Lithium extraction from salt lake brines with high magnesium/lithium ratio: a review

Environmental Chemistry Letters - The demand for lithium is growing rapidly with the increase in electric vehicles, batteries and electronic equipments. Lithium can be extracted from brines, yet...     

Effect of pressure and atmosphere during hydrothermal treatment on the properties of sewage sludge-derived solid fuel

Journal of Material Cycles and Waste Management - Efforts to improve the performance of hydrothermal treatment (HT) in producing high-quality solid fuel from sewage sludge were carried out by...     

Utilization of iron ore tailing for the synthesis of zeolite A by hydrothermal method

Journal of Material Cycles and Waste Management - The iron ore tailing (IOT) is an industrial waste, in which large accumulations represent a serious environmental threat. To reduce the...     

试论生态文明制度体系的构建

建立健全生态文明制度体系是推进我国生态文明建设的重点。党的十八届三中全会通过的《中共中央关于全面深化改革若干重大问题的决定》指出,生态文明制度体系应当包括决策制度、评价制度、管理制度与考核制度等内容。立足社会主义制度建设的中国特色,针对我国生态文明建设的具体需求,本文将生态文明制度体系解构为四大板块:绿色高效决策制度、生态有价评估制度、生态环境监管制度与生态优先考核制度,并进一步明确了各项制度构建工作的具体内容。生态文明制度体系的构建和不断完善,将为全面建成人与自然和谐的美丽中国提供系统保障。     

纳米铁氧化物吸附处理重金属废水的研究进展

概述了用于吸附重金属的主要纳米铁氧化物的种类及其吸附效果,介绍了常见的纳米铁氧化物制备方法及改性方法,讨论了影响纳米铁氧化物吸附重金属的主要因素,并对纳米铁氧化物在水环境保护领域中的研究方向提出了展望:如发展绿色、高效的纳米铁氧化物制备工艺,探讨纳米铁氧化物结构调控和表面功能化对其吸附性能的影响等。     

Difference in the net value of ecological services between natural and artificial forests in China

Land degradation is a global problem that seriously threatens human society. However, in China and elsewhere, ecological restoration still largely relies on a traditional approach that focuses only on ecological factors and ignores socioeconomic factors. To improve the effectiveness of ecological restoration and maximize its economic and ecological benefits, a more efficient approach is needed that provides support for policy development and land management and thereby promotes environmental conservation. We devised a framework for assessing the value of ecosystem services that remain after subtracting costs, such as the opportunity costs, costs of forest protection, and costs for the people who are affected by the program; that is, the net value of ecosystem services (NVES). To understand the difference between the value of a resource and the net value of the ecosystem service it provides, we used data on VES, timber sales, and afforestation costs from China's massive national afforestation programs to calculate the net value of forest ecosystem services in China. Accounting for the abovementioned costs revealed an NVES of ¥6.1 × 10¹² for forests in 2014, which was 35.9% less than the value calculated without accounting for costs. As a result, the NVES associated with afforestation was 55.9% less than the NVES of natural forests. In some regions, NVES was negative because of the huge costs of human-made plantations, high evapotranspiration rates (thus, high water opportunity costs), and low forest survival rates. To maximize the ecological benefits of conservation, it is necessary to account for as many costs as possible so that management decisions can be based on NVES, thereby helping managers choose projects that maximize both economic and ecological benefits.     

网状季胺基阴离子吸附剂制备及吸附性能

以丝瓜络为原料,采用醚化-接枝技术制备出季胺基阴离子交换吸附剂。采用电镜扫描、傅里叶红外光谱、比表面积孔径分布测定仪和元素分析仪等仪器对其进行分析和结构表征,并考察了温度、p H和硝酸盐初始浓度等因素对NO-3去除率的影响。实验结果表明,在20℃,p H值为3~10时,NO-3的吸附率可达90%左右;在不同温度下该吸附过程用Langmuir等温线模型和Freundich等温线模型描述均可;与伪一级动力学方程相比,伪二级动力学方程能更好地描述其吸附动力学方程。     

活性炭吸附和两级Fenton氧化组合工艺处理高盐对氨基苯酚生产废水

采用活性炭吸附和两级Fenton氧化组合工艺对高盐度对氨基苯酚生产废水进行了处理实验研究。结果表明,p H值对活性炭去除有机物的影响较小。当活性炭投加量为4 g/L时,TOC去除率61%。分级加药可以有效提高Fenton氧化对有机物的去除效率。在温度为25℃、p H为3、30%H2O2投加量为3%(V/V)、Fe2+/H2O2摩尔比为0.05时,两级Fenton氧化处理后,出水TOC降至150 mg/L以下。此外,Fenton氧化后形成氢氧化铁污泥颗粒粒径为4.5μm,经过聚丙烯酰胺(PAM)絮凝之后,污泥的粒径明显增加,过滤特性改善。PAM絮凝效果依赖于溶液的p H值,当p H超过10后会失去作用,故在使用过程中需要严格控制溶液的p H值。     

Changes in plasma thyroid hormones and cortisol levels in crucian carp (Carassius auratus) exposed to the extracted microcystins

The endocrine response of crucian carp injected intraperitoneally with extracted microcystins (MC) was investigated in this study. Fish were injected intraperitoneally either with 0.75% NaCl (control) and Microcystis extract corresponding to 150 and 600 microg microcystins per kg body weight. The plasma levels of triiodothyronine (T(3)), thyroxine (T(4)), free triiodothyronine (FT(3)), free thyroxine (FT(4)), and cortisol were determined at 0, 1, 3, 12, 24, and 48h post-administration of MC-containing extract. Treated fish displayed abnormal behaviors, such as a startle response and disoriented swimming, as well as changes in ventilation rates. Plasma cortisol concentrations of fish in both dose groups significantly increased after administration of extracted MC and remained high throughout the experiment, which suggested that MC elicited a stress response in treated fish. The profiles of cortisol changes in treated fish appeared to be dose dependent, indicating that fish in the high dose group experienced greater MC-induced disturbance. Mortality occurred after 12h in the high dose group. Plasma levels of T(4), T(3), FT(4), and FT(3) did not vary significantly between the control fish. In contrast to this, fish exposed to MC-containing extract showed significant declines in T(3), FT(4), and FT(3) levels in a dose-dependent manner throughout the experiment. Plasma T(4) levels, however, did not vary significantly in the low dose group, whereas they decreased significantly at 48h post injection in the high dose group. This study demonstrates that administration of microcystins-containing extract causes a stress response and reduces the plasma levels of thyroid hormones in crucian carp. These results illustrate that microcystins exerted potent effects on the endocrine system of crucian carp, through activating their hypothalamus-pituitary- interrenal axis and disturbing thyroid function.