| With the aggravate of water body eutrophication, cyanobacterial bloom has produced large amount of cyanobacteria during it`s periodic outbreaks in recent years. Masses of cyanobacteria is drained out of lakes every year, and the innocent treatment as well as recycling application become further disposal technological difficulties of the salvage cyanobacteria. This paper makes microcystis aeruginosa immobilized by biologic immobilizing technology to produce biological adsorbent, and then carrys out a series of experiment about Ni2+ adsorption using the new biological adsorbent to study the best adsorption and deabsorption condition. The objective of this paper is to find a new way for the solving of the innocent treatment and recycling application of the salvage cyanobacteria so as to provide a theoretical basis for the bio-sorbent technigue of heavy metal ions. This makes great sense in the protection of the hydrographic environment.Principal results are as follows:(1) During the determination of microcystis aeruginosa growth curve test, adopted counting method, chlorophyll method and optical densitometric method respectively to conduct experiment under laboratory conditions, and analyzed the correlation among the methods above. Research shows that those three determining methods have strong correlation relationship, the other two parameter values can be predicted through a certain indicators under proper conditions.(2) During the preparation of the PVA-SA composite microcystis aeruginosa ball process, the composite microcystis aeruginosa ball was prepared innovatively by the boric acid-borax two stage immobilization process. Comprehensive study on factors of boric acid(H3BO4), calcium chloride(Ca Cl2), borax(Na2B4O3?10H2O), polyvinyl alcohol(PVA) and alginate sodium(SA) was taken out, with review indicators such as performance of the composite ball, leaking of PVA in the immobilization process and removal rate of Ni2+ ions, etc. The single factor experimental results show that the reasonable dosages of the above factors are 3.5%, 2.0%, 3.0%, 9%, 1%. Those factor levels can guarantee better performance of the composite ball, smal er amount of PVA leaking and higher removal efficiency of Ni2+ ions; Using central composite design(CCD) and response surface method(RSM) based on the single factor experiment analyzed boric acid(H3BO4), calcium chloride(Ca Cl2) and borax(Na2B4O3?10H2O) to the influe nce of the removal rate of Ni2+ ions, study found out that when those three factors level respectively on 3.59%、2.21%、2.64%, the removal rate is the highest.(3) In the experiment of absorbing Ni2+ for PVA-SA composite microcyst is aeruginosa ball, we studied the influence of various factors on Ni2+ absorbtion abilit y, such as the conditions of these interesting balls(wet or dry), radius of aeruginosa ball, the amount being used to aborb, the temperature and p H of absorption system et. al. The results indicated that, the wet balls behaved the better absorption ability for absorbing Ni2+ and they also can be used to absorb Ni2+ within a wider concentration range. The optimal using amount appeared between 2g/100 m L and 4g/100 m L for wet balls(0.3 g/100 m L and 0.6g/100 m L for dry balls). The system behaved the best absorption capacity and desorption rate when the radius of balls, p H, and tempreture were 2.8 mm, 7.0, 30℃respectively. The dynamic model and isothermal model of composite microcyst is aeruginosa ball for absorbing Ni2+ indicates that the absorbing process can be well described by using Quasi Secondary Dynamics Equation. In the Langmiur isotherma l model, the correlation coefficient is up to 0.99898 which showed high credibility. It was a monolayer chemical asorbtion and the theoretical saturated asorption amount was 28.361mg/g. the results in desorption – resorption experiment manifested that the composite microcystis aeruginosa ball still behaved high asorption efficiency even when 0.1 mo L/L HCl was used to desorb for the balls,achieving balance after 45 min. |
PDF Full Text Request