| The high salinity wastewater with complex components comes from a wealth of sources; High salinity wastewater is difficult to bedealt with biologically because of the osmotic stress or the broken microbes membrane structure and the depressed enzymes activity. However, some researches have suggested that halophilic microorganisms can balance the osmotic pressure from outside to inside to alleviate salt stress by solute absorption and secretion compatibility. In this paper, based on this characteristic of the halotolerant microbe, the domestication stageof high salinity waste water was simulated. In the condition of increased salt content, the effect of exogenous protective agent on theactivity of sluge in high salinity waste water was investigated in order to be provided as a reference for regulating system stability when under high salinity. By analyzing typical betaine compatible solutes and other comparing experiments in various protective agents,several main conclusions are drawn(1) The result shows that 1mM Betaine added to the salt tolerant sludge at one time can hardly influence the system in the TOC removal rate while the effect is obvious in ammonium-nitrogen removal rate under the progressive domestication process, in which change conventional sludge into 10g/l salt-tolerant sludge.It is found that the activated sludge after domestication is more continued and have improved about 15%.(2) Salt-tolerant sludge is formed from the conventional sludge with every 5g/l gradient of the concentration of Na+. When the Na+ concentration of the sludge increase from 0.05g/l to 5g/l and from 5g/l to 10g/l gradually,it does not have significant impact on the system with adding 1mM betaine. This is different from preliminary experiment results because of glycine betaineused in the form of nitrogen organic matrix. System temperature has a great influence on its role of betaine. This is obvious that the system temperature plays an important role in this process.(3) When the Na+ concentration of the sludge is from 10g/l to 15g/l with the addition of KCl about 40mg/l, the results shows that ammonia nitrogen removal is promoted duo to KCl. The removal rate of ammonia nitroge is above 75% in 90min while by contrast with the blank test. At the same time the nitrate accumulation is inhibited. And the experimental group is 10 mg/l less than the blank test. It does not play animportant role because of the effect of compensation of the aeration time.(4) Salt-tolerant sludge can be made from conventional sludge after proper acclimation. We change the concentration of salt-tolerant sludge from10 g/1 to15 g/1.1 mM trehalose, betaine, choline, L-proline, sugar were added in the process of domestication and KC1 is added as a protective agent. The promoting effect of protective agents shows some differences from the perspective of individual factors of pollutant removal rate.(5) The results combined with grey correlation model have been made about the promoting effect of protective agent. The promotive effect of protective agent after balancing decarburization, nitrogen to phosphorus in 10 g/1-salt-tolerant sludge is as follows: KCl>sugar>trehalose> betaine> choline> L-proline. When the concentration of salt-tolerant sludge is 15g/1 though proper acclimation, the promotive effect of protective agent is KCl> choline> betaine> sugar> L-proline> trehalose.(6) Under the condition of the ordinary heparin wastewater of the salinity range from 12g/1 to 16g/1, the domestication changing the conventional sludge to salt-tolerant sludge is difficult in one time. Adding KCl as a protective agent has certain promotion for the removal rate of ammonia nitrogen andcan last for 10 cycles. |
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