Study On Effective Treatment Of High Concentration Ammonia Nitrogen Wastewater By Combination Of Spirulina And Zeolite

The treatment of high concentration ammonia nitrogen wastewater has been one of the most difficult problems in the world.The purpose of this paper is to use the combination of Spirulina and zeolite to treat high ammonia nitrogen wastewater efficiently.Gaining optimal zeolite by screening and optimizing the zeolite adsorption treatment of high concentration ammonia nitrogen wastewater,the high concentration of ammonia nitrogen is adsorbed by zeolite and the concentration is down to the range of Spirulina available,then the adsorption treated wastewater by zeolite and ammonium adsorption zeolite were used for various methods of cultivation of Spirulina.As the treatment of wastewater,achieving the goals of cultivating Spirulina and generating zeolite at the same time.Tolerance screening study of Spirulina on ammonia nitrogen:Spirulina cells displayed a fast adsorption rate for ammonia nitrogen when in the tolerance range.Among the four Spirulina platensis strains?NCU,SBD 1-10,SP16,SP18?,only Spirulina platensis SBD 1-10 could live in the medium with ammonia nitrogen concentration of 127.2 mg/L,the biomass was 74.3%of biomass obtained in the standard Zarrouk medium,thus Spirulina platensis SBD 1-10 was the best strain for the follow-up testes.The optical density value OD₅₆₀ of Spirulina platensis SBD 1-10and dry weight had a high correlation,the correlation coefficient beyond 0.99,thus OD₅₆₀ could as an indicator of biomass of S platensis.Process using zeolite adsorbed high concentration ammonia nitrogen wastewater:SEM characterization showed that the synthetic zeolite has a greater surface area than the natural zeolite;XRD results showed that the main components of natural zeolite were non-metallic inorganic and the synthetic zeolite was a sodium-zeolite.The pseudo-second order kinetic equation indicated that the adsorption of zeolite to ammonia mainly was chemical adsorption and ion exchange.Both the Langmuir and Freundlich equations could be used to describe the properties of the synthetic zeolite adsorbing ammonia nitrogen,but the latter had a better fitting effect.Only synthetic zeolite performed a good effect in high concentration ammonia nitrogen wastewater,the adsorption amount of ammonia nitrogen in zeolite was 6.12 mg/g at the time of 72h.Orthogonal experiments showed that the adsorption time of zeolite for removal of ammonia was the largest,followed by zeolite quantity,and finally was pH.After comprehensive consideration,selected 350 g/L of zeolite quantity,pH=8,9 h of adsorption time as the best conditions for the process using zeolite adsorbed high ammonia concentration nitrogen wastewater.The study about treatment of high concentration ammonia nitrogen wastewater use the combination of spirulina and zeolite showed:Spirulina platensis SBD 1-10could not directly grow in high concentration ammonia nitrogen wastewater,the nitrogen source utilization rate was less than 30%and the biomass of Spirulina platensis SBD 1-10 was only 49.3%of biomass obtained in the Zarrouk medium when Spirulina and zeolite were cultivated together in the high concentration ammonia nitrogen wastewater which was treated by zeolite in optimal conditions.The solid and liquid was separated after using zeolite adsorption of high concentration ammonia nitrogen wastewater in the optimal condition,using the wastewater which was treated by zeolite,and nitrogen free wastewater added ammonium adsorption zeolite cultivated the Spirulina platensis SBD 1-10 respectively,showed a better nitrogen source utilization rate,more than 90%and 40%respectively,and the biomass of Spirulina were 63.4%and 52.0%of biomass obtained in the Zarrouk medium respectively,and the adsorption property of zeolite was completely regenerated by using ammonium adsorption zeolite cultivated Spirulina.Ammonia nitrogen in the solution of different treatment groups was analysed:ammonia nitrogen in the solution of adsorption treated wastewater was under the Method Detection Limit?2mg/L?in day 8,while ammonia nitrogen in the solution added ammonium adsorption zeolite remained steadily at between 33.3³8.3 mg/L.Nutrient content of Spirulina in different treatment groups were determined,The highest concentrations of protein and Chlorophyll a,b and carotenoids were found in the ammonium adsorption zeolite group,which was 69.80%,22.18?g/ml?22.90?g/ml and 9.61?g/ml,followed by the Zarrouk group,the lowest was the adsorption treated wastewater group,but the total fat content of Spirulina was the highest in adsorption treated wastewater group,which was 28.2%.