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971.
972.
The aquatic environments of the Pearl River Delta in Southern China are subjected to contamination with various industrial chemicals from local industries. In this paper, the occurrence, seasonal variation and spatial distribution of alkylphenol octylphenol (OP) and nonylphenol (NP) in fiver surface water and sediments in the runoff outlets of the Pearl River Delta were investigated. NP and OP were detected in all water and sediment samples and their mean concentrations in surface water during the dry season ranged from 810 to 3366 ng/L and 85.5 to 581 ng/L, respectively, and those in sediments ranged from 14.2 to 95.2 ng/g dw and 0.4 to 3.0 ng/g dw, respectively. In surface water, much higher concentrations were detected in the dry season than those in the wet season. In sediments, the concentrations in the dry season were also mostly higher. High concentrations of NP and OP were found in Humen outlet, likely due to high levels of domestic and industrial wastewater discharges. An ecological risk assessment with the use of hazard quotient (HQ) was also carried out and the HQvalues ranged from 3.6 × 10^-5 to 35 and 64% of samples gave a HQ 〉 1, indicating that the current levels of NP and OP pose a significant risk to the relevant aquatic organisms in the region. 相似文献
973.
微波辅助氢氧化钠改性竹炭对水溶液中铜离子的吸附 总被引:1,自引:0,他引:1
以竹炭为原料,NaOH为改性药剂,采用微波辅助加热的方法对竹炭进行改性,并利用SEM、EDAX、BET、FTIR、pHzpc和Boehm滴定等方法对改性前后的竹炭进行表征.考察了溶液pH、吸附时间、温度和离子强度等对改性竹炭吸附Cu2+的影响.结果表明微波辅助NaOH改性提高了竹炭的比表面积,增加了其表面含氧官能团和总碱基的数量;改性竹炭吸附Cu2+的最佳pH值约为5,吸附过程符合拟二级动力学模型,Langmuir吸附等温方程比Freundlich方程更适合描述Cu2+在改性竹炭上的吸附行为,吸附为放热的物理吸附过程. 相似文献
974.
为评价实现我国2020年碳排放强度和非化石能源发展目标的经济和环境影响,论文应用基于动态CGE模型的中国能源-环境-经济模型,模拟了不同减排政策下的减排效果及经济影响。模拟结果显示,征收40元/t CO2碳税,将碳税作为政府收入、 居民收入、 削减影响较大行业的生产税、 以及用于非化石能源投资,2020年所能实现的减排量分别相当于CO2排放强度在2005年的基础上下降35.87%、 35.80%、 35.07%和40.13%,非化石能源的消费量将占到总消费量的10.99%、 11.00%、 10.75%和15.82%。政策情景下对经济的影响并不是十分显著,GDP的损失不超过0.2%。综合考虑到减排效益和经济影响,将碳税收入用作对非化石能源的投资,不仅有利于促进我国实现2020年碳排放强度目标,而且对于实现非化石能源发展目标也发挥着重要的作用。 相似文献
975.
减少二氧化碳的排放,进一步使其资源化,是中国乃至世界能源生产所需要解决的重大问题。氨法吸收燃煤烟气中的二氧化碳是目前国际上的一个重要研究方向,具有良好的应用前景。为考察燃煤烟气流量以及二氧化碳分压对氨法吸收燃煤烟气中二氧化碳效率的影响,文章在实验室模拟烟气采用氨法吸收烟气中CO2,选用R=50%碳化氨水作为CO2吸收剂,选择填料塔做反应器,考察了烟气流量以及CO2分压对CO2脱除率的影响。研究发现,烟气流量越小,塔内气、液反应时间越长,CO2脱除率越高。在不同烟气流量的条件下,吸收液碳化度均超过130%。混合烟气流量为1 L/min,CO2分压为0.046 MPa时,脱除率最高,反应出液碳化度最大,结晶效果最好。 相似文献
976.
纸塑铝复合包装材料的碳足迹评价与认证 总被引:1,自引:0,他引:1
成都610065摘要:对纸塑铝复合包装的生命周期碳足迹建模、数据收集和计算结果进行了讨论,基于碳足迹评价结果,提出了削减生命周期碳足迹的改进建议,并讨论了碳足迹案例的数据质量. 结果表明:纸塑铝复合包装材料生产80%以上的碳足迹来自纸板、铝箔和塑料的生产,其次是电力和运输;清洁生产、绿色采购和产品设计改进是降低纸塑铝复合包装生命周期碳足迹的有效措施,其中原材料及供应商的选择是最有潜力的措施;此外,应尽可能采用代表产地实际水平的数据,以提高数据质量. 相似文献
977.
The oxidation of As(Ⅲ) with potassium permanganate was studied under conditions including pH, initial As(Ⅲ) concentration and dosage of Mn(Ⅶ). The results have shown that potassium permanganate was an effective agent for oxidizing of As(Ⅲ) in a wide pH range. The pH value of tested water was not a significant factor affecting the oxidation of As(Ⅲ) by Mn(Ⅶ). Although theoretical redox analyses suggest that Mn(Ⅶ) should have better performance in oxidization of As(Ⅲ) within lower pH ranges, the experimental results show that the oxidation efficiencies of As(Ⅲ) under basic and acidic conditions were similar, which may be due to the adsorption of As(Ⅲ) on the Mn(OH)2 and MnO2 resulting from the oxidation of As(Ⅲ). 相似文献
978.
Yangyang Gao Sha Wang Fengjun Yin Pin Hu Xingzu Wang Yuan Liu Hong Liu 《环境科学学报(英文版)》2021,33(3):227-235
The relatively low sensitivity is an important reason for restricting the microbial fuel cell (MFC) sensors’ application in low concentration biodegradable organic matter (BOM) detection. The startup parameters, including substrate concentration, anode area and external resistance, were regulated to enhance the sensitivity of MFC sensors. The results demonstrated that both the substrate concentration and anode area were positively correlated with the sensitivity of MFC sensors, and an external resistance of 210 Ω was found to be optimal in terms of sensitivity of MFC sensors. Optimized MFC sensors had lower detection limit (1 mg/L) and higher sensitivity (Slope value of the linear regression curve was 1.02), which effectively overcome the limitation of low concentration BOM detection. The essential reason is that optimized MFC sensors had higher coulombic efficiency, which was beneficial to improve the sensitivity of MFC sensors. The main impact of the substrate concentration and anode area was to regulate the proportion between electrogens and nonelectrogens, biomass and living cells of the anode biofilm. The external resistance mainly affected the morphology structure and the proportion of living cells of the anode. This study demonstrated an effective way to improve the sensitivity of MFC sensors for low concentration BOM detection. 相似文献
979.
980.