红土吸附砷对其动电电位的影响

研究了遵义红土吸附砷对其动电电位的影响 ,从砷酸根浓度和体系pH对红土动电电位影响的角度作了探讨 ,结果表明 ,砷酸根离子浓度越大 ,Zata电位下降幅度越大 ,Zata电位也越低 ;随着体系pH的升高 ,氧化铁胶体动电电位逐渐下降 ,甚至改变了表面电位的符号。由此得出了红土吸附砷属于专性吸附的结论。     

Decolorization of direct dyes by salt fractionated turnip proteins enhanced in the presence of hydrogen peroxide and redox mediators

The present paper demonstrates the effect of salt fractionated turnip (Brassica rapa) proteins on the decolorization of direct dyes, used in textile industry, in the presence of various redox mediators. The rate and extent of decolorization of dyes was significantly enhanced by the presence of different types of redox mediators. Six out of 10 investigated compounds have shown their potential in enhancing the decolorization of direct dyes. The performance was evaluated at different concentrations of mediator and enzyme. The efficiency of each natural mediator depends on the type of dye treated. The decolorization of all tested direct dyes was maximum in the presence of 0.6mM redox mediator at pH 5.5 and 30 degrees C. Complex mixtures of dyes were also maximally decolorized in the presence of 0.6mM redox mediator (1-hydroxybenzotriazole/violuric acid). In order to examine the operational stability of the enzyme preparation, the enzyme was exploited for the decolorization of mixtures of dyes for different times in a stirred batch process. There was no further change in decolorization of an individual dye or their mixtures after 60 min; the enzyme caused more than 80% decolorization of all dyes in the presence of 1-hydroxybenzotriazole/violuric acid. However, there was no desirable increase in dye decolorization of the mixtures on overnight stay. Total organic carbon analysis of treated dyes or their mixtures showed that these results were quite comparable to the loss of color from solutions. However, the treatment of such polluted water in the presence of redox mediators caused the formation of insoluble precipitate, which could be removed by the process of centrifugation. The results suggested that catalyzed oxidative coupling reactions might be important for natural transformation pathways for dyes and indicate their potential use as an efficient means for removal of dyes color from waters and wastewaters.     

2-氯酚在超临界水-NaOH体系中的脱氯特性

研究了2-氯酚在超临界水-NaOH体系中的脱氯特性,考察了NaOH添加对2-氯酚转化率、Cl-生成率、脱氯选择性等的影响。实验结果表明,NaOH的添加能够显著提高2-氯酚的转化率、Cl-的生成率和脱氯选择性。2-氯酚的转化率随着NaOH添加量的增大而增大,460℃、25 MPa条件下,NaOH添加量与2-氯酚的摩尔比为1∶1时,停留时间27 s时可实现2-氯酚的完全转化。     

南京市区植物叶片氮、硫、铅含量与大气污染评价

通过对南京市区的各功能区植物叶片中的氮、硫、铅元素含量的分析，研究了植物大气环境污染指数，探讨了植物叶片的氮、硫、铅元素含量的季节变化，以及与城市大气环境污染之间的关系。结果表明，植物叶片中，硫、铅元素的含量随季节变化不断增加，而氮元素含量相应减少；各功能区的硫、铅元素含量明显高于清洁对照区；用植物污染指数可以综合评价大气环境的质量状况。     

The influence of maize residues on the mobility and binding of benazolin: investigating physically extracted soil fractions

The amount of non-extractable residues and the distribution of benazolin and its metabolites were evaluated three months after herbicide application (14C-labelled) in physically extracted soil fractions of topsoil layers of undisturbed soil columns with and without incorporated maize straw (14C-labelled). In addition, a variety of wet-chemical and spectroscopic methods were used to characterise the structure of organic carbon within the different soil fractions. The addition of crop residues increased the amount of dissolved organic carbon, enhanced the aromaticity of the organic carbon structure and enforced the aggregation of organomineral complexes. After incorporation of crop residues, an increase in the formation of metabolic compounds of benazolin and of non-extractable residues was detected. These results indicate that the addition of crop residues leads to a decrease in mobility and bioaccessibility of benazolin and its metabolites.     

The Institute of Hydrobiology of the Chinese Academy of Sciences (1 p.)

- The Institute of Hydrobiology (IHB), Chinese Academy of Sciences (CAS) is located at the foot of Luojia Hill and beside the beautiful Donghu Lake in the City of Wuhan, Hubei Province, China. It was founded in 1930 as the Natural History Museum of Academia Sinica, and renamed as the Institute of Zoology and Botany of Academia Sinica in 1934. In 1944, it was divided into two institutes: The Institute of Zoology and Institute of Botany. In 1950, the main part of the Institute of Zoology, the sections of phycology in the Institute of Botany, and some members from other institutes and universities were merged into the Institute of Hydrobiology of the Chinese Academy of Sciences in Shanghai. The institute was moved from Shanghai to Wuhan in 1954.     

Studies on the Measurement of Fluoride in Air and Plant Tissues By the Willard-Winter and Semiautomated Methods

Determinations of F in plant tissues by the Willard-Winter and semiautomated methods have been studied for the presence of determinate and indeterminate errors by multiple linear regression analysis. The results have provided a better understanding of the magnitude of differences between tissue samples required for statistical significance and have suggested that the errors involved are much greater both in number and magnitude than usually assumed. The results have also established that the semiautomated method is a satisfactory alternative to the Willard-Winter method for determining the F content of plant tissues. Investigations of the sources of error in F determinations by the semi-automated method were carried out, and the results indicated a number of ways of reducing errors. Determinations of the F content of air by three methods were compared and studied to estimate the magnitude and locate the sources of error. Here, too, the results indicated that present estimates of the reliability of determinations of the F content of air may be overrated, and they have suggested that improvement in the means of collection of HF is the best way of improving reproducibility.     

Fate of polycyclic aromatic hydrocarbons during composting of lagooning sewage sludge

The fate of 16 polycyclic aromatic hydrocarbons (PAHs), targeted by the USEPA agency, has been investigated during composting of lagooning sludge. Composting shows efficient decrease of the content and the bioavailability of each PAH. Biodegradation and sorption are suggested as the main mechanisms contributing to this decrease. During the stabilization phase of composting, extensive microbial degradation of PAHs, mainly those with a low number of aromatic rings, was achieved following development of intense thermophilic communities. However, partial sorption of PAH to non-accessible sites temporarily limits the mobility mainly of PAHs with a high number of aromatic rings plus acenaphthene and acenaphthylene, and allows them to escape microbial attack. During the maturation phase, the development of a mesophilic population could play an important role in the degradation of the remaining PAH. During this phase of composting, PAH sequestration and binding of their oxidative metabolites within new-formed humic substances might also explain PAH decrease at the end of composting. The tendency of change of content or bioavailability of various PAH compounds during composting is found to be strongly related to the number of their aromatic rings, their molecular weight and structure.     

Fluorine in the soils of the White Sea Basin and bioindication of pollution

Assessment of the pollution level of soils and vegetation by fluorine and heavy metals and also of the state of the soil microflora in the impact zone of Kandalaksha aluminium factory is discussed. The significant pollution of natural media by fluorine in the basin of the White Sea is established. Concentration of the total fluorine in the organogenic horizon of the Al-Fe-humus podzol soil at a distance of 20 km in the northern direction from the source of emission exceeds the background level by a factor of 3. In the epicentre of emission the amount of total fluorine in the soil exceeds the background level by a factor of 7-8 (Tolerable Amount: 4-5-fold). It is noted that the soil becomes more alkaline under the influence of fluorine and the increased content of chromium along the soil profile exceeds PC by a factor of 3 in the vicinity of the factory. The differences in the dimensions of bacterial and fungi biomass along the gradient of pollution were not revealed in the impact zone. But the changes in the taxonomic structure of fungi and in the level of their domination along the gradient of pollution were estimated. Floristic composition of the soil algae is represented mainly by unicellular green algae with Chlamydomonas elliptica and Bracteacoccus minor predominating.     

磺胺和四环素类抗生素对活性污泥性能的影响简

废水处理工艺中抗生素类污染物的存在可能会对生物处理过程产生长期而深远的影响，为探明此类污染物对废水生物处理主体活性污泥性能等方面的影响，采用间歇培养法研究了活性污泥法处理污水时，抗生素类污染物的存在对活性污泥性能如胞外聚合物（EPS）、污染物处理能力、脱氢酶活性和群落结构的影响。结果表明，抗生素的存在会导致活性污泥的胞外聚合物总量及其主要组分蛋白质和多糖增加，以产生保护屏障；且由于污泥絮体解体，细胞破裂导致EPS中DNA和色氨酸含量增加。同时，由于蛋白质大量增加引起的表面负电荷的增加，使污泥疏水性增强，絮凝性能恶化；污泥絮体解体导致污泥颗粒变小，SVI也随之下降；在活性污泥脱氢酶活性急剧下降的同时，出水TOC迅速升高。此外，抗生素类污染物在抑制活性污泥中大部分细菌的同时，对部分菌群也有刺激生长作用，最终导致活性污泥生物群落结构的改变。四环素类抗生素对活性污泥的EPS和絮凝沉降性能的影响大于磺胺类，而对污水处理能力和群落结构的影响则不如磺胺类。抗生素类污染物的长期存在会对活性污泥沉降性能、絮凝性能、脱氢酶活性以及活性污泥群落结构等产生一系列负面影响，进而影响污染物去除效果，导致出水水质恶化。     

The influence of FeCl3 on the photocatalytic degradation of dissolved azo dyes in aqueous TiO2 suspensions

The study concerned decolouration of solutions of azo, anionic (Acid Orange 7, Reactive Red 45, Acid Yellow 23) and cationic (Basic Blue 41 and Basic Orange 66) dyes during illumination with UV (lambdamax 366 nm) irradiation in the presence of TiO2 and FeCl3. The process of decolouration during illumination of the solutions studied containing FeCl3 underwent significant intensification in the case of anionic dyes and unfavourable inhibition in case of cationic dyes. It was also observed that FeCl3 had a diverse influence on the adsorption of the dyes studied on TiO2. The adsorption of anionic dyes and decolouration of solutions before the illumination was observed only in the presence of FeCl3. In case of cationic dyes the addition of FeCl3 caused elimination of these phenomena. An additional cause of decolouration of anionic dyes solutions before illumination was the precipitation of their poorly soluble compounds from Fe3+. The processes of degradation and mineralization of the dye that accompanied decolouration of Acid Orange 7 solutions were also observed. It was stated that similarly to the case of Acid Orange 7, the decolouration of the studied anionic dyes' solutions can depend on the concentration of FeCl3, the amount of TiO2 and the initial concentration of the dye in its solution.     

棕刚玉渣的硬脂酸湿法改性

以棕刚玉渣、硬脂酸为原料,在乙醇体系中进行机械力化学改性研究。分别研究了球磨过程中球料比、球磨时间、转速、硬脂酸用量、浆料浓度等参数对实验样品亲油化度、活化指数的影响。在最佳工艺基础上进行了正交实验,实验结果表明,适宜条件为硬脂酸用量3.5%,球料比4∶1,球磨时间30 min,球磨转速450 r/min,浆料浓度25%时,实验样品的亲油化度和活化指数分别达到46.8%和100%,且完全疏水。     

The separation of catalyst after photocatalytic reactions conducted in the presence of TiO2/FeCl3/UV

One of the problems connected with wastewater treatment by the photocatalytic method in the presence of TiO2 suspension is necessity of the later catalyst separation. The method proposed by us for this purpose, consists in the usage of coagulation of TiO2 suspension with the aid of FeCl3, particularly in the cases when addition of the salt is used in order to intensification of the photocatalytic process. The effects of the TiO2 separation were studied from the mixtures, after photocatalytic Acid Orange 7 degradation, with dosage of FeCl3 at different stages of the process. The coagulation was carried out at different pH values as well as different FeCl3 concentrations. It was stated that nearly 100% of separation and simultaneously, nearly 100% of decolouration of the examined Acid Orange 7 solutions after their illumination in the presence of TiO2/FeCl3 and coagulation which was produced only by increasing of pH of the obtained mixtures, were nearly possible.     

流化床锅炉飞灰活性激发与建材利用的试验研究

流化床锅炉飞灰活性较差,常规的粉煤灰活性激发方法对该飞灰效果不佳.本研究采用了加入适当激发剂的方法激发其活性,结果表明,加入激发剂后水泥胶砂的早期抗折、抗压强度均有100%的增长,后期抗折强度提高约100%、抗压强度提高60%以上,凝结时间和安定性均符合要求.水泥中飞灰掺量达40%时,其胶砂各龄期强度均达到甚至超过了42.5R水泥的强度;飞灰掺量65%～75%时,胶砂强度显示仍可生产一些低强度要求的建材产品,如砌筑水泥、建筑砂浆等.采用XRD、SEM等微观测试手段对飞灰活性激发机理进行了探讨.     

Dry deposition of airborne sulfate and nitrate to soybeans

Dry deposition contributes a substantial part of the total deposition of acidic pollutants and acid precursors to agricultural systems. However, because of the relative intractability of measurement of dry deposition fluxes, little work has been done to directly quantify dry inputs of pollutants to crops. In this research, foliar surface sampling ('leaf-washing') methods were developed and shown to be a practical and fairly precise means of monitoring the accumulation of dry-deposited SO4(2-) and NO3- on plant surfaces. Leaching of these ions from plant tissues was shown to be negligible; however, uptake by plants (e.g. stomatal gas exchange of SO2 or HNO3 and/or assimilation of surface accumulations of materials) is not accounted for by the sampling method. The significance of dry deposition to modification of the chemical microenvironment of leaf surfaces appears to be a factor of 3 to 20 or more greater than that of wet deposition alone. This is due to the cyclic reactivation of accumulated materials by dew and light rains, which may dissolve and mobilize, but not remove, the pollutant surface deposit. Therefore, while dry deposition of SO2 and SO4(2-) containing particles may contribute only part of the total mass of sulfur inputs to crop systems, the exposure of plant surface tissue to pollutants can be dominated by the dry-deposited material. The alteration of leaf surface chemistry may contribute to possible stress-producing mechanisms such as reduction of cuticular integrity, cellular injury and death, enhanced leaching of primary and secondary metabolites, and changes in pathogen infection efficiency.     

Surface-enhanced Raman scattering of the adsorption of pesticide endosulfan on gold nanoparticles

The absorption of pesticide endosulfan on the surface of gold nanoparticles results from the formation of micrometric structures (1–10 μm) with irregular shape because of the aggregation of individual particles. Such aggregation of gold nanoparticles after absorption of pesticide shows a surface-enhanced Raman scattering (SERS) spectrum, whose intensity depends on the concentration of endosulfan. In addition, the discoloration of the colloidal solution and a diminishing of the intensity of the surface plasmon resonance absorption from individual particles were observed by UV-visible spectroscopy. At the same time, a second band between 638 and 700 nm confirms the formation of aggregates of gold nanoparticles as the concentration of endosulfan increases. Finally, we used the SERS intensity of the S?O stretching vibration at 1239 cm^?1 from the SO₃ group as a measure of concentration of pesticide endosulfan. This method could be used to estimate the level of pollution in water by endosulfan in a simple and practical form.     

Enhanced phytoextraction of Pb and other metals from artificially contaminated soils through the combined application of EDTA and EDDS

Chemically enhanced phytoextraction is achieved by the application of chelates to soils. Using pot experiments, the effect of the combined application of EDTA and EDDS on the uptake of Cu, Pb, Zn and Cd by Zea mays L. was studied. Among the tested application ratios of 1:1, 1:2, and 2:1 (EDTA/EDDS), 2:1 of EDTA:EDDS was the most efficient ratio for increasing the concentrations of Cu, Pb, Zn and Cd in the shoots. The combined application of 3.33 mmol kg(-1) soil of EDTA+1.67 mmol kg(-1) soil of EDDS produced 650 mg kg(-1) of Pb in the shoots, which was 2.4 and 5.9 times the concentration of Pb in the shoots treated with 5 mmol kg(-1) of EDTA and EDDS alone, respectively. The total phytoextraction of Pb reached 1710 microg kg(-1) soil, which was 2.1 and 6.1 times the total Pb from 5 mmol kg(-1) EDTA and EDDS alone, respectively. The combined application of EDTA and EDDS also significantly increased the translocation of Pb from the roots to the shoots. The mechanism of enhancing the phytoextraction of Pb by the combined application of EDTA+EDDS did not involve a change in the pH of the soil. The increase in the phytoextraction of Pb by the shoots of Z. mays L. was more pronounced than the increase of Pb in the soil solution with the combined application of EDTA and EDDS. It was thought that the major role of EDDS might be to increase the uptake and translocation of Pb from the roots to the shoots of plants.     

SBR系统静压式滗水器的研究

对SBR系统静压式滗水器进行了研究,与传统SBR系统常用的滗水器进行比较,研究结果表明,该滗水器具有运行稳定、滗水负荷大、能耗低、自动化程度高、造价及维修费用低等特点,减少机械设备,结构简单,便于与SBR系统的控制方式相结合,具有实际应用价值.     

Effect of binary combination of deltamethrin+MGK-264 on the levels of phospholipid and lipid peroxidation in the snail Lymnaea acuminata

Effect of sublethal treatment of (40% and 60% of 48 h LC50) of deltamethrin+MGK on phospholipid level and rate of lipid peroxidation in nervous and foot tissue of Lymnaea acuminata were studied. Maximum reduction in phospholipid (24.10%) level and increase in rate of lipid peroxidation (586.8%) were observed in foot tissue of snail exposed to 60% of 48 h LC50 of deltamethrin+MGK 264 for 96 h. Alterations in the levels of phospholipids and rate of lipid peroxidation were time and concentration dependent. Use of MGK-264 with deltamethrin increases the toxicity of deltamethrin and their action on membrane phospholipids and rate of lipid peroxidation.     

Physico-chemical versus microbial release of c-atrazine bound residues from a loamy clay soil incubated in laboratory microcosms

A loamy clay soil containing unextractable ¹⁴C-ring labeled atrazine residues was incubated in microcosms under abiotic and biotic conditions. The mineralization activity of the soil microflora was evaluated by the release of total CO₂ and ¹⁴C0₂. After 63 days of sample incubation the total organic carbon mineralization was of 1.71%, that of ¹⁴C-residues was of 0.72% of the initial radioactivity. No direct relationship was established between the mineralization of atrazine residues and the global mineralization. The contribution of soil microorganisms in the release of ¹⁴C-residues was weak. The availability of non-extractable residues was mainly controlled by physico-chemical factors. The low value of the reextractability rate and the distribution of bound residues during the soil sample incubation shown the active role of organic matter in detoxification procedure. Ninety percent of the residues remained bound after 63 days of incubation and were thus, potentially available without biocide activity.

The fractionation of soil organic matter allowed to specify the distribution of bound residues within the organic compartments. After a long-stay of pesticides in soils, approximately 65% of bound residues were associated with humin.