本文選題：磷 + 吸附��； 參考：《中國海洋大學(xué)》2014年碩士論文

【摘要】：營養(yǎng)鹽是海洋環(huán)境質(zhì)量監(jiān)測的重要內(nèi)容之一。海水中的磷是引起水體富營養(yǎng)化、赤潮等的主要營養(yǎng)元素之一，水體中的磷量過多會導(dǎo)致藻類過量繁殖進而引起水質(zhì)惡化，嚴重破壞水體的生態(tài)平衡，威脅到水生生物的生存以及人類的健康。海洋中的沉積物能夠吸附水體中的磷減緩水體的富營養(yǎng)化進程，尤其是沉積物中的自然膠體部分（粘土礦物、有機質(zhì)及活性金屬水合氧化物），其能夠通過一系列物理化學(xué)反應(yīng)，如吸附、絡(luò)合、共沉淀等作用，從水體中富集包括磷在內(nèi)的多種污染物及其他有毒物質(zhì)，，對水體中磷的遷移轉(zhuǎn)化發(fā)揮著極其重要的作用；另外，沉積物吸附的磷在一定條件下又可釋放到水體中，嚴重時導(dǎo)致水體富營養(yǎng)化，造成二次污染。由于海洋中的沉積物，尤其是沉積物中的粘土礦物和有機質(zhì)，其對磷的吸附作用對水體富營養(yǎng)化的控制發(fā)揮著非常重要的作用，因此研究沉積物、粘土礦物及有機質(zhì)對磷的吸附作用具有重要的意義。 本論文研究了鹽度和溫度變化對磷酸鹽在高嶺土、腐殖酸上吸附的影響。并從長江口鄰近海域采集沉積物，研究了沉積物自身性質(zhì)（粒度、HCl處理去除碳酸鹽、H2O2處理去除有機質(zhì)等）及環(huán)境因素（介質(zhì)中有機質(zhì)濃度、pH等）對海洋沉積物吸附磷的影響。 主要結(jié)論如下： （1）高嶺土的零凈質(zhì)子電荷點pHPZNPC約為3.8，離子強度對高嶺土的pHPZNPC基本沒有影響。高嶺土對磷的動力學(xué)吸附過程用偽二級動力學(xué)方程描述較好，溫度越高，高嶺土對磷的吸附速率越大。等溫吸附曲線用Langmuir等溫式擬合較好，磷的吸附量隨溫度的升高、鹽度的降低而增加。磷在高嶺土上的吸附是自發(fā)、吸熱、熵增加的過程。 （2）腐殖酸（HA）的零凈質(zhì)子電荷點pHPZNPC在3.5~5.8之間，離子強度對腐殖酸的pHPZNPC影響較大。腐殖酸對磷的動力學(xué)吸附過程用偽二級動力學(xué)方程描述較好，溫度越高，腐殖酸對磷的吸附速率越大。等溫吸附曲線用Langmuir等溫式擬合較好，磷的吸附量隨鹽度的增加而增加；在15~25℃范圍內(nèi)，溫度對磷在腐殖酸上的吸附量幾乎沒有影響；與腐殖酸原樣相比，不溶NSW腐殖酸對磷的吸附能力增大。 （3）沉積物對磷的吸附可用偽二級動力學(xué)方程描述，沉積物粒度越小、初始磷濃度越大，對磷的吸附速率越大。由于沉積物一般含內(nèi)源磷，等溫吸附曲線可用Langmuir-交叉型等溫式擬合，且擬合結(jié)果最好，磷的吸附量隨粒度減小而增加。沉積物經(jīng)HCl處理除去碳酸鹽之后，對磷的吸附能力增強；經(jīng)H2O2處理除去有機質(zhì)之后，對磷的吸附能力減弱。在高濃度的HA介質(zhì)中，沉積物對磷的吸附量與介質(zhì)中HA的濃度正相關(guān)。pH對沉積物吸附磷的影響較為復(fù)雜：pH5時，隨著pH的升高，沉積物對磷的吸附量逐漸增加；pH在5~9范圍內(nèi)，隨著pH的升高，沉積物對磷的吸附量降低；pH9時，隨著pH的升高，沉積物對磷的吸附量增加，且pH約為7~9范圍內(nèi)存在“穩(wěn)定pH范圍”。
[Abstract]:Nutrient is one of the important contents of marine environmental quality monitoring. Phosphorus in sea water is one of the main nutrient elements, such as eutrophication and red tide. Excessive phosphorus content in water will lead to algal overproduction and water quality deterioration, which will seriously damage the ecological balance of water body. It threatens the survival of aquatic organisms and human health. Sediments in the ocean can absorb phosphorus from water bodies to slow down the process of eutrophication, especially the natural colloidal parts of sediments (clay minerals, organic matter and active metal hydrated oxides), which can undergo a series of physical and chemical reactions. Such as adsorption, complexation, coprecipitation and so on, the enrichment of various pollutants, including phosphorus, and other toxic substances from the water body plays an extremely important role in the transport and transformation of phosphorus in the water body. Phosphorus adsorbed by sediment can be released into water under certain conditions, which can lead to eutrophication and secondary pollution. Because sediments in the ocean, especially clay minerals and organic matter in sediments, play a very important role in controlling eutrophication of water bodies, the adsorption of phosphorus by them plays a very important role in controlling eutrophication of water bodies. The adsorption of phosphorus by clay minerals and organic matter is of great significance. The effects of salinity and temperature on phosphate adsorption on kaolin and humic acid were studied. The effects of sediment properties (removal of carbonate and H _ 2O _ 2 by HCl treatment) and environmental factors (concentration of organic matter in medium, pH, etc.) on phosphorus adsorption in marine sediments were studied. The main conclusions are as follows: 1) the zero net proton charge point (pHPZNPC) of kaolin is about 3.8, and the ionic strength has no effect on the pHPZNPC of kaolin. The kinetic adsorption process of phosphorus on kaolin is described by pseudo-second-order kinetic equation. The higher the temperature, the higher the adsorption rate of phosphorus. The isothermal adsorption curve was fitted well by Langmuir isothermal equation. The adsorption capacity of phosphorus increased with the increase of temperature and the decrease of salinity. Phosphorus adsorption on kaolin is a spontaneous, endothermic and entropy increasing process. (2) the zero net proton charge point (pHPZNPC) of humic acid (HA) is in the range of 3.5n5.8.Ionic strength has a great effect on the pHPZNPC of humic acid. The kinetic adsorption process of humic acid on phosphorus was described by pseudo-second-order kinetic equation. The higher the temperature, the higher the adsorption rate of phosphorus. The isothermal adsorption curve was fitted well by Langmuir isothermal equation, and the adsorption capacity of phosphorus increased with the increase of salinity, and the temperature had little effect on the adsorption capacity of phosphorus on humic acid at 1525 鈩

本文編號：1845001