4种烟嘧磺隆多元复配除草剂对意大利蜜蜂和玉米螟赤眼蜂的急性毒性及初级风险评估

为明确4种烟嘧磺隆复配除草剂对意大利蜜蜂和玉米螟赤眼蜂的急性毒性影响并评估其初级风险。采用饲喂法、点滴法和玻璃管药膜法,分别测定了8%烟嘧·氯吡嘧磺隆、16%烟嘧·硝磺·氯吡嘧磺隆、36%烟嘧·莠去津和22%烟嘧·氯吡·氯氟吡氧乙酸异辛酯对意大利蜜蜂成年工蜂和玉米螟赤眼蜂的急性毒性,并分别采用危害商值和安全系数进行初级风险评估。结果表明,上述4种制剂对意大利蜜蜂成年工蜂的经口毒性48 h-LD_(50)(半致死剂量,median lethal dose)分别为68.03、1.60×10~2、1.40×10~2和100μg a.i.·蜂-1,接触毒性48 h-LD_(50)分别为18.53、53.01、89.98和100μg a.i.·蜂-1,危害商值均小于50,对意大利蜜蜂均为低毒且低风险。4种制剂对玉米螟赤眼蜂的急性毒性24 h-LR50(半致死用量,median lethal rate)分别为1.88×10~(-4)、5.46×10~(-4)、2.12×10~(-3)和1.68×10~(-3)mg a.i.·cm~(-2),安全系数分别为0.16、0.23、0.59和0.51,其中8%烟嘧·氯吡嘧磺隆和16%烟嘧·硝磺·氯吡嘧磺隆对玉米螟赤眼蜂为高风险性,36%烟嘧·莠去津和22%烟嘧·氯吡·氯氟吡氧乙酸异辛酯为中等风险性。因此,这4种复配制剂对蜜蜂成年工蜂的风险性较低,但对赤眼蜂的风险性较高,所以在喷洒防除期间应与赤眼蜂释放期错开。     

A novel co-catalyzed system between persulfate and chlorite by sonolysis for removing triphenylmethane derivative

Triphenylmethane (tpm) derivatives (e.g. tpm_CV) have threatened the safety of the aquatic environment due to the potential toxicity and carcinogenicity. In this study, the novel ultrasonic/persulfate/chlorite (US/S₂O₈²⁻/ClO₂⁻) oxidation process was developed for the effective removal of tpm_CV in wastewater. The apparent non-integer kinetics (n around 1.20) of tpm_CV degradation under different factors (R²_Adj > 0.990) were investigated, respectively. Inhibiting effects of anions were greater than those of cations (except Fe(II/III)). The adding of micromolecule organic acids could regulate degradation towards positive direction. The double response surface methodology (RSM) was designed to optimize tpm_CV removal process, and the acoustic-piezoelectric interaction was simulated to determine the propagation process of acoustic wave in the reactor. The possible degradation pathway was explored to mainly include carbonylation, carboxylation, and demethylation. The estimated effective-mean temperature at the bubble-water interface was calculated from 721 to 566 K after introducing the ClO₂⁻, however, the adsorption or partitioning capacity of tpm_CV in the reactive zone was widened from 0.0218 to 0.0982. The proposed co-catalysis of US/S₂O₈²⁻/ClO₂⁻ was based on the determined active species mainly including ClO₂, SO₄⋅⁻, and ⋅OH. Compared with other US-based processes, the operating cost (3.97 $/m³) of US/S₂O₈²⁻/ClO₂⁻ with the EE/O value (16.8 kWh/m³) was relatively reduced.     

基于燃煤电厂超低排放的汞分布特性研究

为掌握超低排放改造后烟气处理装置对汞分布的影响,选择6台有代表性的超低排放火电机组进行现场测试。通过对火电机组入炉煤、炉渣、飞灰、脱硫石膏、末端烟气等样品的测试,得出不同燃烧产物中汞的分布:底渣和湿除出水的汞含量极微;电除尘底灰中的汞所占比重相对较大,平均汞含量占燃烧产物中总汞的比例可达57.97%。依据质量平衡原理,计算出不同超低排放改造工艺路线对汞的协同脱除效率为87.26%~95.60%,并分析了不同污染控制设备对汞排放的影响。     

Seasonal variation in long-range transported dust to a subtropical islet offshore northern Taiwan: Chemical composition and Sr isotopic evidence in rainwater

We investigated chemical and Sr isotopic composition of monthly rainwater collected on Peng-Chia-Yu (PCY) in northern Taiwan. Rainwater ⁸⁷Sr/⁸⁶Sr ratios, Na/Cl, Ca/Cl, Sr/Cl, Sr/Ca, NH₄/Cl, NO₃/Cl, SO₄/Cl and Na/Sr, showed clear seasonal cycles, reflecting mixture of loess carbonates (high Ca/Sr and more radiogenic ⁸⁷Sr/⁸⁶Sr) and seawater (low Ca/Sr and intermediate ⁸⁷Sr/⁸⁶Sr). Model results showed that the former source contributes up to 45% during the winter monsoon period, but seawater is the dominant Sr source in rainwater (>50%) at other times. Two anomalously low ⁸⁷Sr/⁸⁶Sr values occurred in July and August 1998, coinciding with the Merapi eruption in Indonesia. Air-mass backward trajectories and the geochemical and isotopic compositions in rainwater and Merapi lava (i.e. Ca/Sr = 100 and ⁸⁷Sr/⁸⁶Sr = 0.705400) suggested that the Merapi eruption delivered ash across the western equatorial Pacific to PCY. Aerosols leaching experiments were conducted to examine the impact of the 1998 eruption, demonstrating that only a minor terrestrial signature can be extracted by distilled water, implying rapid dispatch of volcanic gases or high-efficiency dissolution of ash related substance in acidic rains.     

水力停留时间对阴离子交换膜生物反应器去除硝酸盐的影响

考察了水力停留时间(HRT)对阴离子交换膜生物反应器去除硝酸盐的影响。实验结果表明,当进水NO3-浓度在113.96~116.01 mg/L范围内,HRT从11.12 h降低到4.82 h,硝酸盐去除率降低,但出水中NO3--N浓度符合我国饮用水水质标准中10 mg/L的要求(NO3-浓度≤44.29 mg/L)。厌氧生物反应器具有良好的反硝化性能,出水NO3-浓度低于20 mg/L。硝酸盐膜通量随着HRT的增加而增加,出水pH值稳定在7左右。     

自制填料与常用湿地填料除磷能力的比较

用石英砂、石灰、水泥和铝粉等材料制作人工湿地填料,并对自制填料、粉煤灰块和钢渣等6种填料的等温吸附特性进行研究,发现自制填料在较低与较高浓度P溶液中吸附率都最高,在P浓度为(10～50 mg/L)时,平均吸附率达96.8%,其次是粉煤灰和钢渣,分别为87.6%和85.4%;填料对P的理论饱和吸附量分别为:自制填料(2 413.6 mg/kg)>粉煤灰块(1 605.8 mg/kg)>钢渣(1 277.5 mg/kg)>碎砖(451.6 mg/kg)>碎石(182.5 mg/kg)>砾石(18.4 mg/kg);填料中金属矿物成分含量高、比表面积大,是除P效果好的原因。     

集中供热锅炉烟气脱硝技术的开发与应用

通过锅炉结构的改进、SCR工艺装置的优化、快速跟踪负荷变化的还原剂制备及控制调节技术的开发和应用等系统性的工作,有效满足了集中供热锅炉房烟气脱硝工程的技术要求,成功开发了集中供热锅炉烟气脱硝技术。在实际工程应用中,确保了在不同负荷段下,锅炉至SCR装置入口段的温度满足脱硝要求,SCR工艺装置能够在不同负荷下连续稳定运行并很好地跟踪负荷的变化,确保氨逃逸率满足设计要求,保证锅炉的安全稳定运行。     

Increased urinary 8-hydroxy-2��-deoxyguanosine levels in workers exposed to di-(2-ethylhexyl) phthalate in a waste plastic recycling site in China

Background

Di-(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in industrial and diverse consumer products. Animal studies indicate DEHP caused developmental, reproductive, and hepatic toxicities. However, human studies of the potential effects of DEHP are limited.

Methods

The exposed site with a history of over 20 years of waste plastic recycling was located in Hunan Province, China. The reference site without known DEHP pollution source was about 50 km far away from the exposed site. In this study, 181 workers working in plastic waste recycling and 160 gender?Cage matched farmers were recruited. DEHP concentrations in water and cultivated soil samples, serum thyroid-stimulating hormone, malondialdehyde (MDA), superoxide dismutase (SOD), urinary 8-hydroxy-2??-deoxyguanosine (8-OHdG), and micronuclei frequency in human capillary blood lymphocytes were analyzed.

Results

Mean levels of DEHP were greater in environment at the recycling site than at reference site (industry wastewater for the exposed: 42.43 ??g/l; well water: 14.20 vs. 0.79 ??g/l, pond water: 135.68 vs. 0.37 ??g/l, cultivated soil: 13.07 vs. 0.81 mg/kg, p?p?p?Conclusions The occupational DEHP exposure might contribute to oxidative deoxyribonucleic acid damage in the male workers.     

腐熟污泥对废水中Cd(Ⅱ)与Zn(Ⅱ)的吸附性能研究

利用腐熟污泥作为一种重金属吸附剂,考察其对水中重金属锌和镉的吸附过程.实验数据的拟合采用了Pseudo-first Order-和Pseudo-second Order 2种动力学模型以及Langmuir和Freundlich 2种吸附等温线模型;拟合结果表明,腐熟污泥对锌与镉的吸附过程符合Pseudo-second ...     

UASB反应器中厌氧氨氧化菌的影响因素研究

在UASB反应器中接种实验室已经驯化好的厌氧氨氧化颗粒污泥,对其进行厌氧氨氧化菌活性提高和影响因素的实验研究。研究表明厌氧氨氧化菌对NH4＋-N和N02--N的适宜浓度负荷均为200mg／L,适宜水力停留时间HRT、温度、pH和进水基质比（N02--N／NH4＋-N）分别为2h、30～35℃、7．5～8．5和0．95～1．2,NH4＋-N、NO2--N和TN的平均去除率分别为97．1％、98．3％和92．7％。