Biological Agents Beryllium-containing Waste Water

It is a kind of prospect wastewater treatment technology that the activated sludge absorbs the wastewater containing metal ion. Especially when the metal concentration in the wastewater is lower than 100mg/l, biosorption is more effective. This paper regard the sludge which the Jinxia sewage treatment plant of Changsha discharges as the microorganism, regard the beryllium-containing wastewater as the investigation object, develop biological agent for Be-containing wastewater, and systematicly study technological process and basic theory. Its main subjects and new achievement are as follows:Develop the S factor ,and make out effective biological agent for Be-containing wastewater,and the removal rate raise 8%. In the pretreatment the relationship between pH and the removal rate of beryllium have been discussed, all conditions of the biological agent's post-treatment such as time, sludge voidage , temperature , pH ,etc.,have been investigated. The impact of influent concentration, velocity of flows, preparation amounts and the mode of influent water on disposal system have been studied further in the continuous experiments. The optimum terms of lime neutralization precipitate - biological purification handling beryllium-containing wastewater have been obtained. The optimum pH of lime neutralization ranged 8-10, the content of beryllium in water can be reduced to about 100μg/L after lime neutralization; The optimum pH of biological agent handling Be-containing wastewater ranged 7-10; Within the range of concentration of trace beryllium, the line of biological agent handling Be-containing wastewater accord with Lagergren's second dynamics equation; Adsorbing process accorded with Freundlich isotherms; Continuous laboratory experiments shows, Optimum purification condition is : velocity of upflow 4L/h, biological agent amount 100mL, treating water amount 1L, influent water concentration 99. 29μg/L; the most remarkable factor of influence on the purification effect of beryllium is influent water concentration . Influent water concentration is invariable in the course of purification. Influencing between upflow and biological agentamount is the second ones.From large-scale research, we find that in different concentration of different kind of Be-containing wastewater biological agent can removal Be below to 5(ig/L, and well fit the national standard.In the system because the joining of S factor just play the function of the catalyst , accelerate velocity of the reaction, various kinds of absorbing removal mechanism are tentatively confirmed. Changing law and reason of pH during absorbing are investigated. And the forms of Be in the activated sludge after absorption was discussed finally. The result shows: The behavior of activated sludge absorbing Be well followed with second dynamics law ; The dispersiveness of activated sludge in the solution is very perfect, Intraparticle diffusion is not the main controlling process. Diffusion rate was mainly controlled by the rate of mass transfer from liquid phase to solid phase. The course of activated sludge absorbing Be belong to fast surface adsorption. The law of absorbing on the activated sludge could be described with Freundlich isotherms, Accords with Langmuir isotherms too. The relativity of Langmuir curve was still higher than Freundlich curve, absorbing course is not quite influenced by temperature; removal mechanism of activated sludge absorbing Be is more complicated, physical absorption, ion exchange, complexation and autoprecipitate and coprecipitation function has already been included. Through continuous extraction research ,show that the main existing forms of Be in the activated sludge is : organic form, residue form and exchange form.In addition, it has probed that the result of desorption of beryllium from sludge by pharmaceutical differently. The result indicates, it is the best that desorption by hydrochloric acid, the rational concentration 0. 5mol/L, desorption time as 6 hours, the best desorption agent dosage lOOmL. It was up to 96.73% of the removal rate. After desorption, regulating pH of the solution back to 5, made sludge circulation and recycle. Through several circulation, the sludge can keep strong ability of absorbing still.The result of study has offered the important basic data for implication, and the process of this research can turn technology into industrialization.