含(han)汞(gong)工(gong)業(ye)廢(fei)水(shui)(shui)主(zhu)要來(lai)源于有色(se)金屬(shu)(shu)冶煉廠、化(hua)(hua)工(gong)廠、農藥廠、造紙(zhi)廠、染料廠及熱工(gong)儀(yi)器儀(yi)表廠等。從廢(fei)水(shui)(shui)中去除無機(ji)汞(gong)的(de)方(fang)法(fa)(fa)有硫化(hua)(hua)物(wu)(wu)(wu)沉(chen)淀法(fa)(fa)、化(hua)(hua)學(xue)(xue)凝(ning)聚法(fa)(fa)、活性(xing)炭吸附法(fa)(fa)、金屬(shu)(shu)還(huan)原法(fa)(fa)、離子交換法(fa)(fa)和(he)微生物(wu)(wu)(wu)法(fa)(fa)等。一般偏堿性(xing)含(han)汞(gong)廢(fei)水(shui)(shui)通常采用(yong)化(hua)(hua)學(xue)(xue)凝(ning)聚法(fa)(fa)或(huo)硫化(hua)(hua)物(wu)(wu)(wu)沉(chen)淀法(fa)(fa)處理(li)。偏酸性(xing)的(de)含(han)汞(gong)廢(fei)水(shui)(shui)可(ke)用(yong)金屬(shu)(shu)還(huan)原法(fa)(fa)處理(li)。低濃度的(de)含(han)汞(gong)廢(fei)水(shui)(shui)可(ke)用(yong)活性(xing)炭吸附法(fa)(fa)、化(hua)(hua)學(xue)(xue)凝(ning)聚法(fa)(fa)或(huo)活性(xing)污(wu)泥法(fa)(fa)處理(li)，有機(ji)汞(gong)rfc-b系列工(gong)業(ye)廢(fei)水(shui)(shui)機(ji)廢(fei)水(shui)(shui)較難處理(li)，通常先將有機(ji)汞(gong)氧化(hua)(hua)為無機(ji)汞(gong)，而后進(jin)行處理(li)。

銅的(de)冶(ye)煉、加工(gong)以(yi)及電鍍等工(gong)業生(sheng)(sheng)產(chan)過(guo)程中(zhong)都會產(chan)生(sheng)(sheng)大量(liang)含(han)銅廢水(shui)(shui)(shui)，其含(han)銅濃度高達(da)幾(ji)十mg/L，這種廢水(shui)(shui)(shui)排(pai)入水(shui)(shui)(shui)體中(zhong)，會嚴重影(ying)響(xiang)水(shui)(shui)(shui)的(de)質(zhi)量(liang)，對(dui)環境造(zao)成污(wu)染。水(shui)(shui)(shui)中(zhong)銅含(han)量(liang)達(da)0.01mg/L時，對(dui)水(shui)(shui)(shui)體自凈有明顯的(de)抑制(zhi)作(zuo)用，超(chao)過(guo)3.0mg/L，會產(chan)生(sheng)(sheng)異味(wei)，超(chao)過(guo)15mg/L，就(jiu)無法引用。因此，工(gong)業廢水(shui)(shui)(shui)必須經過(guo)處(chu)理才能達(da)到(dao)環境要求(qiu)。

下面首先列舉“銅汞廢水處理”中幾個常用的含汞廢水處理方法：

含汞(gong)廢水處理(li)方法(fa)1、化學沉淀法(fa)

含汞(gong)廢(fei)水中(zhong)加入硫化(hua)鈉(na)處(chu)理(li),由(you)于Hg與S有強(qiang)烈的(de)親和力,能生成溶(rong)(rong)度積(ji)小的(de)硫化(hua)汞(gong)而從溶(rong)(rong)液(ye)中(zhong)除(chu)去。所以硫化(hua)物沉淀法是最(zui)常用的(de)一(yi)種沉淀處(chu)理(li)法。沉淀法可(ke)與絮凝、重力沉降、過濾(lv)或溶(rong)(rong)氣(qi)浮選(xuan)等(deng)分(fen)離(li)過程相結(jie)合。這(zhe)些后續(xu)操作可(ke)增加硫化(hua)汞(gong)沉淀的(de)去除(chu)效(xiao)果(guo),但不能提高溶(rong)(rong)解汞(gong)本身的(de)沉淀效(xiao)率。表1列出了硫化(hua)汞(gong)沉淀法的(de)各種數(shu)據。

當(dang)初始(shi)汞(gong)濃(nong)度較(jiao)高時,硫(liu)(liu)(liu)化(hua)(hua)汞(gong)沉淀法可(ke)以(yi)達到99.9%以(yi)上(shang)的(de)(de)去除率(lv)。但即使經過(guo)濾或活(huo)性(xing)(xing)炭深度處理,出水(shui)中(zhong)汞(gong)的(de)(de)最低(di)含量(liang)(liang)(liang)(liang)也(ye)有10～20g/L。在不增加硫(liu)(liu)(liu)化(hua)(hua)物(wu)用量(liang)(liang)(liang)(liang)前提下,在中(zhong)性(xing)(xing)pH值范圍內沉淀效(xiao)果(guo)最佳,當(dang)pH值>9時沉淀效(xiao)率(lv)急劇(ju)降(jiang)低(di)[2]。除了不能(neng)把汞(gong)含量(liang)(liang)(liang)(liang)降(jiang)至10g/L以(yi)下的(de)(de)缺點外,該法還有其他不足之處:(1)在硫(liu)(liu)(liu)化(hua)(hua)物(wu)過(guo)量(liang)(liang)(liang)(liang)較(jiao)多(duo)時會形成可(ke)溶性(xing)(xing)汞(gong)硫(liu)(liu)(liu)絡(luo)合物(wu);(2)硫(liu)(liu)(liu)化(hua)(hua)物(wu)過(guo)量(liang)(liang)(liang)(liang)程度的(de)(de)監測(ce)較(jiao)困難;(3)處理后出水(shui)的(de)(de)殘余(yu)硫(liu)(liu)(liu)會產生污染問題。

硫化物沉淀法反應式及溶度積如下:

2Hg++S2-=Hg2S↓K=1.8×10-45

Hg+S=HgS↓K=1.6×10-54

有的工(gong)廠用硫化氫鈉、明礬(fan)二步處(chu)(chu)理(li)汞含(han)量(liang)為(wei)25mg/L的廢水,處(chu)(chu)理(li)后排(pai)出水汞的含(han)量(liang)可降至(zhi)0.006～0.05mg/L。其方法(fa)原理(li)為(wei)：NaHS+H2O→H2S+NaOH

Hg2++S2-→HgS↓

2KAl(SO4)2→K2(SO4)+Al2(SO4)3

Al3++3OH-→Al(OH)3↓

由(you)于產(chan)生共(gong)沉(chen)淀(dian),故(gu)加(jia)入明礬可(ke)提高(gao)沉(chen)淀(dian)效率硫化物(wu)沉(chen)淀(dian)法(fa)處理所引起(qi)的(de)(de)環(huan)境(jing)問題是富(fu)汞沉(chen)淀(dian)污泥的(de)(de)不斷積累,這種污泥或(huo)者以環(huan)境(jing)可(ke)接受(shou)的(de)(de)方式處置,或(huo)者進一步用以回(hui)收汞。

含汞廢水處理方法(fa)2、混凝法(fa)

用混凝(ning)(ning)法(fa)對(dui)多種(zhong)廢水(shui)(shui)進(jin)行脫汞(gong)(gong)(gong)(gong)處理(li),所用的混凝(ning)(ning)劑(ji)包括(kuo)硫酸鋁明(ming)(ming)礬、鐵(tie)(tie)鹽(yan)(yan)及石灰。在混凝(ning)(ning)法(fa)除汞(gong)(gong)(gong)(gong)的研(yan)究中(zhong)(zhong),先在生活污(wu)水(shui)(shui)中(zhong)(zhong)加入50～60μg/L的無(wu)機汞(gong)(gong)(gong)(gong),然后用鐵(tie)(tie)鹽(yan)(yan)或明(ming)(ming)礬聚集并過(guo)濾(lv),兩種(zhong)方(fang)法(fa)都可使含汞(gong)(gong)(gong)(gong)量(liang)(liang)降低94%～98%。用石灰混凝(ning)(ning)劑(ji)處理(li)500μg/L的高濃度(du)含汞(gong)(gong)(gong)(gong)廢水(shui)(shui),過(guo)濾(lv)后汞(gong)(gong)(gong)(gong)的去除率為70%。某工廠中(zhong)(zhong)試(shi)比(bi)較(jiao)(jiao)了(le)(le)明(ming)(ming)礬和鐵(tie)(tie)鹽(yan)(yan)對(dui)無(wu)機汞(gong)(gong)(gong)(gong)和甲基汞(gong)(gong)(gong)(gong)的處理(li)效果(guo)(guo),結(jie)果(guo)(guo)表明(ming)(ming)鐵(tie)(tie)鹽(yan)(yan)能有效地除去汞(gong)(gong)(gong)(gong)。另(ling)一項研(yan)究結(jie)果(guo)(guo)也報(bao)道了(le)(le)類似的結(jie)果(guo)(guo),此外還發現即使混凝(ning)(ning)劑(ji)用量(liang)(liang)增(zeng)加到(dao)100～150mg/L,也不(bu)能改(gai)善(shan)汞(gong)(gong)(gong)(gong)的去除效果(guo)(guo)。表2列出了(le)(le)混凝(ning)(ning)法(fa)的處理(li)數據。明(ming)(ming)礬處理(li)后汞(gong)(gong)(gong)(gong)的出水(shui)(shui)含量(liang)(liang)為1.5～102μg/L,鐵(tie)(tie)鹽(yan)(yan)處理(li)后則為0.5～12.8μg/L。但當(dang)初(chu)始汞(gong)(gong)(gong)(gong)濃度(du)較(jiao)(jiao)低時(shi),明(ming)(ming)礬和鐵(tie)(tie)鹽(yan)(yan)的混凝(ning)(ning)處理(li)效果(guo)(guo)相似,此時(shi)汞(gong)(gong)(gong)(gong)的出水(shui)(shui)含量(liang)(liang)較(jiao)(jiao)低,為0.5～5.0μg/L。

用明(ming)礬處理(li)含(han)(han)(han)(han)汞(gong)廢(fei)(fei)水(shui)(shui)的優(you)點是節省費用,相當于硫化鈉法(fa)(fa)的1/3,操作簡單,沉降(jiang)速度(du)快,含(han)(han)(han)(han)汞(gong)廢(fei)(fei)水(shui)(shui)中含(han)(han)(han)(han)汞(gong)量經處理(li)后(hou)可(ke)下降(jiang)至0.02～0.03mg/L,但(dan)此法(fa)(fa)對濃度(du)較高(gao)、水(shui)(shui)質較清(qing)的含(han)(han)(han)(han)汞(gong)廢(fei)(fei)水(shui)(shui),其效果不如硫化鈉法(fa)(fa)。在(zai)處理(li)廢(fei)(fei)水(shui)(shui)中同時含(han)(han)(han)(han)有汞(gong)及其他(ta)重金屬(shu)離子情。朱又春等在(zai)混凝法(fa)(fa)基(ji)礎上與微電解過(guo)程結(jie)合,得出結(jie)論(lun)可(ke)使汞(gong)富集在(zai)污泥中,更有利于后(hou)續的混凝操作。

含汞廢(fei)水處理方法3、離子交(jiao)換(huan)法

大(da)孔巰(qiu)基離(li)(li)子(zi)交換(huan)劑對含(han)汞(gong)(gong)(gong)(gong)廢(fei)(fei)水(shui)處(chu)(chu)理(li)(li)有(you)很(hen)好的(de)(de)效(xiao)果。樹(shu)(shu)(shu)脂(zhi)(zhi)上(shang)的(de)(de)巰(qiu)基對汞(gong)(gong)(gong)(gong)離(li)(li)子(zi)有(you)很(hen)強的(de)(de)吸附能力(li)吸附在樹(shu)(shu)(shu)脂(zhi)(zhi)上(shang)的(de)(de)汞(gong)(gong)(gong)(gong),可(ke)用濃鹽酸洗脫(tuo),定(ding)量(liang)回收(shou)。含(han)汞(gong)(gong)(gong)(gong)廢(fei)(fei)水(shui)經(jing)過處(chu)(chu)理(li)(li)后(hou)排出水(shui)含(han)汞(gong)(gong)(gong)(gong)量(liang)可(ke)降至0.05mg/L以下。此外,采用選(xuan)擇吸附汞(gong)(gong)(gong)(gong)的(de)(de)螯合樹(shu)(shu)(shu)脂(zhi)(zhi)處(chu)(chu)理(li)(li)含(han)汞(gong)(gong)(gong)(gong)廢(fei)(fei)水(shui)也正(zheng)在推廣(guang)應用。并(bing)取得(de)了一定(ding)效(xiao)果。在大(da)部分無機(ji)汞(gong)(gong)(gong)(gong)的(de)(de)離(li)(li)子(zi)交換(huan)處(chu)(chu)理(li)(li)技術中,首先需加入氯(lv)氣或次氯(lv)酸鹽或氯(lv)化物(wu)(wu),以形成(cheng)帶負(fu)電荷的(de)(de)汞(gong)(gong)(gong)(gong)氯(lv)絡合物(wu)(wu),然后(hou)用陰離(li)(li)子(zi)交換(huan)樹(shu)(shu)(shu)脂(zhi)(zhi)脫(tuo)除。離(li)(li)子(zi)交換(huan)法(fa)主要用于處(chu)(chu)理(li)(li)背(bei)景氯(lv)化物(wu)(wu)含(han)量(liang)較(jiao)高的(de)(de)工業廢(fei)(fei)水(shui)。一些處(chu)(chu)理(li)(li)數據表明,先經(jing)初步處(chu)(chu)理(li)(li)再用離(li)(li)子(zi)交換(huan)法(fa)進(jin)行二級處(chu)(chu)理(li)(li)所得(de)到的(de)(de)離(li)(li)子(zi)交換(huan)效(xiao)果最佳。

當廢水中(zhong)氯化物濃度不高(gao)(gao)時,采(cai)(cai)用陽離(li)(li)子(zi)交換(huan)樹(shu)脂(zhi)(zhi)(zhi)(zhi)是有(you)效的(de)。含(han)巰基(R–SH)的(de)樹(shu)脂(zhi)(zhi)(zhi)(zhi)如聚硫苯乙烯對(dui)汞(gong)離(li)(li)子(zi)的(de)吸附有(you)很高(gao)(gao)的(de)選擇性(xing)(xing)。硫羥樹(shu)脂(zhi)(zhi)(zhi)(zhi)在歐洲被廣(guang)泛(fan)應用于(yu)汞(gong)正離(li)(li)子(zi)的(de)去(qu)(qu)除。其他高(gao)(gao)親和(he)力(li)的(de)陽離(li)(li)子(zi)樹(shu)脂(zhi)(zhi)(zhi)(zhi)有(you)異硫脲鎓(weng)樹(shu)脂(zhi)(zhi)(zhi)(zhi)和(he)甲(jia)胺(an)酸酯型(xing)樹(shu)脂(zhi)(zhi)(zhi)(zhi)。據(ju)報道(dao)異硫脲鎓(weng)樹(shu)脂(zhi)(zhi)(zhi)(zhi)對(dui)無(wu)(wu)機(ji)汞(gong)和(he)甲(jia)基汞(gong)都有(you)效,而甲(jia)胺(an)酸酯型(xing)樹(shu)脂(zhi)(zhi)(zhi)(zhi)對(dui)汞(gong)有(you)極高(gao)(gao)的(de)親和(he)力(li)和(he)選擇性(xing)(xing)。不管是用來(lai)去(qu)(qu)除汞(gong)氯絡(luo)合物的(de)陰離(li)(li)子(zi)樹(shu)脂(zhi)(zhi)(zhi)(zhi),還是用來(lai)去(qu)(qu)除汞(gong)離(li)(li)子(zi)的(de)陽離(li)(li)子(zi)樹(shu)脂(zhi)(zhi)(zhi)(zhi),它們處理(li)無(wu)(wu)機(ji)汞(gong)的(de)最(zui)低出水含(han)量為1～5μg/L。在中(zhong)性(xing)(xing)或微酸性(xing)(xing)pH值時采(cai)(cai)用二(er)級處理(li)可獲(huo)得最(zui)有(you)效的(de)結果。

用(yong)離(li)子交(jiao)換纖(xian)維凈化(hua)(hua)含(han)汞廢水(shui)的優點是:(1)處(chu)理(li)水(shui)質高、處(chu)理(li)后可(ke)(ke)(ke)使汞含(han)量達0.005mg/L以下;(2)設備(bei)簡(jian)單,離(li)子交(jiao)換纖(xian)維比(bi)表面積(ji)很大,可(ke)(ke)(ke)達40m2/g。吸收(shou)汞的速度快,一般20min就(jiu)可(ke)(ke)(ke)平衡,縮小(xiao)了(le)設備(bei)體積(ji);(3)沒有二(er)次污染,離(li)子交(jiao)換纖(xian)維吸汞飽(bao)和后,可(ke)(ke)(ke)以用(yong)酸液再生,再生液濃度比(bi)原來廢水(shui)要高100倍(bei)以上[4],便于(yu)集中(zhong)處(chu)理(li)和利用(yong),纖(xian)維老化(hua)(hua)后,可(ke)(ke)(ke)以燒掉纖(xian)維,回收(shou)汞鹽。

銅汞廢(fei)(fei)水處(chu)理(li)之含汞廢(fei)(fei)水處(chu)理(li)方法4、吸附法

活(huo)(huo)性炭(tan)(tan)法能有效地吸附(fu)廢(fei)(fei)水(shui)(shui)中(zhong)的(de)(de)(de)汞(gong)(gong),我國(guo)有些工廠已采(cai)用此法處理含(han)汞(gong)(gong)廢(fei)(fei)水(shui)(shui),但該方法只適用于(yu)處理低(di)濃(nong)度(du)(du)的(de)(de)(de)含(han)汞(gong)(gong)廢(fei)(fei)水(shui)(shui)。廢(fei)(fei)水(shui)(shui)含(han)汞(gong)(gong)濃(nong)度(du)(du)高時,可(ke)先進行一級處理,降低(di)廢(fei)(fei)水(shui)(shui)中(zhong)汞(gong)(gong)濃(nong)度(du)(du)后(hou)(hou)(hou)再用活(huo)(huo)性炭(tan)(tan)吸附(fu)。將含(han)汞(gong)(gong)量1～2mg/L以(yi)下(xia)的(de)(de)(de)廢(fei)(fei)水(shui)(shui)通(tong)(tong)過(guo)活(huo)(huo)性炭(tan)(tan)濾塔,排出水(shui)(shui)含(han)汞(gong)(gong)量可(ke)下(xia)降至0.01～0.05mg/L。回收汞(gong)(gong)后(hou)(hou)(hou)活(huo)(huo)性炭(tan)(tan)可(ke)再生并重復利(li)用。日本(ben)某生產蒽醌染料工廠的(de)(de)(de)廢(fei)(fei)水(shui)(shui)中(zhong)含(han)汞(gong)(gong)量為50～60mg/L,先加(jia)入(ru)石灰(hui)水(shui)(shui)攪拌(ban)、沉(chen)(chen)淀反應,在沉(chen)(chen)降槽中(zhong)分(fen)離成沉(chen)(chen)淀和(he)(he)清(qing)液,通(tong)(tong)過(guo)石灰(hui)沉(chen)(chen)淀法可(ke)以(yi)除去96%的(de)(de)(de)汞(gong)(gong),清(qing)液中(zhong)的(de)(de)(de)含(han)汞(gong)(gong)量降至1～3mg/L,再將清(qing)液送入(ru)粒(li)狀活(huo)(huo)性炭(tan)(tan)槽,吸附(fu)后(hou)(hou)(hou)廢(fei)(fei)水(shui)(shui)中(zhong)含(han)汞(gong)(gong)量可(ke)以(yi)降至0.1～0.01mg/L,廢(fei)(fei)水(shui)(shui)最后(hou)(hou)(hou)流(liu)入(ru)廢(fei)(fei)水(shui)(shui)處理場,再稀釋10～20倍(bei)后(hou)(hou)(hou)放掉。活(huo)(huo)性炭(tan)(tan)的(de)(de)(de)處理效果與(yu)很多因(yin)素(su)有關(guan),其中(zhong)包括汞(gong)(gong)的(de)(de)(de)初始形態和(he)(he)濃(nong)度(du)(du)、活(huo)(huo)性炭(tan)(tan)的(de)(de)(de)用量和(he)(he)種(zhong)類、pH控制值以(yi)及活(huo)(huo)性炭(tan)(tan)與(yu)含(han)汞(gong)(gong)廢(fei)(fei)水(shui)(shui)的(de)(de)(de)接觸(chu)時間等(deng)。增大(da)活(huo)(huo)性炭(tan)(tan)用量以(yi)及增加(jia)接觸(chu)時間都可(ke)以(yi)提高汞(gong)(gong)的(de)(de)(de)去除率。

從表4數據(ju)可(ke)(ke)見,活性炭對(dui)高濃(nong)度(du)含(han)(han)(han)(han)(han)汞(gong)(gong)(gong)(gong)(gong)廢(fei)(fei)(fei)水(shui)具有(you)較高的(de)(de)去(qu)(qu)(qu)除(chu)率(85%～99%);對(dui)低濃(nong)度(du)汞(gong)(gong)(gong)(gong)(gong)的(de)(de)去(qu)(qu)(qu)除(chu)率雖然(ran)(ran)并不高,但出水(shui)中(zhong)(zhong)汞(gong)(gong)(gong)(gong)(gong)含(han)(han)(han)(han)(han)量最低。因(yin)此,活性炭處理(li)(li)初始汞(gong)(gong)(gong)(gong)(gong)含(han)(han)(han)(han)(han)量小于1μg/L的(de)(de)廢(fei)(fei)(fei)水(shui),去(qu)(qu)(qu)除(chu)率雖然(ran)(ran)低于70%,但出水(shui)汞(gong)(gong)(gong)(gong)(gong)含(han)(han)(han)(han)(han)量卻可(ke)(ke)達(da)0.25μg/L以下。而同樣處理(li)(li)初始汞(gong)(gong)(gong)(gong)(gong)含(han)(han)(han)(han)(han)量為(wei)(wei)10～100μg/L的(de)(de)廢(fei)(fei)(fei)水(shui),汞(gong)(gong)(gong)(gong)(gong)去(qu)(qu)(qu)除(chu)率雖達(da)90%以上,但出水(shui)汞(gong)(gong)(gong)(gong)(gong)含(han)(han)(han)(han)(han)量最高達(da)到20μg/L。有(you)證據(ju)表明當pH值(zhi)降(jiang)至2～4時,汞(gong)(gong)(gong)(gong)(gong)去(qu)(qu)(qu)除(chu)率將有(you)所(suo)升高。另(ling)一項研究中(zhong)(zhong)也(ye)觀察到這種pH效應,在(zai)含(han)(han)(han)(han)(han)汞(gong)(gong)(gong)(gong)(gong)10g/L的(de)(de)廢(fei)(fei)(fei)水(shui)中(zhong)(zhong)加入(ru)100mg/L的(de)(de)粉狀活性炭,當pH值(zhi)從9降(jiang)為(wei)(wei)7時,去(qu)(qu)(qu)除(chu)率從50%升至80%。在(zai)其他研究中(zhong)(zhong),人們還選(xuan)擇了其他物質(zhi)作為(wei)(wei)吸附(fu)劑,，采(cai)(cai)用(yong)40%AlCl3溶液改性過的(de)(de)膨潤土(tu)在(zai)pH值(zhi)為(wei)(wei)8～9下處理(li)(li)含(han)(han)(han)(han)(han)汞(gong)(gong)(gong)(gong)(gong)廢(fei)(fei)(fei)水(shui),出水(shui)汞(gong)(gong)(gong)(gong)(gong)含(han)(han)(han)(han)(han)量0.0351mg/L。于瑞蓮采(cai)(cai)用(yong)硫(liu)酸對(dui)天(tian)然(ran)(ran)膨潤土(tu)改性后處理(li)(li)含(han)(han)(han)(han)(han)汞(gong)(gong)(gong)(gong)(gong)廢(fei)(fei)(fei)水(shui),pH值(zhi)為(wei)(wei)8條件下,去(qu)(qu)(qu)除(chu)率達(da)到97.1%。研究了TiO2復合吸收劑對(dui)含(han)(han)(han)(han)(han)汞(gong)(gong)(gong)(gong)(gong)廢(fei)(fei)(fei)水(shui)的(de)(de)處理(li)(li),可(ke)(ke)將汞(gong)(gong)(gong)(gong)(gong)含(han)(han)(han)(han)(han)量100μg/L的(de)(de)水(shui)樣中(zhong)(zhong)汞(gong)(gong)(gong)(gong)(gong)離子達(da)到97.7%的(de)(de)去(qu)(qu)(qu)除(chu)率,吸附(fu)劑經再生(sheng)后可(ke)(ke)以再利(li)用(yong)。

銅汞(gong)廢(fei)水處理之(zhi)含汞(gong)廢(fei)水處理方法(fa)5、還原法(fa)

無機汞離子經還原(yuan)可轉變(bian)為金屬汞,然(ran)后(hou)通過過濾或其他技術進行分離。還原(yuan)劑種類很多,包括鐵、鉍、錫、鎂、銅、錳、鋁(lv)、鉛、鋅、肼、氯(lv)化(hua)(hua)亞錫和硼氫化(hua)(hua)鈉。有(you)關這些還原(yuan)方法的處(chu)理數(shu)據見表5。雖然(ran)文獻中(zhong)關于還原(yuan)法的討論很多,但實際處(chu)理數(shu)據卻較少。還原(yuan)法的主要優(you)點是汞能以金屬單質的形(xing)式回收。

鐵(tie)(tie)(tie)和鋅(xin)較好(hao),因其價格(ge)低,溶液(ye)中(zhong)損失少,反應(ying)速(su)度較高(gao)。用鐵(tie)(tie)(tie)時(shi)(shi),pH值應(ying)適當,堿性(xing)大(da)了會生成(cheng)(cheng)氧化(hua)(hua)鐵(tie)(tie)(tie)和氫(qing)氧化(hua)(hua)鐵(tie)(tie)(tie)沉淀,pH=6～9時(shi)(shi),汞(gong)(gong)(gong)(gong)(gong)(gong)回(hui)收(shou)量(liang)最多(duo),pH值低于5時(shi)(shi),發生氫(qing)氣,減少了有效(xiao)(xiao)面積;用鋅(xin)時(shi)(shi),pH=9～11為最好(hao),在微堿性(xing)或酸性(xing)溶液(ye)中(zhong),鋅(xin)易于取代汞(gong)(gong)(gong)(gong)(gong)(gong),可(ke)(ke)(ke)使(shi)含(han)汞(gong)(gong)(gong)(gong)(gong)(gong)1～400mg/L,pH=2～11的(de)(de)廢(fei)水(shui)經處(chu)理后收(shou)到(dao)(dao)良好(hao)效(xiao)(xiao)果。鐵(tie)(tie)(tie)粉(fen)(fen)(fen)還(huan)原法是酸性(xing)介(jie)質中(zhong),鐵(tie)(tie)(tie)粉(fen)(fen)(fen)與無機(ji)汞(gong)(gong)(gong)(gong)(gong)(gong)離子起氧化(hua)(hua)-還(huan)原反應(ying)而(er)釋放出(chu)汞(gong)(gong)(gong)(gong)(gong)(gong),經過濾(lv)后除(chu)(chu)去。用一步法處(chu)理含(han)汞(gong)(gong)(gong)(gong)(gong)(gong)量(liang)為450～600mg/L的(de)(de)廢(fei)水(shui)時(shi)(shi),用對(dui)應(ying)于廢(fei)水(shui)質量(liang)2%的(de)(de)鐵(tie)(tie)(tie)粉(fen)(fen)(fen)處(chu)理后,含(han)汞(gong)(gong)(gong)(gong)(gong)(gong)量(liang)可(ke)(ke)(ke)降到(dao)(dao)0.5～5.0mg/L,去除(chu)(chu)率在90%以(yi)上。二步法可(ke)(ke)(ke)將含(han)汞(gong)(gong)(gong)(gong)(gong)(gong)量(liang)降到(dao)(dao)0.05mg/L。大(da)約40kg鐵(tie)(tie)(tie)粉(fen)(fen)(fen),可(ke)(ke)(ke)去除(chu)(chu)1kg汞(gong)(gong)(gong)(gong)(gong)(gong)。鋅(xin)粉(fen)(fen)(fen)還(huan)原法用于處(chu)理較高(gao)pH值(9～11)的(de)(de)含(han)汞(gong)(gong)(gong)(gong)(gong)(gong)廢(fei)水(shui)效(xiao)(xiao)果最好(hao)。用2mm粒徑鋅(xin)粒填充10cm厚的(de)(de)還(huan)原濾(lv)床(chuang),含(han)汞(gong)(gong)(gong)(gong)(gong)(gong)廢(fei)水(shui)通過濾(lv)床(chuang)過濾(lv)13s,便可(ke)(ke)(ke)使(shi)廢(fei)水(shui)凈(jing)(jing)化(hua)(hua)到(dao)(dao)含(han)汞(gong)(gong)(gong)(gong)(gong)(gong)200μg/L,而(er)在110s內可(ke)(ke)(ke)凈(jing)(jing)化(hua)(hua)到(dao)(dao)含(han)汞(gong)(gong)(gong)(gong)(gong)(gong)5μg/L。鋁(lv)(lv)(lv)粉(fen)(fen)(fen)接觸法適用于處(chu)理含(han)汞(gong)(gong)(gong)(gong)(gong)(gong)單(dan)一的(de)(de)廢(fei)水(shui),當鋁(lv)(lv)(lv)粉(fen)(fen)(fen)與汞(gong)(gong)(gong)(gong)(gong)(gong)離子接觸時(shi)(shi),汞(gong)(gong)(gong)(gong)(gong)(gong)離析(xi)和鋁(lv)(lv)(lv)生成(cheng)(cheng)鋁(lv)(lv)(lv)汞(gong)(gong)(gong)(gong)(gong)(gong)齊(汞(gong)(gong)(gong)(gong)(gong)(gong)與鋁(lv)(lv)(lv)結合成(cheng)(cheng)的(de)(de)合金),附著于鋁(lv)(lv)(lv)粉(fen)(fen)(fen)表面,再將此(ci)鋁(lv)(lv)(lv)粉(fen)(fen)(fen)加熱(re)分解(jie)即可(ke)(ke)(ke)得(de)到(dao)(dao)汞(gong)(gong)(gong)(gong)(gong)(gong)。鋁(lv)(lv)(lv)粉(fen)(fen)(fen)添加量(liang)越多(duo),除(chu)(chu)汞(gong)(gong)(gong)(gong)(gong)(gong)效(xiao)(xiao)率越高(gao)。采用填料過濾(lv)法比投(tou)加鋁(lv)(lv)(lv)粉(fen)(fen)(fen)效(xiao)(xiao)果較好(hao),該法能使(shi)含(han)汞(gong)(gong)(gong)(gong)(gong)(gong)廢(fei)水(shui)達(da)到(dao)(dao)排放標準。

銅汞廢水處(chu)(chu)理(li)之含汞廢水處(chu)(chu)理(li)方法(fa)6、過濾法(fa)

過(guo)濾(lv)(lv)(lv)(lv)法是(shi)采用(yong)鎂的(de)(de)(de)(de)有機物、玻(bo)(bo)璃(li)柱、鐵屑(xie)(xie)等(deng)作濾(lv)(lv)(lv)(lv)料,通(tong)過(guo)過(guo)濾(lv)(lv)(lv)(lv)去(qu)除廢(fei)(fei)水中的(de)(de)(de)(de)汞(gong)(gong)(gong),脫(tuo)(tuo)汞(gong)(gong)(gong)效率在80%～90%之間(jian)。采用(yong)含(han)鎂的(de)(de)(de)(de)無(wu)機礦物為過(guo)濾(lv)(lv)(lv)(lv)介質,含(han)汞(gong)(gong)(gong)廢(fei)(fei)水按120～200L/m2•min的(de)(de)(de)(de)流速通(tong)過(guo)38cm厚(hou)的(de)(de)(de)(de)濾(lv)(lv)(lv)(lv)墊一(yi)次,脫(tuo)(tuo)汞(gong)(gong)(gong)率達83%。含(han)氯化(hua)汞(gong)(gong)(gong)2mg/L的(de)(de)(de)(de)廢(fei)(fei)水通(tong)過(guo)內裝玻(bo)(bo)璃(li)珠(zhu)(或(huo)砂礫)的(de)(de)(de)(de)玻(bo)(bo)璃(li)柱,可除去(qu)90%的(de)(de)(de)(de)氯化(hua)汞(gong)(gong)(gong)。含(han)汞(gong)(gong)(gong)廢(fei)(fei)水通(tong)過(guo)鐵屑(xie)(xie)填(tian)充(chong)層的(de)(de)(de)(de)表面(mian),離解出的(de)(de)(de)(de)鐵離子(zi)使汞(gong)(gong)(gong)析(xi)出沉(chen)淀,但(dan)必(bi)須維持鐵屑(xie)(xie)填(tian)充(chong)層的(de)(de)(de)(de)表面(mian)始(shi)終不能變(bian)為氧化(hua)鐵,所以該(gai)法的(de)(de)(de)(de)缺點是(shi)需要時常酸洗表面(mian)層。

下面(mian)是“銅汞廢水處理(li)”中含銅廢水處理(li)方法(fa)：

含銅廢水(shui)處理方法1、化學(xue)沉淀法

這(zhe)(zhe)種方法(fa)適用(yong)(yong)于(yu)含銅(tong)量在800～1000mg/L以(yi)下的廢(fei)(fei)水(shui)(shui),是用(yong)(yong)堿提高廢(fei)(fei)水(shui)(shui)PH至生成氫氧化銅(tong)沉淀.這(zhe)(zhe)種方法(fa)可以(yi)取得(de)良好(hao)效(xiao)果,一般采用(yong)(yong)堿性廢(fei)(fei)水(shui)(shui)去沉淀.但沉淀中雜質(zhi)分離麻煩,平時處(chu)理費用(yong)(yong)較高。

銅汞廢水處理之含銅廢水處理方法(fa)2、置換法(fa)

在酸性條件下,用鐵(tie)屑等(deng)較(jiao)活潑(po)金屬將銅置換出來(lai).這種(zhong)方法可以(yi)達(da)到治理(li)要求,但沉淀中雜(za)質分離困難,污泥量多(duo)。

銅汞廢水處理之含銅廢水處理方(fang)法3、離(li)子交換(huan)法

這種方法適用業(ye)含(han)銅濃(nong)度(du)在(zai)50～200mg/L的廢水(shui).濃(nong)度(du)過高,廢水(shui)PH勢必較低,若(ruo)用弱(ruo)酸(suan)性陽離子(zi)交換樹(shu)脂,很難(nan)吸附銅離子(zi);若(ruo)用強酸(suan)性陽離子(zi)交換樹(shu)脂交換容(rong)量則較小,再生時要用較多(duo)的酸(suan).用陽樹(shu)脂處理含(han)銅量較低廢水(shui),鐵(tie)離子(zi)也會被樹(shu)脂吸附,洗脫后(hou)難(nan)以分離。

銅汞廢水處(chu)理之含銅廢水處(chu)理方法4、電解法

電(dian)解法(fa)在處理硫酸鹽鍍銅廢(fei)水中得到了廣泛使(shi)(shi)用,特別是電(dian)解法(fa)—離子(zi)交(jiao)換法(fa)組(zu)合,或是使(shi)(shi)用電(dian)解法(fa)----化學(xue)沉淀(dian)法(fa)組(zu)合。

  使用微信“掃一掃”功能添加“谷騰環保網”

相關文章