微波强化有机改性膨润土对磷的吸附特性研究

利用十六烷基三甲基溴化铵(CTMAB)在微波辐射条件下对浙江临安膨润土进行改性,制得有机改性膨润土,利用其含磷模拟废水进行处理,考察了不同的工艺条件如有机改性剂用量、微波辐射强度、辐照时间、吸附时间、改性膨润土投加量、pH值对废水中磷去除效果的影响。结果表明:在有机改性剂用量为3 mmol/g,微波辐照强度为96 W/g,微波辐照时间8 min为最佳制备条件。改性膨润土用量为12 mg/L,反应时间为15 min,溶液pH为7及常温条件下,改性膨润土对浓度为50 mg/L的含磷废水去除率达到97.3%,吸附符合Freundlich吸附等温方程。     

三废处理中辐照技术的进展

辐射技术用于三废处理的研究是70年代环境污染问题日益严重,环境保护技术的开发变得十分紧迫的时候迅速兴起的.辐照技术具有许多传统三废处理方法所无法比拟的     

γ-射线辐照法改善城市污水厂剩余污泥厌氧消化特性的研究

采用γ-射线辐照法对城市污水厂剩余污泥进行预处理,从固体组分、可溶性组分及厌氧产气量等角度来探讨γ-射线辐照法改善城市污水厂剩余污泥厌氧消化特性的可行性.结果表明,经γ-射线辐照处理后,污泥的平均粒径减小,在辐照剂量为6.51～30.75 kGy范围内,粒径的减小率达30%～50%;可溶性有机组分随着辐照剂量升高而增加,当辐照剂量为19.4 kGy时,SCOD增加率达552.5%;与未辐照相比,污泥经2.48、6.51、11.24 kGy辐照处理后,厌氧消化累计产气量分别增加8.89%、19.74%和35.81%.γ-射线辐照法是一种有效的改善污泥厌氧消化特性的方法,11.24 kGy左右的剂量可作为污泥预处理的最佳剂量.     

微波紫外耦合辐射降解间硝基苯磺酸钠及活性炭再生

针对活性炭吸附法处理污水所面临的吸附剂物耗大及其所形成的危险废弃物处置难题,采用微波紫外耦合辐射技术对活性炭无害化再生。以活性炭吸附电镀废水中的间硝基苯磺酸钠(3-NBSA)为研究对象,考察了p H对活性炭吸附3-NBSA效果的影响,研究了活性炭的吸附动力学和吸附等温线,最后探讨了微波功率、微波辐照时间、空气流量及再生次数对活性炭再生效果和再生损耗率的影响。实验结果表明,p H在2~8范围内对活性炭吸附效果影响不大,活性炭吸附动力学符合准二级动力学模型,等温吸附特性可用Freundlich等温方程式来描述。活性炭再生实验的最佳工艺条件:微波功率为500W,微波辐照时间为10 min,空气流量为0.024 m3/h。最佳工艺条件下活性炭的再生率达到99.62%,且连续再生5次后仍能达到90.02%。实验表明,在微波紫外耦合辐射作用下比只在微波作用下,活性炭的再生效果和3-NBSA的降解效果更好。     

微波技术在污水处理中的研究进展和应用

微波技术因其独特的热效应和非热效应在水处理领域起着重要的作用。微波技术发展至今可分为4个方面:(1)微波直接辐射法处理污水;(2)微波场辅助活性炭处理污水;(3)微波与其他技术(光催化技术、金属催化剂等)联合应用处理污水;(4)微波辐照再生与制备催化剂。微波技术对各类污染物(如染料、氨氮废水、焦化废水和酚类、酸类和酯类等有机废水)的降解率影响显著。从降解效率的角度看,现代化微波工艺将朝着微波与高级氧化技术的联合应用方向发展,其联合反应机制和配套装置也有待做更多研究。     

微波炉快速测定城市污泥湿度的探讨

用额定电压为220 V、振荡频率为2 450 MHz、输出功率为800 W的微波炉对5～30 g城市污泥辐照2～30 min。由不同时间对城市污泥进行微波辐照后的质量损失率、残余湿度以及挥发性固体（VS）含量的变化表明：用微波炉可简便、快速地测定城市污泥的湿度。为提高微波炉测定湿度的准确性，应减少取样量，进行重复辐照，并根据相邻2次辐照导致的质量变化幅度逐次缩短辐照时间；在辐照过程中应避免引起样品突然释放大量VS，辐照至恒重为止。     

48 V软包锰酸锂电动车动力电池的梯次利用

针对我国面临的体量巨大的电动踏板车的动力锂离子电池退役后处理处置问题,研究了动力电池回收再梯次利用的具体方法。以市场上大量退役的48 V软包锰酸锂动力电池为研究对象,对退役电池的容量、内阻、放电性能以及电池组的损耗分布进行了研究,从而提出了修复后梯次利用作为电动踏板车动力电池的策略。研究结果表明:不同损耗程度的电池组的损耗各有差异,剩余电量为70%的损耗组以个别单体损耗为主但其余未损耗单体一致性较好,可进行更换修复后重新服役;40%损耗组损耗单体数增加同时一致性尚可,更换受损单体后无法直接服役,需定制并联组形式重新使用;20%单体与一致性均较差,可直接拆解回收再利用。     

γ-射线辐照法改善城市污水厂剩余污泥厌氧消化特性的研究

采用γ-射线辐照法对城市污水厂剩余污泥进行预处理，从固体组分、可溶性组分及厌氧产气量等角度来探讨γ-射线辐照法改善城市污水厂剩余污泥厌氧消化特性的可行性。结果表明，经γ-射线辐照处理后，污泥的平均粒径减小，在辐照剂量为6．51-30．75kGy范围内，粒径的减小率达30％-50％；可溶性有机组分随着辐照剂量升高而增加，当辐照剂量为19．4kGy时，SCOD增加率达552．5％；与未辐照相比，污泥经2．48、6．51、11．24kGy辐照处理后，厌氧消化累计产气量分别增加8．89％、19．74％和35．81％。γ-射线辐照法是一种有效的改善污泥厌氧消化特性的方法，11．24kGy左右的剂量可作为污泥预处理的最佳剂量。     

微波辐照糠醛渣制备活性炭及其性能研究

以糠醛渣及废炭粉为原料,通过掺合活化剂K2CO3成形后,在微波辐照下活化制备活性炭.研究K2CO3掺合比、辐照功率、活化气体CO2流量、辐照时间对活性炭结构与脱硫性能的影响,并设计正交实验优化工艺条件.结果表明,在最佳工艺条件下,即K2CO3掺合比为1.0:2.0(质量比)、辐照功率为640 W、CO2流量为200 mL/min、辐照时间为10 min时,活性炭的吸附和脱硫性能较佳.扫描电镜和脱硫实验表明,后处理前后的活性炭在结构和脱硫性能以及脱硫机制上差异较大.     

微波辐射加热合成蒽醌的清洁生产正交实验研究

微波辐射加热合成蒽醌反应,速度快、产率高、无污染,是一种很有应用价值的清洁生产方法。观测了微波辐照条件下蒽醌产率的变化情况及影响因素,着重研究了邻苯甲酰苯甲酸环化脱水缩合生成蒽醌的最佳反应条件及蒽醌产率与影响因素间的关系。     

Uptake of radionuclides by plants after the Chernobyl accident

Gamma-radioactivity of a wide variety of plant samples was measured. Measurements showed that radioactivity in plants depended on the area of surface exposed, the developmental season of the plants, and on the external morphology of their above-ground parts. Autoradiographs on several plants showed the presence of radioactivity in certain spots (hot spots) which were distributed randomly on the surface of the plants and differed in size and activity.     

Contributions to ecological chemistry CVII1. Fate of lindane-14C in lettuce, endives and soil under outdoor conditions.

In seven successive outdoor experiments, lindane-14C was applied to lettuce or endive leaves as an aqueous formulation (about 12 mg on 20 plants for each experiment). The growing periods varied between 21 and 37 days. After this time, between 4.5% and 13.9% of the applied radiocarbon was recovered from the plants. Conversion rates to soluble metabolites as well as to unextractable residues appeared to be dependent on weather conditions. During the summer months, the radiocarbon in plants consisted of 36% soluble metabolites and of 30% unextractable residues (average of 4 experiments); in autumn, the conversion rates were much lower. The following metabolites were identified in both plant species by gas chromatography/mass spectrometry: a polar group (a free trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol, conjugates of the latter two compounds, and unidentified water-soluble products) amounting to 35% of the radioactivity in plants cultivated in summer, and a nonpolar group (a dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3,5, and/or 1,2,4,5-tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, and gamma-pentachlorocyclohexene) amounting to 1% of the radioactivity in plants cultivated in summer. The 20 cm top-soil layer had about 14% of the total radioactivity applied to all plants. Six % of the radioactivity recovered from the soil was soluble metabolites and about 50% was not extractable. The soluble metabolites comprised a polar group (free and conjugated 2,3,4,6-tetrachlorophenol, pentachlorophenol, and unidentified water soluble products) amounting to 5% of the radioactivity in the soil as well as a nonpolar group (1,2,3-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,3,5 and/or 1,2,4,5-tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, and gamma-pentachlorocyclohexene) amounting to 1% of the radioactivity in the soil.     

Bioavailability, biological activity and characterization of bound residues of diflubenzuron in wheat.

Wheat grain was treated with radiolabeled diflubenzuron at 100 ppm and stored for various periods; up to 6 months. The grain was surface washed, Soxhlet-extracted with methanol, and the residues determined. A relative constant amount of bound residues (4%), i.e., non-extractable radioactivity, was found 4 months after application and remained constant. More than 97% of the extractable radioactivity in the grain after 6 months was identified as diflubenzuron. When the bound residues were fed to rats, 47% of the administered dose was eliminated via the urine and the remainder via feces within 96 h. Diflubenzuron was the major component in the urine. Adding bound residues to housefly media resulted in a dose-dependent mortality of housefly pupae. Bound residues were biologically active, preventing the emergence of adult houseflies. Supercritical fluid extraction of the bound residues extracted 92% and 96% of the radioactivity associated with grain and feces, respectively. Only diflubenzuron was present in these extracts. The bioavailability and biological activity of bound residues of diflubenzuron have been demonstrated and the identity of the radioactivity was shown to be parent compound. Based on these findings, bound pesticide residues can no longer be ignored or overlooked in the evaluation of pesticide residues and their possible toxicological implications.     

Radiological hazard assessment of natural gross radioactivity in some cosmetic products

Many kinds of cosmetic products were analyzed to determine gross radioactivity. In this study, gross alpha/beta radioactivity concentrations in 51 cosmetic samples were determined. The examined cosmetic products consist of blusher, eye shadow, lipstick, nail polish, shampoo, hand cream, cellulite cream, baby powder, soap, and toothpaste. The gross alpha–beta activity concentrations were measured with a nuclear spectroscopic system which contains gas-flow proportional counters. The highest gross alpha/beta activity concentrations were found in eye shadow samples of 1.621Bq g^?1 for alpha and 6.471Bq g^?1 for beta. The total effective doses due to gross radioactivity for skin were calculated. Although the effective dose of eye shadow samples had the highest value, the effective doses due to gross radioactivity concentrations in this study were found to be lower than the radiological limits given by the authorities.     

Fate of atrazine and chlorpyrifos during solid state fermentation--examination of processes

Solid state fermentation (SSF) was investigated as a means to dispose of two commonly used pesticides, chlorpyrifos (O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate) and atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine). SSF experiments were carried out in bench-scale bioreactors (equipped with CO2 and volatile organic traps) containing a mixture of lignocellulosic materials and a radiolabeled pesticide. Ethyl acetate-extractable, alkali soluble, and alkali insoluble fractions were evaluated for radioactivity following a 60-d incubation period at 40 degrees C. The majority of the [2,6-pyridyl-14C]chlorpyrifos was associated with the ethyl acetate extract (about 74%), 17% was trapped as organic volatiles by polyurethane foam traps and < 0.5% of the chlorpyrifos was mineralized to CO2. Only small amounts of the radioactivity were associated with alkali soluble (0.0003%) and alkali insoluble (0.3%) fractions. In the [14C-U-ring]atrazine bioreactors, very little of the radioactivity volatilized (<0.5%) and less than 0.5% was mineralized to CO2. Approximately 57% of the applied radioactivity was associated with the ethyl acetate extract while 9% and 24% of the radioactivity was associated with the alkali soluble (humic and fulvic acids) and alkali insoluble fractions, respectively. Possible reaction mechanisms by which covalent bonds could be formed between atrazine (or metabolites) and humic substances were investigated. The issue of bound atrazine residue (alkali soluble fraction) was at least partially resolved. Oxidative coupling experiments revealed that formation of covalent bond linkages between amino substituent groups of atrazine residue and humic substances is highly unlikely.     

Concentrations of heavy metal and radioactivity in surface water and sediment of Hazar Lake (Elaziğ, Turkey)

Concentration of heavy metals and natural gross radioactivity were measured in the surface water and sediment of Hazar Lake (Elazi?, Turkey). Eight sampling sites were pre-defined in different locations of the lake. A preliminary study on heavy metals (Zn, Fe, Mn, Ni, Cu, Cr, Co and Pb), major elements (Na, K, Ca, Mg) concentrations and natural radioactivity related to 226Ra, gross-alpha and gross-beta radiations in the surface water and deep sediments were determined. The obtained results showed that, in general, the heavy metals (Zn, Fe, Mn, Ni, Cu and Pb) and major elements (Na, K, Ca, Mg) concentrations in water did not exceed WHO (World Health Organization, 1999), EC (Europe Community, 1998), EPA (Environment Protection Agency, 2002) and TSE-266 (Turkish Standard, 1997) guidelines. Generally, heavy metals and major elements concentration of the sediments were found decrease in sequence of Fe>Mg>Ca>Mn>Zn>Ni>Cr>Cu>Co>Pb. The results of this study indicated that a general absence of serious pollution in the Hazar Lake. The results obtained from the radioactivity determination indicate that the surface water radioactivity concentration of 226Ra, gross-alpha and gross-beta were ranging from 0.52+/-0.02 to 2.02+/-0.06 Bq/l and from 0.65+/-0.03 to 2.52+/-0.07 Bq/l and from 0.01+/-0.01 to 0.14+/-0.01 Bq/l, respectively. Deep sediment radioactivity concentrations of 226Ra is ranging from 0.07+/-0.03 to 0.32+/-0.07 Bq/g.     

Fate and distribution of 14C-atrazine in a tropical oxisol

The herbicide atrazine is the most commonly detected pesticide in groundwater world-wide. A new microcosm test-system was used to determine the fate of 14C-atrazine in a Brazilian oxisol. 14C Ring-labelled atrazine was applied in a mixture with the commercial product Gesaprim 500 (Novartis) at a rate of 3 kg ha-1. During two months, about 1% of the initially applied amount was lost by volatilization. The mineralization of the pesticide, measured directly using 14CO2 evolved from the applied pesticide, was between 0.09% and 0.16%, whereas less than 0.2% was leached. The distribution of radioactivity in the soil profile showed that most of the radioactivity remained in the top soil down to a 3 cm depth. The radioactivity in the upper 3 cm of the column was adsorbed perferably in fulvic acid (FA) and human fractions.     

Life stage- dependent bioconcentration of a nonylphenol isomer in Daphnia magna

Bioaccumulation is an important aspect for the fate and effects of xenobiotics in the environment. In this study we used a radiolabeled nonylphenol isomer to investigate the bioconcentration in Daphnia magna at different ages. Apart from the total radioactivity we measured the metabolism of p353-NP in D. magna, to calculate the amount of p353-NP compared to total radioactivity found within the daphnids. Bioconcentration factors, based on wet weight, calculated from the rate constants for total radioactivity in neonates and adults were 4271 kg/l and 760 kg/l respectively, leading to a 5.6 deviance in bioconcentration. This deviance was even more pronounced, nearly one order of magnitude, for the p353-NP concentration with bioconcentration factors of 302 kg/l for neonates and 31 kg/l for adults. We were able to describe the bioconcentration for all daphnids by a weight-dependent one- compartment model. These results pointed out that it is not possible to compare bioconcentration experiments conducted with different substances and different sized daphnids. Additionally it was shown that it is not possible to describe the bioconcentration by measuring the total radioactivity. Metabolism of nonylphenol occurs at a very fast rate and bioconcentration is not triggered by the partition between two phases, but by metabolism. Discrimination between the two mechanisms was achieved using radiolabeled substances and a pseudo two-compartment model to describe metabolism and elimination by two rate constants which afterwards can be compared between different substances.     

Dissipation and metabolism of C-spiroxamine in soil under laboratory condition

Spiroxamine [SPX] belongs to a spiroketalamine group of substances. The biodegradation of [1,3-dioxolane-4-¹⁴C]-SPX has been examined in 2 soils of different physicochemical properties. The total recovery of radioactivity from soils was 98.6-103.5% of that applied. The total amount of extractable radioactivity declined with a simultaneous increase in non-extractable radioactivity. Volatile organics were detected at lower levels; however, mineralization played a marked effect on the route of SPX dissipation. The half-life ranges between 37 and 44 d. SPX does not undergo any enantioselective degradation. 4 metabolites: despropyl-SPX, desethyl-SPX, SPX N-oxide and SPX acid were identified, applying mass spectrometric technique. Sorption-desorption data fitted well with a Freundlich model in log form (r², 0.99). K_Dsorp ranged between 44 and 230, suggesting SPX ought to be considered as a substance with low leaching potential [groundwater ubiquity score (GUS), <1.8]. Furthermore, an overall low desorption of 1-11% indicates firm retention of SPX by the soils.