本文選題：鎘　切入點(diǎn)：黃瓜　出處：《山東農(nóng)業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：目前,由于工業(yè)廢水、酸沉降和不合理的農(nóng)田施肥措施導(dǎo)致土壤的酸化進(jìn)程加快,致使土壤中重金屬離子溶解度提高,有效態(tài)含量增加,移動(dòng)性增強(qiáng),不僅對(duì)作物產(chǎn)生毒害,也對(duì)人體健康構(gòu)成威脅。本試驗(yàn)通過添加調(diào)理劑降低土壤pH,研究酸化后土壤中鎘形態(tài)的變化,探究土壤酸化對(duì)鎘形態(tài)及有效性的影響。通過研究酸化土壤條件下鎘的賦存形態(tài)的變化和轉(zhuǎn)化規(guī)律,對(duì)于揭示土壤酸化對(duì)重金屬溶解度和釋放潛力的影響具有一定的意義。研究結(jié)果如下:(1)鎘脅迫下黃瓜株高受到抑制,在(0~300μmol·L~（-1）)鎘濃度范圍內(nèi),華南型均高于等鎘濃度時(shí)的其它4種類型。中低鎘濃度(0~50μmol·L~（-1）)可以刺激黃瓜幼苗根體積的增加,鎘濃度為100~300μmol·L~（-1）時(shí)明顯抑制根的生長。各類型黃瓜幼苗的抗氧化酶(SOD、POD、CAT)活性整體呈現(xiàn)先增后降的趨勢,歐美溫室型POD和CAT活性低于其它類型。50μmol·L~（-1）鎘濃度以下時(shí),幼苗地上部鎘含量整體高于根部,100~300μmol/L濃度時(shí)則相反;300μmol·L~（-1）時(shí),歐美加工型和華北Ⅰ型地上部鎘含量顯著低于其它處理,表現(xiàn)出較好的低累積特征。(2)隨著培養(yǎng)時(shí)間的延長,隨調(diào)理劑用量的增加顯著的降低了土壤pH值,至56d時(shí),最大降低了1.83個(gè)單位。土壤pH值的降低對(duì)土壤中鎘的賦存形態(tài)有顯著影響,減少了土壤中碳酸鹽態(tài)鎘的含量,使其轉(zhuǎn)化成可交換態(tài)鎘。隨pH值的降低,鐵錳結(jié)合態(tài)鎘的含量增加。但pH值對(duì)土壤中有機(jī)結(jié)合態(tài)和殘?jiān)鼞B(tài)的鎘含量無顯著影響。(3)15g·kg~（-1）調(diào)理劑用量顯著增加了印度芥菜的生物量,促進(jìn)了其葉和根的生長。但高用量的調(diào)理劑抑制了其生長。30g·kg~（-1）用量的調(diào)理劑對(duì)印度芥菜的生理代謝有顯著的抑制作用。其中葉綠素含量、凈光合速率等光合指標(biāo)及抗氧化酶活性均顯著低于對(duì)照。15g·kg~（-1）的調(diào)理劑用量對(duì)其無顯著影響。隨調(diào)理劑用量的增加,抑制了土壤脲酶、蔗糖酶、過氧化氫酶的活性,促進(jìn)了土壤酸性磷酸酶的活性,各處理之間差異顯著。15g·kg~（-1）調(diào)理劑用量降低了芥菜單位質(zhì)量中鎘的含量,但因其生物量的增加,增加了鎘的積累量,與對(duì)照相比增加了169.86%。(4)試驗(yàn)表明調(diào)理劑的施用,使土壤的pH降低,使?jié)撛诶脩B(tài)和不可利用態(tài)的鎘轉(zhuǎn)化為可利用態(tài)的鎘,增加了超積累植物印度芥菜鎘的吸收量,減少了土壤中鎘的含量。但土壤的pH降低,使土壤中重金屬鎘離子濃度增大,有效態(tài)含量增加,移動(dòng)性增強(qiáng)。因此,土壤酸化對(duì)土壤重金屬鎘的形態(tài)轉(zhuǎn)化和溶出的影響應(yīng)該引起關(guān)注,通過有效的措施防止土壤酸化,降低土壤和蔬菜中的重金屬污染顯得尤為重要。
[Abstract]:At present, due to industrial wastewater, acid deposition and unreasonable fertilization measures in farmland, the acidification process of soil is accelerated, and the solubility of heavy metal ions in soil is increased, the effective state content is increased, and the mobility is enhanced, which is not only toxic to crops, but also harmful to crops. In this study, the pH of soil was reduced by adding conditioning agent to study the changes of cadmium forms in acidified soil. The effects of soil acidification on the forms and availability of cadmium were studied. The results were as follows: the plant height of cucumber was inhibited under cadmium stress, in the range of 300 渭 mol 路L ~ (-1) ~ (-1) CD ~ (2 +), the effect of soil acidification on the solubility and release potential of heavy metals was studied. The South China type was higher than the other four types when the concentration of cadmium was equal. The root volume of cucumber seedlings could be increased by 50 渭 mol 路L ~ (-1) of low and low cadmium concentration. The activity of antioxidant enzyme SODPOD (CAT-1) of cucumber seedlings increased first and then decreased. The activities of POD and CAT in Europe and America were lower than those in other types of cucumber seedlings under cadmium concentration of .50 渭 mol 路L ~ (-1), and the activities of POD and CAT in greenhouse type were lower than those in other types of cucumber seedlings under the cadmium concentration of .50 渭 mol 路L ~ (-1), while the activities of POD and CAT in Europe and America were lower than those in other types of cucumber seedlings. When the CD content in shoot was higher than that in root (100 渭 mol 路L ~ (-1)), the CD content of American and European type and type 鈪，

本文編號(hào)：1588054