本文關(guān)鍵詞：不同堆腐條件下污泥中多環(huán)芳烴變化特征及在土壤—植物中遷移規(guī)律　出處：《沈陽農(nóng)業(yè)大學(xué)》2016年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 污泥堆腐 多環(huán)芳烴 遷移規(guī)律

【摘要】：近年來,我國(guó)污泥產(chǎn)量劇增,尋求合理的污泥處理處置出路已成為急需攻克的難題。污泥經(jīng)堆腐后土地施用被認(rèn)為是最有前途的污泥處置方式。多環(huán)芳烴是污泥中普遍存在的有機(jī)污染物,目前對(duì)污泥中多環(huán)芳烴去除及在土壤中遷移轉(zhuǎn)化方面研究比較匱乏。為此,本文研究了不同模擬堆腐條件下污泥中14種多環(huán)芳烴變化特征、篩選多環(huán)芳烴去除條件,揭示污泥堆腐過程中多環(huán)芳烴與不同形態(tài)腐殖質(zhì)結(jié)合特征,研究了污泥室外堆腐過程中有機(jī)質(zhì)腐熟變化及多環(huán)芳烴變化特征。通過田間小區(qū)和室內(nèi)翁栽試驗(yàn)探討堆腐污泥施用過程中多環(huán)芳烴在土壤-植物中遷移規(guī)律。取得的主要結(jié)論如下：1.沈陽市4座典型污水處理廠污泥的有機(jī)質(zhì)、氮、磷和鉀養(yǎng)分含量豐富。重金屬Cu、Cd、Pb、Zh、Ni和Cr在各污泥中均被檢出,以Zn和Cu為主。在污泥進(jìn)行土地施用時(shí),Cu和Cd最先成為限制因子,以CJ/T309-2009污泥農(nóng)用年施用量0.75 kg m-2計(jì)算,有1種污泥在酸性土壤上的安全施用年限為10年,其余污泥為28-47年。各污泥中14種多環(huán)芳烴總量介于2.63～18.3 mgkg-1,且均以3～4環(huán)為主,均來自燃燒源。與CJ/T 309-2009限定值(≤5mg kg-1)相比,有3種污泥的多環(huán)芳烴總量分別超標(biāo)266.7%、48.4%和14.5%。因此,只要施用合理,重金屬不再是污泥土地施用的限制因素,但在施用前必須經(jīng)堆腐無害化預(yù)處理,使多環(huán)芳烴類有機(jī)污染物含量降低。2.室內(nèi)模擬堆腐試驗(yàn)表明,不同調(diào)理劑對(duì)多環(huán)芳烴去除效果依次為草炭-稻草草炭-花生殼單一稻草單一花生殼單一草炭；隨含水量增加,多環(huán)芳烴去除率呈先增加后降低變化規(guī)律,最佳含水量為55%；隨溫度增加,多環(huán)芳烴去除率呈先增加后降低變化,最佳溫度為35℃；隨通氧量增加,多環(huán)芳烴去除率也呈先增加后降低變化,最佳通氧量為8.64 L h-1kg-1,不通氧時(shí)小分子多環(huán)芳烴去除效果變差。整體來講,3-4環(huán)PAHs去除效果優(yōu)于5環(huán)、6環(huán)和2環(huán)。正交試驗(yàn)結(jié)果表明,不同因素對(duì)多環(huán)芳烴去除影響大小依次為調(diào)理劑種類含水量通氧量溫度。在污泥：草炭：稻草=3：1：2、55%含水量、38℃和通氧量為7.92 Lh-1kg-1堆腐條件下,污泥中多環(huán)芳烴去除率最大,為79.6%。3.不同模擬堆腐條件下污泥中總有機(jī)碳變化規(guī)律與多環(huán)芳烴一致。以草炭-稻草為調(diào)理劑時(shí)胡敏酸碳含量和H/F比增幅大于其它調(diào)理劑,35℃時(shí)胡敏酸碳含量和H/F比增幅大于其它溫度。污泥堆腐過程中胡敏酸碳含量隨含水量增加而提高,但55%含水量條件下總有機(jī)碳降幅最大。污泥堆腐過程中胡敏酸碳含量和H/F比隨通氧量增加而降低,但通氧量為8.64 L h-1 kg-1時(shí)總有機(jī)碳降幅最大。因此,在污泥堆腐實(shí)踐中,前期應(yīng)增加通氧量以提高多環(huán)芳烴去除效果,后期減少通氧量以提高腐殖化程度。4.不同模擬條件下污泥堆腐過程中腐殖酸與多環(huán)芳烴之間呈正相關(guān),胡敏酸與多環(huán)芳烴之間呈負(fù)相關(guān)(45%含水量和10.8 Lh-1 kg-1通氧量除外),富旱酸與多環(huán)芳烴之間均呈正相關(guān),H/F比與多環(huán)芳烴之間也呈負(fù)相關(guān)。堆腐的前15天,多環(huán)芳烴在不同形態(tài)腐殖質(zhì)中的含量高低表現(xiàn)為殘?jiān)鼞B(tài)堿溶態(tài)水溶態(tài),堆腐的后15天則表現(xiàn)為堿溶態(tài)殘?jiān)鼞B(tài)水溶態(tài)。堆腐前后殘?jiān)鼞B(tài)多環(huán)芳烴含量由2508.0 ng g-1下降為198.8 ng g-1；堿溶態(tài)含量由1125.4 ng g-1下降為569.7 ng g-1；水溶態(tài)則由137.5 ng g-1下降為27.0 ng g-1。表明隨堆腐進(jìn)行,PAHs與腐殖質(zhì)結(jié)合越緊密,PAHs的生物有效性降低。5.室外堆腐試驗(yàn)結(jié)果表明,污泥堆腐結(jié)束時(shí)總有機(jī)碳較堆腐前下降44.9%,C/N比由20.7下降為14.9,H/F比由0.51增加到2.47。堆腐產(chǎn)物結(jié)構(gòu)疏松、顏色為褐色,無明顯臭味,有泥土氣息。三維熒光光譜和紅外光譜顯示水溶性有機(jī)物共軛結(jié)構(gòu)和芳香結(jié)構(gòu)增多,紫外光譜和紅外光譜也顯示污泥堆腐后胡敏酸和富里酸芳構(gòu)化、腐殖化程度提高。堆腐結(jié)束時(shí)多環(huán)芳烴總量去除率為81.4%,表現(xiàn)為3～4環(huán)多環(huán)芳烴去除效果明顯優(yōu)于5環(huán)、6環(huán)和2環(huán)化合物。堆腐前2-6環(huán)芳香烴分布特征表現(xiàn)為4環(huán)3環(huán)5環(huán)6環(huán)2環(huán)；堆腐結(jié)束時(shí)已檢不出2個(gè)苯環(huán)的萘和苊烯,而3～6環(huán)分布特征表現(xiàn)為4環(huán)5環(huán)3環(huán)6環(huán)。6.田間試驗(yàn)表明,堆腐污泥施用(2～25kgm-2)改善了土壤的機(jī)械組成,施用量為25kg m-2時(shí)的土壤質(zhì)地已接近沙壤土；土壤有機(jī)碳、全氮和全磷肥力水平由6級(jí)提高到3-5級(jí)。堆腐污泥施用增加了土壤中多環(huán)芳烴含量,施用量為25 kg m-2的土壤中多環(huán)芳烴含量為137.6 ng g-1,滿足荷蘭土壤質(zhì)量控制標(biāo)準(zhǔn),屬于無污染水平(200 ng g-1。)。施用堆腐污泥促進(jìn)了樟子松苗木和高羊茅生長(zhǎng),但樟子松苗木和高羊茅生長(zhǎng)效應(yīng)分別在施用量超過20kgm-2和10 kg m-2時(shí)出現(xiàn)抑制,因此年施用量宜分別控制在20 kgm-2和10 kg m-2以內(nèi)。忽略多環(huán)芳烴降解因素,按年施用量2 kg m-2計(jì)算,連續(xù)施用19年,土壤中多環(huán)芳烴含量為199.9 ng g-1,仍屬于無污染水平。此外,多環(huán)芳烴在樟子松苗木和高羊茅地上和地下部分的遷移系數(shù)均1,且均以小分子化合物為主。樟子松苗木對(duì)多環(huán)芳烴的富集作用大于高羊茅,并且對(duì)小分子多環(huán)芳烴的生物富集系數(shù)均1,對(duì)大分子多環(huán)芳烴的生物富集系數(shù)1。
[Abstract]:In recent years, China's sludge production surge, to find a reasonable way for sludge treatment and disposal has become an urgent problem. The sludge composting after land application is considered to be the most promising method for sludge disposal. Polycyclic aromatic hydrocarbons are ubiquitous organic pollutants in sludge, the removal and transformation of the soil in the study the lack of polycyclic aromatic hydrocarbons in the sludge. Therefore, this paper studies the different simulation of 14 kinds of polycyclic aromatic hydrocarbons change characteristics of sludge composting conditions, screening of PAHs removal conditions, reveals the sludge composting process of polycyclic aromatic hydrocarbons and different forms of combined humus characteristics, organic matter maturity changes and variation characteristics of polycyclic aromatic hydrocarbons on the outdoor sludge composting process. By the field and indoor test on PAHs Weng planted composting of sewage sludge in the process of migration in soil plant in law. The main conclusions are as follows 1.: Shenyang City 4 sewage treatment plant sludge organic matter, nitrogen, phosphorus and potassium nutrient rich. Heavy metals Cu, Cd, Pb, Zh, Ni and Cr were detected in the sludge, with Zn and Cu. The land application of sludge, Cu and Cd first become a limiting factor CJ/ T309-2009, with years of sludge application was 0.75 kg m-2, there are 1 kinds of sludge in acid soil on the safe use of life for 10 years, the remaining sludge is 28-47. The sludge in 14 total PAHs ranged from 2.63 to 18.3 mgkg-1, and with 3 to 4 rings are mainly from combustion sources. With the CJ/T 309-2009 limit value (= 5mg kg-1) compared with the total PAHs in 3 kinds of sludge were 266.7% and 48.4% 14.5%. exceed the standard, therefore, as long as the application is reasonable, the heavy metal is no longer limiting factors for land application of sludge, but the application must be approved by the composting harmless pretreatment, the aromatic hydrocarbon content of organic pollutants Simulation experiments show that the.2. indoor composting decreased, different bulking agents on PAHs removal followed by peat peat - straw peanut shell peanut straw single single single peat; with increasing water content of PAHs removal rate showed a trend of decrease after the first increase, the optimum water content is 55%; with the increase of temperature, the removal rate of polycyclic aromatic hydrocarbons the change was reduced after the first increase, the optimum temperature is 35 DEG C; with the increase of oxygen, PAHs removal rate was decreased after the first increase, the optimum oxygen content is 8.64 L h-1kg-1, no oxygen molecules PAHs removal effect becomes worse. Overall, 3-4 ring PAHs removal effect was better than the 5 ring, 6 ring and 2 rings. The orthogonal experiment results show that the effect of different factors on the removal of PAHs is in turn type oxygen moisture conditioner temperature. In the sludge: peat: straw moisture =3:1:2,55%, 38 DEG C and oxygen Composting conditions for 7.92 Lh-1kg-1, the maximum removal rate of polycyclic aromatic hydrocarbons in sludge, 79.6%.3. simulation of different variation of total organic carbon in sludge reactor under the condition of rot is consistent with PAHs. Peat - straw as a conditioner when the content of Hu Min acid carbon and H/F was larger than other than the conditioner, 35 degrees of Hu Min acid and H/F carbon content an increase in temperature is larger than that of the other. The content of Hu Min in the process of sludge heap rot acid carbon increased with water content increasing, but the 55% moisture conditions of total organic carbon in the largest decline. Sludge heap of humic acid carbon content and H/F ratio with the composting process of oxygen increased, but the amount of oxygen for a maximum of 8.64 L H-1 kg-1 the decline of total organic carbon in sludge composting. Therefore, in practice, should be early increase of oxygen to improve the removal efficiency of PAHs, reduce oxygen later in order to improve the degree of humification of different.4. under simulated conditions of humic acid in the process of sludge heap rot Positive correlation with PAHs, there was a negative correlation between Hu Min acids and polycyclic aromatic hydrocarbons (45% water and 10.8 Lh-1 kg-1, except oxygen) between rich dry acid and polycyclic aromatic hydrocarbons were positively correlated between H/F ratio and PAHs is also negatively related. 15 days before composting, the content of polycyclic aromatic hydrocarbons in performance different forms of humus in the residual alkali soluble water soluble, composting after 15 days showed alkali soluble fraction of water soluble. Before and after composting residual PAHs decreased from 2508 ng to 198.8 g-1 ng g-1; alkali soluble content decreased from 1125.4 ng to 569.7 g-1 ng g-1; water soluble by 137.5 ng g-1 decreased to 27 ng g-1. showed that with composting, PAHs and combined humus more closely, the bioavailability of PAHs reduced.5. outdoor composting test results showed that the sludge composting at the end of the total organic carbon decreased by 44.9% compared with the heap rot before C/N than by 20.7 闄嶄負(fù)14.9,H/F姣旂敱0.51澧炲姞鍒，

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