燃煤電廠含氟廢水處理的研究

1、燃煤電廠含氟廢水處理的研究湘潭工學(xué)院環(huán)境工程與化工新技術(shù)研究所(湖南湘潭,411201夏暢斌王金球摘要采用燃煤電廠的粉煤灰作原料制備聚硅酸鋁(PSAA混凝劑,通過化學(xué)沉淀、絡(luò)合、凝聚和絮凝等反應(yīng)來處理電廠含氟廢水。結(jié)果表明,本法處理含氟廢水工藝簡(jiǎn)單、操作方便、成本低廉,并可達(dá)到以廢治廢的目的。關(guān)鍵詞燃煤電廠,粉煤灰,PSAA混凝劑,含氟廢水燃煤電廠在濕式除塵過程中產(chǎn)生大量氟濃度高并且懸浮物(粉煤灰超標(biāo)的廢水,如直接排放必然污染環(huán)境,因此,必須對(duì)此進(jìn)行處理使之達(dá)到排放或回用的要求。含氟廢水的處理一般為吸附法、電凝聚法和混凝沉淀法等13。其中混凝沉淀法應(yīng)用最為廣泛。粉煤灰是以煤為燃料的火力發(fā)電廠排

2、出的固體廢棄物,每10000kW發(fā)電機(jī)組排灰渣量約1萬t,其中85%為粉煤灰。目前,我國堆放的粉煤灰達(dá)4億t以上,而且還以每年300多萬t的速度在增加,而我國粉煤灰利用率不到30%,而用于研制PSAA混凝劑來處理含氟廢水的研究報(bào)道甚少。我們利用粉煤灰研制的PSAA混凝劑處理熱電廠含氟廢水,取得了較理想的結(jié)果,并達(dá)到了以廢治廢、資源綜合利用的目的。1實(shí)驗(yàn)部分111儀器DBJ621型定時(shí)變速攪拌機(jī);PXD3型數(shù)字式離子計(jì); PF2型氟離子選擇電極;221型玻璃電極;F YX1型高壓反應(yīng)釜。112粉煤灰、含氟廢水的成分分析實(shí)驗(yàn)用粉煤灰和含氟廢水取自湘潭電廠和株洲電廠,主要成分如表1和表2。113試劑

3、8121mg/mL(以Ca2+計(jì)電石渣(原濃度為16142%; PSAA混凝劑(自制:液體產(chǎn)品,p H值為23,有效濃度為6%,具體制備方法可參考文獻(xiàn)4。114實(shí)驗(yàn)方法表1粉煤灰的主要成分%粉煤灰種類SiO2Al2O3Fe2O3CaO MgO燒失量湘電浮選灰46176291186155418811239105株電粉煤灰481653011641252168113210184表2含氟廢水的主要成分廢水種類p H值F-/mgL-1SS/mgL-1湘電廢水676010015002000株電廢水67559012001600用DBJ621型定時(shí)變速攪拌機(jī)在6個(gè)1L的塑料燒杯中同時(shí)進(jìn)行試驗(yàn),取C0=78mg

4、/L的含氟廢水,改變電石渣用量、反應(yīng)時(shí)間、PSAA用量、靜置沉降時(shí)間等條件進(jìn)行試驗(yàn),取距液面25mm處的上清液測(cè)定水中F-濃度。2結(jié)果與討論211投加電石渣對(duì)除氟效果的影響21111攪拌時(shí)間與除氟率之間的關(guān)系取含氟廢水,電石渣用量為160mg/L,與廢水充分混勻,靜置30min后上清液的水質(zhì)分析結(jié)果如圖1所示。由圖1可見,反應(yīng)時(shí)間對(duì)除氟效果的影響較大,反應(yīng)時(shí)間短,除氟效率低,反應(yīng)速度快;時(shí)間長(zhǎng),速度慢。大部分F-是在加入電石渣后反應(yīng)20min之內(nèi)去除的,反應(yīng)時(shí)間再長(zhǎng)對(duì)除氟無明顯的影響,因此選擇反應(yīng)時(shí)間為20min。21112不同電石渣用量下的除F-結(jié)果表2TX209的絮凝效果絮凝劑懸浮物含量/

5、10-6加藥前加藥后加藥量/10-6加藥方式3#藥1123265465156015TX209121527303794015連續(xù)加藥(3TX209用于煉鋼除塵水處理絮凝效果優(yōu)于3#藥。(4TX209運(yùn)行成本比3#藥下降了30%,是一種有推廣價(jià)值的高分子陰離子聚丙烯酰胺類絮凝劑。參考文獻(xiàn)1肖錦,紀(jì)永亮1我國絮凝劑發(fā)展的現(xiàn)狀與對(duì)策197水處理技術(shù)研究討論會(huì)論文集12國家環(huán)境保護(hù)局編委會(huì)1水和廢水的監(jiān)測(cè)分析方法1作者簡(jiǎn)介:第一作者焦木森,1944年生,1969年畢業(yè)于天津大學(xué),現(xiàn)就職于天津化工研究設(shè)計(jì)院,高級(jí)工程師。收稿日期:1999-06-24試驗(yàn)研究工業(yè)水處理199911,19(6湖南省科技攻關(guān)項(xiàng)

6、目(01096254子課題。取含氟廢水水樣,加入一定量的電石渣,反應(yīng)時(shí)間為20min ,靜置30min ,電石渣用量對(duì)除氟效果的影響見圖2。從圖2可看出,電石渣用量越大,上清液中殘余的F -濃度越小,但p H 值會(huì)逐漸升高。根據(jù)殘F(tuán) -濃度和上清液的p H 值,我們選擇電石渣用量為80mg/L ,這時(shí)殘余的F -濃度為25mg/L ,p H 值為815。然后加PSAA 進(jìn)一步處理 。圖1不同攪拌時(shí)間下的除F - 效果圖2不同電石渣用量下的除F -效果212PSAA 用量對(duì)除氟效果的影響取一定的廢水,電石渣用量為80mg/L ,反應(yīng)時(shí)間為 20圖3不同PSAA 用量下的除氟結(jié)果min ,加PSA

7、A 混凝劑后反應(yīng)20min ,PSAA 的用量對(duì)除氟效果的影響見圖3所示。從圖3可看出,隨著PSAA 用量的增加,殘余F -離子濃度逐漸降低。當(dāng)PSAA 的用量大于30mg/L 以后,殘余的F -離子濃度幾乎不變,這時(shí)上清液中殘余的F -為23mg/L ,F -去除率達(dá)97%,p H 值為715,同時(shí)測(cè)得SS 的去除率為9615%。引起這些變化的主要原因是與PSAA 的性質(zhì)和它的除氟機(jī)理有關(guān)。213混凝沉降時(shí)間對(duì)除氟效果的影響取25mg/L 的預(yù)除氟廢水在6個(gè)1L 的燒杯中同時(shí)進(jìn)行試驗(yàn),各加入30mg/L 的PSAA 混凝劑,快攪拌1min ,慢攪5min ,沉降不同的時(shí)間,再分別測(cè)定上清液中

8、的含氟量。結(jié)果表明,上清液中殘余含氟量隨著沉降時(shí)間的延長(zhǎng)而降低,當(dāng)沉降時(shí)間達(dá)20min 后,水中殘余含氟量趨于一固定值,表明PSAA 已基本完成了沉淀、絡(luò)合、凝聚和絮凝等過程,由于PSAA 是在酸性條件下制備的,酸浸液中已經(jīng)有相當(dāng)一部分的Ca 2+離子,能夠與F -生成沉淀;當(dāng)PSAA 投入到堿性介質(zhì)中,Al 3+、Fe 3+等都能形成多核羥基絡(luò)正離子對(duì)F -離子具有吸附和絡(luò)合作用以及對(duì)水中的懸浮物具有脫穩(wěn)作用;在無機(jī)高分子聚硅酸的橋連網(wǎng)捕下,將細(xì)小的膠粒聚集成大的絮團(tuán)而迅速沉降。所以PSAA 混凝劑具有良好的除氟和凈水效果。PSAA 混凝劑的除氟機(jī)理是沉淀、絡(luò)合、凝聚和絮凝等多種作用于一體,

9、是良好的除氟、凈水劑。3結(jié)論利用電石渣及從粉煤灰研制的PSAA 混凝劑處理熱電廠含氟廢水,能夠使含氟為78mg/L 的原水經(jīng)兩級(jí)除氟后,氟去除率達(dá)97%,出水含氟量降至工業(yè)廢水的排放標(biāo)準(zhǔn)以下,可用于熱電廠的除塵水或冷卻水。用本法除氟與其它除氟法相比,就地取材,操作簡(jiǎn)單,處理后的水質(zhì)達(dá)到了回用的要求。實(shí)現(xiàn)了以廢治廢、減少環(huán)境污染、綜合利用的目的,為熱電廠廢棄資源的綜合治理提供了理論依據(jù)。參考文獻(xiàn)1馬志毅等1用粉煤灰處理含氟水的研究1中國環(huán)境科學(xué),1991;11(6:4604632R Tzimou -Tsitouridou et al.Water and Waste Treatment ,1985

10、;(5:40,48493王榕樹等1活性氧化鋁/硅膠吸附劑對(duì)環(huán)境水體的脫氟行為研究及應(yīng)用初探1環(huán)境科學(xué)學(xué)報(bào),1992;12(3:3333394夏暢斌等1煤矸石灰渣研制硅酸鋁混凝劑及應(yīng)用研究1中國環(huán)境科學(xué),1996;16(5:396400作者簡(jiǎn)介:第一作者夏暢斌,1960年生,1989年畢業(yè)于中國礦業(yè)大學(xué)北京研究生部,現(xiàn)就職于湘潭工學(xué)院環(huán)境工程與化工新技術(shù)研究所,副教授。收稿日期:1999-06-05高床在漏鹽條件下精制凝結(jié)水的能力DIANA L ,KEE L 2ING,SA LL IE FISHER,HERMAN HAMANN,IWC 9665在實(shí)驗(yàn)室利用失效樹脂和再生樹脂裝置,對(duì)壓水堆(PWR

11、 凝結(jié)水精制器所遇到的各種不同量鹽(NaCl 泄漏條件下的交換容量,進(jìn)行了針對(duì)性研究。(圖6,表2,參6(劉魁元供稿工業(yè)水處理199911,19(6含氮雜環(huán)水處理劑FNP C 緩蝕性能研究PROG RESS OF DI METHY LDI A LLY LAMMONI UM CH LORI DE (DMDAACPOLY MERS RESE ARCHESZhao Huaz hang et al (Department of Environmental Engineering,Shandong Uni2 versity,Jinan250100:Chin.J.Ind.Water Treat.,19(6

12、, 1999,pp.14The structure,properties,polymerization and application of DMDAAC polymers and their copolymer are reviewed in this pa2 per,which is a kind of cationic quaternary polyelectrolyte with a low price.It is widely used in wastewater treatment,textile in2 dustry,petroleum industry and so on.K

13、ey wordsdimethyldiallylammonium chloride polymers, polymerization,wastewater treatmentAPPLICATI ON OF ClO2TO I NDUSTRI A L WASTEWATER TRE AT ME NTChen Hongling et al(Jingjiang Environment Monitoring Station,Jingjiang214500:Chin.J.Ind.Water Treat.,19(6,1999,pp.56Researches on the utilization of ClO2f

14、or treating different industrial wastewater are reported in this paper.The result shows the technology of ClO2combination is simple,the opera2 tion is convenient,the cost is low,the result is good and the ex2 tended future is wide.K ey wordsClO2,germicide,galvanization wastewaterST UDY ON F LOCCU LA

15、TI ON K I NETICS OF T URBU LE NCEW u Daoji and Tan Fengx un(Shandong Architectural and Civil Engineering Institute,Jinan250014Chin.J.Ind.Water Treat.,19(6,1999,pp.67The paper describes a study on flocculation kinetics which proceeded on hydraulic characteristic of turbulence,and the anal2 ysis of ki

16、netic factors.Vortex shear force and inertial centrifugal force are the cause of flocculation,and the vortes shear force is the dominant kinetic factor.The high efficiency of flocculation technology is presented.K ey wordsturbulence,flocculation,vortex shear force VARI ATI ON I N THE COMPOSITI ON,CO

17、NCE NTRATI ON AND TOXICITY OF ORG ANIC POLLUT ANTS I N M UNICIPA L SEWAGE WASTEWATER TRE AT ME NT PROCESSM a Mei et al(SK L EAC,Research Center for Eco-Environmental Sci2 ence,Beijng100085:Chin.J.Ind.Water Treat.,19(6, 1999,pp.912The efficiencies of municipal wastewater treatment processes are evalu

18、ated in terms of a group of collective parameters,com2 position and concentration variation of micropollutants,as well as changes in acute toxicity.While the outflow of the secondary treatment based on active sludge technology can meet satisfactori2 ly the National Integrated Wastewater Discharge St

19、andard,but a limited removal of persistent organic pollutants and acute toxicity can be expected.K ey wordsmunicipal sewage,biological treatment,mi2cropollutantsDEG RADATI ON OF THE DYEI NG WASTEWATER BY PH OTO2 E LECTROCAT A LYSEYao Qingz hao and L iu Zhengbao(Nanjing Railway Medical College.Nanjin

20、g210009:Chin.J. Ind.Water Treat.,19(6,1999,pp.1516Optically transparent electrode(O TEcoated with nanos2 tructured thin TiO2films was made,which is used as the work2 ing electrode and catalyst.The method of electrochemical assist2 ing photocatalysis degradation of the dyes in aqueous solution is stu

21、died.K ey wordsphotocatalyst,photoelectrocatalyst,dye,elec2 trochemistryST UDY ON THE TRE AT ME NT OF F LUORI DE-CONT AI NI NG WASTEWATER I N COA L FUE LI NG-POWER PLANTXia Changbin and W ang Jinqiu(Institute of Environmental Eng. &Chemical Hi-tech.Xiangtan Polytechnic University,Xiang2 tan41120

22、1:Chin.J.Ind.Water Treat.,19(6,1999,pp.18 19Polysilicate aluminum was prepared.from fly ash in coal-fueling power plant,and used as defluorider and coagulant in the treatment of fluoride wastewater in coal-fueling power plant by chemical deposition,complexation,agglomeration and floccula2 tion.The r

23、esults show that this method is more simple for opera2 tion and has lower operational cost.Furthermore,this wastewa2 ter can be treated by waste.K ey wordscoal-fueling power plant,fly ash,PSAA co2 agulant,fluoride-containing wastewaterRESE ARCH ON THE CORROSI ON I NHI BITI ON PERFORMANCE OF N-HETEROCY C LE-CONT AI NI NG WATER TRE AT ME NT AGE NT FNPCYin Hua et al(Dept.of Bio-technology, Jinan University,Guangzhou510632:Chin.J.Ind.Water Treat.,19(6,1999,pp.2022The experiments of corrosion prevention of A3steel in1.0 mol/L hydrochloric acid were carried out by using