含銅廢水如何處理?
銅(tong)(tong)(tong)的冶煉、加工(gong)以及電鍍等工(gong)業(ye)生產(chan)過(guo)程中(zhong)都會產(chan)生大量(liang)含(han)銅(tong)(tong)(tong)廢(fei)水(shui),其(qi)含(han)銅(tong)(tong)(tong)濃(nong)度高達幾十mg/L,這種廢(fei)水(shui)排(pai)入水(shui)體(ti)中(zhong),會嚴(yan)重影響水(shui)的質量(liang),對環境造(zao)成(cheng)污染(ran)。水(shui)中(zhong)銅(tong)(tong)(tong)含(han)量(liang)達0.01mg/L時,對水(shui)體(ti)自凈有明(ming)顯(xian)的抑制作用,超過(guo)3.0mg/L,會產(chan)生異味,超過(guo)15mg/L,就無法(fa)引(yin)用。因此(ci),工(gong)業(ye)廢(fei)水(shui)必須經過(guo)處(chu)(chu)理才能(neng)達到環境要求(qiu)。本文介(jie)紹了幾種常用的含(han)銅(tong)(tong)(tong)廢(fei)水(shui)處(chu)(chu)理方(fang)法(fa)。
1 化學沉(chen)淀法
化(hua)學(xue)沉(chen)淀(dian)(dian)法(fa)(fa)是銅和大(da)(da)多數重(zhong)金屬的常規處(chu)理(li)(li)(li)(li)方法(fa)(fa),一(yi)般酸性(xing)含(han)(han)銅污(wu)(wu)水(shui)(shui)經調整ph值(zhi)后(hou)(hou)(hou),再經沉(chen)淀(dian)(dian)過濾(lv),能達到(dao)(dao)出水(shui)(shui)含(han)(han)銅<0.5mg/L。化(hua)學(xue)法(fa)(fa)處(chu)理(li)(li)(li)(li)含(han)(han)銅鍍廢(fei)水(shui)(shui)具(ju)有(you)(you)(you)技術成(cheng)(cheng)熟、投資(zi)少(shao)、處(chu)理(li)(li)(li)(li)成(cheng)(cheng)本低、適應性(xing)強、管理(li)(li)(li)(li)方便(bian)、自動化(hua)程度高等諸多優點,在(zai)適當(dang)的條件下,處(chu)理(li)(li)(li)(li)后(hou)(hou)(hou)的廢(fei)水(shui)(shui)中銅離子的質(zhi)量濃度顯(xian)著低于國(guo)標規定(ding)的污(wu)(wu)水(shui)(shui)排放(fang)標準。化(hua)學(xue)沉(chen)淀(dian)(dian)法(fa)(fa)不足之處(chu)在(zai)于產(chan)生含(han)(han)重(zhong)金屬污(wu)(wu)泥,若污(wu)(wu)泥沒(mei)有(you)(you)(you)得(de)到(dao)(dao)妥(tuo)善的處(chu)理(li)(li)(li)(li)還會產(chan)生二(er)次(ci)污(wu)(wu)染(ran),用化(hua)學(xue)法(fa)(fa)處(chu)理(li)(li)(li)(li)含(han)(han)銅廢(fei)水(shui)(shui),首(shou)先必須破除絡(luo)合劑,使銅以(yi)離子形式存在(zai)于清洗廢(fei)水(shui)(shui)中,否則(ze)會形成(cheng)(cheng)銅絡(luo)合物,處(chu)理(li)(li)(li)(li)后(hou)(hou)(hou)的出水(shui)(shui)銅含(han)(han)量依(yi)然很(hen)高,其次(ci)固液分離效果對出水(shui)(shui)銅含(han)(han)量影響較(jiao)大(da)(da),所(suo)以(yi)設計處(chu)理(li)(li)(li)(li)工(gong)藝時要(yao)加重(zhong)力澄(cheng)清池和砂濾(lv),這樣占地(di)面積就(jiu)很(hen)大(da)(da),此外,只有(you)(you)(you)ph值(zhi)控(kong)制適宜,澄(cheng)清池設計合理(li)(li)(li)(li),沉(chen)渣沉(chen)淀(dian)(dian)性(xing)能良好或用過濾(lv)進行三級(ji)處(chu)理(li)(li)(li)(li),出水(shui)(shui)銅含(han)(han)量才能穩定(ding)達到(dao)(dao)0.5mg/L以(yi)下。
2 電解(jie)法
電解(jie)法(fa)在處理硫(liu)酸鹽鍍銅廢水中得(de)到了廣泛使用,特(te)別(bie)是電解(jie)法(fa)—離子交換法(fa)組(zu)合,或(huo)是使用電解(jie)法(fa)----化學沉淀法(fa)組(zu)合。
3 吸附法
吸(xi)(xi)(xi)附(fu)法是利(li)用材料(liao)的(de)(de)物理吸(xi)(xi)(xi)附(fu)和化學(xue)吸(xi)(xi)(xi)附(fu)等作(zuo)用去除(chu)廢水(shui)中有害(hai)物質的(de)(de)方法,該法應用廣泛(fan),活性炭,沸石分子(zi)篩,粉煤灰,礦物等對銅(tong)離(li)子(zi)的(de)(de)吸(xi)(xi)(xi)附(fu)作(zuo)用及應用均有報道,吸(xi)(xi)(xi)附(fu)法處理含銅(tong)廢水(shui),吸(xi)(xi)(xi)附(fu)劑來源(yuan)廣泛(fan),成(cheng)本(ben)低,操作(zuo)方便(bian),吸(xi)(xi)(xi)附(fu)效(xiao)果好,但吸(xi)(xi)(xi)附(fu)劑的(de)(de)使用壽命短,再生困難(nan),難(nan)以(yi)回收銅(tong)離(li)子(zi)。
4 離子(zi)交換法
這種方法適用(yong)(yong)業(ye)含銅濃度(du)在50~200mg/L的廢水.濃度(du)過高,廢水PH勢必較(jiao)低(di),若用(yong)(yong)弱酸性(xing)陽離(li)子交(jiao)換樹(shu)脂,很難吸附(fu)(fu)銅離(li)子,若用(yong)(yong)強酸性(xing)陽離(li)子交(jiao)換樹(shu)脂交(jiao)換容量則(ze)較(jiao)小,再(zai)生時要用(yong)(yong)較(jiao)多的酸,用(yong)(yong)陽樹(shu)脂處(chu)理含銅量較(jiao)低(di)廢水,鐵離(li)子也(ye)會被樹(shu)脂吸附(fu)(fu),洗(xi)脫(tuo)后(hou)難以分離(li)。
5 焦磷(lin)酸(suan)銅廢水處(chu)理
焦(jiao)磷(lin)酸(suan)鹽(yan)鍍銅(tong)(tong)(tong)漂(piao)洗廢(fei)水中(zhong)主(zhu)要含有(you)P2O44-、Cu(P2O4)26-、HPO42-、K+、NH4+、Fe2+、Ca2+、Mg2+等離子(zi)。可用(yong)堿性(xing)陰離子(zi)交換樹(shu)脂回收焦(jiao)磷(lin)酸(suan)銅(tong)(tong)(tong)離子(zi)。用(yong)亞鐵(tie)(tie)共沉(chen)淀法也可有(you)效的處理焦(jiao)磷(lin)酸(suan)鹽(yan)鍍銅(tong)(tong)(tong)廢(fei)水。焦(jiao)磷(lin)酸(suan)鹽(yan)鍍銅(tong)(tong)(tong)鍍液中(zhong)主(zhu)要成(cheng)分是(shi)焦(jiao)磷(lin)酸(suan)銅(tong)(tong)(tong)和焦(jiao)磷(lin)酸(suan)鉀(jia),它們相互作(zuo)用(yong)生成(cheng)焦(jiao)磷(lin)酸(suan)銅(tong)(tong)(tong)鉀(jia)螯合物(wu),在pH為(wei)8~9時(shi),銅(tong)(tong)(tong)的主(zhu)要存在形(xing)式(shi)為(wei)[Cu(P2O4)2]6-銅(tong)(tong)(tong)處于比較穩定的螯合狀態,加入硫酸(suan)亞鐵(tie)(tie),將銅(tong)(tong)(tong)還原(yuan)為(wei)Cu2O,而鐵(tie)(tie)以(yi)二價或三價氫氧化(hua)物(wu)形(xing)式(shi)存在,利(li)用(yong)鐵(tie)(tie)的氫氧化(hua)物(wu)的凝聚作(zuo)用(yong),將Cu2O吸(xi)附,發生共沉(chen)淀,從而達到(dao)除銅(tong)(tong)(tong)的目的。該工(gong)藝簡單,操(cao)作(zuo)方便。此外(wai)還可用(yong)漂(piao)白粉(fen)破壞絡合物(wu),使銅(tong)(tong)(tong)離子(zi)解離出來生成(cheng)氫氧化(hua)銅(tong)(tong)(tong),再進行固液分離。在操(cao)作(zuo)中(zhong)應注意(yi)漂(piao)白粉(fen)的加入量以(yi)及pH值的調節(jie)等問題。
6 置(zhi)換法
在酸性條件下,用鐵屑等較活潑(po)金屬將銅置換出來。這種方法可以達到治(zhi)理要求,沉淀(dian)中雜質分離困難,污泥量多。
7 氰化含銅廢水處理
氰(qing)(qing)(qing)化(hua)鍍銅廢液中含氰(qing)(qing)(qing)化(hua)物濃度高(gao),大多數工廠采用(yong)含氰(qing)(qing)(qing)廢水處理(li)相同(tong)的氯堿法。這(zhe)種(zhong)方法需要消耗(hao)大量的藥劑。除此(ci)之外還可采用(yong)離子交換(huan)法進行處理(li),但其含氰(qing)(qing)(qing)量不應大于100mg/L。

使用微信“掃一掃”功能添加“谷騰環保網”