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541.
盐泥吸附剂对直接染料的平衡吸附行为和热力学性质研究 总被引:1,自引:0,他引:1
以染料废水处理用盐泥吸附剂的开发为目的,在静态吸附条件下,研究了含镁盐泥对直接大红、直接深蓝和直接黑3种直接染料的吸附行为,并对吸附过程的热力学进行了分析。结果表明,吸附平衡数据都能够较好地符合Langmuir和Freundlich吸附等温方程,但Langmuir方程能够更好地描述吸附等温线。在25~30℃范围内,3种直接染料在盐泥上的吸附是一个吸热过程,同时伴随着熵值的增加,反应的吉布斯自由能变小。吸附是物理和化学吸附并存的吸附过程,主要推动力为化学键力(化学吸附),同时可能存在范德华力(物理吸附),吸附焓变在74120~87332 kJ/mol之间。 相似文献
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545.
随着科技进步和经济发展,地下卤水和岩盐矿床逐步得到开发利用,该类矿床开采引起的环境影响日益受到关注。本文在分析水溶开采岩盐矿钻探工艺和采输工程基础上,重点分析了岩盐矿水溶开采项目环境影响评价中的污染源及源强,着重阐述了重点污染源的环境影响。并针对特征环境影响因素提出了指导性的环境防护措施。 相似文献
546.
生物有机肥料对温室蔬菜硝酸盐和土壤盐分累积的影响 总被引:1,自引:0,他引:1
探讨了 3种有机肥料对温室苋菜、芹菜硝酸盐和土壤盐分累积的影响。结果表明 :施用有机肥可显著降低蔬菜硝酸盐含量。用 3种有机肥料处理栽培的芹菜NO3- 含量平均值为 2 133mg/kg ,比用蔬菜专用肥 (对照 )的低 1617mg/kg ,其中施用大三元生物有机肥的芹菜NO3- 值最低 ,为 180 3mg/kg,比对照低 1947mg/kg。施用大三元生物有机肥的土壤盐分 (EC)含量也最低 ,0~ 10cm耕层的盐分为 0 0 79S/m ,比对照低 0 0 2 4S/m ;10~ 2 0cm耕层的盐分为 0 0 5 5S/m ,比对照低 0 0 10S/m。 相似文献
547.
泌盐盐生植物研究进展 总被引:39,自引:1,他引:38
根据盐生植物的抗盐生理机制及其形态结构和生态学特征 ,可将盐生植物区分为真盐生植物 (euhalophyte)、泌盐盐生植物 (recretohalophyte)和假盐生植物 (pseudohalophyte)三种类型[1 ] ,每一种类型都有其独特的形态结构、生理功能和生态特征 .泌盐盐生植物体中具有特殊的泌盐结构———盐腺或盐囊泡 ,可将植物体内过多的盐分排到体外 ,故能很好地适应盐渍生境 ,在多种盐渍生境中皆能生存 ,如盐湖、盐漠、盐渍草甸、盐沼等 .中国地域广阔 ,存在各种盐生植物生境 ,但是 ,由于我国专门从事研究盐生… 相似文献
548.
Lignin-derived phenols, C/N ratios and ratios of refractory to total organic matter were used to study the sources, distribution, and diagenesis of sedimentary organic matter along estuary, river bank, and salt marsh systems. The Changjiang Estuary showed a higher signal of terrestrial organic matter at the river mouth which decreased farther offshore. The locations along the Qiantang River were affected by their adjacent surroundings, and the Andong salt marsh showed higher terrestrial organic matter signal at the upper marsh compared to the lower marsh. All studied areas showed slight increases in organic matter decomposition farther downstream and towards the sea. Study of these three different systems will improve our understanding on their ecotoxicological impact. The Changjiang Estuary had higher pollutant levels near the river mouth, which decreased farther offshore due to dilution. The midstream Qiantang River was most likely affected by pollution from their adjacent surroundings. Pollutants were likely to be accumulated in the Andong salt marsh due to the presence of marsh plants and small-sized particles. Organic pollutants were likely to be decomposed during transport along the systems. The ability of the sediments to release inorganic pollutants was determined by whether these systems were oxic or anoxic. 相似文献
549.
Sirajum Munira Annemieke Farenhorst 《Journal of environmental science and health. Part. B》2017,52(12):887-895
Phosphate fertilizers and herbicides such as glyphosate and MCPA are commonly applied to agricultural land, and antibiotics such as tetracycline have been detected in soils following the application of livestock manures and biosolids to agricultural land. Utilizing a range of batch equilibrium experiments, this research examined the competitive sorption interactions of these chemicals in soil. Soil samples (0-15 cm) collected from long-term experimental plots contained Olsen P concentrations in the typical (13 to 20 mg kg?1) and elevated (81 to 99 mg kg?1) range of build-up phosphate in agricultural soils. The elevated Olsen P concentrations in field soils significantly reduced glyphosate sorption up to 50%, but had no significant impact on MCPA and tetracycline sorption. Fresh phosphate additions in the laboratory, introduced to soil prior to, or at the same time with the other chemical applications, had a greater impact on reducing glyphosate sorption (up to 45%) than on reducing tetracycline (up to 13%) and MCPA (up to 8%) sorption. The impact of fresh phosphate additions on the desorption of these three chemicals was also statistically significant, but numerically very small namely < 1% for glyphosate and tetracycline and 3% for MCPA. The presence of MCPA significantly reduced sorption and increased desorption of glyphosate, but only when MCPA was present at concentrations much greater than environmentally relevant and there was no phosphate added to the MCPA solution. Tetracycline addition had no significant effect on glyphosate sorption and desorption in soil. For the four chemicals studied, we conclude that when mixtures of phosphate, herbicides and antibiotics are present in soil, the greatest influence of their competitive interactions is phosphate decreasing glyphosate sorption and the presence of phosphate in solution lessens the potential impact of MCPA on glyphosate sorption. The presence of chemical mixtures in soil solution has an overall greater impact on the sorption than desorption of individual organic chemicals in soil. 相似文献
550.
采用超声吹脱-次氯酸钠氧化工艺处理酮连氮法制肼废水,优化了工艺条件,并进行了尾水处理与盐分回收。实验结果表明:在超声声能密度0.08 W/mL、吹脱气量2 000 L/h、次氯酸钠溶液(有效氯10%)投加量15mL/L、反应时间20 min的最优条件下,COD、氨氮和肼类物质去除率分别达到96.97%、99.02%和96.60%,处理成本约为30元/t(以废水计);尾水经蒸馏处理后可满足GB 8978—1996《污水综合排放标准》的一级B标准,回收NaCl纯度为98.92%,达到GB/T 5462—2015《工业盐》的精制工业盐一级标准。 相似文献