挤出式污泥脱水装置在大牛地气田含醇含油污泥处理中的应用

在大牛地气田天然气开发过程中,产生大量含有甲醇、凝析油的污泥,为避免污泥污染环境,需使用专门的脱水设备处理污泥,降低污泥含水率,然后将污泥焚烧。经传统板框式脱水机、带式脱水机等脱水设备处理后的泥饼含水率在75%-85%之间,需要进行二次干化处理,而新型的挤出式污泥脱水装置处理后的泥饼含水率最低可降低到65%,无需进行二次干化处理,大大提高了污泥处理效率,同时也取得了较好的安全效益和经济效益。     

大庆石化公司炼油污水“三泥”处理技术

分析了"三泥"装置运行现状,针对"三泥"在储存罐、浓缩罐、预处理系统、离心机的脱水技术进行了研究;提出了对离心脱水机出口脱油线、脱液线、配药系统、离心脱水机"堰板"问题进行改进。采用在浓缩罐底部出泥线前加阀,使浓缩罐底部能脱水,解决污泥在预处理系统含水率高的问题;采用在搅拌池底部出泥线阀前加阀,解决污泥上离心机前含水率高的问题。重新利用调节隔油池对污泥脱水,把握滤液回到污水处理场浮选池水质质量。解决了污泥处理效率低、污泥脱水困难、泥饼含水率高、自动化程度低等问题。     

PAC调理剂对全自动板框压滤机污泥深度脱水的影响

传统板框脱水采用"石灰+FeCl3"作为污泥调理剂,存在干基增量大、泥饼热值较低、作业环境较差等问题.通过中试试验考察了PAC对污泥深度脱水过程的影响.结果表明:随着PAC投加量增高,脱水泥饼含水率降低;滤室中污泥含水率变化速率随着隔膜挤压时间的延长逐渐减缓;当进料浓度从3.3％提高到7.6％时,压滤机过滤速率明显提高了40％左右.相较于传统污泥调理剂,采用PAC作为污泥调理剂可使污泥热值较高、干基增量较小,可显著提高污泥焚烧经济价值.     

叠螺式脱水机在含油污泥脱水中的应用

为了确定伊拉克某油田污水处理站含油污泥处理设备,对比分析了板框式压滤机、带式压滤机、离心式脱水机和叠螺式脱水机等常用含油污泥机械脱水设备的技术特点和应用范围,并对叠螺式脱水机实际运行情况进行了现场调研。分析和现场调研结果表明,叠螺式脱水机集污泥浓缩和脱水于一体,具有出泥含水率低、占地面积小、易分离、不堵塞,可以实现自清洗,可用于低浓度污泥等特点,叠螺式脱水机简化了油田污泥处理工艺流程,降低了地面工程建设投资及运行成本,是含油污泥进行脱水的较好选择。介绍了伊拉克某油田污水处理站含油污泥叠螺式脱水机的选型设计。     

车载式底泥处理一体化设备结构及应用报告

运用车载式底泥处理一体化设备,采用高分子絮凝剂(聚合氯化铝、聚丙烯酰胺)对深圳茅洲河1#底泥厂底泥进行絮凝脱水实验。通过对设备进料物质分析,得出底泥中含固率为10%,其中沙粒占50%左右,采用分级分筛系统,可提高单套一体化设备的处理能力。检测设备进料和设备出口处泥饼的含水率,发现在进料含水率在91%～97%范围内时,其脱水泥饼的含水率均低于60%,泥饼含水率为50. 5%～58. 9%。     

污泥深度脱水分析和全自动压滤机应用实践

从过滤速率方程可见，影响污泥深度脱水的主要因素有污泥性质(r、μ)、压力、泥饼厚度和时间。通过污泥调理、增加压力、降低泥饼厚度可以改善污泥的脱水效率和脱水后泥饼含水率，但要同时考虑经济性、安全性和污泥减量化、稳定化、无害化和资源化的需要。滤布行走式全自动压滤机，可以实现无人辅助卸泥全自动运行，单一调理剂聚合硫酸铁有效投加量占绝干污泥的比例为1.47%～2.1%,泥饼含水率50.15%～53.45%。     

活性炭联合正弦波电场促进污泥脱水

利用活性炭联合正弦波电场促进污泥脱水,通过对泥饼电流、温度及泥饼、滤液的性质分析探究活性炭对污泥脱水的促进机理。结果表明,活性炭可以提升污泥导电性,增强污泥中的电化学反应,从而降低了泥饼含水率。在占空比为100%,投加量为5%污泥干重时,泥饼含水率为43%;活性炭可以吸附滤液中有机物组分,相比未投加,投加5%活性炭的总有机碳值降低了1.708g/L,降低了滤液处理成本。     

聚丙烯酸絮凝剂在印染污泥低温热处理中的应用

污泥脱水是实现污泥减量化和资源化利用的关键步骤。研究了自制聚丙烯酸絮凝剂PR在低温热处理条件下对印染污泥脱水性能的影响,探究其脱水机理。结果表明,PR能显著改善污泥的脱水性能。最佳工艺条件:PR用量15 mg/g,硫酸用量0.002 mL/g,75℃下热处理30 min。处理后污泥比阻降至2.80×10~(12) m/kg,降低了98.80%,泥饼含水率降至84.59%,结合水含量降至28.27%。     

湛江某再生水厂低影响污泥系统扩容改造分析

由于湛江市某再生水厂处理水量提高,其产生的污泥量由干泥量14 t DS/d提高至16.6 t DS/d,超过原有污泥脱水系统的处理能力.该工程在保留及利用原有脱水机、投药设备等的基础上,新增了污泥机械浓缩设备及其配套的进出料系统、PAM药剂投加系统,将原污泥脱水系统的进泥含水率由99.2％降低至97％,并新增污泥离心脱水机.在尽量降低对现况系统的影响下,提高原有污泥系统处理能力,为其他污水处理厂的扩容升级提供了借鉴和参考.     

污泥的机械脱水实例

<正> 在污水处理过程中随着污水的净化、沉淀下大量污泥,一般初次沉淀池的污泥含水率为95％左右,生物滤池后的二次沉淀池的污泥含水率为96％左左,活性污泥的含水率则高达99％以上。由于含水率大,污泥量多,给污泥的处理和利用带来一定的困难,因而需要浓缩、脱水或干化,以减少污泥体积。例如含水率为95％的污泥经脱水后含水率降到70％时,污泥重量仅为脱水前的16.7％;如果含水率为99.5％的污泥经浓缩和脱水后含水率降到70％时,污泥重量仅为脱水前的1.67％。     

高盐高有机制药废水污泥电渗透高干脱水

为研究高盐高有机制药废水污泥的电渗透脱水效果,深入认识化学污泥的电脱水过程,本文采用电渗透高干脱水技术对经抽滤脱水的高盐高有机制药废水化学污泥进行深度脱水,考察了泥饼初始pH的改变对污泥电渗透高干脱水过程中阴阳极污泥的含水率、电流、电导率、pH、zeta电位与能耗的影响,验证了对高盐高有机制药废水污泥实行电渗透高干脱水的可行性,解析了化学污泥电渗透脱水过程的机制。结果表明,泥饼pH为2、3、4时,zeta电位为正值,电渗流反向流动,无法脱水;pH增至5时,zeta电位为负值,电渗流从阴极脱除,污泥含水率从53.2%降至44.8%,脱水效果最好;但pH增至6时,脱水量有所降低。污泥电导率随pH的增加而降低。pH为5时初始电流最大。脱水15min时,即污泥含水率降至45.5%时,能源利用率最高。     

掺加粉煤灰的污泥沉降浓缩效果与利用

改善污泥浓缩和脱水性能有利于污泥的处置和利用,从污泥用于建材原材料的角度,试验研究了粉煤灰在污泥沉降浓缩过程中的作用。结果显示,粉煤灰的最佳掺量为5%时,脱水混合物含水率为60%左右,低于纯污泥脱水后80%左右的含水率,将大大有利于后续的处理与利用;经粉煤灰改性后浓缩脱水得到的污泥可用作烧制陶粒。     

钢铁厂中央污水污泥脱水性能的改善

“PAC＋PAM”乃常见的水处理工艺,通过与助凝剂膨润土组合改良后,不但可以保证水质稳定,而且可以改善污泥脱水性能,使脱水后污泥含水率降低约15％,同时药剂的协同增效作用可以降低药剂使用量10％左右。     

市政污泥水热法脱水试验研究

市政污泥具有水分含量高、脱水困难的特点,水热法工艺可改善其脱水性能,降低污泥含水率,有利于实现污泥的无害化、稳定化及资源化利用.考察了反应温度、pH值、泥浆浓度、保温时间、泥浆过滤温度等工艺条件对污泥脱水效果的影响.结果 显示,在反应温度为180℃、pH值为6.85、生污泥与水的质量比约为2:1、保温时间为30 min...     

Experimental Study on Thermal Hydrolysis and Dewatering Characteristics of Mechanically Dewatered Sewage Sludge

After mechanical dewatering, sewage sludge has a moisture content of around 80 wt% and further disposal is required. A new sewage sludge semi-drying (dewatering) process is proposed and verified. It combines thermal hydrolysis and subsequent mechanical dewatering, with less energy consumption than traditional thermal drying. Sludge treated using this new process satisfies further disposal requirements (e.g., landfill or autothermal incineration). In the present study, a high-pressure test reactor was used to study the thermal hydrolysis of dewatered sludge. Thermally hydrolyzed sludge was subsequently dewatered by centrifugal sedimentation or by pressure filtration. The amount of organic compounds returning to the water phase was also measured. According to the results from centrifugal settling tests, the optimal thermal hydrolysis treatment temperature was 180°C. The moisture content then dropped to 1.44 kg/kg dry solids (DS; 59 wt%) after dewatering under relative centrifugal force of 9,000 × g from 5.67 kg/kg DS (85 wt%). Pressure filtration further reduced the moisture content of filter cakes to only 0.5 kg/kg DS (33 wt%, hydrolysis temperature 180°C). After thermal hydrolysis, the heating value of sludge (moisture-free basis) was about 80% that of the untreated sludge.     

A Study for Development of Real-Scale Thermal Filter Press Dewatering (TFPD)

Real-scale thermal filter press dewatering equipment (plate size: 630 mm × 630 mm) was installed and operated at a waterworks for one year in an attempt to achieve sludge reduction. During the period, the dewaterability was evaluated according to the seasonal sludge properties in order to compare the dewaterability of thermal dewatering and mechanical dewatering, as well as to determine the economics of thermal dewatering. According to the results, the winter season sludge showed a 36% decrease in water content and a two-thirds reduction in dewatering velocity compared to the summertime sludge. In addition, the dewatered cakes of the thermal filter press dewatering equipment showed a lower specific cake resistance and water content in the dewatered cakes than the mechanical filter press dewatering equipment, indicating superior dewaterability. This was attributed to the easier removal of the filtrate remaining in the capillary tubes due to thermal dewatering. The energy consumption for thermal dewatering was 300 kJ/dry solids (DS) kg. A comparison of the sludge dryers indicated that it is possible to produce dewatered cakes that consume less energy and can be recycled. According to the performance evaluation results, the real-scale thermal filter press dewatering equipment had high adaptability to the changes in seasonal sludge, showing excellent dewaterability compared to the mechanical filter press dewatering equipment, and was economical due to the lower energy consumption.     

Dewatering of Biomass Using Liquid Bio Dimethyl Ether

An interesting integrated configuration in a thermochemical conversion biorefinery that is producing dimethyl ether (DME) is to use a small fraction of the BioDME for dewatering of the solid biomass feedstock. Therefore, the use of liquid BioDME was investigated in this study for pressurized dewatering of biomass at room temperature. Water was removed in liquid form from wet sawdust and wet wood chips using liquid DME in a laboratory-scale batch unit. Both the sawdust and the wood chips could be dewatered in a short time (minutes) to a moisture content of 15% (w/w) from an initial content of approximately 55% (w/w). Longer DME treatment times (hours) lowered the moisture content even further down to 8% (w/w), indicating that the transport phenomena in the porous biomass and the solubility of DME in water influence the dewatering characteristics. The DME dewatering performance, 12–22 g DME per g water removed, was similar to literature data on coal dewatering using liquid DME. The present study showed that DME dewatering of the solid biomass feedstock has potential as an energy-efficient dewatering process, especially in an integrated thermochemical conversion biorefinery.     

超声破乳脱水及浮渣脱水资源化利用

介绍了炼厂浮渣脱水技术的发展及超声破乳脱水领域的研究成果;综述了超声破乳脱水的优点有：在恰当的超声处理条件下能减少絮凝剂用量20％以上,浮渣超声脱水技术可加快浮渣处理速率,缩短脱水时间,超声处理5 min后浮渣含水率与沉降72 h后的效果相当,最终脱水率提高6％～7％,而且采用超声波破乳脱水技术进行浮渣破乳脱水,将脱水后浮渣应用于延迟焦化生产过程,可实现资源化利用,同时解决环保问题,获得较好的经济效益与社会效益。     

Involvement of Gypsum (CaSO4 · 2H2O) in Water Treatment Sludge Dewatering: A Potential Benefit in Disposal and Reuse

Abstract

This research assessed the use of gypsum (CaSO₄ · 2H₂O) as a skeleton builder for sludge dewatering since polymer conditioning of sludge affected only the rate of water release, not the extent of dewatering. The use of gypsum as a physical conditioner, in association with a polymer, could improve sludge filterability. More significantly, gypsum serves as a skeleton builder, forming a permeable and rigid lattice structure that can remain porous under high positive pressure during the compression step after the cake growth of the filtration, thereby maintaining the size of the micro‐passages through which water is expressed. Experiments using a high pressure cell apparatus showed that a further decrease of two to seven percent of the equilibrium moisture content of the sludge cake was achieved, for sludge thicknesses for dewatering of 1 to 10 cm, by the addition of gypsum with 60% of the original sludge solids when compared to the single polymer conditioning. The importance of the addition of gypsum in alum sludge dewatering is not only the improvement in the extent of dewatering, but also the potential application of transforming dewatered alum sludge from “waste” for landfill to useful “fertilizer” or to be used as a filter medium/adsorbent for wastewater treatment engineering.     

A study of the improvement in dewatering behavior of wastewater sludge through the addition of fly ash

Wastewater sludge is classified as a difficult dewatering material (DDM) due to the high cake specific resistance (CSR). On the other hand, fly ash is classified as an easy dewatering material (EDM), which suggests that it might be able to improve the dewaterability of wastewater sludge. The water content and cake specific resistance of dewatered sludge without the addition of fly ash were 80% and 2.9×10¹⁴ kg/m, respectively. When 50% (by dry weight) fly ash was added to the sludge, the water content and cake specific resistance decreased to 29.4% and 2.9×10¹³ kg/m, respectively. The cake specific resistance and water content decreased with increasing fly ash additions. Therefore, the production of sludge cake can be reduced by adding fly ash, which can help minimize the social and environmental problems caused by the need to dispose of wastewater sludge.