Study On Performance In The Removal Of Algae By Inorganic/Organic Composite Modified Bentonite

Increasingly serious water eutrophication problem has become a global environmental problem, which mainly due to algae blooms. How scientific, efficient to remove algae and control the growth of algae has become a critical research. In this paper, by the adsorption characteristics of bentonite, a mixture of modifier prepared the alkyl glucoside quaternary ammonium and AlC13-6H2O and microwave, we compounded inorganic-organic composite modified bentonite to study the impact of cyanobacteria growth, the removal law and the deposition model of flocculation kinetics. Finally we summed up the algae removal mechanism by inorganic-organic composite of modified bentonite.AlCl3-6H2O, alkyl glucoside quaternary ammonium and bentonite has a certain inhibition to the growth of cyanobacteria, but there are some shortcomings and deficiencies. AlCl36H2O made algal cells settlement by electrical and neutralizing action and adsorption; Two kinds of alkyl glucoside quaternary ammonium cyanobacteria play a good role in the killing cyanobacteria, and have a similar law of algaecide, because of the different carbon chain length leading to the pros and cons of the algaecide effect; Unmodified bentonite has no effect on the removal of cyanobacteria, instead of their flocculation resulting in little algal cell deposition. Combine the three advantages, add0.52g modified bentonite in batches, and control pH in7.63or so, which made the removal efficiency of74.33%of cyanobacteria after24h. In addition, the density of algal cells has a greater impact on the removal of cyanobacteria. Smaller density of algal cells bought about a narrow range of effective dosage and formed small and loose flocs. With the increase in the density of algae solution, the range of effective dosage expansion led to the removal rate of algae further increased, but it is not proportional to the increase degree of the concentration.In experiments, we respectively selected spectrophotometer and fluorescence spectrometer methods for the determination of the quasi-second order kinetic equation of deposited cyanobacteria by modified bentonite. While we examined the amount of organic modifier, bentonite and modified bentonite, along with the pH value in detail to influence on settlement rate. It found that excessive use of organic modifiers, bentonite and modified bentonite haven’t improved removal efficiency of cyanobacteria by single factor experiments. Generally, organic modifiers in the13mg to remove cyanobacteria can reach the best results; when the bentonite is0.52g, it can achieve the best degree in adsorption of cyanobacteria; the concentration of modified bentonite should be controlled in13g/L to make cyanobacteria settling velocities fastest; pH of system in the range from6.54to8.66better conformed cyanobacteria removal environment. Furthermore, the fluorescence spectrometer method could avoid the modified bentonite caused substantial changes of the transmittance in spectrophotometer, and exclude the effect of bentonite own settlement, for reflecting the substance of flocculation and sedimentation more accurately.Based on the above results, the inorganic-organic composite modified bentonite as an ideal algaecide has a good effect on cyanobacteria removal, which is worthy of further study and promoting the application.