COST COMPARISON BETWEEN CESSPOOL AND SANITARY SEWERAGE SYSTEMS IN SAUDI URBAN AREAS1

ABSTRACT: Extensive use is made of on-site wastewater disposal systems of cesspools due to the absence of a sanitary sewerage system in Saudi urban areas. This system has caused the groundwater table to rise to a public nuisance level. A health risk has also evolved. There are several infrastructural, environmental, and social impacts from this, resulting in great financial losses. Examples are: surface water flooding, damage to foundations of buildings and asphalt street pavements, flooded basements and added construction costs required for excavation, dewatering, insulation materials, and special cements. Most of these costs are indirectly being paid by the private and public sectors. This study compares the estimated costs of damage and losses with the estimated costs of building, operating, and maintaining sanitary sewerage systems in the cesspool-served areas. The annual cost of the cesspool system, depending on the severity of the adverse impacts, ranges from 2.2 to 4.4 times the annual cost of the sanitary sewerage system. Remedies for these impacts are very expensive, and delays in the implementation of the sanitary sewerage facility will make the damage recovery more expensive, and in some cases, impossible. Thus, it is recommended that highest priority to be given to the sanitary sewerage systems in Saudi urban areas.     

Sustainable wastewater management for small communities in the Middle East and North Africa

Accelerated expansion of wastewater services to small communities in the Middle East and North Africa (MENA) is essential in order to address serious concerns over water scarcity and pollution in addition to meeting the demand for convenience and protecting public health. Centralized and conventional wastewater systems are currently the preferred choice of planners and decision-makers in MENA. Water and funding are not available to provide these centralized conventional services to small communities. This paper presents an integrated approach to sustainable wastewater management for small communities in MENA under the severe water resources crisis. The approach calls for a paradigm shift from centralized conventional wastewater systems to decentralized wastewater systems. Management of wastewater in MENA should start at home. Wastewater generation should be reduced through a combination of domestic water conservation measures. On-site systems must be improved and monitored to control pollution and to recover water for non-potable water uses. Should the circumstances not allow the use of on-site systems, wastewater should be transported and managed through a community system applying the principles of decentralized wastewater management and using the settled sewers for wastewater transportation where appropriate. This approach will facilitate the accelerated and sustainable extension of environmentally responsible wastewater services to MENA's small communities. It offers great potential for cost reduction, accommodates the necessary domestic water conservation efforts, reduces freshwater inputs in wastewater transportation thus eliminating unnecessary demand on freshwater, reduces associated environmental risks and increases wastewater reuse opportunities.     

Evaluation of Generic Types of Drilling Fluid Using a Risk-Based Analytic Hierarchy Process

The composition of drilling muds is based on a mixture of clays and additives in a base fluid. There are three generic categories of base fluid - water, oil, and synthetic. Water-based fluids (WBFs) are relatively environmentally benign, but drilling performance is better with oil-based fluids (OBFs). The oil and gas industry developed synthetic-based fluids (SBFs), such as vegetable esters, olefins, ethers, and others, which provide drilling performance comparable to OBFs, but with lower environmental and occupational health effects. The primary objective of this paper is to present a methodology to guide decision-making in the selection and evaluation of three generic types of drilling fluids using a risk-based analytic hierarchy process (AHP). In this paper a comparison of drilling fluids is made considering various activities involved in the life cycle of drilling fluids.This paper evaluates OBFs, WBFs, and SBFs based on four major impacts—operations, resources, economics, and liabilities. Four major activities—drilling, discharging offshore, loading and transporting, and disposing onshore—cause the operational impacts. Each activity involves risks related to occupational injuries (safety), general public health, environmental impact, and energy use. A multicriteria analysis strategy was used for the selection and evaluation of drilling fluids using a risk-based AHP. A four-level hierarchical structure is developed to determine the final relative scores, and the SBFs are found to be the best option.     

Integrated Risk Framework for Onsite Wastewater Treatment Systems

Onsite wastewater treatment systems (OWTS) are becoming increasingly important for the treatment and dispersal of effluent in new urbanised developments that are not serviced by centralised wastewater collection and treatment systems. However, the current standards and guidelines adopted by many local authorities for assessing suitable site and soil conditions for OWTS are increasingly coming under scrutiny due to the public health and environmental impacts caused by poorly performing systems, in particular septic tank-soil adsorption systems. In order to achieve sustainable onsite wastewater treatment with minimal impacts on the environment and public health, more appropriate means of assessment are required. This paper highlights an integrated risk based approach for assessing the inherent hazards associated with OWTS in order to manage and mitigate the environmental and public health risks inherent with onsite wastewater treatment. In developing a sound and cohesive integrated risk framework for OWTS, several key issues must be recognised. These include the inclusion of relevant stakeholders throughout framework development, the integration of scientific knowledge, data and analysis with risk assessment and management ideals, and identification of the appropriate performance goals for successful management and mitigation of associated risks. These issues were addressed in the development of the risk framework to provide a generic approach to assessing risk from OWTS. The utilisation of the developed risk framework for achieving more appropriate assessment and management techniques for OWTS is presented in a case study for the Gold Coast region, Queensland State, Australia.     

电气浮法处理钻井废水实验研究

对电气浮法处理模拟钻井废水进行了实验研究,分析了工艺参数(电气浮时间、电极间距、电气浮后静止停留时间、废水温度和电流密度)对电气浮法处理效果的影响。实验结果表明,电气浮法处理钻井废水受许多因素的影响,掌握这些因素对电气浮处理的影响规律,有助于合理选取最佳参数,达到既高效又节能地处理钻井废水的效果。研究结果表明:最佳电气浮时间为10min,电极间距推荐选用1.0cm,电气浮后静止停留时间选用5min,废水适宜处理温度为30～50℃,选择电流密度小、电气浮处理时间长的组合工艺能达到最佳处理效果。     

水再生回用的研究进展与对策

本文对城市生活污水和工业生产废水的再生回用技术进行了比较全面系统的评述，将物理化学方法和生物方法进行了对比介绍；对水再生回用技术的发展趋势进行了展望，提出了水再生回用的发展对策。     

Electricity price and Southern California’s water supply options

This paper evaluates the impact of fluctuating electricity prices on the cost of five options to increase the water supply to urban areas in Southern California—new surface storage, water purchases, desalination, wastewater recycling, and conservation.We show that the price of electricity required to produce and transport water influences the cost of water supply options and may alter the decision makers economic ranking of these options. When electricity prices are low, water purchase is the cost effective option. When prices exceed US$ 86/MWh, conservation of electricity and water through installation of high efficiency clothes washers is the most effective option.     

CT4-35钻井废水处理剂的研制及应用

CT-35是一种高效的钻井废水处理剂，与其它常用药剂相比，该混凝剂对处理高浓度钻井废水特别是处理难度很大的磺化类废水有明显的优势。介绍了CT4-35研制、生产工艺，用它处理现场钻井废水的情况。现场使用表明：利用CT4-35处理钻井废水，COD的去除率可达85％以上，浊度去除率为100％，处理后出水呈中性（PH6～8），色度小于原水样的1／10，出水清澈透明，并且产生的污泥量少。通过对处理前、后出水的水质分析，证明其中无药剂残留。     

稠油污水深度处理与回用技术探讨

文章介绍了新疆油田在稠油污水处理和回用方面的关键技术和成熟经验,采用强酸性树脂软化技术和化学清洗技术实现了稠油污水回用注汽锅炉。六九区污水处理站采用高效水质稳定技术,使处理后的污水达到了GB 8978—1996《污水综合排放标准》的二级标准,稠油污水在处理后符合GB 1576—2008《工业锅炉水质》的要求,大幅度降低了注汽锅炉的运行成本;将60℃以上的稠油污水替代清水回注稀油油藏,热水驱油,改善了驱油效果,同时根据污水温度较高的特点,对注水井井口的保温工艺进行改进,实现了稠油污水热能的综合利用,为油田污水治理和回用提供了借鉴。     

印钞造纸废水回用中试研究

本课题以印钞造纸废水回用为目标，通过中试研究表明采用生物处理为核心工艺，结合废水深度处理技术。完全能使废水出水水质达到工业用水标准，从而为今后实际工程上马提供了较可靠的试验依据。     

Impacts of Bakken Shale Oil Development on Regional Water Uses and Supply

The Bakken shale play in western North Dakota is one of the largest unconventional oilfields in the United States, but published research about impacts on the region's water resources is rare. In this study, besides examining North Dakota water management policies and activities, we also analyzed three datasets: the Bakken horizontal well completion data (2008‐2014), North Dakota permitted water consumption data (2000‐2014), and groundwater level and streamflow observations in western North Dakota (2000‐2014). We found from 2008 to 2014, the annual total industrial water uses for Bakken shale oil development ranged between 0.5 and 10% of statewide total consumptive water use. The percentage increases were between 3.0 and 40% within the Bakken oil production region. The increased population of temporary oilfield service workers contributed additional domestic water use, which was equivalent to ~15% of annual industrial water use for the shale oil development in the Bakken. Despite being in a semiarid region, the impact of Bakken development on regional water supply was limited because the water in the Bakken was adaptively managed and the region received on average over 20% more precipitation than normal during 2008‐2014. Of the 15 glaciofluvial aquifers under study, 12 have seen water levels increasing or unchanged and the water levels for the remaining 3 aquifers have decreased.     

城市污水处理厂恶臭浓度分布规律及其防治措施

城市污水处理厂的主要大气污染物之一为恶臭污染,恶臭问题已经成为环境领域的一个重要研究课题。恶臭污染物的来源主要是初沉池等水流湍动处,其成分主要是含氮化合物、含硫化合物、含氧有机物等。分析了恶臭污染物的来源、成分和浓度分布等,对确定城市污水处理厂的卫生防护距离进行了讨论,并介绍了目前国内外主要恶臭污染防治措施。湿式吸收氧化法和生物过滤法这两种技术是当前发展和应用的方向。     

聚丙烯工业废水排放的治理措施

在利用间歇式液相本体法工艺生产聚丙烯时,易产生大量废水,包括闪蒸水环真空泵排放水、聚合釜轴封冷却水排放水、聚合升温用热水罐溢流水等。应最大限度地减少废水的排放量。已经采取的废水减排措施包括:对于真空泵逐渐调小供水量(即减少了排放量);将轴封冷却水收回重复利用;维持热水罐的水位稳定,避免产生溢流。采取上述措施在满足生产要求的同时,最大限度地减少了废水排放量。     

工业园区水污染防治技术与管理政策需求分析

工业园区水污染防控是“十二五”期间我国水环境治理的重要任务之一,但目前还普遍存在一些技术和管理上的不足,导致处理效果不理想。本文就此问题,对园区企业在废水预处理、收集和处理、末端排放、水循环利用和管理机制方面存在的问题进行了讨论和分析;从技术和管理两大方面,对园区水污染防治的需求进行了分类探讨,并对环境主管部门、园区管理者和环境服务商提出了工作建议。     

Investigating the quantitative and qualitative status of effluent in the wastewater treatment plant in Iran Central Iron Ore

The aim of present study was to investigate the quality of the produced effluent from different units of the Iran Central Iron Ore in Bafq city and comparison of effluent with the standards. This study presents the physicochemical and biological parameters data of effluent of three Sequencing batch reactors (SBR) with a capacity of 160 m³?d^?1. Most common parameters include pH, total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), biochemical oxygen demand (BOD₅), chemical oxygen demand (COD), heavy metals, and total coliforms and fecal coliforms as biological indicators. Then, for each SBR system, the average of each parameter was determined, and results were compared with the standard recommended by the Iranian Environmental Protection Agency. Based on the results, some of the parameters, including BOD₅, COD, and TSS in the wastewater treatment plant (WWTP) effluent, are higher than the permitted amount for discharge to the surface water. Considering the BOD₅, COD, and TSS concentration in WWTPs, the treated wastewater is only suitable for agricultural and irrigation use. Therefore, wastewater produced by Iran Central Iron Ore Co. will need additional treatment to achieve standard quality of water before discharge in surface water and adsorbent well.     

The impacts of recreation and tourism in the remote North Kimberly region of Western Australia

The environmental impacts created by recreational visitors to the wet-dry tropics of Western Australia raise questions about the type of visitor and the capacity of remote areas to 'carry increasing numbers of visitors. This paper looks at those questions in regard to some of the more remote natural attractions in the tropical North Kimberley region. Three locations—Cape Domett at the mouth of the Ord River, the Admiralty Gulf and the Mitchell Plateau—illustrate the differences between attractions, visitors, patterns of visitor behavior and their impacts on the local environment. As the highly variable nature of the Australian wet-tropics renders the use of conventional site indicators of carrying capacity difficult, an ecological alternative is proposed for research. The dominance of local and other Australian four-wheel drivers to the Kimberley and the impacts they create are shown to challenge the government's promotion of the region to overseas visitors and its notion of tourism as a sustainable industry.     

Regeneration of industrial district wastewater using a combination of Fenton process and ion exchange—A case study

Regeneration studies of wastewater effluent from an organized industrial district (OID) for possible reuse in textile industry as process water was investigated. Advanced treatment methods including Fenton process, polyaluminium chloride (PAC) coagulation and ion exchange were applied on OID effluent. In Fenton process removal efficiencies for suspended solids (SS), chemical oxygen demand (COD), SAC₄₃₆ (spectral absorption coefficient), SAC₅₂₅ and SAC₆₂₀ were determined 61%, 36%, 35%, 49% and 67%, respectively. After Fenton process, wastewater samples were coagulated with PAC. Optimum removal efficiencies for SS, COD, Fe ion, SAC₄₃₆, SAC₅₂₅ and SAC₆₂₀ were determined 83%, 18%, 93%, 32%, 36% and 58%, respectively. Ion exchange experiments were conducted on chemically coagulated wastewater samples to improve the quality of wastewater. Optimum dosage of resins was determined. The experiments revealed that 1:1 resin ratio (20 mL H-type resin:20 mL OH-type resin) gave the best removal rates for the parameters considered in this study. Study results indicated that quality of the wastewater was suitable for the process water characteristics of textile industry and unit wastewater treatment cost was determined as 2.54 €/m³.     

钻井污水与采油污水混合处理

中原油田产生的钻井污水的化学需氧量(COD)、矿化度、色度、悬浮物及含油量均比较高,直接外排将会对周边生态环境造成污染,与采油污水混合处理又将导致处理后的水质达不到标准,因而采用将钻井污水处理后再与采油污水混合的方法,这种混合污水进入采油污水处理系统的试验结果表明,处理后的钻井污水与采油污水配伍性良好,净化水无结垢倾向,处理后的净化水与杀菌剂、缓蚀剂相容性良好,其主要指标均达到部颁注水水质标准。     

我国油田产出水再利用技术现状及展望

随着我国油气田勘探开发力度加大和新环保法的实施,油田开采过程中耗水量大和污水处理问题是我国油气田企业面临的共同难题。从污水余热回收、污水回注、压裂液重复利用、钻井废水再利用四个方面,介绍了国内油田产出水再利用技术研究进展与应用现状,指出目前存在的污水余热再利用应用范围不广、回注污水利用不合理、化工原料未回收利用等主要问题。并通过文献调研,展望了油田污水再利用技术的发展方向,指出需从污染源头防控入手,研发更加经济环保的液体配方,并深入研究从污水中取热、取水及取化工原料的循环再利用技术,因地制宜制定相应的水质及污水配伍性实验评价标准,实现从源头至末端治理相结合的油田污水清洁生产。     

混凝沉降法处理洗衣废水的实验研究

洗涤废水含有表面活性剂和磷酸盐物质,直接排入水体会造成水体的污染,增加给水处理厂的处理难度,甚至会引起水体富营养化。本实验是通过投加PAC和PAM絮凝沉降联合活性炭吸附来处理商业洗涤废水,以去除废水中的COD。实验表明：采用PAC PAM 活性炭工艺处理洗衣废水的效果较好,投药过程COD的去除率可以达到60％以上,经过活性炭过滤后,总的去除率可以达到86％。出水ODD可以降至在50mg／L左右。