共查询到19条相似文献，搜索用时 109 毫秒
1.
为了阐明黏土方法治理有害赤潮的生态环境效应，研究了有机改性黏土对海水中营养盐和溶解氧、化学耗氧量、pH等主要水质因子的影响。结果表明，有机改性黏土对营养盐，尤其是磷酸盐有一定的吸附作用，吸附量随水体中磷酸盐浓度的增加而增大，不同有机改性黏土对海水中磷酸盐的吸附能力为：有机改性黏土Ⅰ〉有机改性黏土Ⅱ〉有机改性黏土Ⅲ。通过有机改性黏土对磷酸盐的吸附再释放作用研究，进一步探讨了磷酸盐释放作用对赤潮异弯藻（Heterosigma akashiwo）、东海原甲藻（Prorocentrum donghaiense）等赤潮生物生长的影响。实验结果表明，经过有机改性的黏土有利于提高其对磷酸盐的吸附能力，降低对磷酸盐的解吸率，缓解海水富营养化程度，虽然少量被吸附的磷酸盐能缓慢释放，但仍不足以维持赤潮生物的正常生长。同时利用有机改性黏土治理赤潮能显著改善溶解氧、pH、化学耗氧量等水质指标，有利于治理赤潮后的环境修复。 相似文献
2.
大亚湾养殖海区沉积物中营养盐的解吸——吸附 总被引：9，自引：0，他引：9
研究了天然海水体系大亚湾养殖海区表层沉积物营养盐的解吸－吸附规律。结果表明,沉积和扣磷酸盐和硅酸盐解吸２小时基本达到平衡,而铵盐、硝酸盐和亚硝酸盐０．５小时内基本达到平衡;各营养盐的解吸随ＰＨ值（小于８）降低而增大,随ＰＨ值（大于８）升高略有增加;盐度仅在低于１０时对各营养盐的解吸有影响。研究了磷酸盐在沉积物上的吸附等温线。 相似文献
3.
采用溶液插层法,利用壳聚糖和蒙脱土制备了壳聚糖/蒙脱土插层复合物,使用红外光谱和X-射线衍射分析对其结构进行了表征;以此复合物为活性红染料RR136的吸附剂,考察了复合物中壳聚糖与蒙脱土的摩尔比、染料溶液pH值和浓度、吸附温度及吸附剂用量等因素对吸附性能的影响。结果表明,吸附反应的最佳条件是以壳聚糖与蒙脱土摩尔比为5∶1的插层复合物为吸附剂,反应温度20℃,RR136溶液pH为3。壳聚糖/蒙脱土插层复合物对活性红染料的吸附更符合Langmuir模型,吸附热力学参数ΔGo、ΔHo和ΔSo值分别为-3.338kJ·mol-1(30℃),-37.98kJ·mol-1和-114.77J·mol-1·K-1,表明壳聚糖/蒙脱土插层复合物对活性红染料的吸附是自发的、以物理吸附为主的放热反应。 相似文献
4.
厦门港表层沉积物对海水中铅的吸附动力学 总被引：1，自引：0，他引：1
模拟研究厦门港表层沉积物对海水中Ｐｂ的吸附动力学及水环境条件的影响，当海水温度由２０－３０℃、ＰＨ５－８和盐度３０－４变化时，吸附速率分别提高约５０％、、个数量和５倍。吸附速率与盐度之间呈负指数相关关系。吸附过程可用交换吸附动力学模式描述。测定吸附速率常数、表观活化能和平衡吸附量等参数研究表明，沉积物对Ｐｂ的吸附性质以华东作用为主。 相似文献
5.
粘土表面改性是提高粘土絮凝有害藻华效率的重要方法。本文融合铁系与铝系絮凝剂的优点,将两者复合,制备出了不同Fe含量的铁铝复合改性粘土,考察其对东海原甲藻(Prorocentrum donghaiense)、赤潮异弯藻(Heterosigma akashiwo)和塔玛亚历山大藻(Alexandrium tamarense)的去除效率。结果表明,铁的复合对原改性粘土去除藻华生物的效率具有提升作用,该作用随Fe含量的增加而增大,最高可达20%—30%。本研究还采用Zeta电位仪和粒子成像测速仪测定了复合改性粘土在海水中的表面特征和絮凝特性,发现与原改性粘土相比,铁铝复合改性粘土体系中,随Fe含量的增多,粘土表面电位最高可提升15%;稳定絮凝体指数(γ)降低,絮体强度增加。因此, Fe盐的引入,可以有效提高改性粘土颗粒表面正电性和絮体的抗破坏能力,从而增强改性粘土的絮凝除藻效果。 相似文献
6.
7.
使用多种改性方法对几种国产天然沸石进行改性处理,提高其铵氮吸附率,制备符合海水硝酸盐氮同位素预处理要求的沸石。发现重力筛选可提高沸石铵氮吸附率16%以上,钠改性及酸改性后钠改性可提高沸石铵氮吸附率80%以上,微波改性和超声波改性均可进一步提高沸石铵氮吸附率。改性处理后,几种沸石在酸性条件下对低浓度铵氮吸附率达90%以上,其氮同位素分馏较美国UOP沸石分馏系数更小,且更稳定。改性后的国产沸石更适于海水硝酸盐氮同位素预处理。应用改性后沸石对长江口海域硝酸盐水样进行了分析,结果表明,改性后沸石可以应用于海水中溶解态硝酸盐的氮同位素分析,为海水中溶解态氮的来源问题及循环机理研究等提供了有效信息。 相似文献
8.
9.
关于控制水体中重金属含量的因素,六十年代以来文献陆续有所报导.在海水体系中粘土矿物对重金属的固定作用的研究,较早期的有Chester(1965)的伊利石吸附海水中钴和锌的研究.近五年来又见有Rermers[1]、Murray[2]、Meyers[3]、O'conner[4]、Weijden[5]以及Robin[6]等进一步分别探讨了粘土矿物对重金属吸附作用的影响因素、吸附能力及吸附动力学等问题,其中有的还提出了吸附作用的模式. 相似文献
10.
11.
12.
In June 2003 and 2006 concentrations of nutrient were determined in the Changjiang Estuary. The data indicated that phosphate and nitrate did not behave conservatively in the estuary, but silicate behaved conservatively. An important mobilization of phosphate and nitrate was observed from the river up to halfway in the estuary. Both input flux (from river to estuary) and output flux (from estuary to coastal zone) of phosphate, silicate and nitrate were calculated from statistical interpretations of the salinity profiles. There was a large discrepancy between input and output fluxes of phosphate and nitrate. The river fluxes of silicate, phosphate and nitrate (fr) are augmented 5.3%, 28.9% and 36.6% in June 2003 and 1.0%, 62.5%, 31.7% in June 2006 by internal inputs (fi). The phosphate and nitrate fluxes are enhanced through the estuarine process, while silicate flux is unaltered. The authors present some long-term data for nutrient concentrations and the ratios of silicon to nitrogen to phosphorus in the Changjiang Estuary. Silicate level falled in the last two decades, while concentration of nitrate increased. Phosphate concentration had no significant change. 相似文献
13.
Interactions between dissolved petroleum hydrocarbons and pure and humic acid-coated mineral surfaces in artificial seawater 总被引：7，自引：0，他引：7
The adsorption of total petroleum hydrocarbons (TPHs) on suspended particles in the marine environment is an important process affecting the fate of oils spilled in the ocean. Adsorption kinetics and adsorption isotherms of the water-soluble fraction of Fuel Oil No. 6 were performed on pure and humic acid-modified montmorillonite, alumina and kaolinite. The rates of adsorption on all sorbents are very fast and a pseudo-equilibrium is reached within 0.5 h. Linear adsorption isotherms were obtained for TPH and individual aromatic hydrocarbons on all sorbents. Higher sorption coefficients (Kd) were obtained for the humic acid-coated clays compared to the pure clays. However, a great contribution of mineral surface to overall adsorption was found on humic acid-modified particles in this study. A linear relationship between the log K and log Kow was also found for individual compounds on both pure alumina (log Km) and humic acid-coated alumina (log Koc). 相似文献
14.
15.
在三次采油领域里,吸附滞留量是影响化学剂驱油效果的关键因素之一。结合现场实施注聚采油工艺出现的各种问题,在基础理论的指导下,通过室内模拟实验45℃条件下,利用淀粉-碘化镉比色法研究了聚丙烯酰胺水溶液在不含油石英砂中的静态吸附及人造均质岩心中的动态滞留规律,并考察了高岭土对其滞留量产生的影响。实验结果表明,吸附等温线基本符合S型,溶液浓度在1 200 mg/L附近达饱和吸附;高岭土的存在使聚合物在石英砂中的吸附量及岩心中的滞留量增加,随着高岭土含量的增加,吸附滞留量由0.353 mg/g增加到0.794 mg/g。相同实验条件下,吸附量要远远多于滞留量。 相似文献
16.
The natural Na-type montmorillonite (Na-MMT) was treated with HNO3 to obtain acid-activated montmorillonite (acid-MMT). The materials were characterized by XRD, XRF, SEM, and N2 adsorption–desorption at low temperature. Results indicated that the structure and textural properties of MMT were significantly changed via acid activation. Meanwhile, the potential use of acid-MMT as adsorbent for the removal of phenol from aqueous solution was evaluated. Important parameters which affected adsorption, such as contact time, pH of solution, and mass of acid-MMT had been investigated. The removal of phenol was decreased with the increase of pH value, and increased with the increase of contact time and mass of acid-MMT. The equilibrium data in aqueous solutions were well represented by the Freundlich isotherm. 相似文献
17.
S.N. De Sousa 《Estuarine, Coastal and Shelf Science》1983,16(3):299-308
Behaviour of silicate, nitrate and phosphate in the Mandovi Estuary was studied during the premonsoon season. The study shows that silicate is removed from the water column while nitrate showed an internal source. This nitrate source has been identified as the wash water from an iron ore screening plant which discharges the muddy waste directly into the river. Applying mixing relations, the distribution of this nitrate both up- and downstream of the outfall has been studied. Phosphate showed very low concentrations in the low salinity region; however, its concentration increased slightly towards the higher salinity region. 相似文献
18.
东海沉积物间隙水中K,Na,Xa,Mg硅酸盐的热力学平衡 总被引：1，自引：0，他引：1
研究了东海沉积物间隙水中Ｋ，Ｎａ，Ｃａ，Ｍｇ硅酸盐的热力学平衡，结果表明，间隙水中的镁有明显转移，在较高的ｐＨ（〉８．５）下，可形成带Ｍｇ（ＯＨ）２夹层的无序海泡石（Ｗ）沉淀，从而有效地除去间隙水中的镁及溶解硅，海底到盐矿物钙长石，钾长石可风化为钙蒙脱石，高岭石等，钠长石仅表现为溶解，使间隙水中钠浓度增高。 相似文献
19.
The extent and mechanisms of adsorption of marine pore water organic matter to montmorillonite were studied in a series of batch and sequential adsorption experiments. Pore water natural organic matter (pNOM) and easily extracted natural organic matter (eNOM) were collected from Liberty Bay (Puget Sound, WA, USA) sediments. The pNOM and eNOM were each divided into two size fractions using a 1000 D ultrafilter. Batch adsorption isotherms were approximately linear, and the >1000 D fractions of both pNOM and eNOM had larger partition coefficients (Kd) than the <1000 D fractions. A two-component fit of the sequential adsorption data indicated that pNOM and eNOM contained a similar amount of NOM (30%) that was not surface reactive toward montmorillonite. After correcting the batch adsorption Kds for the non-reactive components, the Kds estimated by batch and sequential adsorption were identical (2.7 l/kg for >1000 D pNOM and eNOM, and 1.6 l/kg for <1000 D pNOM and eNOM). Mechanisms of adsorption were investigated by systematically changing conditions (pH, temperature and ionic composition) of >1000 D fractions during batch isotherm experiments. Adsorption of NOM was found to decrease with increased temperature, suggesting that hydrophobic effects were not the dominant adsorption mechanisms in this system. Ion exchange was also not an important adsorption mechanism because adsorption increased with ionic strength. The observed enhancement in adsorption with ionic strength indicated that van der Waals interactions were important in the adsorption of NOM. Ligand exchange was found to be a significant mechanism since the presence of SO42− in solution reduced the amount of NOM adsorbed. Ca2+ enhanced adsorption slightly more than Na+, suggesting that cation bridging was involved. The relative contributions of van der Waals interactions, ligand exchange and cation bridging were estimated to be approximately 60%, 35% and 5%, respectively, for adsorption of NOM in a CaCl2 solution. 相似文献