三苯基锡和三丁基锡对大型蚤(Daphnia magna)的毒性作用研究

本研究测定了三苯基锡（ＴＰＴ）和三丁基锡（ＴＢＴ）对大型蚤（Ｄａｐｈｎｉａ ｍａｇｎａ）的急性毒性及慢性毒性,同时研究了环境因素（腐殖酸、硬度、酸度）对ＴＰＴ和ＴＢＴ的２４ｈ－ＥＣ５０的影响。结果表明,ＴＰＴ和ＴＢＴ对大型蚤的２４ｈ－ＥＣ５０分别为１３．３３ｕｇＳｎ．１＾－１和３．９１ｕｇＳｎ．１＾－１,慢性实验结果表明,ＴＰＴ对大型蚤的生长繁殖有一定的抑制作用。     

偶氮染料定量结构-生物降解关系(QSBR)研究

利用量子化学原理剖析了偶氮染料的脱色机制,所得结果与文献中关于染料结构与脱色能力之间关系的结论基本一致,以脱色能力为染料生物降解能力的表征,建立了定量结构生物降解性模型,模型预测结果与实验结果基本吻合。     

卡鲁塞尔氧化沟反应器两相流PIV图像处理研究及实验分析

在单相数字粒子图像测速度(PIV)技术的基础上,研究了PIV两相流动的测试及图像处理方法.利用数学形态学的原理以及互相关法,对两相粒子图像进行标定、识别、区分和流场分析,编辑了相应的软件.并采用此技术对卡鲁塞尔氧化沟模型直道及弯道段二维液固两相流速进行测量,克服了传统点测量方法无法获取全场流动同步信息的缺陷,较好地反映了不同位置处固液流动分布的基本特性.结果表明,沟内径向流速远小于轴向,流速大小相差约一个数量级;同一断面上轴向流动分布是决定水力特性的主要因素;径向流速和水体动能是决定污泥沉积位置的主要因数,固相总体流速小于液相.     

《贵州省环境污染排放标准》中涉气项目修订原则与方法

以贵州省地方大气污染物排放标准为例,在充分分析其原标准存在问题的基础上,结合近年来颁布实施的环境质量标准、综合或行业污染物排放标准以及工作场所有害因素职业接触限值作为标准浓度限制值Cm,严格按照制定地方大气污染物排放标准的技术方法,重新计算了该省固定排放源的排放限值。计算时,首次以所涉行业区位商作为设置经济技术参数Ke值的重要依据,克服了对欠发达地区经济技术参数"一刀切"的缺点,增加了标准的经济技术可行性。通过计算,地方标准的排放限值更趋于合理,符合国家对地方标准的有关要求。     

我国太阳能光伏发电产业发展方向及产业政策

随着新世纪的到来,出于对环保和未来能源供应的考虑,可再生能源在世界能源消费中的比重逐渐加大。其中,太阳能光伏发电技术的发展和应用颇为世人所瞩目。本文从国有光伏产品市场特点出发,分析了国产光伏系统在市场竞争中的优势和劣势所在,指出了当前我国太阳能光伏发电系统企业在市场中缺乏竞争力的原因。在此基础上,提出相应的解决方案。     

Light-induced variation in environmentally persistent free radicals and the generation of reactive radical species in humic substances

• Light irradiation increased the concentration of free radicals on HS. • The increased spin densities on HS readily returned back to the original value. • The “unstable” free radicals induced the formation of reactive radical species. • Reactive radicals’ concentration correlated strongly with EPFRs’ concentration. Environmentally persistent free radicals (EPFRs) in humic substances play an essential role in soil geochemical processes. Light is known to induce EPFRs formation for dissolved organic matter in aquatic environments; however, the impacts of light irradiation on the variation of EPFRs in soil humic substances remain unclear. In this study, humic acid, fulvic acid, and humin were extracted from peat soil and then in situ irradiated using simulated sunlight. Electron paramagnetic resonance spectroscopy results showed that with the increasing irradiation time, the spin densities and g-factors of humic substances rapidly increased during the initial 20 min and then gradually reached a plateau. After irradiation for 2h, the maximum spin density levels were up to 1.63 × 10¹⁷, 2.06 × 10¹⁷, and 1.77 × 10¹⁷ spins/g for the humic acid, fulvic acid, and humin, respectively. And the superoxide radicals increased to 1.05 × 10¹⁴–1.46 × 10¹⁴ spins/g while the alkyl radicals increased to 0.47 × 10¹⁴–1.76 × 10¹⁴ spins/g. The light-induced EPFRs were relatively unstable and readily returned back to their original state under dark and oxic conditions. Significant positive correlations were observed between the concentrations of EPFRs and reactive radical species (R² = 0.65–0.98, p<0.05), which suggested that the newly produced EPFRs contributed to the formation of reactive radical species. Our findings indicate that under the irradiation humic substances are likely to be more toxic and reactive in soil due to the formation of EPFRs.     

Reduced cadmium accumulation in tobacco by sodium chloride priming

Environmental Science and Pollution Research - Cadmium (Cd) pollution threatens agricultural security worldwide. This study tested the efficacy of priming chemicals to decrease Cd uptake by tobacco...     

Fe~0协同生物麦饭石的PRB系统井下原位处理煤矿酸性废水

针对煤矿酸性废水(AMD)具有污染组分多、危害程度严重、地面处理成本高等特点,以固定SRB污泥的生物麦饭石作为PRB活性填料,并添加Fe0构建生物-非生物协同去污的新型PRB井下原位修复系统,对AMD开展了连续动态、变负荷的模拟修复研究。实验结果表明,3个动态柱对p H均具有较强的调节能力,同时仅以麦饭石作为活性填料的PRB-3对Fe2+、Mn2+、NH3-N具有较好的去除效果,最大去除速率分别为45.77、9.23和12.10 mg/(L·d);以Fe0协同生物麦饭石的PRB-2在碳源充足时对SO2-4、Fe2+、Mn2+、NH3-N最高去除速率分别为552.29、57.64、14.51和7.05mg/(L·d),而相同条件下只以生物麦饭石作为活性填料的PRB-1对上述污染物的最高去除速率分别为446.62、57.20、10.87和3.53 mg/(L·d);应用PRB-2系统处理AMD不仅可以实现多种污染物的同步去除,还能实现无外加碳源的井下原位长效修复。     

Sorption–desorption and transport of trimethoprim and sulfonamide antibiotics in agricultural soil: effect of soil type,dissolved organic matter,and pH

Use of animal manure is a main source of veterinary pharmaceuticals (VPs) in soil and groundwater through a series of migration processes. The sorption–desorption and transport of four commonly used VPs including trimethoprim (TMP), sulfapyridine, sulfameter, and sulfadimethoxine were investigated in three soil layers taken from an agricultural field in Chongming Island China and two types of aqueous solution (0.01 M CaCl₂ solution and wastewater treatment plant effluent). Results from sorption–desorption experiments showed that the sorption behavior of selected VPs conformed to the Freundlich isotherm equation. TMP exhibited higher distribution coefficients (K _d?=?6.73–9.21) than other sulfonamides (K _d?=?0.03–0.47), indicating a much stronger adsorption capacity of TMP. The percentage of desorption for TMP in a range of 8–12 % is not so high to be considered significant. Low pH (<pK _a of tested VPs) and rich soil organic matter (e.g., 0–20 cm soil sample) had a positive impact on sorption of VPs. Slightly lower distribution coefficients were obtained for VPs in wastewater treatment plant (WWTP) effluent, which suggested that dissolved organic matter might affect their sorption behavior. Column studies indicated that the transport of VPs in the soil column was mainly influenced by sorption capacity. The weakly adsorbed sulfonamides had a high recovery rate (63.6–98.0 %) in the leachate, while the recovery rate of TMP was only 4.2–10.4 %. The sulfonamides and TMP exhibited stronger retaining capacity in 20–80 cm and 0–20 cm soil samples, respectively. The transport of VPs was slightly higher in the columns leached by WWTP effluent than by CaCl₂ solution (0.01 M) due to their sorption interactions.