試驗設添加表面活性劑(APG)和不加(jia)表面(mian)活性劑(ji)的(de)對照(CK)兩個處理(li),每個處理(li)3個重復。表面(mian)活性劑(ji)APG的(de)添(tian)加(jia)量為100mg kg?1(堆料)。在堆置過程中,分別于堆肥(fei)的(de)第0d、3d、5d、7d、14d、21d、28d從堆肥(fei)的(de)不同部位采集樣品,充(chong)分混合后測定堆肥(fei)的(de)微(wei)生物數(shu)量以及酶活性。試驗共堆制30 d(2008年8月11日~9月9日)。
堆肥(fei)溫度(du)由PT-100鉑電極(ji)測(ce)定(ding),測(ce)定(ding)位置(zhi)為(wei)堆肥(fei)中心部位,分別(bie)(bie)在每天上午10:00和下午17:00測(ce)定(ding)。微(wei)生物數量測(ce)定(ding)采用平板菌落(luo)計數法[29]。細菌、放線菌、真菌計數所用培(pei)養(yang)基分別(bie)(bie)為(wei)牛肉(rou)膏蛋白胨(dong)瓊(qiong)脂培(pei)養(yang)基、孟加(jia)拉(la)紅瓊(qiong)脂培(pei)養(yang)基、改(gai)良高(gao)氏一號培(pei)養(yang)基。
酶(mei)(mei)(mei)活(huo)性(xing)(xing)測(ce)(ce)(ce)定(ding)(ding)(ding)方法(fa)(fa)(fa):脲酶(mei)(mei)(mei)活(huo)性(xing)(xing)測(ce)(ce)(ce)定(ding)(ding)(ding)是(shi)以脲素(su)為基(ji)質進行(xing)酶(mei)(mei)(mei)促(cu)反(fan)應,測(ce)(ce)(ce)定(ding)(ding)(ding)生成的(de)氨量(liang)來(lai)表示脲酶(mei)(mei)(mei)活(huo)性(xing)(xing);過氧(yang)化(hua)(hua)(hua)氫酶(mei)(mei)(mei)活(huo)性(xing)(xing)測(ce)(ce)(ce)定(ding)(ding)(ding)采(cai)用(yong)(yong)滴(di)定(ding)(ding)(ding)法(fa)(fa)(fa),在酸(suan)性(xing)(xing)條件下用(yong)(yong)0.1mol L?1高(gao)錳酸(suan)鉀滴(di)定(ding)(ding)(ding)反(fan)應混合物(wu)(wu)中的(de)過氧(yang)化(hua)(hua)(hua)氫,根據高(gao)錳酸(suan)鉀的(de)濃度和體積(ji)(ji)以及過氧(yang)化(hua)(hua)(hua)氫濃度求(qiu)得(de)過氧(yang)化(hua)(hua)(hua)氫體積(ji)(ji),用(yong)(yong)反(fan)應前后(hou)(hou)過氧(yang)化(hua)(hua)(hua)氫消耗量(liang)表示過氧(yang)化(hua)(hua)(hua)氫酶(mei)(mei)(mei)活(huo)性(xing)(xing),活(huo)性(xing)(xing)單位為mmol g?1;轉(zhuan)(zhuan)化(hua)(hua)(hua)酶(mei)(mei)(mei)活(huo)性(xing)(xing)是(shi)以蔗糖(tang)(tang)為底(di)物(wu)(wu),經轉(zhuan)(zhuan)化(hua)(hua)(hua)酶(mei)(mei)(mei)水解(jie)后(hou)(hou)生成還(huan)原(yuan)糖(tang)(tang),然后(hou)(hou)采(cai)用(yong)(yong)3,5-二(er)(er)硝基(ji)水楊酸(suan)比(bi)色(se)法(fa)(fa)(fa)進行(xing)測(ce)(ce)(ce)定(ding)(ding)(ding),活(huo)性(xing)(xing)單位以mg(葡萄糖(tang)(tang)) g?1 24h?1;纖(xian)(xian)維(wei)(wei)素(su)酶(mei)(mei)(mei)活(huo)性(xing)(xing)測(ce)(ce)(ce)定(ding)(ding)(ding)采(cai)用(yong)(yong)DNS法(fa)(fa)(fa),即(ji)用(yong)(yong)羧(suo)甲基(ji)纖(xian)(xian)維(wei)(wei)素(su)鈉鹽(yan)作底(di)物(wu)(wu),經纖(xian)(xian)維(wei)(wei)素(su)酶(mei)(mei)(mei)水解(jie)后(hou)(hou)生成還(huan)原(yuan)糖(tang)(tang),然后(hou)(hou)同(tong)樣(yang)用(yong)(yong)3,5-二(er)(er)硝基(ji)水楊酸(suan)法(fa)(fa)(fa)測(ce)(ce)(ce)定(ding)(ding)(ding)還(huan)原(yuan)糖(tang)(tang)含(han)量(liang),纖(xian)(xian)維(wei)(wei)素(su)酶(mei)(mei)(mei)活(huo)性(xing)(xing)的(de)單位是(shi)μg·min?1。
生物表面(mian)活(huo)性(xing)劑(ji)(ji)作為由微生物產生的(de)一(yi)類(lei)新型表面(mian)活(huo)性(xing)劑(ji)(ji),相(xiang)(xiang)對于化(hua)學表面(mian)活(huo)性(xing)劑(ji)(ji)有低毒性(xing)、可降(jiang)解(jie)性(xing)和(he)生態相(xiang)(xiang)容(rong)性(xing)、高效性(xing)和(he)穩定性(xing)等諸(zhu)多優勢,因此(ci)不(bu)僅在石(shi)油開采和(he)運(yun)輸(shu)、制藥工(gong)(gong)業(ye)(ye)、食(shi)品工(gong)(gong)業(ye)(ye)、紡織工(gong)(gong)業(ye)(ye)和(he)化(hua)妝品工(gong)(gong)業(ye)(ye)等領(ling)域應用(yong)廣(guang)泛,而且在環(huan)境(jing)工(gong)(gong)程(cheng)(cheng)領(ling)域特別是土壤修復中的(de)應用(yong)也得到了(le)越(yue)來越(yue)多的(de)關(guan)注(zhu)。在固體有機廢棄物好氧堆肥過程(cheng)(cheng)中加(jia)入(ru)生物表面(mian)活(huo)性(xing)劑(ji)(ji),可改善堆肥處理的(de)微環(huan)境(jing),促(cu)進有機質的(de)降(jiang)解(jie),加(jia)快堆肥進程(cheng)(cheng)。
然(ran)而,生(sheng)(sheng)物(wu)(wu)表(biao)(biao)(biao)面活(huo)性(xing)劑(ji)(ji)仍(reng)只有少(shao)數產(chan)品(pin)走向市場,大多數品(pin)種(zhong)處于試(shi)驗研究(jiu)階段,主要是由于它的(de)生(sheng)(sheng)產(chan)成本(ben)較高,據估計(ji)生(sheng)(sheng)物(wu)(wu)表(biao)(biao)(biao)面活(huo)性(xing)劑(ji)(ji)是化(hua)學(xue)表(biao)(biao)(biao)面活(huo)性(xing)劑(ji)(ji)成本(ben)的(de)3~10倍。同時,一(yi)些生(sheng)(sheng)產(chan)生(sheng)(sheng)物(wu)(wu)表(biao)(biao)(biao)面活(huo)性(xing)劑(ji)(ji)的(de)菌劑(ji)(ji)如(ru)銅(tong)綠假單(dan)胞菌(Pseudomonas aeruginosa)是農用(yong)(yong)堆(dui)肥(fei)(fei)(fei)和(he)微生(sheng)(sheng)物(wu)(wu)肥(fei)(fei)(fei)料所(suo)禁用(yong)(yong)的(de)菌種(zhong)。因此,生(sheng)(sheng)物(wu)(wu)表(biao)(biao)(biao)面活(huo)性(xing)劑(ji)(ji)應(ying)用(yong)(yong)于農用(yong)(yong)堆(dui)肥(fei)(fei)(fei)受到極大的(de)限制(zhi)。根據文獻(xian)報道(dao),添加化(hua)學(xue)表(biao)(biao)(biao)面活(huo)性(xing)劑(ji)(ji)吐溫-80能夠增加纖(xian)維素酶活(huo)性(xing),促進(jin)纖(xian)維素類物(wu)(wu)質的(de)生(sheng)(sheng)物(wu)(wu)降解(jie)。將化(hua)學(xue)表(biao)(biao)(biao)面活(huo)性(xing)劑(ji)(ji)應(ying)用(yong)(yong)于好氧堆(dui)肥(fei)(fei)(fei)以(yi)加速(su)堆(dui)肥(fei)(fei)(fei)進(jin)程,至今少(shao)有報道(dao)。