何品晶, 徐延春, 呂 凡, 邵立明
(1. 同濟(jì)大學(xué) 污染控制與資源化研究國家重點(diǎn)實(shí)驗(yàn)室, 上海 200092;2. 同濟(jì)大學(xué) 固體廢物處理與資源化研究所, 上海 200092;3. 住房和城鄉(xiāng)建設(shè)部村鎮(zhèn)建設(shè)司農(nóng)村生活垃圾處理技術(shù)研究與培訓(xùn)中心, 上海 200092)
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芬頓和雙氧水紫外處理穩(wěn)定滲濾液的光譜特征
何品晶1,2,3, 徐延春1,2, 呂凡1, 邵立明2,3
(1. 同濟(jì)大學(xué) 污染控制與資源化研究國家重點(diǎn)實(shí)驗(yàn)室, 上海 200092;2. 同濟(jì)大學(xué) 固體廢物處理與資源化研究所, 上海 200092;3. 住房和城鄉(xiāng)建設(shè)部村鎮(zhèn)建設(shè)司農(nóng)村生活垃圾處理技術(shù)研究與培訓(xùn)中心, 上海 200092)
為研究芬頓(Fenton)法和雙氧水紫外(H2O2-UV)法處理穩(wěn)定(填埋場)滲濾液過程中不同類別有機(jī)物的去除規(guī)律,采用三維熒光光譜(3D-EEM)和254 nm波長紫外吸光度(SUVA254),結(jié)合熒光區(qū)域一體化(FRI)EEM數(shù)據(jù)處理方法,分析總有機(jī)物去除水平相近條件下,兩種處理方法去除不同有機(jī)物水平和組分變化的特征.結(jié)果表明:兩種處理方法中,均是蛋白質(zhì)類物質(zhì)比腐殖質(zhì)類物質(zhì)優(yōu)先被去除,酪氨酸類物質(zhì)比色氨酸類物質(zhì)優(yōu)先被去除;較高的總有機(jī)碳(TOC)去除率段比低去除率段能去除更大比例的最難降解腐殖質(zhì)類物質(zhì).在相近的TOC去除水平下,H2O2-UV法比Fenton法對(duì)腐殖質(zhì)類物質(zhì)的去除更有效,且能更多地去除胡敏酸類物質(zhì);Fenton法處理中,F(xiàn)e2+投加量的增加能更多地通過絮凝沉淀作用去除胡敏酸類物質(zhì).Fenton和H2O2-UV作為預(yù)處理方法應(yīng)用時(shí),為了既能達(dá)到較好處理效果又能節(jié)約成本,應(yīng)選擇對(duì)腐殖質(zhì)類物質(zhì)去除率更高的H2O2-UV技術(shù)作為預(yù)處理方法.
芬頓法; 雙氧水紫外法; 穩(wěn)定滲濾液; 三維熒光光譜; 254 nm波長紫外吸光度
生活垃圾填埋齡較長的滲濾液,5日生化需氧量與化學(xué)需氧量的質(zhì)量濃度比一般小于0.1[1-2],基本達(dá)到生物穩(wěn)定,簡稱為穩(wěn)定滲濾液[3].此類滲濾液難以通過生物法進(jìn)行有效處理[4],目前大多需要采用納濾和反滲透處理;但是,這些膜處理技術(shù)沒有污染物降解功能,污染物富集于處理產(chǎn)生的濃縮液中,需要二次處置.高級(jí)氧化(advanced oxidation processes,AOPs)方法則具有污染物分解功能,在適當(dāng)?shù)目刂茥l件下,可將難降解的大分子有機(jī)物部分分解為易降解的小分子有機(jī)物[5-7],可與生物處理銜接,低成本地提高穩(wěn)定滲濾液的有機(jī)物降解水平,這是AOPs技術(shù)應(yīng)用發(fā)展的主要方向.因此,需要研究AOPs處理?xiàng)l件對(duì)穩(wěn)定滲濾液中不同類別有機(jī)物的降解規(guī)律.
芬頓(Fenton)法和雙氧水紫外(H2O2-UV)法是AOPs技術(shù)中代表性的兩種處理方法[8-9].目前的研究中,F(xiàn)enton和H2O2-UV對(duì)滲濾液的處理效果仍主要以化學(xué)需氧量(chemical oxygen demand, COD)、總有機(jī)碳(total organic carbon, TOC)和5日生化需氧量(biochemical oxygen demand for five days, BOD5)[10-14]等綜合性有機(jī)物總量指標(biāo)進(jìn)行表征.這些綜合性指標(biāo)不能反映溶解性有機(jī)物(dissolved organic matters, DOM)種類的變化.相比而言,采用熒光光譜[15]和UV-Vis(ultraviolet-visible, 紫外-可見光)吸收光譜[16-17]測試滲濾液的DOM,能從化學(xué)結(jié)構(gòu)角度解析DOM的種類變化;采用熒光區(qū)域一體化(fluorescence regional integration, FRI)方法處理三維熒光光譜(three dimensional fluorescence excitation-emission matrix spectroscopy,3D-EEM)譜圖,可實(shí)現(xiàn)對(duì)有機(jī)物的定性定量分析.254 nm波長紫外吸光度(specific ultraviolet light absorbance at 254nm,SUVA254)反映了總有機(jī)物中具有芳香結(jié)構(gòu)物質(zhì)的比例,可間接體現(xiàn)DOM的腐殖化程度.故在AOPs處理穩(wěn)定滲濾液過程中,研究EEM特征性指標(biāo)和SUVA254的變化,可以辨別不同結(jié)構(gòu)有機(jī)物的組成變化規(guī)律,提供探究其處理機(jī)制的依據(jù).EEM已成功應(yīng)用于污水處理廠出水和醫(yī)藥廢水的Fenton[18]和H2O2-UV[19]處理過程中痕量個(gè)人護(hù)理品去除的研究;SUVA254也已應(yīng)用于表征面包發(fā)酵工業(yè)污水Fenton脫色處理過程中的腐殖質(zhì)類物質(zhì)含量[20];Wang等[21]還研究了SUVA254在H2O2-UV處理地表水和地下水自然有機(jī)物質(zhì)中腐殖酸的去除變化.而同時(shí)應(yīng)用有機(jī)物總量指標(biāo)、EEM特征性指標(biāo)和SUVA254分析穩(wěn)定滲濾液的Fenton和H2O2-UV處理過程中,DOM分類去除特征的研究還較為鮮見.
本文以生活垃圾填埋場的穩(wěn)定滲濾液為研究對(duì)象,以TOC去除率為總有機(jī)物去除指標(biāo),對(duì)比分析了相近TOC去除水平下,F(xiàn)enton法和H2O2-UV法處理穩(wěn)定滲濾液的EEM特征性指標(biāo)和SUVA254的變化規(guī)律,探討了兩種處理方法對(duì)穩(wěn)定滲濾液中不同種類有機(jī)物的去除特征.可為Fenton法或H2O2-UV法預(yù)處理穩(wěn)定滲濾液、提高其可生化性的技術(shù)應(yīng)用提供依據(jù).
1.1實(shí)驗(yàn)材料
實(shí)驗(yàn)所用滲濾液取自上海市某生活垃圾填埋場,其填埋齡為24年.經(jīng)4 000g離心后,測得滲濾液的CODCr質(zhì)量濃度為(976±11) mg·L-1,TOC質(zhì)量濃度為(276±2) mg·L-1,BOD5與CODCr質(zhì)量濃度比為0.143±0.002.具備穩(wěn)定滲濾液的典型水質(zhì)特征.
1.2實(shí)驗(yàn)方法
Fenton和H2O2-UV兩種處理方法中的實(shí)驗(yàn)參數(shù)均通過對(duì)相關(guān)文獻(xiàn)中處理?xiàng)l件進(jìn)行總結(jié)后確定.
1.2.1Fenton處理實(shí)驗(yàn)條件
取150 mL經(jīng)4 000g離心后的滲濾液,加入至250 mL錐形瓶中,用6 mol·L-1HCl調(diào)節(jié)pH值為3.5~4.0,再根據(jù)測得的4 000g離心后滲濾液的TOC值和設(shè)定的w(H2O2)/wTOC(H2O2與TOC的質(zhì)量比,見表1),加入一定量的H2O2,根據(jù)設(shè)定的w(H2O2)/w(Fe)(H2O2與Fe的質(zhì)量比,見表1),加入一定量的FeCl2.然后,用鋁箔封口后,置于振蕩培養(yǎng)箱(SPX-250-2-S,上海躍進(jìn)醫(yī)療器械廠)中,于25 ℃, 200 r·min-1下震蕩1 h,再用6 mol·L-1NaOH調(diào)節(jié)pH值為7.0~7.5.每組實(shí)驗(yàn)設(shè)三平行.
表1 Fenton處理實(shí)驗(yàn)條件Tab.1 Experimental condition of Fenton treatment
1.2.2H2O2-UV處理實(shí)驗(yàn)條件
取150 mL經(jīng)4 000g離心后的滲濾液,加入250 mL錐形瓶中,用6 mol·L-1HCl調(diào)節(jié)pH值為3.5~4.0,再根據(jù)測得的TOC值和設(shè)定的w(H2O2)/wTOC(見表2),加入一定量的H2O2.放入10 W的紫外燈管(GPH212T5L-10W,寧波榭光電子有限公司)后,用硅膠塞封口,具體裝置見圖1.置于振蕩培養(yǎng)箱(SPX-250-2-S,上海躍進(jìn)醫(yī)療器械廠)中,于25 ℃,200 r·min-1震蕩.震蕩處理時(shí)間見表2.然后,用6 mol·L-1NaOH調(diào)節(jié)pH值為7.0~7.5.每組實(shí)驗(yàn)設(shè)三平行.
表2 H2O2-UV處理實(shí)驗(yàn)條件Tab.2 Experimental condition of H2O2-UV treatment
圖1 H2O2-UV處理的實(shí)驗(yàn)裝置圖Fig.1 Experimental setup in H2O2-UV treatment
1.3測試指標(biāo)
采用COD測定儀(HACH, 美國)測定CODCr.采用BOD自動(dòng)測定儀(OxiTop IS 12, WTW, 美國)測定BOD5,測試瓶置于20 ℃生化培養(yǎng)箱(SPX-250B-Z,上海博訊實(shí)業(yè)有限公司)中,培養(yǎng)5 d后測定.采用TOC測定儀(TOC-V, Shimadzu, 日本)測定TOC.采用熒光分光光度計(jì)(Cary Eclipse, Varian, 美國)的掃描模式記錄EEM熒光光譜,參照Zheng等[22]的方法測試,并整理數(shù)據(jù).SUVA254為液體樣品在254 nm下吸光度和TOC的比值,其單位為 L·mg-1·m-1,利用Shao等[23]提出的方法測試.
1.4數(shù)據(jù)分析方法
采用Chen等[24]提出的熒光區(qū)域一體化(fluorescence regional integration, FRI)分析方法,將EEM光譜劃分為5個(gè)區(qū)域.5個(gè)激發(fā)-發(fā)射區(qū)域分別為:(Ⅰ)酪氨酸類物質(zhì)區(qū),λEx/λEm(激發(fā)波長/發(fā)射波長)=(200~250) nm/(290~330) nm;(Ⅱ)色氨酸類物質(zhì)區(qū),λEx/λEm=(200~250) nm/(330~380) nm;(Ⅲ)富里酸類物質(zhì)區(qū),λEx/λEm=(200~250) nm/(380~550) nm;(Ⅳ)微生物副產(chǎn)品區(qū),λEx/λEm=(250~400) nm/(290~380) nm;(Ⅴ)胡敏酸類物質(zhì)區(qū),λEx/λEm=(250~400) nm/(380~550) nm.每個(gè)區(qū)域的熒光響應(yīng)百分比Pi,n(i為指定區(qū)域所代表的特定結(jié)構(gòu)物質(zhì),n為每個(gè)區(qū)域的熒光數(shù)據(jù)點(diǎn)數(shù)),可以定量反映指定區(qū)域所代表的特定結(jié)構(gòu)物質(zhì)的相對(duì)豐度.其中,PⅠ,n表示酪氨酸類物質(zhì)的相對(duì)豐度,PⅡ,n表示色氨酸類物質(zhì)的相對(duì)豐度,PⅢ,n表示富里酸類物質(zhì)的相對(duì)豐度,PⅣ,n表示微生物副產(chǎn)物類物質(zhì)的相對(duì)豐度,PⅤ,n表示胡敏酸類物質(zhì)的相對(duì)豐度.因此,可用PⅢ,n+PⅤ,n表示DOM中腐殖質(zhì)類物質(zhì)的相對(duì)豐度,PⅠ,n+PⅡ,n表示蛋白質(zhì)類物質(zhì)的相對(duì)豐度;(PⅢ,n+PⅤ,n)/(PⅠ,n+PⅡ,n),可反映DOM中腐殖質(zhì)類物質(zhì)和蛋白質(zhì)類物質(zhì)的相對(duì)含量;PⅤ,n/PⅢ,n,可反映腐殖質(zhì)類物質(zhì)中胡敏酸類物質(zhì)和富里酸類物質(zhì)的相對(duì)含量;PⅡ,n/PⅠ,n,可反映蛋白質(zhì)類物質(zhì)中色氨酸類物質(zhì)和酪氨酸類物質(zhì)的相對(duì)含量.
2.1不同F(xiàn)enton和H2O2-UV處理?xiàng)l件下穩(wěn)定滲濾液的TOC去除率
不同F(xiàn)enton和H2O2-UV處理?xiàng)l件下穩(wěn)定滲濾液的工況編號(hào)及TOC去除率分別見表3和表4.
表3不同F(xiàn)enton處理?xiàng)l件下穩(wěn)定滲濾液的工況編號(hào)和TOC去除率
Tab.3Serial number and TOC removal efficiency of mature leachate when treated under different Fenton treatment conditions
w(H2O2)/wTOCw(H2O2)/w(Fe)工況編號(hào)TOC去除率/%31.0F152.87(5.23)32.5F250.69(4.68)310.0F339.66(1.93)320.0F432.77(1.66)12.5F539.57(3.61)62.5F657.23(1.19)102.5F763.60(0.26)
注: 括號(hào)中數(shù)值代表標(biāo)準(zhǔn)差.
表4不同H2O2-UV處理?xiàng)l件下穩(wěn)定滲濾液的工況編號(hào)和TOC去除率
Tab.4Serial number and TOC removal efficiency of mature leachate when treated under different H2O2-UV treatment conditions
w(H2O2)/wTOC處理時(shí)間/h工況編號(hào)TOC去除率/%31H12.78(0.53)32H29.22(0.41)34H315.50(2.64)36H417.17(4.21)38H527.05(3.72)68H639.60(5.12)108H751.52(2.56)
注: 括號(hào)中數(shù)值代表標(biāo)準(zhǔn)差.
由表3和表4可見,F(xiàn)enton和H2O2-UV處理中穩(wěn)定滲濾液的TOC去除率均與H2O2的投加比(w(H2O2)/wTOC)呈正相關(guān)關(guān)系;Fenton和H2O2-UV兩種方法均在w(H2O2)/wTOC=10時(shí)取得最大的TOC去除率(分別為63.60%和51.52%).Fenton與H2O2-UV處理比較,相同w(H2O2)/wTOC時(shí),F(xiàn)enton處理的TOC去除率明顯高于H2O2-UV處理,即使將H2O2-UV的處理時(shí)間延長至8 h也沒有改變這種狀況;而且,在w(H2O2)/wTOC一定的條件下,降低w(H2O2)/w(Fe)的比值(增加Fe2+投加),TOC去除率也相應(yīng)提高.這一現(xiàn)象表明,F(xiàn)enton處理中投加Fe2+具有催化和協(xié)同去除有機(jī)物的雙重作用[4],兩種處理方法及Fenton處理中w(H2O2)/w(Fe)的不同比例均可使有機(jī)物的去除途徑產(chǎn)生差異.為調(diào)控處理出水的組成條件,應(yīng)進(jìn)一步分析處理方法和條件對(duì)有機(jī)物分類去除的影響.
2.2相近TOC去除水平Fenton和H2O2-UV處理出水的有機(jī)物光譜特征
為在一個(gè)相對(duì)統(tǒng)一的基準(zhǔn)下比較處理方法和條件對(duì)有機(jī)物分類去除的影響,選擇TOC去除率基本一致的工況,對(duì)照分析其EEM特征峰值和SUVA254的異同,以討論有機(jī)物分類去除的特征.雖然DOM中還存在一些不具有芳香結(jié)構(gòu)的非熒光基團(tuán)類物質(zhì)不能被三維熒光光譜和SUVA254所表征,但二者所體現(xiàn)的芳香類物質(zhì)的變化可代表性反映穩(wěn)定滲濾液中難降解有機(jī)物的去除轉(zhuǎn)化規(guī)律,從而總體了解處理過程水質(zhì)的特征性變化.
2.2.1TOC去除水平為40%工況條件下Fenton和H2O2-UV處理出水的有機(jī)物光譜特征
據(jù)表3和表4,F(xiàn)3,F(xiàn)5和H6三個(gè)工況的TOC去除率基本一致,均接近40%.這三個(gè)工況處理出水的EEM特征峰值和各峰值的比值以及SUVA254見圖2.其中R為原穩(wěn)定滲濾液的工況編號(hào).
a EEM特征峰值
b EEM各峰值的比值及SUVA254圖2 TOC去除水平為40%時(shí)不同F(xiàn)enton和H2O2-UV處理?xiàng)l件下穩(wěn)定滲濾液的光譜特征Fig.2 Spectroscopic characteristics of mature leachate under different Fenton and H2O2-UV treatment conditions at a TOC removal efficiency of about 40%
由圖2a可見,TOC去除率均為約40%時(shí)各工況的出水與穩(wěn)定滲濾液原水比較,PⅠ,n和PⅡ,n下降,PⅢ,n和PⅤ,n上升,而PⅣ,n基本不變.結(jié)果表明,F(xiàn)enton和H2O2-UV處理出水DOM中蛋白質(zhì)類物質(zhì)的相對(duì)含量均減少,腐殖質(zhì)類物質(zhì)的相對(duì)含量增加(參見圖2b中(PⅢ,n+PⅤ,n)/(PⅠ,n+PⅡ,n)的變化),相對(duì)于分子量較大、結(jié)構(gòu)比較穩(wěn)定的腐殖質(zhì)類物質(zhì),兩種處理方法均更易于去除易被氧化的蛋白質(zhì)類物質(zhì);同樣,兩種方法處理后的PⅡ,n/PⅠ,n均比原滲濾液增大,即蛋白質(zhì)類物質(zhì)中,兩種方法均是優(yōu)先去除酪氨酸類物質(zhì);代表中間分子量的PⅣ,n不變,則可能是因?yàn)槠浼缺谎趸癁榱烁唵蔚姆肿?,同時(shí)更復(fù)雜的有機(jī)物分解產(chǎn)生了此類中間產(chǎn)物,反應(yīng)過程穩(wěn)定的條件下,其比例相對(duì)不變.
兩種處理方法比較,H2O2-UV處理出水的(PⅢ,n+PⅤ,n)/(PⅠ,n+PⅡ,n)和SUVA254均更低,說明H2O2-UV法比Fenton法對(duì)腐殖質(zhì)類物質(zhì)去除更有效.比較兩種處理方法出水的PⅤ,n/PⅢ,n,F(xiàn)enton處理后的PⅤ,n/PⅢ,n比原滲濾液增大,H2O2-UV處理后的PⅤ,n/PⅢ,n比原滲濾液略微減小,表明H2O2-UV處理比Fenton處理能更多地去除胡敏酸類物質(zhì),這也與兩種處理出水的SUVA254值差異一致.這一結(jié)果與Fenton兼具絮凝沉淀作用可直接去除大分子物質(zhì)的概念有些差異,原因可能是在該TOC去除水平下,H2O2-UV法對(duì)胡敏酸類物質(zhì)的氧化效率超過了Fenton法對(duì)其的沉淀效率.
Fenton處理中,在w(H2O2)/w(Fe)=2.5,w(H2O2)/wTOC=1時(shí),PⅤ,n/PⅢ,n值比w(H2O2)/w(Fe)=10,w(H2O2)/wTOC=3時(shí)要小,即相近的TOC去除水平下,相較于富里酸類物質(zhì),H2O2投加量低、Fe2+投加量高的條件下比H2O2投加量高、Fe2+投加量低的條件下能更多地去除分子量更大、結(jié)構(gòu)更加穩(wěn)定的胡敏酸類物質(zhì),這體現(xiàn)了Fe2+投加量高時(shí)Fenton處理更強(qiáng)的絮凝沉淀作用[11].
2.2.2TOC去除水平為50%工況條件下Fenton和H2O2-UV處理出水的有機(jī)物光譜特征
據(jù)表3和表4,F(xiàn)1,F2和H7三個(gè)工況的TOC去除率均接近50% (50%~53%),這三個(gè)工況處理出水的EEM特征峰值和各峰值的比值,及SUVA254見圖3.
a EEM特征峰值
b EEM各峰值的比值及SUVA254圖3 TOC去除水平為50%時(shí)不同F(xiàn)enton和H2O2-UV處理?xiàng)l件下穩(wěn)定滲濾液的光譜特征Fig.3 Spectroscopic characteristics of mature leachate under different Fenton and H2O2-UV treatment conditions at a TOC removal efficiency of about 50%
圖3a為TOC去除率大致為50%時(shí),F(xiàn)enton和H2O2-UV處理出水和滲濾液原水對(duì)比的EEM特征峰值的相對(duì)豐度變化.可見,與TOC去除率為40%時(shí)比較(圖2a),出水中腐殖質(zhì)類物質(zhì)的相對(duì)含量均相應(yīng)減少;Fenton處理后的(PⅢ,n+PⅤ,n)/(PⅠ,n+PⅡ,n)(圖3b)較原水增大,但幅度明顯小于TOC去除率為40%時(shí),而H2O2-UV處理后的(PⅢ,n+PⅤ,n)/(PⅠ,n+PⅡ,n)反而較原水下降.相對(duì)應(yīng)地,由圖3b可見,F(xiàn)enton處理后的PⅤ,n/PⅢ,n比滲濾液原水增大,H2O2-UV處理后的PⅤ,n/PⅢ,n則比原水略減小.上述結(jié)果表明,兩種處理在達(dá)到較高TOC去除水平時(shí),DOM去除途徑有一定的變化,腐殖質(zhì)類物質(zhì)去除的比例逐步升高.其中,H2O2-UV法能去除更高比例的胡敏酸類物質(zhì),SUVA254值也更低.根據(jù)徐蘇云等[11]的研究,隨著Fe2+投加量的增加,絮凝沉淀作用對(duì)有機(jī)物的去除增強(qiáng);兩種Fenton處理?xiàng)l件比較,w(H2O2)/w(Fe)更低者的(PⅢ,n+PⅤ,n)/(PⅠ,n+PⅡ,n)和PⅤ,n/PⅢ,n均更低;故分子量更大、結(jié)構(gòu)更加復(fù)雜的腐殖質(zhì)類物質(zhì)和胡敏酸類物質(zhì)更多地被絮凝沉淀去除.
2.3Fenton法和H2O2-UV法作為預(yù)處理方法的條件選擇
上述實(shí)驗(yàn)結(jié)果顯示,F(xiàn)enton和H2O2-UV處理穩(wěn)定滲濾液時(shí),在較高的TOC去除率段(大于50%)比低去除率段(小于40%)能去除更高比例的最難降解DOM(腐殖質(zhì)類物質(zhì)),對(duì)于這種趨勢也延伸至更高的去除率(工況F6:去除率57.23%,(PⅢ,n+PⅤ,n)/(PⅠ,n+PⅡ,n)=1.04;工況F7:去除率63.60%,(PⅢ,n+PⅤ,n)/(PⅠ,n+PⅡ,n)=0.920).而化學(xué)氧化作為與生物處理銜接的預(yù)處理技術(shù),應(yīng)較高比例地去除難降解DOM.因此,F(xiàn)enton和H2O2-UV作為預(yù)處理方法應(yīng)用時(shí),應(yīng)選擇可達(dá)到較高TOC去除率(如大于50%)的操作條件.但是,更高的去除率也意味著更多的藥劑消耗和成本.據(jù)此分析,在Fenton和H2O2-UV兩種方法中,應(yīng)選擇對(duì)DOM中腐殖質(zhì)類物質(zhì)去除率更高的H2O2-UV技術(shù)作為預(yù)處理方法.
(1) 兩種處理方法中,均是蛋白質(zhì)類物質(zhì)比腐殖質(zhì)類物質(zhì)優(yōu)先被去除;蛋白質(zhì)類物質(zhì)中,均是酪氨酸類物質(zhì)比色氨酸類物質(zhì)優(yōu)先被去除;微生物副產(chǎn)物類物質(zhì)的相對(duì)含量基本不變.兩種處理在達(dá)到較高TOC去除水平時(shí),DOM去除途徑有一定的變化,較高的TOC去除率段(大于50%)比低去除率段(小于40%)能去除更高比例的最難降解DOM(腐殖質(zhì)類物質(zhì)).
(2) 在相近的TOC去除水平下,H2O2-UV法比Fenton法對(duì)腐殖質(zhì)類物質(zhì)的去除更有效,且能更多地去除胡敏酸類物質(zhì);Fenton處理中,相較于富里酸類物質(zhì),F(xiàn)e2+投加量的增加能更多地通過絮凝沉淀作用去除胡敏酸類物質(zhì).
(3) 紫外光譜分析結(jié)果表明,兩種方法處理穩(wěn)定滲濾液后,DOM中具有芳香性類物質(zhì)的比例下降,腐殖化程度降低,并且在相近TOC去除水平下,H2O2-UV處理后比Fenton處理后穩(wěn)定滲濾液的腐殖化程度要低.
(4) Fenton和H2O2-UV作為預(yù)處理方法應(yīng)用時(shí),應(yīng)選擇可達(dá)到較高TOC去除率(如大于50%)的操作條件.同時(shí),為節(jié)約藥劑消耗和減少成本,在兩種方法中,應(yīng)選擇對(duì)DOM中腐殖質(zhì)類物質(zhì)去除率更高的H2O2-UV技術(shù)作為預(yù)處理方法.
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Spectroscopic Characteristics of Mature Leachate During Fenton and H2O2-UV Treatment Process
HE Pinjing1,2,3, XU Yanchun1,2, Lü Fan1,SHAO Liming2,3
(1. State Key Laboratory of Pollution Control and Resource Reuse,Tongji University,Shanghai 200092,China; 2. Institute of Waste Treatment and Reclamation,Tongji University,Shanghai 200092,China; 3. Centre for Technology Research and Training on Household Waste in Small Towns and Rural Area of the Ministry of Housing Urban-Rural Development (MOHURD), Shanghai 200092, China)
In order to determine the removal rule of different organic matters during mature landfill leachate Fenton treatment and H2O2-UV treatment, the three dimensional fluorescence excitation-emission matrix (3D-EEM) spectroscopy and specific ultraviolet light absorbance at 254 nm (SUVA254) combined with fluorescence regional integration (FRI) EEM data processing method were applied to analyze component evolution characteristics of different organic matters. The results show that both protein-like compounds rather than humic-like substances, tyrosine-like compounds rather than tryptophan-like compounds are preferentially removed by these two treatment. A greater proportion of the most difficult degradative humic-like substances is removed when TOC removal efficiency is higher. Under similar TOC removal efficiency, the H2O2-UV method is more effective to eliminate humic-like substances than the Fenton method, and can eliminate more humic-acid-like compounds. In Fenton treatment, more humic-acid-like compounds can be precipitated with an increasing dosage of Fe2+. The H2O2-UV method should be chosen as the pretreatment method because of its higher humic-like substances removal efficiency in order that not only a better treatment result can be achieved, but also more cost can be saved.
Fenton method; H2O2-UV method; mature leachate; three dimensional fluorescence excitation-emission matrix spectroscopy; specific ultraviolet light absorbance at 254 nm
2015-02-08
國家“九七三”重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃(2012CB719801);上海市2014年度“科技創(chuàng)新行動(dòng)計(jì)劃”技術(shù)標(biāo)準(zhǔn)項(xiàng)目(14DZ0501500)
何品晶(1962—),男,教授,博士生導(dǎo)師,工學(xué)博士,主要研究方向?yàn)楣腆w廢物處理與資源化.E-mail:solidwaste@#edu.cn
X703.1
A