新型除磷混凝剂的研制与应用＊

实验以处理金属表面所产生的磷化废水为研究对象,系统地分析了在新型混凝剂的使用过程中,pH值、温度、石灰投入量、沉降时间、助剂A等因素对脱磷效果的影响。结果表明,含磷量为18mg/L、COD为300mg/L、SS为150mg/L、pH值为5.7～6.5的废水,石灰投入量为300mg/L、沉降时间为10min左右、温度为25℃、pH值调节至9.0、加入5mL助剂A处理后,废水中磷含量为0.25～0.35mg/L、COD为80mg/L、SS为60mg/L,满足《污水综合排放标准》(GB8978—1996)中的一级标准。     

环评有效性问题的制度思考

从我国环评的现状出发,探讨了我国环评在环评启动时间、建设项目分类环境管理、建设项目环境影响评价分级审批、环评报告内容和结论、公众参与等方面存在的问题,提出了明确环评启动时间、环评报告审批与稽查分离、环评机构和环评工程师市场化、提高公众参与的专业化程度的制度性建议。     

PCDDs/PCDFs and PCBs in water samples from the Three Gorge Reservoir

The Three Gorge Reservoir (TGR) is the largest reservoir in China and its water quality is an important health concern, we have determined the concentrations of PCDDs/PCDFs and PCBs in the water samples collected at three seasons: August 2004, January 2005 and August 2005. The results showed that the average WHO-TEQ of total dioxins-like compounds (PCDDs/PCDFs+PCBs) was 0.06558 pg l(-1), ranged from 0.0008 to 0.32439 pg l(-1), which are much lower than other reported water sources. The main dioxins (PCDDs/PCDFs) are hepta- and octa-chlorinated dibenzo-p-dioxins (CDDs) and chlorinated dibenzofurans (CDFs). Since the levels of dioxins may change after the last water-store stage, the present study provides important data to compare the water quality in the TGR in the future.     

Concentration statistics for mixing-controlled reactive transport in random heterogeneous media

Uncertainty in the distribution of hydraulic parameters leads to uncertainty in flow and reactive transport. Traditional stochastic analysis of solute transport in heterogeneous media has focused on the ensemble mean of conservative-tracer concentration. Studies in the past years have shown that the mean concentration often is associated with a high variance. Because the range of possible concentration values is bounded, a high variance implies high probability weights on the extreme values. In certain cases of mixing-controlled reactive transport, concentrations of conservative tracers, denoted mixing ratios, can be mapped to those of constituents that react with each other upon mixing. This facilitates mapping entire statistical distributions from mixing ratios to reactive-constituent concentrations. In perturbative approximations, only the mean and variance of the mixing-ratio distribution are used. We demonstrate that the second-order perturbative approximation leads to erroneous or even physically impossible estimates of mean reactive-constituent concentrations when the variance of the mixing ratio is high and the relationship between the mixing ratio and the reactive-constituent concentrations strongly deviates from a quadratic function. The latter might be the case in biokinetic reactions or in equilibrium reactions with small equilibrium constant in comparison to the range of reactive-constituent concentrations. When only the mean and variance of the mixing ratio is known, we recommend assuming a distribution that meets the known bounds of the mixing ratio, such as the beta distribution, and mapping the assumed distribution of the mixing ratio to the distributions of the reactive constituents.     

不同栽培基质对石山珍稀濒危植物苗期生长的影响

对 6种石山珍稀濒危植物在石灰岩土壤和酸性红壤上的苗期生长状况及体内化学元素含量进行了对比研究 ,结果表明 :(1 )每种植物在 2种土壤上的物候学特征基本一致 ;(2 )小花异裂菊和青檀在石灰岩土壤上生长量比酸性土壤上高 ,海南椴在酸性土壤上生长量比石灰岩土壤上高 ;(3 ) 6种植物体内Ca、B 2种化学元素的含量是石灰岩土上比酸性土上高 ;除小花异裂菊外 ,Al在其它 5种植物中的含量都是酸性土上高于石灰岩土上 ,小花异裂菊则是石灰岩土上高于酸性土上 ;(4 )K、Zn、B的生物吸收系数是石灰岩土高于酸性土 ,而N、P、Ca、Mg、Fe、Al、Mn则是酸性土高于石灰岩土。     

Evaluating Controlling Factors to Ali/(Ca + Mg) Molar Ratio in Acidic Soil Water, Southern and Southwestern China: Multivariate Approach

Al_i/(Ca + Mg) molar ratio in soil water has been used as an indicator to the effects of acid deposition on terrestrial ecosystems. However, the main factors controlling this ratio have not been well documented in southern and southwestern China. In this study, we presented the variation in inorganic aluminum (Al_i) and Al_i/(Ca + Mg) molar ratio in different sites and soil horizons based on two to three years monitoring data, and evaluated the main factors controlling Al_i/(Ca + Mg) molar ratio using principle component analysis (PCA) and partial least square (PLS) regression. Monitoring data showed although Al_i/(Ca + Mg) molar ratios in most soil water were lower than assumed critical 1.0, higher molar ratios were found in some soil water at TSP and LXH site. Besides acid loading, both soil properties and soil water chemistry affected the value of Al_i/(Ca + Mg) molar ratio in soil water. Partial least square (PLS) indicated that they had different relative importance in different soil horizons. In A-horizon, soil aluminum saturation (AlS) had higher influence on Al_i/(Ca + Mg) molar ratio than soil water chemistry did; higher soil aluminum saturation (AlS) led to higher Al_i/(Ca + Mg) molar ratio in soil water. In the deeper horizons (i.e., B₁-, B₂- and BC-horizon), inorganic aluminum (Al_i) in soil water had more and more important role in regulating Al_i/(Ca + Mg) molar ratio. On regional scale, soil aluminum saturation (AlS) as well as cation exchange capacity (CEC) was the dominant factor controlling Al_i/(Ca + Mg) molar ratio. This should be paid enough attention on when making regional acid rain control policy in China.     

Hydroxyl radical generation and oxidative stress in Carassius auratus liver as affected by 2,4,6-trichlorophenol

With Carassius auratus, one of the main economic fish species in Eastern China as test material, this paper studied the hydroxyl radical generation and oxidative stress in its liver under the effect of 2,4,6-trichlorophenol (2,4,6-TCP). Different doses of 2,4,6-TCP were injected intraperitoneally into the fishes, and the Electron paramagnetic resonance (EPR) spectra of hepatic free radicals, activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-s-transferase (GST), levels of reduced glutathione (GSH) and oxidized glutathione (GSSG), and malondialdehyde (MDA) contents were determined 24h after injection. The results showed that under the effects of 2,4,6-TCP, the generation of free radical that was considered to be hydroxyl radical increased significantly, the activities of antioxidant enzymes decreased, with CAT most strongly affected and followed by SOD and GST, the GSH level decreased significantly while GSSG level had little difference, resulting in a decreased GSH/GSSG ratio, and the MDA content increased significantly. All the test parameters showed that C. auratus was subjected to oxidative stress and damage when exposed to 2,4,6-TCP.     

生物可降解螯合剂[S,S]-乙二胺二琥珀酸和乳酸乙酯提取土壤中重金属的研究

研究了生物可降解的有机螯合剂[S,S]-乙二胺二琥珀酸([S,S]-EDDS,简写为EDDS)和乳酸乙酯(EL)对重金属污染土壤中重金属的提取效率,并用X射线衍射(XRD)和红外光谱(FT-IR)分析了螯合剂提取对土壤理化性质的影响.结果表明:EDDS对土壤中的Cd、Cu、Pb和Zn有较高的提取率,效果比EL好;EDDS和EL混合提取的重金属提取率增加,但相比单独使用EDDS没有超过10%.FT-IR分析表明,提取前后FT-IR谱图中特征吸收频率没有显著改变,但强度有所改变.XRD分析表明,提取前后土壤晶格结构发生明显的变化,螯合剂提取改变了土壤微观结构.     

三株白腐菌产锰过氧化物酶活性及其对多环芳烃的降解

比较研究了β-环糊精(β-CD)对3株黄孢原毛平革菌(Phanerochaete chrysosporium)CGMCC5.776、GIM3.383和GIM3.393产锰过氧化物酶(MnP)和降解多环芳烃(PAHs)的影响.结果表明:3株菌都能分泌出高活性的MnP,β-CD能显著提高MnP的活性.加入2.0 g/Lβ-CD的体系培养到第12天时.酶活性最高达到2 912.5 U/L;而且β-CD能显著提高PAHs的降解率,两者之间存在较好的相关性.加入1.0 g/L β-CD的体系对比不加β-CD的体系,PAHs的降解率提高了1～2倍.PAHs的降解同时受到MnP活性、PAHs表观溶解度和分子结构稳定性等因素的影响.     

NO催化氧化的初步研究

利用一套小型动态试验装置进行配气实验，分析了一系列金属氧化物对气体中低浓度ＮＯ转化率的催化活性顺序为Ｃｒ＞Ｆｅ＞Ｃｏ＞Ｍｎ＞Ｃｕ，并对其综合影响进行了分析。通过实验总结出适宜的反应条件及催化剂配方，为以后研究提供了重要的数据资料。