表面活性劑的(de)(de)(de)增氧(yang)(yang)原理(li)(li)：在(zai)(zai)養殖水(shui)(shui)(shui)(shui)體(ti)中(zhong)(zhong)(zhong)加入表(biao)(biao)面(mian)(mian)活(huo)性(xing)劑(ji)后(hou)，能使養殖水(shui)(shui)(shui)(shui)體(ti)中(zhong)(zhong)(zhong)氧(yang)(yang)的(de)(de)(de)飽(bao)和(he)溶解(jie)度增大。根據水(shui)(shui)(shui)(shui)合物形(xing)成(cheng)(cheng)理(li)(li)論(lun)和(he)雙膜理(li)(li)論(lun)，由(you)于氧(yang)(yang)氣(qi)(qi)在(zai)(zai)水(shui)(shui)(shui)(shui)中(zhong)(zhong)(zhong)的(de)(de)(de)溶解(jie)度很小，所以(yi)在(zai)(zai)水(shui)(shui)(shui)(shui)體(ti)中(zhong)(zhong)(zhong)水(shui)(shui)(shui)(shui)－氧(yang)(yang)合物一般首(shou)先在(zai)(zai)氣(qi)(qi)－液(ye)(ye)界面(mian)(mian)形(xing)成(cheng)(cheng)，然后(hou)慢(man)慢(man)從氣(qi)(qi)相向液(ye)(ye)相擴散。在(zai)(zai)含(han)有(you)表(biao)(biao)面(mian)(mian)活(huo)性(xing)劑(ji)的(de)(de)(de)水(shui)(shui)(shui)(shui)體(ti)中(zhong)(zhong)(zhong)，由(you)于表(biao)(biao)面(mian)(mian)活(huo)性(xing)劑(ji)的(de)(de)(de)增溶作用，水(shui)(shui)(shui)(shui)溶液(ye)(ye)中(zhong)(zhong)(zhong)形(xing)成(cheng)(cheng)的(de)(de)(de)表(biao)(biao)面(mian)(mian)活(huo)性(xing)劑(ji)膠束中(zhong)(zhong)(zhong)溶解(jie)有(you)大量的(de)(de)(de)氧(yang)(yang)氣(qi)(qi)，這樣在(zai)(zai)表(biao)(biao)面(mian)(mian)活(huo)性(xing)劑(ji)水(shui)(shui)(shui)(shui)溶液(ye)(ye)中(zhong)(zhong)(zhong)水(shui)(shui)(shui)(shui)－氧(yang)(yang)合物的(de)(de)(de)形(xing)成(cheng)(cheng)不僅可(ke)以(yi)在(zai)(zai)氣(qi)(qi)－液(ye)(ye)界面(mian)(mian)發生，也同時可(ke)以(yi)在(zai)(zai)水(shui)(shui)(shui)(shui)體(ti)內部發生，降(jiang)低了(le)水(shui)(shui)(shui)(shui)－氧(yang)(yang)合物形(xing)成(cheng)(cheng)時間，提(ti)高了(le)氧(yang)(yang)在(zai)(zai)水(shui)(shui)(shui)(shui)體(ti)中(zhong)(zhong)(zhong)的(de)(de)(de)溶解(jie)度。??

常規水(shui)質改(gai)良劑(ji)中，我們(men)往往會使用(yong)到大量的絮凝劑(ji)，如(ru)硫酸(suan)鋁鉀、硫酸(suan)鋁、聚合氯化(hua)鋁（ＰＡＣ）和聚合硫酸(suan)鐵（ＰＦＳ）等，存(cun)在(zai)(zai)用(yong)量大、效果不穩定、形成二次污染等弊端(duan)。目(mu)前聚二乙(yi)基二甲(jia)基氯化(hua)氨(an)、聚氨(an)、聚丙(bing)烯酸(suan)鈉和丙(bing)烯酰胺等高分子表面活性劑(ji)已(yi)在(zai)(zai)逐(zhu)步替代上(shang)述傳統凈水(shui)劑(ji)。

國(guo)內廣泛采用的(de)高分子絮凝(ning)劑主要是(shi)(shi)聚(ju)(ju)丙烯酰(xian)(xian)胺系列的(de)產品，聚(ju)(ju)丙烯酰(xian)(xian)胺是(shi)(shi)一種線性(xing)(xing)的(de)水溶性(xing)(xing)共聚(ju)(ju)物，改性(xing)(xing)后制得(de)的(de)陽離子聚(ju)(ju)丙烯酰(xian)(xian)胺為(wei)固體粉(fen)末，易溶于水，有很強的(de)吸(xi)濕和絮凝(ning)作用，屬線性(xing)(xing)高分子表面活性(xing)(xing)劑，帶有正(zheng)電荷，可使懸浮的(de)有機膠體和有機化合物有效絮凝(ning)。 

其絮凝(ning)機理為(wei)：長鏈高分子(zi)與污水中固體顆粒表面(mian)（一(yi)(yi)般呈負電(dian)性如粘(zhan)土）發生多(duo)點吸(xi)(xi)附；高分子(zi)鏈很長，可(ke)以同(tong)(tong)時吸(xi)(xi)附在幾個(ge)(ge)固體顆粒上使它們橋聯在一(yi)(yi)起(qi)；吸(xi)(xi)附了幾個(ge)(ge)固體顆粒的長鏈分子(zi)，相互還可(ke)通過共(gong)同(tong)(tong)吸(xi)(xi)附固體顆粒或(huo)互相纏繞而彼此橋聯在一(yi)(yi)起(qi)，形成絮凝(ning)團塊（或(huo)團粒）。 

在高密度養殖(zhi)水(shui)體中(zhong)，由于投入大量飼(si)料，往往會在水(shui)體表(biao)面形成一層油(you)膜，阻(zu)隔了(le)空(kong)氣與水(shui)體的接觸(chu)。選擇合適的表(biao)面活(huo)(huo)性(xing)劑可使油(you)膜逐漸(jian)卷縮(suo)成油(you)珠被水(shui)流(liu)拖離、滾動、集中(zhong)至下風(feng)口處。表(biao)面活(huo)(huo)性(xing)劑用量較(jiao)大時可使其(qi)乳化(hua)、以微粒形態(tai)懸浮于水(shui)體中(zhong)，可消除(chu)油(you)膜。