Research On Conditioning Paper Sludge Using Enzymes And Its Mechanism

Paper sludge is a kind of industry sludge,which is a by-product of wastewatertreatment operations. The increasing amounts of waste activated sludge derived fromwastewater treatment operations had become a serious environmental problemconcerned by modern society.Sludge dewatering is of paramount importance inwastewater treatment systems as it reduces sludge volume and, consequently, the costof transporting sludge to its ultimate disposal site. Sludge conditioning is an importantway to achieve the purpose of deeply dewatering.Enzymes were used to condition paper sludge in this paper, the effect ofconditioning on properties of sludge and mechanism were detected and analyzed,which was to make us clearly realize the effect of conditioning on properties of sludgeand mechanism.Besides,a kind of cationic surfactant was used to condition papersludge which had been preconditioned by enzymes,then sludge properties weredetected and analyzed.Firstly,some properties of paper sludge were analyzed, including water content,organic material content, pH value, ash content,C, H, S, N content and metal contentof sludge in three sedimentation tanks.Besides, COD、SS、SVI、SV30were analyzedand optical microscope photoes of sludge were got.The results showed that watercontent was high, organic material content was high, pH value of three sludges wasalkalescent, metal elements were varied, lots of bacteria were in wet sludge.Secondly，a kind of cationic surfactant was used to condition paper sludge whichhad been preconditioned by diferent dosages of neutral-cellulose orneutral-protease,then sludge properties were detected and analyzed. The results showthat enzyme with CTMAB treatment on activated sludge have certain improvementeffect on some properties of sludge.Thirdly, diferent kinds and dosages of enzymes were used to condition activedsludge, test methods and conditions were discussed in experiments,then diferentdosages of neutral-cellulose and neutral-protease were used to condition actived sludgediferent time,then enzymatic treatment effects on waste activated sludge werediscussed. Experimental datas show that enzymatic treatment on activated sludge havecertain improvement effect on some properties of sludge.At last, neutral-cellulose and neutral-protease were used to condition actived sludge,then composition of EPS, specific surface area and pore size of particles,andsurface of disposed sludge were detected, then mechanism was analyzed.The resultsshow that enzymes degrade protein and polysaccharide of EPS in the sludge，destroying the structure of EPS, in addition, dispersing sludge particles, increasingspecific surface area, reducing pore diameter, which affect the properties of the sludge.