Removal of Cu2+ and dye from wastewater using the heavy metal precipitant N,N-bis-(dithiocarboxy)piperazine

We found that a new heavy metal precipitant, disodium N,N-bis-(dithiocarboxy)piperazine, both precipitates Cu²⁺ ions removes the dye from wastewater. The precipitation was based on a coordination polymerization reaction while the removal of the dye could be mainly attributed to an hydrophobic adsorption at pH 7.     

Extraction,chemical compositions,and cytotoxic activities of essential oils of Thevetia peruviana

Abstract

In this study, The essential oil of flowers, fruits, and leaves of Thevetia peruviana, which were collected in Vietnam, were being reported for the first time. The essential oil of flowers was extracted by different methods: n-hexane extraction, distillation water, and supercritical CO₂ extraction. The compositions of essential oil of different parts of Thevetia peruviana were analyzed by GC-FID and GC/MS systems. Major chemical compositions of essential oil were identified as monoterpenes, sesquiterpenes, terpenoids, and sterol. The activities of total essential oil extracts of the Thevetia peruviana exhibit inhibitory activities against five cancer cell lines.     

Size and shape effects of MnFe2O4 nanoparticles as catalysts for reductive degradation of dye pollutants

• Size and shape-dependent MnFe₂O₄ NPs were prepared via a facile method. • Ligand-exchange chemistry was used to prepare the hydrophilic MnFe₂O₄ NPs. • The catalytic properties of MnFe₂O₄ NPs toward dye degradation were fully studied. • The catalytic activities of MnFe₂O₄ NPs followed Michaelis–Menten behavior. • All the MnFe₂O₄ NPs exhibit selective degradation to different dyes. The magnetic nanoparticles that are easy to recycle have tremendous potential as a suitable catalyst for environmental toxic dye pollutant degradation. Rationally engineering shapes and tailoring the size of nanocatalysts are regarded as an effective manner for enhancing performances. Herein, we successfully synthesized three kinds of MnFe₂O₄ NPs with distinctive sizes and shapes as catalysts for reductive degradation of methylene blue, rhodamine 6G, rhodamine B, and methylene orange. It was found that the catalytic activities were dependent on the size and shape of the MnFe₂O₄ NPs and highly related to the surface-to-volume ratio and atom arrangements. Besides, all these nanocatalysts exhibit selectivity to different organic dyes, which is beneficial for their practical application in dye pollutant treatment. Furthermore, the MnFe₂O₄ NPs could be readily recovered by a magnet and reused more than ten times without appreciable loss of activity. The size and shape effects of MnFe₂O₄ nanoparticles demonstrated in this work not only accelerate further understanding the nature of nanocatalysts but also contribute to the precise design of nanoparticles catalyst for pollutant degradation.     

区域农业生产脆弱性及干旱诊断分析

以山东区域农业生产作为案例，根据主要作物历年产量波动分析，发现趋势产量年际间变化较为平稳，而气象产量年际间变化幅度较大，说明山东农业生产存在着气候脆弱性。通过对比分析光、温生产潜力和光、温、水生产潜力及气象因子对产量的直接、间接通径系数，得出气象产量主要受降水因索的制约，水分是气候资源组合中的薄弱环节，也是山东农业的主要限制因索。历年作物生长期内降水达不到需水要求的概率为20％～35％。各作物不同生育时段的受旱概率相差较大，最低为7％，高的达50％～85％，这些结果为区域农业生产的减灾防灾提供了依据。     

泥化夹层压缩试验的损伤特征及损伤方程研究

泥化夹层的损伤破坏是影响边坡稳定性的重要因素,为研究其损伤机理,进行了不同围压条件下的压缩试验,通过试验数据和试样破坏外观分析损伤情况;利用CT扫描仪在试验不同加载时刻对泥化夹层进行实时CT扫描,结合MATLAB图像二值化处理,得到不同围压下泥化夹层损伤识别图像,反映了内部损伤发展情况;最后根据推广的应变等价原理,通过变形模量确定损伤变量,获得泥化夹层损伤变量与轴向应变的关系。结果表明:①泥化夹层强度普遍表现出随围压增加而增加的规律,破坏应变取为10%,由于泥化夹层自身组成及结构存在差异性,导致个别试样的强度规律不明显;②泥化夹层内部存在薄弱层,加载过程中会出现阶段性的小幅度塌缩,强度曲线上反映为阶段性的应变突增现象;③无围压和一定围压情况下的损伤破坏方式不同,无围压时为脆性破坏,裂缝萌生、开展,一定围压时表现为塑性破坏,泥化夹层被压缩,孔洞裂隙闭合,破坏方式改变临界围压介于0～50kPa;④通过本文方法建立的损伤方程与不同围压下的室内试验结果拟合良好,该方法合理可行。     

电导率法快速鉴别潲水油

许多地方出现了潲水油(或地沟油)回流到食用油市场的现象,为寻找鉴别潲水油的方法,研究了用电导率法鉴别潲水油。将油样和水混合,经过超声波振荡,用电导率仪对其水相进行测定。实验结果表明经过处理的潲水油和合格食用植物油,其水相的电导率值有明显差别,处理后的合格食用植物油水相电导率都在10μs/cm以下,最小的只有3.75μs/cm,而潲水油和水的混合物经过超声振荡后,其水相电导率几乎在100μs/cm以上,最高可达173.4μs/cm。初步认为可将电导率测定作为鉴别潲水油和合格食用植物油的一种方法。     

湖南耐寒桉树优良单株组培研究

本研究以湖南省林业技术推广总站在湖南选育的17个耐寒桉树优良单株为试验材料,进行组培繁殖,有14个优良单株成功地诱导出了愈伤组织或芽。结果表明,以一年生扦插苗的当年生嫩枝作为外植体来源,污染率低且愈伤组织和芽的诱导率高;0.25％氯化汞消毒15—20分钟,可将污染率控制在70％以下,且对外植体的损害最小;按树最佳的诱导培养基为:1/2MS+BA_(1.0)+IBA_(0.25),最佳的继代培基为:MS+BA_(1.0)+KT_(1.0)+VB2_(10)。     

Exposure to PCBs, through inhalation, dermal contact and dust ingestion at Taizhou, China--a major site for recycling transformers

Air samples containing gaseous and particulate phases were collected from e-waste workplaces and residential areas of an intensive e-waste recycling area and compared with a reference site. The highest total concentration of PCBs was detected at transformer recycling workshops (17.6 ng m(-3)), followed by the residential area (3.37 ng m(-3)) at Taizhou, and the lowest was obtained at the residential area of the reference site, Lin'an (0.46 ng m(-3)). The same trend was also observed with regards to PCB levels in dust samples. The highest average PCBs level of 2824 ng g(-1) (dry wt) was found in the transformer recycling workshops, and was significantly higher than that of residential areas of Taizhou (572 ng g(-1) dry wt) and Lin'an (42.4 ng g(-1) dry wt). WHO-PCB-TEQ level in the workshops of Taizhou was 2216 pg TEQ(1998)g(-1) dry wt or 2159 pg TEQ(2005)g(-1) dry wt, due to the high abundance of PCB 126 (21.5 ng g(-1) dry wt), which contributed 97% or 99% of WHO-PCB-TEQs. The estimated intake of PCBs via dust ingestion and dermal absorption by transformer recycling workers were 77.5×10(-5) and 36.0×10(-5) pg WHO-PCB-TEQ(1998)kg(-1)d(-1), and 67.3×10(-5) and 31.3×10(-5) pg WHO-PCB-TEQ(2005)kg(-1)d(-1), respectively.     

Occurrence and behavior of emerging contaminants in surface water and a restored wetland

Pollution mitigation is an important target for restored wetlands, and although there is much information in relation to nutrient removal, little attention has been paid to emerging contaminants. This paper reports on the occurrence and attenuation capacity of 17 emerging contaminants in a restored wetland and two rivers in North-East Denmark. The compounds belong to the groups of pharmaceuticals, fragrances, antiseptics, fire retardants, pesticides, and plasticizers. Concentrations in surface waters ranged from 2 to 1476 ng L⁻¹. The compounds with the highest concentrations were diclofenac, 2-methyl-4-chlorophenoxyacetic acid (MCPA), caffeine, and tris(2-chloroethyl) phosphate (TCEP). The herbicide concentrations increased after a rain-fall event, demonstrating the agricultural run-off origin of these compounds, whereas the concentration of the other emerging contaminants was rather conservative. The mitigation capacity of the restored wetland for the compounds ranged from no attenuation to 84% attenuation (19% on average). Hence, restored wetlands may be considered as a feasible alternative for mitigating emerging contaminants from river waters.     

宝应县畜禽养殖业的现状调研及污染防治对策

调查了宝应县畜禽养殖业的发展现状及分布情况,阐述了该县畜禽养殖业的污染防治状况,分析了污染防治中存在的主要问题,并提出了当地畜禽养殖业污染防治的基本思路和治理措施,对贯彻落实防治措施提出了建议。