湿法变相静电分离净化工艺对烟气脱硫除尘效果研究

通过湿法喷淋使锅炉烟气中的SO2等气体污染物被石灰水吸收而转入液相,再利用高压静电分离进一步去除烟气中的含硫雾滴及细尘粒等,是一种新型的高效脱硫除尘工艺。实验研究结果表明,在石灰水中Ca(OH)2含量为0.90%,石灰水用量为0.4 t/h的条件下的脱硫效率可达99%;湿式静电分离的电压对除尘效率具有显著影响,随着电压升高,除尘效率呈明显增大趋势。     

Bioelectrochemical acidolysis of magnesia to induce struvite crystallization for recovering phosphorus from aqueous solution

A novel struvite crystallization method induced by bioelectrochemical acidolysis of magnesia(MgO) was investigated to recover phosphorus(P) from aqueous solution using a dual-chamber microbial electrolysis cell(DMEC). Magnesium ion(Mg~(2+)) in the anolyte was firstly confirmed to automatically migrate from the anode chamber to the cathode chamber, and then react with ammonium(NH+4) and phosphate(PO_4~(3-)) in the catholyte to form struvite. Recovery efficiency of 17.8%–60.2% was obtained with the various N/P ratios in the catholyte. When MgO(low solubility under alkali conditions) was added into the anolyte, the bioelectrochemical acidolysis of MgO naturally took place and the released Mg~(2+)induced struvite crystallization in the cathode chamber for P recovery likewise.Besides, there was a strong linear positive correlation between the recovery efficiency and the MgO dosage(R~2= 0.935), applied voltage(R~2= 0.969) and N/P ratio(R~2= 0.905). Increasing the applied voltage was found to enhance the P recovery via promoting the MgO acidolysis and the released Mg~(2+)migration, while increasing the N/P ratio in the catholyte enhanced the P recovery via promoting the struvite crystallization. Moreover, the electrochemical performance of the system was promoted due to more stable anolyte pH and lower pH gradient between the two chambers. Current density was promoted by 10%, while the COD removal efficiency was improved from 78.2% to 91.8% in the anode chamber.     

磷酸二氢钾-磷酸氢二钠缓冲溶液调控下白菜对钼矿区重金属污染土壤的修复

取同质钼矿区土壤放于通风处自然风干,平行A、B两组盆栽实验。A组直接投放不同浓度的磷酸二氢钾-磷酸氢二钠缓冲溶液50 ml,B组做对照,种植白菜,待白菜生长50 d后再投加一次缓冲溶液50 ml,60 d后收割其地上部分及对应土壤进行消解。采用ICP-AES分析土壤及植物体中各种重金属元素的含量,研究了在磷酸二氢钾-磷酸氢二钠缓冲溶液在其不同浓度梯度下投加,白菜地上部分对钼矿区重金属污染土壤的修复潜力。结果表明：在投加磷酸二氢钾-磷酸氢二钠缓冲溶液的条件下均能显著提高白菜的地上部分富集土壤中重金属元素的能力（Cd除外）,但缓冲溶液对白菜积累重金属能力的促进作用也存在重金属元素种类及浓度梯度之间的差异;投加pH=7.3磷酸二氢钾-磷酸氢二钠缓冲溶液可以较好地去除钼矿区污染土壤中的Cr、Mo、Ni、Pb;投加pH=7.7磷酸二氢钾-磷酸氢二钠缓冲溶液可以较好地去除钼矿区污染土壤中的As、Cu、Hg、Zn。     

河口有机物在固-液界面迁移转化研究进展

河口复杂的水动力条件和丰富的泥沙含量,使得河口水体中固-液界面过程成为控制河口有机物迁移转化的关键环节.本文总结了有机物固-液界面吸附机理以及河口区有机物在悬浮物-水界面、沉积物-水界面的迁移转化,并对今后研究工作提出几点看法.     

固化污泥中Cu、Zn形态的转化及对浸出毒性的影响

污泥经过固化处理后,能稳定其中的重金属,降低其浸出毒性,减少对环境的二次污染。但固化污泥中重金属的潜在毒性与其形态有着紧密的联系,仅仅通过浸出毒性指标不能全面反映固化污泥中重金属的潜在污染。通过Tessier五步浸提法分析污泥固化前后、不同固化材料掺入量对重金属形态的影响,并对其形态与浸出毒性进行对比分析。研究结果表明,污泥固化后Cu、Zn的有机结合态变化最大,一般情况下Cu、Zn的浸出毒性指标均不能全面反映其潜在毒性。     

The relationship between chemical elements in soil and whole blood,and fluorosis induced by coal-fired pollution

To study the relationship between chemical elements in soil and whole blood, and fluorosis induced by coal-fired pollution, ecological and case–control studies were carried out. We determined the concentrations of 11 chemical elements and pH values in soil in two fluorosis-affected counties in Chongqing, China, and analyzed the correlation between these values and prevalence of dental fluorosis. Ni, I, F, Hg, and pH values positively correlated with fluorosis prevalence (P?<?0.05); these soil parameters may be related to coal-fired pollution fluorosis. Cu, Zn, Ca, Mg, and Fe concentrations in whole blood, and fluoride levels in urine of residents in epidemic and non-epidemic areas were determined. Cu, Zn, Mg, and Fe levels of the children in the case group were lower than those of the children in the external control group; urine fluoride level in the children in the case group was higher than that of the children in the internal and external control groups (P?<?0.05). The levels of Mg, Fe, and urine fluoride were higher in the case adult group than in the internal adult control group (P?<?0.05). Anti-fluoride elements were deficient in endemic areas.     

Birth of healthy children after preimplantation diagnosis of β-thalassemia by whole-genome amplification

Preimplantation genetic diagnosis (PGD) offers couples at risk for transmitting an inherited disorder the possibility to avoid the need to terminate affected pregnancies. PGD for monogenic diseases is most commonly accomplished by blastomere biopsy from cleavage-stage embryos, followed by PCR-based DNA analysis. However, the molecular heterogeneity of many monogenic diseases requires a diagnostic strategy capable of detecting a range of mutations and compound genotypes. With the above considerations, we developed an accurate and reliable strategy for analysis of β-globin gene mutations, applicable for PGD for the wide spectrum of β-thalassemia major mutations in the Chinese population. The strategy involves primer-extension preamplification (PEP), followed by nested PCR and reverse dot blot (RDB) for mutation detection since it facilitates simultaneous analysis of more than one mutation in a single cell. This report describes the application of the strategy in two clinical IVF/PGD cycles at risk for transmitting β-thalassemia major, which resulted in the first thalassemia-free children born after PGD in China. Copyright © 2003 John Wiley & Sons, Ltd.     

The curve of ion exchange ratio(%)-pH of the interaction between suspended particles with Cd(Ⅱ) in the Yellow River

Ｔｈｅｃｕｒｖｅｏｆｉｏｎｅｘｃｈａｎｇｅｒａｔｉｏ（％）ｐＨｏｆｔｈｅｉｎｔｅｒａｃｔｉｏｎｂｅｔｗｅｎｓｕｓｐｅｎｄｅｄｐａｒｔｉｃｌｅｓｗｉｔｈＣｄ（Ⅱ）ｉｎｔｈｅＹｅｌｏｗＲｉｖｅｒＹａｎｇＨｏｎｇｗｅｉ，ＪｉａｏＸｉａｏｂａｏ，Ｇｕ...     

土地利用与流域水环境管理研究

从土地利用活动与环境的关系着手，分析得出物质流动是联系两者纽带的结论；提出了污染物及沉积物输移的计算模型；最后，探讨了通过土地利用来改善水环境的措施和方法。     

浅谈二重源解析技术

针对中国扬尘污染较严重和扬尘污染源的特殊性,人们提出了二重源解析技术,解决了源解析计算中存在的一些问题,如扬尘和其他它单一尘源类的共线性等问题,但在该技术的应用中同样存在一些问题.对二重源解析技术的原理、存在缺陷以及相应的改进、需注意的问题进行了论述,为环保工作者提供相应的参考.