法(PHA),对芳烃联合装置地下管线测漏处理过程中存在的风险进行了分析,确定了应采取的安全措施,取得了明显效果.     

中国自然灾害和减灾的对策

2006年5月9日防灾科技学院揭牌暨建校30周年庆典之际,马宗晋院士应邀为我校师生作了题为“中国自然灾害和减灾的对策”的学术报告,受到全校师生的热烈欢迎和一致好评。马宗晋院士是我国著名的地质学家,曾担任中国地震局地质研究所所长（现为中国地震局地质研究所名誉所长）,长期从事地质构造、地震预报、地球动力学方面的研究工作,完成了多项国家级重大研究课题。1972年,他率领地震小组,首创渐进式预报模式,提出长中短临渐近蕴震模式,成为中国预报强震的主要思想和工作程序,该模式的预报思想一直影响至今。其间,对海城、松潘等大地震的预测,乃至对唐山大地震的中期估计和短期预报分析都有重要影响,该模式在国际上被誉为“中国式地震预报”;他还提出了地球动力学的模式构想,建立了三个全球的构造系统,论证了地球变动的韵律性和非对称性,从而提出以壳、幔、核细分层角差运动为基础的地球自转与热、重、流联合的动力模式构想,对全球构造动力模式进行了新的分析与综合,为灾害和矿产研究提供了部分基础;提出了综合减灾系统工程设计。马宗晋院士1995年兼任国务院三部委中国重大自然灾害综合研究组组长;2005年任国家减灾委专家委员会主任。 马宗晋院士的报告以大量的研究数据系统地论述了中国的自然灾害和减灾的对策。我国是一个灾害频发、灾种繁多、灾情严重、经济损失巨大的国家,很好的学习和掌握马宗晋院士报告的观点和精神,对于推进我国的防灾减灾事业和从事防灾减灾教育事业均具有十分重要的意义。 我学报编辑部在认真学习和整理马宗晋院士报告的基础上,决定在学报的“院士专家论谈”专题栏目,陆续刊载以“中国自然灾害和减灾的对策”为题的系列文章,并经马院士同意和审核,马智同志编辑整理。我们认为,这对于全国各地从事防灾减灾事业的部门和工作人员,是十分有帮助的。希望各地从事防灾减灾事业和其他工作的读者能够关注这个栏目。[编者按]     

Heavy metals in zooplankton from the Southern Baltic

Samples of zooplankton and suspended matter were collected using a Bongo net (0.33/0.50 mm mesh net), and Nucleopore filters, respectively, from the Southern Baltic off Poland. Major classes of zooplankton, and selected heavy metals (Fe, Co, Ni, Mn, Pb, Cd, Cu, Zn, Cr) were determined in the collected samples. Concentrations of heavy metals in zooplankton were corrected for metals contributed by particulate matter adhering to zooplankton organisms. Heavy metals levels measured in nearshore samples (Bay of Gdańsk, Pomeranian Bay) were higher than those in the samples from the open sea. The only exception was cadmium exhibiting larger concentrations in the offshore as compared to the nearshore samples (0.8 vs. 1.3 microg/g d.w.). This was attributed to decreased concentrations, of both dissolved and particulate cadmium, caused by algal bloom. Larger concentrations of heavy metals in the Bay of Gdańsk in comparison with the Pomeranian Bay (e.g. Cd-1.3 vs. 0.8 microg/g, Cu-20.5 vs. 8.3 microg/g, Pb-12.9 vs. 1.2 microg/g, Cr-12.4 vs. 1.4 microg/g) were attributed to the direct discharge of the Vistula river to the Bay of Gdańsk, while the Pomeranian Bay receives the Odra river runoff indirectly, via the Szczecin Lagoon. The nonlinear estimation of the data set was used to evaluate concentrations of heavy metals in Copepoda and Cladocera. Copepoda proved to be enriched with heavy metals in comparison with Cladocera.     

Polycyclic aromatic hydrocarbons (PAHs) in the aerosol in Beijing, China, measured by aminopropylsilane chemically-bonded stationary-phase column chromatography and HPLC/fluorescence detection

We developed a useful analytical method for the determination of polycyclic aromatic hydrocarbons (PAH) concentrations in the aerosol of China. We used an accelerated solvent extraction (ASE) method for the extraction of PAHs from the aerosol samples, in order to reduce the extraction time and the solvent volume used. The optimum purification method was developed, with aminopropylsilane chemically-bonded stationary-phase column chromatography, in order to remove many co-extractives which cannot be removed by conventional purification methods using silica-gel column chromatography. HPLC/fluorescence detection (FLD) was adopted as the analytical method, because it has very high sensitivity to PAH and it is easy to install, operate, and maintain as compared with GC/MS. With the analytical method developed in this study, the recovery and precision (RSD) for most of the PAHs ranged from 75% to 129% and from 2.8% to 22.7%, respectively. The concentrations of PAHs in the aerosol samples collected from October 2003 to April 2005 in Beijing, China were determined using the newly developed method. SigmaPAHs, which is the sum of the concentrations of all detected PAHs, was 177.8 +/- 239.9 ng m(-3) (n = 64). The SigmaPAHs concentration in the heating season (305.1 +/- 279.0 ng m(-3), n = 33) was 7.2 times higher than that in the non-heating season (42.3 +/- 32.0 ng m(-3), n = 31). These strong seasonal variations in atmospheric PAH concentration are possibly due to coal combustion for residential heating in winter.     

Methods for the preparation of a biodesulfurization biocatalyst using Rhodococcus sp

Several methods to prepare a biodesulfurization (BDS) biocatalyst were investigated in this study using a strain of Rhodococcus sp. 1awq. This bacterium could selectively remove sulfur from dibenzothiophene (DBT) via the "4S" pathway. DBT, dimethylsulfoxide (DMSO), sodium sulphate and mixed sulfur sources were used to study their influence on cell density, desulfurization activity, desulfurization ability, and the cost of biocatalyst production. In contrast to that observed from bacteria cultured in DBT, only partial desulfurization activity of strain 1awq was induced by DBT after cultivation in a medium containing inorganic sulfur as the sole sulfur source. The biocatalyst, prepared from culture with mixed sulfur sources, was found to possess desulfurization activity. With DMSO as the sole sulfur source, the desulfurization activity was shown to be similar to that of bacteria incubated in medium with DBT as the sole sulfur source. The biocatalyst prepared by this method with the least cost could remove sulfur from hydrodesulfurization (HDS)-treated diesel oil efficiently, providing a total desulfurization percent of 78% and suggesting its cost-effective advantage.     

Arsenic chemistry in the rhizosphere of Pteris vittata L. and Nephrolepis exaltata L

This greenhouse experiment evaluated the influence of arsenic uptake by arsenic hyperaccumulator Pteris vittata L. and non-arsenic hyperaccumulator Nephrolepis exaltata L. on arsenic chemistry in bulk and rhizosphere soil. The plants were grown for 8 weeks in a rhizopot with a soil containing 105 mg kg(-1) arsenic. The soil arsenic was fractionated into five fractions with decreasing availability: non-specifically bound (N), specifically bound (S), amorphous hydrous-oxide bound (A), crystalline hydrous-oxide bound (C), and residual (R). P. vittata produced larger plant biomass (7.38 vs. 2.32 mg plant(-1)) and removed more arsenic (2.61 vs. 0.09 mg pot(-1) arsenic) than N. exaltata. Plant growth reduced water-soluble arsenic, and increased soil pH (P. vittata only) in the rhizosphere soil. P. vittata was more efficient than N. exaltata to access arsenic from all fractions (39-64% vs. 5-39% reduction). However, most of the arsenic taken up by both plants was from the A fraction (67-77%) in the rhizosphere soil, the most abundant (61.5%) instead of the most available (N fraction).     

Distribution and relationships between selected chemical elements in green alga Enteromorpha sp. from the southern Baltic

The concentrations of heavy metals (Cd, Cu, Ni, Pb, Zn and Mn) and macroelements (K, Na, Ca and Mg) were determined in green alga Enteromorpha sp. from the coastal zone of the southern Baltic including Gulf of Gdańsk and Vistula Lagoon in 2000-2003. In order to estimate the degree of accumulation of each element by the green alga, concentration and discrimination factors (CFs) with respect to seawater were calculated. The results of factor analysis (FA) and ANOVA clearly indicate geographical differences between concentrations of chemical elements. Enteromorpha sp. from Vistula Lagoon and the southern Baltic exhibited higher levels of Mn and Ni, and Na and K, respectively. Anthropogenic impact of Cu, Pb and Zn, possibly originated from municipal sewage, was identified in alga samples collected in the Gulf of Gdańsk, especially in the vicinity of Gdynia. From comparison our data with those published earlier results that Pb content in Enteromorpha sp. from the Gulf of Gdańsk decreased within 1978-2003 reflecting reducing use of leaded petrol in Baltic countries in this period. The alga Enteromorpha sp. can be used for biomonitoring surveys of metal contaminants in coastal areas of the Baltic Sea.     

应用重组孕激素基因酵母测定饮用水中内分泌干扰物的方法

研究了用重组孕激素受体基因酵母测定饮用水中内分泌干扰物的方法,并利用该种方法检测了南方某水厂不同处理工艺过程水样对孕激素受体活性的抑制水平.结果表明,重组孕激素受体基因酵母能够与孕激素专一性的结合,诱导产生明显的剂量-效应关系,EC₅₀值为0.5 nmol/L,具有较高灵敏度;环境内分泌干扰物五氯酚和壬基酚具有孕激素受体抑制活性,其IC₅₀值分别为2.4μmol/L和3.7μmol/L;重组孕激素受体基因/报道基因的酵母技术是一种筛选和定量分析具有孕激素受体抑制活性的内分泌干扰物的快速、有效方法.结合固相萃取的前处理技术,重组孕激素受体基因酵母对水厂不同处理工艺水样检测出明显的孕激素受体抑制活性,抑制率均大于58%,表明重组孕激素受体基因酵母检测技术能够快速监测和鉴别水样中具有抑制孕激素受体活性的物质.