MAP-SBBR组合工艺处理污泥压滤废水的研究

发布时间：2018-07-26 15:41

【摘要】：污泥处理过程需要进行污泥厌氧消化,厌氧消化后的污泥经压滤脱水处理后产生大量废水,该种废水氨氮浓度在500~1000mg/L,处理难度较大,不适宜直接进行生化处理,需先进行物化法预处理。高氨氮废水的物化处理方法有磷酸铵镁(MAP)沉淀法、吹脱法和离子交换法等,其中磷酸铵镁沉淀法具有反应快,操作简单,无二次污染等优点,且产物可做肥料使用但MAP法存在沉淀剂成本过高的问题。为解决这个问题,本研究选用手机触摸屏抛光时产生的废磷酸作为MAP法磷源进行试验。废水经MAP预处理后,可去除大量氨氮使氨氮浓度降到生化处理范围内(200mg/L以下)再进行SBBR工艺处理,进一步去除氨氮。为了使MAP-SBBR组合工艺的达到较好的处理效果,本文研究包括MAP的预处理试验和SBBR工艺运行试验两部分。具体研究内容包括:(1)MAP的预处理试验:考察了磷源种类、镁源种类、反应时间、p H值、氮磷镁比、初始氨氮浓度和静置时间对氨氮去除效果和磷的残余浓度的影响并确定最佳反应条件,分析MAP处理成本。(2)SBBR工艺运行试验:以SBR反应器作为对照,通过测定系统进出水COD、氨氮、总磷、p H、亚硝氮和硝态氮浓度和总氮浓度来考察SBBR的废水处理能力。本试验结果如下:(1)废磷酸作为MAP沉淀剂磷源处理污泥压滤废水氨氮的效果与普通磷盐相差不大。在常温下,最优的反应条件是p H=9,氮镁磷摩尔比为1:1:1,曝气搅拌10min,氨氮的去除率可达84.91%,残余磷浓度6.49mg/L,出水氨氮浓度低于200mg/L,有利于后续生化处理。(2)氯化镁和硫酸镁作为MAP镁源的氨氮去除效果无明显差别,而氧化镁由于溶解度不高,在反应时间较短的情况下,氨氮去除效果较差。MAP沉淀法去除氨氮的效果受反应时间和静置时间的影响较小,受p H和氮镁磷比的影响较大。MAP处理前可进行预曝气处理提高压滤废水p H,减少后续调节p H所需药剂,节省成本,实际生产中p H宜控制在9左右;氮镁磷摩尔比控制在1:1:1既可以保持较好的氨氮去除率,又可保证较低残余磷浓度;提高磷的投加量可提高氨氮的去除率,但出水中的残余磷浓度也会提高;提高镁的投加量有利于降低出水中磷的残余磷浓度;同时减少磷盐和镁盐的投加量与单独减少磷盐投加量相比,对氨氮的处理效果无明显差别;在相同的p H和氮镁磷摩尔比的条件下,废水氨氮浓度越高,氨氮去除效率越高。(3)与SBR工艺相比,SBBR耐冲击负荷能力较强,氨氮处理效果稳定,MAP-SBBR组合工艺运行一个月出水氨氮平均浓度12.03mg/L,可达污水综合排放标准(GB 8978-1996)二级标准。SBBR进水氨氮浓度从145.00 mg/L到431.39mg/L,氨氮去除率保持在90%以上,最好时达99.89%。SBBR的COD去除率波动较大,去除率在4.74%-64.49%之间。SBBR除磷效果较差,当MAP预处理n(P):n(N):n(Mg)=0.9:1.0:1.0时,SBBR出水磷浓度可达污水综合排放标准(GB 8978-1996)三级标准。SBBR工艺中进水氨氮浓度越高,越有利于亚硝态氮的积累,由于废水生化性较差,碳氮比较低导致反硝化反应受阻,TN去除效果较差且氨氮浓度较高时,需补充碱度,维持正常的p H,保证氨氮的去除效果。综上所述,本文利用废磷酸作为MAP法的磷源处理污泥压滤液厌氧出水中的氨氮是可行的。以废磷酸为磷源的MAP沉淀法可使废水氨氮浓度降低到200mg/L以下,同时引入磷元素,调节废水碳氮磷比,为后续生物法处理创造有利条件。SBBR工艺有较好氨氮去除效果、操作简单、稳定性好,SBBR出水氨氮浓度可达到综合污水排放标准。该研究为污泥压滤废水的综合处理提供了思路和指导,有利于污泥处理行业的发展。
[Abstract]:Sludge anaerobic digestion is needed in the process of sludge treatment. The sludge after anaerobic digestion is treated by pressure filtration and dehydration to produce a large amount of wastewater. The concentration of ammonia nitrogen in this kind of wastewater is at 500~1000mg/L. It is difficult to deal with the wastewater. It is not suitable for direct biochemical treatment. It is necessary to pretreat the chemical process first. The method of physical and chemical treatment of high ammonia nitrogen wastewater has magnesium ammonium phosphate (MAP) precipitation. The precipitation method, blow off method and ion exchange method, of which ammonium phosphate precipitation method has the advantages of quick reaction, simple operation, no two pollution and so on, and the product can be used as fertilizer, but the cost of precipitant is too high in MAP method. In order to solve this problem, the waste phosphoric acid produced by the handset touch screen polishing is selected as the MAP phosphorus source. After MAP pretreatment, a large amount of ammonia nitrogen can be removed to reduce the concentration of ammonia to the biochemical treatment range (less than 200mg/L) and then be treated by SBBR process to further remove ammonia nitrogen. In order to make the MAP-SBBR combination process achieve better treatment effect, this study includes the two parts of the preconditioning test of MAP and the operation test of SBBR process. The contents include: (1) the pretreatment test of MAP: the type of phosphorus source, the type of magnesium source, the reaction time, the P H value, the ratio of nitrogen, phosphorus and magnesium, the effect of the initial ammonia nitrogen concentration and the stationary time on the removal efficiency of ammonia nitrogen and the residual concentration of phosphorus, and the determination of the optimum reaction conditions, and the analysis of the rational cost of the MAP. (2) the operation test of SBBR process: the SBR reactor is used as the control, By measuring the COD, ammonia nitrogen, total phosphorus, P H, nitrite nitrogen and nitrate nitrogen concentration and total nitrogen concentration, the wastewater treatment capacity of SBBR was investigated. The results are as follows: (1) the effect of waste phosphoric acid as a MAP precipitant phosphorus source to treat the ammonia nitrogen of the sludge pressure filter wastewater is not similar to that of the ordinary phosphorus salt. At normal temperature, the optimum reaction condition is p H=9, nitrogen The mmmmmmmmmmole ratio is 1:1:1 and aeration stirring 10min, the removal rate of ammonia nitrogen can reach 84.91%, the residual phosphorus concentration is 6.49mg/L, the concentration of ammonia nitrogen in the effluent is lower than 200mg/L, which is beneficial to the subsequent biochemical treatment. (2) the effect of magnesium chloride and Magnesium Sulfate as the MAP magnesium source has no obvious difference, while the solubility of Magnesium Oxide is not high and the reaction time is short. Under the poor removal efficiency of ammonia nitrogen, the effect of ammonia nitrogen removal by.MAP precipitation method is less affected by reaction time and static time. Under the influence of P H and nitrogen and magnesium phosphorus ratio, pre aeration can be used to improve the P H of filter wastewater before.MAP treatment, reduce the subsequent regulation of P H and save the adult version. In actual production, P H should be controlled at about 9; nitrogen and magnesium phosphorus The mole ratio control in 1:1:1 can not only maintain better ammonia nitrogen removal rate, but also guarantee lower residual phosphorus concentration; increasing the dosage of phosphorus can increase the removal rate of ammonia nitrogen, but the residual phosphorus concentration in the effluent will also be improved; the increase of the dosage of magnesium is beneficial to reducing the concentration of phosphorus in the effluent and reducing the amount of phosphorus salt and magnesium salt at the same time. There is no significant difference in the treatment effect of ammonia nitrogen alone. Under the same p H and MMP mole ratio, the higher the ammonia nitrogen concentration in the wastewater, the higher the ammonia nitrogen removal efficiency. (3) compared with the SBR process, the impact load capacity of SBBR is stronger, the ammonia nitrogen treatment is stable, and the MAP-SBBR combination process runs for one month of ammonia nitrogen. The average concentration of 12.03mg/L can reach the standard of wastewater discharge standard (GB 8978-1996) two grade standard.SBBR from 145 mg/L to 431.39mg/L, and the removal rate of ammonia nitrogen remains above 90%. The best COD removal rate of 99.89%.SBBR is fluctuating, and the removal rate is poor at 4.74%-64.49%. MAP pretreatment n (P) = = = = = = = = = = = = = = = = = 4.74%-64.49% = = = = = = MAP = = = = MAP = = = = = MAP = = = = = = = MAP = = = = = = = MAP = = = = = = = = = = = MAP = = = = = = = MAP = = = = = = MAP = = = = = = = MAP = = = = = = = = = = = = = = MAP = P) = When 0.9:1.0:1.0, the concentration of SBBR effluent can reach the standard of wastewater discharge standard (GB 8978-1996), the higher the concentration of ammonia nitrogen in the three grade standard process, the more beneficial to the accumulation of nitrite nitrogen. Because of the poor biochemical property of the wastewater, the lower carbon and nitrogen is hindered by the denitrification reaction, and when the TN removal effect is poor and the concentration of ammonia nitrogen is high, the alkalinity needs to be supplemented. In this paper, using waste phosphoric acid as the phosphorous source of the MAP method to treat the ammonia nitrogen in the anaerobic effluent of the sludge pressure filtrate is feasible. The MAP precipitation method with waste phosphoric acid as the phosphorus source can reduce the concentration of ammonia nitrogen to below 200mg/L with the waste phosphoric acid as the phosphorus source. At the same time, it can be introduced into the phosphorus element and adjust the carbon, nitrogen and phosphorus ratio of the waste water to the follow-up life. The process of material processing to create favorable conditions for.SBBR has better ammonia nitrogen removal effect, simple operation and good stability. The concentration of ammonia nitrogen in SBBR effluent can reach the standard of comprehensive sewage discharge. This study provides ideas and guidance for the comprehensive treatment of sludge pressure filtration wastewater, which is beneficial to the development of sludge treatment industry.
【学位授予单位】：华南农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X703

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