斜管沉淀池处理净水厂排泥水工艺优化研究

以净水厂排泥水为研究对象,考察了斜管沉淀池对排泥水的处理效果。结果表明,随着进泥负荷的不断增大,斜管沉淀池出水的上清液浊度和CODMn含量都逐渐升高,阴离子聚丙烯酰胺或聚合氯化铝与聚丙烯酰胺的联合投加都可以改善排泥水的沉降性能,且只要聚丙烯酰胺的投加量大于2 mg/L,就可以形成较大且密实的矾花;投加聚丙烯酰胺药剂后,可应对由于净水工艺进行沉淀池冲洗后排泥水性质的恶化,改善排泥水的沉降性能,降低出水浊度,提高出泥浓度。     

基于板框压滤强化脱水工艺的污泥化学调理研究

采用石灰、聚合硫酸铁(PFS)、阳离子聚丙烯酰胺(PAM)等对污水厂浓缩池污泥进行化学调理,然后采用板框压滤设备进行强化脱水,考察了不同药剂对污泥的调理效果。结果表明:当Ca O和PFS投加量分别为污泥干基的14%和7%,即按2∶1的比例进行复合调理时,污泥脱水效果最理想,泥饼含水率可降至59.0%;阳离子PAM虽然对污泥脱水的强化作用不明显,但是合理的投加可大大缩短板框压滤设备的进泥时间,提高压榨效率。     

pH值对水厂排泥水的调质作用研究

通过混凝试验,以沉降比、上清液浊度、氨氮和CODMn作为考察排泥水沉降浓缩处理性能的指标,研究了pH值调质对污泥沉降性能的影响。结果表明:在弱酸性(pH=6.0～6.8)条件下,使用阴离子型聚丙烯酰胺(PAM)能有效地改善污泥沉降浓缩后的上清液水质;进行pH值调质时,投酸量与排泥水的浓度有关;运行中应严格控制pH值的调节,pH<5时不利于沉降,pH>7时调质效果不明显。     

钢厂污泥处理系统中离心脱水机的调试研究

以某钢厂的污泥处理系统为例,探讨了离心脱水机在调试过程中的絮凝剂选择、主机转速的调整、扭力矩的确定以及进泥量与污泥含水率的关系。调试过程历时半个月,通过烧杯试验和上机试验最终确定采用离子度为40%、分子质量为6 000 ku的阳离子聚丙烯酰胺(PAM)作为污泥脱水的絮凝剂;以产泥含水率为评价指标,确定最佳主机转速为2 500 r/min、最佳扭力矩为17N·m。另外发现,进泥含水率越低,则出泥含水率亦越低,但进泥含水率偏低时会导致离心机处理能力下降;增大进泥含水率可提高离心机的最大进泥量,但出泥含水率随之升高,因此,在离心机选型时一定要明确污泥含水率参数,在调试过程中,要根据实际情况确定合适的进泥量。     

硝酸铁强化不同浓度污泥自热高温微好氧消化效果

采用自热高温微好氧消化(ATMAD)工艺在硝酸铁强化下进行污泥批式消化试验,考察了不同进泥浓度对稳定化效果的影响。结果表明:在进泥TS为4.5%~6.5%范围内,硝酸铁对ATMAD工艺污泥消化过程的强化效果随进泥浓度的降低而提高;硝酸铁对上清液中SCOD、VFA和氮等指标的强化去除效果均随进泥浓度的降低而增强;较低进泥浓度下p H值和磷等指标却相对较高。综合考虑强化消化的效果和自热升温的需求,进泥TS浓度选择5.5%为佳。     

旋流气浮/固定床生物膜/电催化氧化处理油田污水

为探究物理/生物/电化学法对油田污水的处理效能,分别考察了旋流气浮净化器、固定床生物膜反应器和电催化氧化反应器对油田污水的处理效能,明确了投药量、电流密度、电解时间等对处理效果的影响,并利用SPSS软件对运行参数进行了优化。结果表明,旋流气浮作为预处理工艺,其最佳聚合氯化铝(PAC)投加量、聚丙烯酰胺(PAM)投加量、反应时间分别确定为400mg/L、8 mg/L和17 min,出水油含量、SS和COD分别降到4.5、18.5、392.6 mg/L左右,为后续生物处理提供了保证;电催化氧化作为深度处理单元,其最佳电流密度、极板间距和电催化氧化时间分别为45 m A/cm~2、2 cm和90 min。组合工艺对油田污水有良好的处理效果,最终出水检测不到油含量,COD和SS浓度分别降到100、50 mg/L以下。     

蒙脱石粉与阴离子聚丙烯酰胺联用处理极低浊度水的强化混凝工艺

通过模拟混凝工艺,考察了单独投加蒙脱石粉溶液、阴离子聚丙烯酰胺溶液以及两者联用时极低浊度水(<5 NTU)的处理效果。结果表明:单独投加蒙脱石粉溶液以及阴离子聚丙烯酰胺溶液对去除水体浊度、氨氮效果不佳,两者联用能够有效降低极低浊度水的浊度和氨氮质量浓度,可作为处理极低浊度水的强化混凝工艺,能够低成本提高原工艺的混凝沉淀效果以及给水污泥的沉降性能。     

非均相UV/Fenton反应体系处理聚丙烯酰胺废水

制备了负载在粗孔硅胶上的含铁催化剂,将其用于非均相UV/Fenton反应体系处理聚丙烯酰胺(PAM)废水,考察了催化剂投量、H2O2投量、PAM初始浓度对PAM降解效果的影响.试验结果表明,制备的含铁催化剂具有较高的催化活性,在催化剂投量为0.67 g/L、H2O2投量为7.5 mL/L(249.75 mg/L)条件下反应120 min后,对PAM、TOC的去除率均可达70%以上,且该体系中PAM的降解规律遵循一级反应动力学方程;对PAM的降解率随其初始浓度的增加呈下降趋势.进一步研究发现,PAM的降解速率随H2O2初始浓度与PAM初始浓度之比呈线性上升规律.     

污泥浓缩深脱一体机在供水污泥脱水中的应用

针对不同泥质的供水污泥,开发了污泥浓缩脱水一体化工艺及其成套中试设备(浓缩深脱一体机),并优化了设计和运行参数。对于脱水性较好的供水污泥,仅需投加聚丙烯酰胺(PAM),该设备在进泥量较小的条件下即可使出泥含水率低于70%;对于脱水性较差的污泥,分别考察了联合投加PAM和污泥改性剂,以及联合投加PAM和石灰乳两种调理方案对污泥脱水效能的影响,并对不同调理方案进行了技术和经济指标分析。结果表明,在达到目标含水率前提下,当单独投加PAM、联合投加PAM和改性剂、联合投加PAM和石灰乳调理污泥时,设备处理量分别为130、200和330 kgDS/h,处理成本分别为171.24、262.44和150.60元/tDS。因此,联合投加PAM和石灰乳进行供水污泥调理可提高产能、降低处理成本,推荐在实际生产中使用。     

辐流沉淀池药剂替代投加试验初步效果

针对黄河流域夏秋季泥沙含量大、浊度高的特点,多数水厂采用投加聚丙烯酰胺（PAM）达到快速沉降的目的,但聚丙烯酰胺（PAM）中单体的残留有一定的毒性,近几年,本水厂以聚合氯化铝（PAC）和阳离子聚二甲基二烯丙基氯化铵（PDMDAAC）进行复配,代替聚丙烯酰胺（PAM）进行投加试验,取得了良好的净水效果,基本消除了聚丙烯酰胺（PAM）单体的残毒,饮用水水质进一步提高。     

Power economy characteristics of an activated sludge aeration tank

The air feed rate to meet a given oxygen uptake rate in the activated sludge aeration tank was expressed by using the concept of the air diffuser performance, previously proposed by the present authors. Using the relationship between the BOD removal and the oxygen uptake rate, a procedure to predict the power economy, which is defined as the amount of BOD removed per unit power consumption of the air feeding, and the effluent quality of the activated sludge process under various operating conditions was presented. The effect of operating parameters in the tank; the MLSS concentration; the hydraulic retention time and the BOD loading on the power economy and the effluent quality were extensively evaluated. The results calculated by the proposed procedure were compared with the statistic data of operating conditions in the municipal wastewater treatment plants in Japan. A method to improve the effluent quality while maintaining a high power economy was also discussed.     

聚丙烯酰胺预处理自来水厂污泥

合理选用聚丙烯酰胺(PAM)并确定其最佳投量可降低自来水厂污泥处理费用，为此选用具有代表性的阳离子和阴离子两种类型PAM预处理自来水厂的污泥。研究结果表明：投加两种类型的PAM均可显著改善污泥的脱水性能，但阴离子型PAM的投量较低；根据毛细吸水时间(CST)变化得到的PAM最佳投量与测定比阻得到的最佳PAM投量一致，故可用CST替代比阻检测污泥的脱水性能；测定离心液和滤液粘度也是确定PAM最佳投量的一种快速、可靠的方法，也可用于PAM投量的在线控制。     

Dissolved-air foam separation to clarify turbid waters

An experimental investigation is presented of the foam separation of turbidity constituents, primarily clays, from natural waters at approximately neutral pH. A cationic surfactant, cetyldimethylbenzylammonium chloride, is used as the collector-frother. A continuous flow clarification unit has been designed and utilized, relying on the precipitation of dissolved-air bubbles (with the air dissolved at 40–80 psig) from suspension to provide the interfacial area for particle attachment and flotation. Data from 91 experiments is correlated on the basis of an empirical model. The effluent turbidity (particle concentration in terms of optical density) and effluent surfactant concentration are related to the five independent variables by stepwise, linear multiple regression analysis. A second order model relates the effluent turbidity to the feed rate, feed turbidity, feed surfactant concentration, the recirculation rate, and the liquid column height, with an accuracy of 20 per cent. Scale-up considerations are included, and an operating-cost estimate is given for a 1000 gal day⁻¹ clarification unit.     

高密度沉淀池的运行控制

通过对高密度沉淀池运行指标的监测,探讨了高密度沉淀池运行的合理工况.结果表明:可以用浊度快速估测混合区进泥水浓度;加药和回流都应该根据反应区污泥的浓度进行控制和调整;高密度沉淀池的进水流量对出水浊度影响较大,可以在保持处理干固量一定的情况下,尽量降低进泥流量.     

铝离子浓度对厌氧处理城市污水混凝污泥的影响

通过实验室小试,考察了城市污水经混凝处理所产污泥的厌氧消化性能.结果表明,与单独采用聚合氯化铝混凝的初沉污泥和剩余污泥相比,经聚合氯化铝与聚丙烯酰胺联合混凝的污泥,其厌氧消化性能更理想.通过产甲烷毒性试验、毒性驯化与毒性恢复试验,可以推断混凝剂中铝离子对甲烷菌产甲烷活性的影响类别为代谢毒素类;铝离子对产甲烷菌的50%活性抑制浓度为0.4 mg/L,相当于聚合氯化铝的投加量为40～60 mg/L.建议采用聚丙烯酰胺类絮凝剂与铝类混凝剂联合处理的方法来降低铝的用量,以提高混凝污泥后续处理的效率.     

Thickening of waste activated sludge by biological flotation

Waste activated sludge was thickened by biological flotation without polymer flocculant dosage. The BIOFLOT® process utilizes the denitrifying ability of activated sludge bacteria. Gaseous products of anaerobic nitrate reduction cause spontaneous flotation of the sludge suspended solids. Laboratory tests confirmed the dependence of sludge thickening efficiency on available nitrate concentration, flotation time and temperature. Full-scale experiments were performed in a fully automatized unit for discontinuous sludge thickening from wastewater treatment plants with a capacity of up to 5000 I.E. Waste activated sludge from wastewater treatment plants at Pisek. Milevsko and Björnlunda was thickened from 6.2, 10.7 and 3.5 g/l MLSS to 59.4, 59.7 and 66.7 g/t MLSS, respectively. Concentrations of COD, ammonium and phosphate ions were decreased in sludge water. The average nitrate consumption for bioflotation was 21.2 mg NO₁⁻ per 1 g of MLSS of activated sludge. Flotation time ranged from 4 to 48 h.     

外压浸入式超滤膜处理排泥水上清液的研究

采用外压浸入式中空纤维超滤膜处理排泥水重力浓缩上清液。试验结果表明,当温度从16℃下降到2℃时,TMP从0．032MPa上升到0．055MPa。排泥水经6h重力浓缩后,上清液浊度为9．99～80．33NTU,CODMn为5．36～18．64mg／L;超滤膜出水浊度为0．08～0．11NTU,CODMn小于3mg／L,颗粒数小于1个／mL。在排泥水上清液水质波动较大情况下,经超滤处理后,出水水质优于常规处理工艺出水,加氯后可直接进入清水池。     

The effect of operational parameters of the process of sludge ozonation on the solubilisation of organic and nitrogenous compounds

An evaluation of various operational parameters on the process of sludge ozonation was carried out based on semi-batch experiments. Particular reference has been given to examine the main parameters affecting the solubilisation of organic matter and nitrogenous compounds. Various sets of experiments were undertaken using real sewage sludge to feed a semi-industrial ozonation plant. Applying ozone dosages between 25 and 35 mg O(3)/gTSS, the organic matter solubilisation obtained through ozonation increases proportionally to ozone dosage until a maximum value of 430 mg COD/L. Concerning the nitrogenous compounds, no variation in nitrite concentration and a low increase in nitrate concentration were attained, regardless of the applied ozone dosage. Little increase in ammonia concentration was achieved for low ozone dosages, whilst applying dosages higher than 20 mg O(3)/gTSS, the variation of ammonia increased proportionally with ozone dosage. Experiments using hydraulic retention time (HRT) between 10 and 60 min resulted in a similar COD solubilisation, confirming a rapid rate of cell lysis during ozonation of sludge.