化学生物絮凝、悬浮填料移动床硝化工艺优化研究及曝气控制初探

以氨氮浓度作为悬浮填料生物反应器的控制指标,来控制优化反应过程中的曝气量和曝气时间,以达到既能使氨氮硝化令氨氮出水达标,又能优化曝气量,节约运行成本的目的。试验结果表明:对于不同的污水排放标准,化学生物絮凝和悬浮填料床组合工艺有不同的最佳工艺条件。(1)当要求达到城镇污水处理厂污染物排放二级标准时,工艺参数为:可以省去悬浮填料床工艺阶段。(2)当要求达到城镇污水处理厂污染物排放一级B标准时,工艺参数为:悬浮填料床阶段水力停留时间(HRT)为2·3h左右,气水比为2·5∶1;化学生物絮凝阶段混凝剂(聚氯化铝铁)投加量为80mg/L(…     

温度对强化混凝-悬浮填料床生物氧化工艺运行的影响

利用中试装置分别研究了冬季低温(7～15 ℃)、水温回升(14～22 ℃)和较高水温(27～32 ℃)等条件下的工艺运行效果.结果表明当生物段HRT为3.3～6 h、预处理PAC投加剂量30 mg/L、填料投配率30%的条件下,温度对CODCr、SS、TP的处理效果影响很小,对生物硝化和反硝化的影响较大.当水温为7～13 ℃时,出水NH3-N平均在7.84 mg/L,TN的去除率只有18.4%;而水温20 ℃以上,出水NH3-N浓度＜1 mg/L;TN的去除率达到50%.低温时污水经过组合工艺处理后,出水的氮、磷仍能达到＜城镇污水处理厂污染物排放标准＞(GB 18918-2002)一级B标准.     

塑料填料曝气生物滤池处理河水的应用研究

以曝气生物滤池（BAF）处理河水时出水氨氮小于0．5mg／L为目标,通过试验室小试对几种新型塑料填料的挂膜性能、硝化速率等进行了对比研究,选出了最佳填料为4号。通过现场中试对4号填料的挂膜运行情况、气量要求、硝化速率及氨氮冲击负荷等情况进行了研究。结果表明,在试验条件下,4号填料完全能够满足处理要求。同时具有压力损耗低、反冲洗频率低的优点。     

某园区污水处理厂问题诊断与优化运行措施

以海河流域某工业园区采用UCT(悬浮填料)工艺的高排放标准污水处理厂为例,结合生产运行实际,对诊断的运行问题进行了分析,并对其精细化优化运行措施进行了研究,结果表明:通过优化碳源投加点(由缺氧池1改至"厌氧池"),在硝化液DO为6.89mg/L和内回流比200%下,系统脱氮效能强化约5mg/L;通过将厌氧池改为消氧区并按AO脱氮工艺运行,可控制硝化液高浓度DO导致的进水碳源损耗,在内回流比200%和硝化液DO为3～4mg/L下,系统脱氮效能平均强化2.14mg/L,可节省碳源乙酸钠溶液投加成本7.1万元/月,节省运行电费2.4万元/月;通过基于进水磷酸盐浓度确定化学协同除磷药剂投加量,在99%进水磷酸盐不超过1.18mg/L和PAC溶液投加量20mg/L下,二级出水磷酸盐通常不超过0.24mg/L,与优化前相比,化学协同除磷药剂投加量降低120mg/L,节省投加成本8.6万元/月;通过提升二沉池集水槽液位控制跌水充氧作用,低温季节反硝化滤池单元碳源投加量可降低约7mg/LCOD,投加成本可节省约7.1万元/月。     

南方某大型水质净化厂降氨氮中试研究

在南方某大型水质净化厂对6种填料(4种悬浮填料和2种固定填料)进行氨氮去除研究.结果显示,常温条件下,6种填料中,4#不能达标,1#、2#、3#、5#、6#在进水氨氮小于2 mg/L时满足出水要求,1#、5#、6#在大于6 mg/L满足出水要求,低温条件下仅5#、6#满足出水要求.1#、2#、3#、4#、5#、6#最大...     

MBBR工艺在制药废水中的应用

某制药厂提标改造工程将原有活性污泥生物系统升级改造为移动床生物膜反应器(MB-BR),在生化池内投加好氧活性生物填料.改造后,平均出水COD 78 mg/L,氨氮3.3 mg/L,总氮70.8 mg/L,各项指标好于当地的纳管标准.分别对系统活性污泥及生物膜进行菌群结构分析,发现活性污泥及生物膜系统内丰度较高的功能菌分...     

CAST工艺低负荷状态下处理城市污水脱氮模式探析

结合污水处理厂CAST工艺运行实践,开展了生产性试验,对CAST工艺在低负荷运行状态下处理城市污水脱氮模式进行了研究.通过优化工艺参数控制,探索不同脱氮模式的控制条件,实现同步硝化反硝化、短程硝化反硝化和传统硝化反硝化有机结合的耦合脱氮模式.保证各项出水指标稳定达标的情况下,出水NH_3-N的去除率达到90%以上,出水TN去除率在55%以上,取得了良好的脱氮效果.利用耦合脱氮模式进行脱氮,不仅有利于提高出水水质,还有利于优化城市污水处理过程、降低能耗、实现节能减排.     

数学模型在污水处理厂优化控制过程中的应用

通过小试结合模拟计算,分析了某污水处理厂现有运行存在的不足.试验表明,内回流比对提高脱氮率的作用是有限制条件的;对于溶解氧的控制,要根据系统硝化反应的需要来确定;缺氧区/总体积的比例是影响脱氮效果的一个关键因素,在保证硝化不受影响的前提下,增大缺氧区使反硝化进行得更充分,有助于提高系统的脱氮能力.通过模拟计算,对其工艺参数进行了优化组合,在不改变池容、不增加其他处理设施的情况下提出了优化方案,确定其最佳工艺控制参数为:缺氧区/总体积的比例为0.45,混合液内回流比为200%,好氧区溶解氧2 mg/L.调整后的出水总氮为21.77 mg/L,去除率较改造前提高了4%,出水氨氮浓度为1.16 mg/L,去除率提高了7.2 %.     

多级生物滤池工艺脱氮效能研究

为实现BAF工艺的高效稳定脱氮,采用了外加碳源的后置反硝化三级BAF工艺(C+N+DN).研究了水温、污染物负荷、硝化液回流等条件下低碳氮比生活污水的脱氮效果.结果表明,在无硝化液回流的条件下,水温高于23℃时,系统具有高效稳定的脱氮效果,出水NH3-N稳定低于5 mg/L;水温低于23℃时,系统出水NH3-N明显升高.当水温为12～23℃时,采取50%硝化液回流并降低负荷后,硝化和反硝化效果明显提高,C柱和N柱对NH3-N和TN的去除率分别提高了19%和22%,最终出水中NH3-N与TN稳定达到<城镇污水处理厂污染物排放标准>(GB18918-2002)一级A标准.     

投加生物填料强化低温条件下局部改造后AB工艺研究

针对齐齐哈尔AB污水处理工艺A段生化吸附高效性、对氮磷等典型污染物去除效果低等特点,在不扩建新的构筑物条件下,充分利用原始AB工艺A段特性,通过将B段局部改造为A/O工艺,能够达到强化氮磷污染物的去除效果。由于冬季水温较低,改造后的工艺不能保证稳定的出水水质,故通过投加悬浮生物填料进行生物强化。试验表明,在低温情况下,通过将B段改为A/O工艺,局部投加悬浮生物填料,能够使各项污水排放指标实现达标排放。     

ANAMMOX工艺在生活污水深度处理中的应用研究

随着水环境质量的恶化,高能低耗的污水深度处理技术成为当前研究热点,尤其是对于低C/N比的城市生活污水脱氮技术的研究。试验以城市生活污水的二级出水为研究对象,采用ANAMMOX下向流生物滤池,当二级出水NH3-N=15-35mg/L,CODCr=25-45mg/L,TOC=9-12mg/L,水温=25-28℃时,ANAMMOX下向流生物滤池脱氨率达80%-100%,不仅适用于处理高氨废水,也可用于城市生活污水深度处理中。试验发现pH可以用来指示ANAMMOX反应的进行,同时也可以用来指示ANAMMOX反应进程的快慢。试验中还发现,厌氧氨氧化反应速率与NO2--N含量有关,原水中NO2--N含量的增多有利于ANAMMOX工艺处理效果。     

加压富氧生物活性炭在碱减量印染废水深度处理中的应用研究

加压富氧生物活性炭法(PRBAC)是在生物活性炭法(BAC)的基础上发展的一种新方法。它通过在生物活性炭柱中增加压力,提高溶解氧浓度以强化生物作用来提高污染物的去除率。试验证明,对碱减量印染废水二级生化处理出水进行深度处理,加压富氧生物炭能保持对水中多种污染物的高去除率,且出水中COD,BOD,NH_3-N,SS,色度,浊度等指标均达到生活杂用水水质标准,其中NH_3-N的去除率可达97％以上。     

Dinitrogen oxide detection for nitrification failure early warning systems.

Experiments were conducted in order to establish whether N2O could be used to predict nitrification failure (through non-invasive means). Previous research had shown a strong correlation between N2O gas and NH3 in the effluent, giving rise to the possibility N2O can be used as an indicator for failure in the nitrification process. Two pilot-scale activated sludge plants were used, each with two lanes. The smaller consisted of a 601 aeration tank and a 201 clarifier; the larger pilot plant had an aeration tank of 3151 and a clarifier of 1001. The small pilot plant experiments showed that N2O gas was given off almost immediately from O2 deprivation/NH3 shock loads, but did not follow the expected trend of the time lag of NH3 in the effluent. This led to further investigation in the hydrodynamics and mixing characteristics of aeration basins, where a second larger pilot plant was used. Further experiments were conducted of high NH3 loadings and O2 deprivation, showed that work of was reproducible. However, it was also shown that with partial nitrification failure, a different N2O response of a continual rise was observed.     

Efficiencies of residual organic pollutants removal from secondary effluent by switching of coagulation- air flotation -filtration processes.

It is an essential task to remove the residual organic pollutants (ROP) from secondary effluent of a Wastewater Treatment Plant (WWTP) in wastewater reclamation and reuse processes. Four different compared flow schemes would be achieved for further purification of the secondary effluent by switching of different valves. In order to mainly remove non-biodegradable residual organic pollutants under various operating conditions, the optimum technology and economic process was obtained in the advanced purification flow scheme at a flow of 3200 m(3)/d in Harbin Wenchang WWTP. Conclusions under a lot of experiments show that: choosing the coagulation-settler plus biofilm filter for advanced purification process is reasonable; during the stable operation phase, this process showed good performance in removing the COD, BOD5, TP, NH3-N and SS; the removal rates are 50%, 39%, 67%, 50%, 80% respectively. The effluent is able to excel the requirements for wastewater reuse standards. The unit cost of the water is 0.542 yuan/m(3), which is far below the fee paid for supply water, long-distance transfer water or seawater desalination through economic analysis.     

曝气生物滤地在污水回用中去除氨氮的试验研究

采用曝气生物滤地(BAF)工艺处理某污水处理厂模拟二级出水,研究了水力负荷及滤料层高度对NH_3-N去除效果的影响.试验结果表明,当进水NH_3-N≤25 mg/L时,平均NH_3-N去除率达到93.12%,出水NH_3-N可降至3 mg/L以下.当水力负荷为1.44 m~3/(m~2·h),HRT为1.8 h时,氨氮的去除效果最好,去除率达到95.32%,出水NH_3-N在1.5 mg/L以下.BAF对NH_3-N的去除作用主要发生在滤料的中上层.     

氨吹脱-A2/O工艺处理高浓度养殖废水

介绍了氨吹脱-A2/O工艺处理高浓度养殖废水的工程实例.运行结果表明,CODCr的平均去除率为97.4%,NH3-N去除率为91.9%,出水的各项指标均符合<畜禽养殖业污染物排放标准>.该工艺具有剩余污泥少,耐冲击负荷能力强,难降解有机物去除效率高等优点.     

移动式污水处理系统应用于分散生活污水的试验研究

针对分散型生活污水量小面广的特点,开发出移动式污水处理系统,系统由生化预处理池和车载式移动污水处理设备组成.中试结果表明,采用该组合工艺,出水CODCr＜40 mg/L,BOD5＜10 mg/L,TP＜0.5 mg/L,TN＜10 mg/L,NH3-N＜1 mg/L,其平均去除率分别达到86.69%,94.89%,89.40%,74.35%和97.89%.出水指标均能达到＜城镇污水处理厂污染物排放标准＞(GB 18918-2002)一级A排放标准.     

Nitrogen removal from piggery waste using the combined SHARON and ANAMMOX process.

Nitrogen removal in piggery waste was investigated with the combined SHARON-ANAMMOX process. The piggery waste was characterized as strong nitrogenous wastewater with very low C/N ratio. For the preceding SHARON reactor, ammonium nitrogen loading and conversion rates were 0.97 kg NH4-N/m3 reactor/day and 0.73 kg NH4-N/m3 reactor/day, respectively. Alkalinity consumption for ammonium conversion was 8.5 gr bicarbonate utilized per gram ammonium nitrogen converted to NO2-N or NO3-N at steady-states operation. The successive ANAMMOX reactor was fed with the effluent from SHARON reactor. Nitrogen loading and conversion rates were 1.36 kg soluble N/m3 reactor/day and 0.72 kg soluble N/m3 reactor/day, respectively. The average NO2-N/NH4-N removal ratio by ANAMMOX reaction was 2.13. It has been observed that Candidatus "Kuenenia stuttgartiensis" were dominated in the ANAMMOX reactor based on FISH analysis.     

Nitrogen removal in recirculated duckweed ponds system.

Duckweed-based ponds (DWBPs) have the potential for nitrogen (N) removal from wastewater; however, operational problems such as duckweed die-off regularly occur. In this study, effluent recirculation was applied to the DWBPs to solve the above problem as well as to investigate N removal mechanisms. Two pilot scale recirculated DWBPs were employed to treat municipal wastewater. The average removal efficiencies for TN, TKN and NH4-N were 75%, 89% and 92%, respectively at TN loading of 1.3 g/m2.d and were 73%, 74% and 76%, respectively at TN loading of 3.3 g/m2.d. The effluent of the system under both operational conditions had stable quality and met the effluent standard. Duckweed die-off was not observed during the study, which proves the system stability and effluent recirculation which is thought to be a reason. N-mass balance revealed that nitrification-denitrification and duckweed uptake play major roles in these recirculated DWBPs. The rates of nitrification-denitrification were increased as TN loading was higher, which might be an influence from an abundance of N and a suitable condition. The rates of N uptake by duckweed were found similar and did not depend on the higher TN loading applied, as the duckweed has limited capacity to assimilate it.     

Electrolytic degradation of biorefractory organics and ammonia in leachate from bioreactor landfill.

Electrochemical oxidation was applied to treat the effluent from bioreactor landfill with leachate recirculation, characterised as poor biodegradability and high NH3-N concentration. In this study, the effluent was electrolysed in a batch reactor with Ti/TiO2-IrO2-RuO2 anode and stainless steel cathode. The oxidation of dissolved organic matter (DOM) during electrolysis was evaluated based on the evolution of molecular weight grade, hydrophilic fractionation (humic acid, fulvic acid and hydrophilic fractions), specific ultraviolet absorbance (SUVA254) and AOX. The impact of the initial NH3-N concentration on the oxidation was discussed. The results showed that at a current density of 100 mA/cm2, electrolysis time of 1.5 h and electrode gap of 1 cm, NH3-N with an initial concentration of 1.2 g/L could be completely eliminated and 56% of COD with an initial concentration of 1.2 g/L could be removed, which illustrated that the electrolysis-produced chlorine preferentially oxidised ammonia. The electrolysis mainly resulted in the degradation of humic substances and other high molecular DOM, followed by the increase of BOD/COD ratio and decline of SUVA254 of the leachate. The current efficiencies for COD and ammonia oxidation gradually decreased during the electrolysis, with the latter obviously higher than the former. At the optimal electrolysis time of 1.5 h, NH3-N could be totally removed and the BOD/COD ratio could be enhanced to 0.3, which was also favourable to control the AOX at a reasonable level.