曝气量对好氧颗粒污泥处理效果的影响研究

为探究在不同曝气条件下,好氧颗粒污泥自身结构以及脱氮除磷性能,利用SBR反应器培养好氧颗粒污泥,通过静态试验分别控制反应器内的曝气量为2、2.3、2.5、2.8、3.0和3.5L/min的条件下并对反应器出水进行检测,分析在不同曝气量条件下对好氧颗粒污泥污染物去除效果的影响。通过试验发现,当曝气量在2.5～2.8L/min范围内时,好氧颗粒污泥对污染物的去除效果比较理想。曝气量主要影响颗粒污泥对氮和磷的去除效果,而对有机物的去除效果影响不大,合理地控制曝气量有助于污染物的去除。     

海水混凝法强化除磷的试验研究

城市污水处理厂的污泥上清液中TP含量高，回流到进水端会增加进水的TP负荷。经过对化学除磷技术的研究，发现在特定条件下，将含有Ca^2＋、Mg^2＋等金属离子的海水加入污泥上清液可实现化学除磷的目的。采用正交试验得到了该技术的最佳操作条件：水温为20℃，pH值为10．5，海水与污泥上清液的混合比例为1：5，搅拌时间为10min，静沉时间为20min。在静态试验中，对污泥上清液中PO4^3- -P的平均去除率可达96％，动态处理的平均去除率为92％。该技术不仅除磷效果好，而且处理成本也较投加铝盐、氢氧化钙的大为降低，同时生成的沉淀物为MAP、HAP，可以作为肥料施用。可见，该技术能够有效去除污泥上清液中的磷，适用于沿海地区城市污水处理厂的升级改造。     

电化学除磷过程的条件优化与机理研究

为优化电化学除磷过程的条件并探究反应机理,通过模拟实际污水研究了初始pH值、初始磷浓度C_0及曝气强度j对电化学除磷过程的影响,同时对不同条件下电化学除磷过程进行了动力学分析。结果表明:随着初始pH值的增加,TP去除率先增加后减小;随着电解时间的增加,溶液pH值增大。当C_0为5 mg/L、电解时间为60 min、初始p H值为6～8时,TP去除率达到84. 5%以上;且当初始pH值为7时,TP去除率达到最高值,为87. 69%。C_0越高,TP去除率越低,但除磷的能耗也越低。当C_0为9 mg/L时,电解60 min后,TP去除率为72. 79%,去除单位质量磷的能耗仅为0. 059 kW·h/g,比C_0为5 mg/L时节约能耗0. 025 kW·h/g。当j为0. 14～0. 28 L/min时,电解60 min后,TP去除率达到86. 0%以上,比j为零时至少提高了43. 6%。动力学拟合结果表明,电化学除磷过程中存在着化学配位反应和吸附反应。当pH值为3～5时,除磷过程以化学配位反应为主,当pH值为7～11时,除磷过程则以吸附反应为主;且pH值增加不会减弱除磷过程中的吸附反应。当C_0为8～9 mg/L时,化学配位作用的除磷效果达到极限水平。曝气一方面有利于Fe~(2+)氧化为Fe~(3+),促进化学配位反应,另一方面可以缓解电极钝化,提高除磷效率。     

污泥有机负荷对TP去除的影响

通过改变人工合成污水的浓度、流量和污泥浓度 ,探讨有机污泥负荷对无回流间隙曝气系统 ( Non-Backflow Intermittent Aeration System,缩写为 NBIAS)脱氮除磷和有机物去除效果的影响。试验表明 ,在通过改变进水流量或浓度而引起污泥负荷变化的条件下 ,当进水 CODcr为 3 0 0～ 40 0 mg/ L,流量为 0 .5 L/ h,污泥浓度为 2 .0 g/ L(对应污泥负荷为 0 .3 g CODcr/ ( g MLSS· d) )左右时 ,系统去除有机物、氮、磷总体效果最佳     

化学混凝强化去除微氧EGSB出水中的TP

采用硫酸铝混凝强化去除微氧EGSB反应器出水中的TP,考察了混凝时间和沉淀时间、混凝剂投量、pH和温度等对强化除磷效果的影响,以分析微氧EGSB/化学混凝组合工艺作为生活污水再生回用工艺的可行性。结果表明,在最佳Al3+/TP值(质量比)为1.5～2.3、混凝时间为20min、沉淀时间为20min的条件下,对TP的去除率可达94.6%～96.4%,出水TP可降至0.29mg/L,达到了GB18918—2002的一级A标准,证明了微氧EGSB/化学混凝组合工艺作为生活污水再生回用工艺是可行的。硫酸铝的混凝除磷效果对pH的变化较敏感,最佳pH值范围为6.5～7.2,此时对TP的去除率可达到90.8%～92.1%;微氧EGSB反应器出水pH值为6.5～8.5,投加硫酸铝后能获得85%以上的TP去除率,出水TP最高可达0.85mg/L,因此需要适当调节pH使出水TP0.5mg/L,以满足回用要求。硫酸铝混凝除磷的适宜温度为10～25℃,微氧EGSB反应器出水的温度满足此要求。     

CASS工艺处理高校生活污水的试验研究

为了优化CASS工艺的运行参数,通过正交试验重点研究了污泥负荷、污泥沉降比(SV)、DO浓度、曝气时间等对COD、氨氮和TP去除效果的影响。结果表明,CASS工艺对有机物的去除效果较好,且抗冲击负荷能力较强;污泥负荷和SV值对COD、氨氮和TP去除效果的影响较大,而曝气时间和DO浓度的影响相对较小;试验条件下,CASS工艺的最佳运行参数如下:污泥负荷为0.50 kgCOD/(kgMLSS·d)、SV值为32%、曝气时间为2.5～3.0 h、DO为2.0～2.5 mg/L。     

SBR工艺脱氮除磷研究进展

概述了SBR脱氮工艺中的同步硝化/反硝化，亚硝化脱氮现象，讨论了影响SBR除磷的碳源，聚磷菌与非聚磷菌竞争，pH值，好氧曝气，污泥龄，水力停留时间等因素，并对SBR工艺中脱氮与去除之间的相互影响进行了探讨，最后给出了可以同时脱氮除磷的一种SBR运行方式。     

SBR脱氮除磷最佳运行模式的研究

SBR反应器脱氮除磷的适宜运行工况为"瞬时进水-厌氧-曝气-缺氧-沉淀-排水排泥-闲置".在此运行工况下,研究COD、TN、NH3-N、TP去除敛果来探讨厌氧时间、曝气时间、缺氧时间与脱氮除磷和有机物去除之间的关系,并确定最佳厌氧时间、曝气时间、缺氧时间,进而得出生物脱氮除磷SBR工艺的最佳运行模式.     

强化混凝-沉淀-砂滤工艺去除海水中藻类的试验研究

通过考察强化混凝中混凝剂种类及投加量、氧化性助凝剂种类及投加量、氧化时间、pH以及水力条件等因素对海水中Chl-a、CODMn去除效果的影响,确定了试验参数,并后续加入砂滤工艺考察其除藻效果.结果表明:在调节海水pH值为5～6,选用3 mg/L高锰酸钾预氧化30min后,投加混凝剂聚合氯化铝铁(PAFC)对Chl-a和CODMn均有较佳的去除效果.强化混凝-沉淀-砂滤工艺对Chl-a平均去除率可以达到80%以上,对CODMn去除率在50%左右,对浊度的去除率大干97%.     

自热式高温好氧消化污泥稳定化系统

设计了一套自热式高温好氧消化(ATAD)中试系统用于城市污水污泥的稳定化处理.通过批式运行,考察了进泥含固率、消化时间、曝气量及循环污泥流量等因素对反应温度及挥发性悬浮固体(VSS)去除率的影响以及pH值的变化、脱氢酶活性及病原菌的灭活情况.结果表明,适宜的进泥含固率为5%～8%(VSS浓度为26～48g/L);消化时间为10～11d;最佳曝气量为0.8～0.9 m3/(m3·h);最佳循环回流量为12～14 m3/h;运行期间pH值呈上升趋势,出泥pH值为7.5～8.0.在上述工艺条件下,ATAD系统反应器内温度可达到54℃,对VSS的去除率为48.7%,病原菌的灭活率可达到100%,出泥可达到美国A级污泥标准.     

The precipitation of phosphorus from wastewater through pH variation in the presence and absence of coagulants

Phosphorus and calcium present in the aeration tanks of two activated sludge systems were found to form an inorganic precipitate with a stoichiometric molar ratio Ca: P = 2. Variations in the solution pH resulted in the release of P and Ca into the solution (lower pH) or the precipitation of them from solution (higher pH). Lowering of the pH due to the addition of the aluminum coagulants resulted in the release of phosphorus and calcium into the solution and therefore in an apparent lower efficiency of the coagulants. It was also found that after the addition of the coagulants, the nature of the supernatant suspended solids changed from biological to chemical.     

SBR工艺对低碳量城市污水的反硝化除磷研究

广州地区的城市污水含碳量低，碳、氮、磷浓度比例失调，采用传统工艺处理很难达到理想的脱氮除磷效果，为此采用SBR工艺对其进行处理，考察了该工艺的反硝化除磷效果。结果表明，在厌氧／缺氧／好氧的运行模式下，采用逐步增加缺氧段运行时间的方法可有效提高污泥的反硝化除磷性能；在试验进水水质条件下，反应器厌氧运行30min、缺氧运行3h、好氧运行1h可保证对磷的稳定高效去除，出水TP〈1mg／L；ORP值无法指示缺氧反硝化与吸磷过程，pH值可作为缺氧吸磷结束的指示参数，而ORP和pH值均可作为好氧吸磷结束的控制参数。     

Simultaneous removal of carbon and nutrients from an industrial estate wastewater in a single up-flow aerobic/anoxic sludge bed (UAASB) bioreactor

Simultaneous removal of carbon and nutrients (CNP) in a single bioreactor is highly significant for energy consumption and control of reactor volume. Basically, nutrients removal is dependant to the ratio of biochemical oxygen demand to chemical oxygen demand (BOD₅/COD). Thus, in this study the treatment of an industrial estate wastewater with low BOD₅/COD ratio in an up-flow aerobic/anoxic sludge bed (UAASB) bioreactor, with an intermittent regime in aeration and discharge, was investigated. Hydraulic retention time (HRT) of 12-36 h and aeration time of 40-60 min/h were selected as the operating variables to analyze, optimize and model the process. In order to analyze the process, 13 dependent parameters as the process responses were studied. From the results, it was found, increasing HRT decreases the CNP removal efficiencies. However, by increasing the BOD₅ fraction of the feed, the total COD (TCOD), slowly biodegradable COD (sbCOD), readily biodegradable COD (rbCOD), total nitrogen (TN), and total phosphorus (TP) removal efficiencies were remarkably increased. Population of heterotrophic, nitrifying and denitrifying bacteria showed good agreement with the results obtained for TCOD and TN removal. The optimum conditions were determined as 12-15 h and 40-60 min/h for HRT and aeration time respectively.     

强化AB法的脱氮除磷功能研究

针对AB法的运行特点及在脱氮除磷方面的局限性，采用了外加碳源，间歇曝气等措施来强化AB法的脱氮除磷功能，小试结果表明，仅利用厂内碳源（即将A段部分污泥回流到间歇曝气池）仍不能实现满意的除磷效果，同时从厂外引入碳源（投加乙酸钠或引入高浓度啤酒废水）则系统的脱氮除磷效果将有较大的改善。     

提高SBR工艺中脱氮除磷处理效果的措施

利用序批式反应器(SBR)试验装置对城市生活污水进行处理研究，讨论了影响SBR脱氮除磷的碳源、pH值、好氧曝气等因素，并对SBR工艺中脱氮除磷的相互影响进行了探讨，提出了可以同时脱氮除磷的一种SBR的运行方式。     

The microbiology of an activated sludge waste-water treatment plant chemically treated for phosphorus removal

Microbiological research was conducted on a dual, secondary wastewater treatment system which was part of The Pennsylvania State University wastewater treatment plant. Each aeration basin received identical wastewater which was the effluent from a high rate trickling filter. One of the aeration basins was dosed with aluminum sulfate for the purpose of phosphorus removal. The other aeration basin (control) was operated in the conventional manner without alum addition. Plate counts performed on combined chemical-biological sludge and control activated sludge revealed that a higher number of viable micro-organisms was contained in the chemical-biological sludge, but the magnitude of difference between the two sludges was significant depending on the culture medium employed. Results suggest the aluminum flocs formed in the chemical-biological treatment enmesh dispersed wastewater micro-organisms, some of which are qualitatively unlike those indigenous to natural activated sludge. The combined chemical-biological sludge contained significantly higher numbers of lipolytic, gelatinolytic, and thiosulfate oxidizing micro-organisms and, possibly, fewer nitrite oxidizing micro-organisms than did control activated sludge. Alum did not appear to affect flagellated protozoa in mixed liquor; however, amoeboid and ciliated protozoa were found less frequently in alum dosed than in control mixed liquor. The settled effluent from the combined chemical-biological aeration basin generally contained fewer total coliforms, fecal coliforms, and fecal streptococci than did counterpart control effluents.     

Behavior of nitrogen and phosphorus during batch aerobic digestion of waste activated sludge—continuous aeration and intermittent aeration by control of DO

The purpose of this study is to find the behavior of nitrogen and phosphorus during aerobic digestion. Waste activated sludge samples from a municipal wastewater treatment plant were digested under 30 days batch operation, aerating continuously and intermittently. If the cycle time of intermittent aeration was decided so that the DO in a digestion tank did not become zero, the reduction rate of sludge solids and the behavior of nitrogen and phosphorus in the intermittent aeration were similar to those in the continuous aeration. The percentage of biomass nitrogen (phosphorus) in the initial total nitrogen (phosphorus) decreased and finally became 20% (30%). Forty per cent of the initial MLSS remained finally. On the other hand, the percentage of liquid phase nitrogen (phosphorus) increased during digestion and reached 60% (70%). It is considered that considerable portion of the initial total nitrogen (phosphorus) remains in liquid phase after aerobic digestion under sufficient supply of oxygen. Contents of nitrogen and phosphorus in residual biomass increased a little and decreased thereafter. Also, contents of them in reduced biomass increased monotonously.     

序批式一体化膜生物反应器的脱氮除磷效果

采用序批式一体化膜生物反应器(SBSMBR)处理模拟生活污水,考察了其脱氮除磷效果.该工艺通过合理控制单个反应器的曝气时间和曝气量来构建交替式厌氧/好氧环境,试验中反应器内混合液的污泥沉降性能始终保持良好,平板膜没有进行化学清洗,未产生不可逆的膜污染;不同工况下系统对COD、氨氮、总氮和总磷的平均去除率分别达到96.39%、97.79%、89.30%和43.79%,且系统的抗冲击负荷能力强.     

Application of response surface methodology for simultaneous carbon and nitrogen (SND) removal from dairy wastewater in batch systems

The application of batch systems to the direct treatment of dairy wastewater was investigated. Batch experiments were conducted to study the organics removal and simultaneous nitrification and denitrification (SND) process. The experiment was conducted by varying four independent parameters (mixed liquor suspended solids, chemical oxygen demand [COD]/N ratio, aeration time and cycling time), using a central composite design under response surface methodology. The process responses of five dependent parameters (COD, Total kjehldahl nitrogen (TKN), NO₃ ^?, effluent NO₃ ^? and effluent total nitrogen) were studied, and in each case, the percentage removal in batch runs was determined with each process displayed in contour plots. Finally, after optimizing the process conditions, the best treatment of dairy wastewater under optimized conditions was established and the responses were shown. This study shows that microbial granules cultivated under the alternating aerobic/anaerobic conditions in batch systems could efficiently remove organic carbon and convert all the ammonium to nitrogen gas.     

Influence of wastewater treatment on sludge production and processing

The challenge of stricter wastewater standards is resulting in configuration changes to wastewater treatment. As facilities upgrade, the type of sludge produced is changing, with growing quantities of secondary and chemical sludge at the expense of primary sludge. It is already understood that secondary sludge is harder to treat than its primary equivalent; therefore, increasing the quantity of this type of sludge will have detrimental impacts downstream. As legislation tightens further, extended aeration times may be required during processing to remove more nutrients. Work has shown that extended aeration further exacerbates the treatability of secondary sludge. This paper explains how tightening wastewater legislation fundamentally alters the nature of the sludge produced, and how these alterations impact further processing, especially with respect to sludge production and type; sludge energy content; performance of anaerobic digestion and dewatering, and potential for thermal energy recovery.