Economic evaluation of alternative wastewater treatment plant options for pulp and paper industry

Excessive water consumption in pulp and paper industry results in high amount of wastewater. Pollutant characteristics of the wastewater vary depending on the processes used in production and the quality of paper produced. However, in general, high organic material and suspended solid contents are considered as major pollutants of pulp and paper industry effluents. The major pollutant characteristics of pulp and paper industry effluents in Turkey were surveyed and means of major pollutant concentrations, which were grouped in three different pollution grades (low, moderate and high strength effluents), and flow rates within 3000 to 10,000 m³/day range with 1000 m³/day steps were used as design parameters. Ninety-six treatment plants were designed using twelve flow schemes which were combinations of physical treatment, chemical treatment, aerobic and anaerobic biological processes. Detailed comparative cost analysis which includes investment, operation, maintenance and rehabilitation costs was prepared to determine optimum treatment processes for each pollution grade. The most economic and technically optimal treatment processes were found as extended aeration activated sludge process for low strength effluents, extended aeration activated sludge process or UASB followed by an aeration basin for medium strength effluents, and UASB followed by an aeration basin or UASB followed by the conventional activated sludge process for high strength effluents.     

河道复氧/生物填料工艺处理受污染河水的中试

设计人工模拟河道,考察了河道复氧/生物填料工艺净化受污染河水的效果.通过筛选生物填料以及改变曝气强度、曝气方式和水体流速,探寻了该组合工艺用于苏州受污染河流治理时适宜的运行方式和工艺参数.结果表明,在进行曝气复氧的同时于河道中设置弹性填料,对COD、NH,-N和TP的去除率分别可达38%、62%和42%,浊度也降至8 NTU左右.这表明,对于流速缓慢的滞流水体,采用河道复氧/生物填料工艺进行净化是可行的.     

上流式两段曝气生物滤池工艺设计

仙女河污水处理厂采用了上流式两段曝气生物滤池,其主要特点是体积小、处理效率高、出水水质好、流程简单、集生物氧化和截留悬浮固体于一体,在有效去除水中有机物的同时,脱氮效果良好。该工艺不设二沉池,节省了基建投资,且自动化控制水平高,可降低运行成本。     

Combination of Advanced Oxidation Processes and biological treatments for wastewater decontamination--a review

Nowadays there is a continuously increasing worldwide concern for development of alternative water reuse technologies, mainly focused on agriculture and industry. In this context, Advanced Oxidation Processes (AOPs) are considered a highly competitive water treatment technology for the removal of those organic pollutants not treatable by conventional techniques due to their high chemical stability and/or low biodegradability. Although chemical oxidation for complete mineralization is usually expensive, its combination with a biological treatment is widely reported to reduce operating costs. This paper reviews recent research combining AOPs (as a pre-treatment or post-treatment stage) and bioremediation technologies for the decontamination of a wide range of synthetic and real industrial wastewater. Special emphasis is also placed on recent studies and large-scale combination schemes developed in Mediterranean countries for non-biodegradable wastewater treatment and reuse. The main conclusions arrived at from the overall assessment of the literature are that more work needs to be done on degradation kinetics and reactor modeling of the combined process, and also dynamics of the initial attack on primary contaminants and intermediate species generation. Furthermore, better economic models must be developed to estimate how the cost of this combined process varies with specific industrial wastewater characteristics, the overall decontamination efficiency and the relative cost of the AOP versus biological treatment.     

Comparison of the cost of the pressurized wastewater treatment process with other established treatment processes

A biological wastewater treatment unit under the influence of pressure was operated at pressures of up to 6 bar. It was demonstrated the capability of operating effectively with high carbonaceous oxidation and nitrification efficiencies at loadings of up to 13 g BOD m⁻² day. Another advantage of the pressurized treatment unit was observed to be its low sludge production. The cost of the pressurized treatment unit has, however, become an important factor for the applicability of the pressurized treatment unit. An investigation was carried out to determine the approximate cost of a proposed full-scale pressurized unit. The comparison between the pressurized unit and the established treatment processes were made for three populations of 500, 1000 and 3000 persons. The costs were then compared with those of various other conventional biological treatment processes capable of treating an equivalent wastewater load. The conventional processes selected for comparison were the activated sludge, biological filtration and conventional RBC.

The sludge disposal cost for the pressurized unit was appreciably lower than that for the other processes. The results indicated that the cost of the pressurized unit (present value for a 20-yr period) and the costs of the activated sludge and conventional RBC processes were found to be similar for the smaller populations. However, a substantial saving could be obtained with the pressurized unit for the larger populations. In addition, there was an indication that the land requirement of the pressurized treatment unit decreased appreciably as the flow rate increased.     

中小型城市污水处理厂技术经济调查与分析

通过网络调查和实地走访等方式对我国已建的100余座污水处理厂进行了技术经济调查.对工艺类型、投资、规模、成本等关键参数进行了统计分析,得出了不同工艺类型的建造投资与流量的函数关系;比较了不同工艺类型的直接运行成本和总成本;按照污染物单因子（BOD、COD、SS、氨氮、磷）计算得出单位污染物的处理成本.为了便于优化设计和科学决策,还利用现行手册中的典型设计,拟合计算出主要单体处理构筑物的费用模型.     

利用排水沟渠处理污水技术研究

利用合流制排水沟渠处理污水是一项新技术。通过室内试验和实际模型试验,对利用合流制排水沟处理污水的工艺,效率,抗冲刷能力,生物载体等进行了研究,结果表明处理效率达到或超过一般生物膜法的水平,基建投资和运行费用大大降低。利用排水沟渠处理污水与传统的推流式生物氧化法有所不同,在内源呼吸期ＣＯＤ值有所上升,对此现象进行了理论探讨,并建立了ＣＯＤ和溶解氧变化过程数学模式,还对设置初次沉淀段进行了经济分析。     

造纸中段废水深度处理方法探析

从造纸中段废水的处理现状出发，对其深度处理的必要性和紧迫性进行了讨论，并以广泛研究和实际应用的废水深度处理方法为基础，对其应用于中段废水深度处理的可行性进行了分析。对于造纸中段废水的深度处理，单一的处理方法均存在其应用局限性，其中物化法有成本高、吸附剂再生困难、污泥量大等缺点，生物法则难以进一步降低废水的COD，生态法易受土地资源及气候等条件的制约。分析表明，只有通过不同方法的联合，优势互补，才能做到经济性和实用性的统一。     

污水处理中曝气催化铁(一级半处理)新工艺

曝气催化铁是一种新型的一级半处理工艺。介绍了对曝气催化铁工艺的摇床试验和中试试验,证明COD、总磷、磷酸盐的平均去除率低于城镇污水处理厂二级排放标准。最后对该工艺的运行费用进行了分析。研究说明该工艺操作简便,运行稳定,投资与运行费用有望大幅度降低。     

上海市泗塘污水处理厂脱氮除磷达标改造工程实践

在对泗塘污水处理厂现有处理工艺优化诊断基础上，指出了该厂升级改造的瓶颈所在，介绍了污水处理厂达标改造的原则，比较论证了分点进水倒置A／A/O、生物除磷＋辅助化学除磷工艺和分流处理工艺两个方案，介绍了工艺除臭及尾水消毒措施。该工程为老厂脱氮除磷工艺改造提供了一套完整的技术方案和工作流程，出水水质能稳定达标。     

Application of a Biological Iron Removal Process at Grove Water-Treatment Works

This paper describes the process of biological iron removal with specific reference to the new water-treatment plant at Grove (near Retford), operated by Anglian Water Services. The reasons for selection of a biological-treatment process are discussed together with process design, commissioning experiences, and details of plant performance.
The raw-water data suggested that a biological removal process would be feasible and would offer capital cost savings over a conventional aeration and filtration process. Further investigations were carried out in a pilot plant. A summary of the data which were collected during the performance trials is presented, which demonstrates the successful application of the process.     

Side-Stream Treatment of Raw-Sludge Liquors using Activated Sludge: Pilot Investigations and Full-Scale Design Rationale

The end of sludge disposal at sea in 1998 will lead to increased volumes of sludge requiring treatment and disposal. Accordingly, there will be further quantities of high-strength liquors arising from sludge thickening and dewatering processes, and additional treatment capacity will therefore be required at treatment works.
This paper describes a three-year project to develop a dedicated side-stream treatment process for the treatment of raw-sludge liquors at Knostrop sewage-treatment works (Leeds) based on the activated-sludge process. Large pilot-scale trials are described which assisted in the construction of simple process design models for full-scale design. Together with additional pilot-scale aeration testing and modelling, a cost model for a full-scale plant was developed, allowing the lowest whole-life cost plant, based on 'net present cost'analysis, to be specified.     

南太子湖污水处理厂地下水渗入量预测

污水处理厂的处理规模是影响工艺选择、基建费用和运行管理费用的决定性因素，而地下水的渗入量又是影响处理规模的重要因素。以南太子湖污水处理厂为例，在实时监测的基础上，以节点流量衡算法预测了污水处理厂近、远期的地下水渗入量。     

污水厂生物除臭设计中存在的问题探讨

生物除臭技术因其工艺简单、基建费用低等优点而得到广泛应用,因此对目前污水厂生物除臭系统设计中存在的问题进行了探讨.从臭气的收集系统,臭气成分、浓度、风量的设定,生物除臭的动力学模型以及生物处理装置的选用等四个方面进行了分析和总结,可为污水厂的除臭系统设计提供借鉴.     

Treatment and Disposal Scheme for the Sewage of Athens

The sewage from the Greater Athens area is discharged without treatment to the nearby Saronicos Gulf. Recently the Greek government decided to implement an appropriate treatment and disposal scheme, on the basis of a study of the hydrodynamic behaviour of the Gulf and the fate of the discharged pollutants. The study was conducted with the aid of suitable hydrodynamic and water quality models for a number of alternative treatment schemes, ranging from primary treatment to biological treatment with seasonal nitrogen removal, combined with outfalls of different lengths. The results indicate that, although none of the examined schemes will lead to an immediate substantial impact, the scheme that includes biological treatment with seasonal nitrogen removal can eliminate the danger of serious ecological disturbances at a reasonable cost.     

丹麦Lundtofte污水处理厂的运行和管理

介绍了丹麦Lundtofle 污水处理厂的机械设备、污水处理工艺(活性污泥法)、污泥处理(厌氧、消化、焚烧)的操作和运行情况,并给出了详细的运行费用方面的数据,包括药剂费、能耗等.     

工艺优化诊断技术用于污水厂的改造

随着污水排放标准不断提高,污水厂需改造处理工艺以满足稳定达标排放的要求,同时还需进行工艺优化以降低运行成本、节省基建费用和运行费用.对上海市曲阳、松江污水厂现有处理工艺做了优化诊断,主要采用系统分析方法通过现场考察、大规模数据收集、利用国际水协活性污泥模型（ASM2D）等工具,建立了符合污水厂实际运行状况的水质模型,全面评价了两厂目前的工艺状况和瓶颈所在,对几种可能的工艺改造方案进行了定量模拟预测,提出了能确保达标的改造设计工艺和优化方案.该项目为老厂工艺改造提供了一套完整的技术方案和工作流程,使老厂改造工艺具有脱氮除磷功能,出水水质能稳定达标,并预计工艺诊断优化成果的具体实施可为污水厂节省一次性基建费用10%～30%和运行费用15%～40%.     

印染废水深度处理工程及工艺改进

采用曝气生物滤池(BAF)/臭氧预氧化/BAF组合工艺对印染废水二级生化处理出水进行深度处理,COD从进水的90～160 mg/L左右稳定降至30 mg/L以下,色度从进水的64～128倍左右降至2～4倍,出水浊度<1 NTU,排放水质达到回用要求,处理成本为1.43元/m~3.之后又对工艺进行改进,设计出一体化装置,COD去除率>70%,其他指标均达到排放标准,处理成本仅为0.89元/m~3.     

淮安市第二污水处理厂一期工程的设计与运行

淮安市第二污水处理厂一期工程采用一级强化处理/曝气生物滤池工艺,介绍了工艺流程、主要处理单元的设计参数及运行管理经验.该工艺对COD、BOD5、SS、NH3-N及TP都有较好的处理效果,出水水质稳定达到了<城镇污水处理厂污染物排放标准>(GB 18918-2002)的一级B标准.     

折流式曝气生物滤池处理小城镇污水的工艺设计

结合重庆市三峡库区新生镇污水厂的工程设计，介绍了厌氧水解池＋折流曝气生物滤池处理小城镇污水的工艺特点、主要设计参数、技术经济指标等。该工艺具有占地面积小、除污效率高的优点，同时能够节约造价和运行费用，且管理简便。