Design Of Treatment Facilities Research Articles

Unraveling the role of ballast surface charge at floc growth behavior in ballasted flocculation

This study was emphasized on unraveling the concealed role of surface charge characteristics of employed ballasts at suspended solids interaction with employed ballasts during floc formation in ballasted flocculation (BF). The purpose was to investigate possibilities in surface charge modulation of employed ballasts leading to enhanced aggregation and ballast embedment during floc growth. The ballasts with varied surface charge (-37.8 mV to + 33.6 mV) and equivalent specific gravity (SG: 5.09) were employed in BF process in this study. This Ballasted flocculation study was conducted using a static mixer device in this study, and characteristics of ballasted flocs (size and settling velocity of aggregates) were analyzed by charge coupled device camera. These image analysis investigations revealed that ballast particles and suspended solids experience attractions and repulsions during aggregation subject to ballast surface charge. However, appropriate ballast selection (surface charge characteristics) corresponding to influent characteristics, and optimization of applied ballast concentration (2gL-1) corresponding to ballast surface charge characteristics (SC: +1.23) resulted in 99% clarification (1 NTU residual turbidity) accomplished in a quick settling interval (30 s) with efficient consumption of applied ballasts compared to previous studies. The real-time velocity observations (using CCD camera) also confirmed this rapid clarification exhibiting superficial sedimentation (102.4mh−1) of the aggregated flocs. Therefore, this study concluded that appropriate ballast selection and optimalization of applied ballast concentration corresponding to surface charge characteristics and influent properties can lead to rapid clarification of micropollutants, and instantaneous sedimentation with efficient ballast consumption. This can lead to efficient treatment facility design with shorter hydraulic retention time, compact space requirements, and capability to produce high quality effluent discharge from highly turbid influent.

Removal of Manganese from Mine Drainages by the Passive Slag Reactor and Active Treatment System: Proposals for the Design of Treatment Facilities

망가니즈는 국내 광산배수에서 철에 이어 두 번째로 배출허용기준을 많이 초과하는 원소이나, 자연정화하기 어려워 그간 active 시설에서 처리해 왔다. 망가니즈 제거용 자연정화시설인 슬래그반응조가 도입 단계에 있으며, 이의 설계 인자들에 대하여 관련된 연구들로부터 제안하였다. 설계 인자는 필요 수위차, 매질 구성, 처리효율 변화, 그리고 체류시간을 포함한다. 또한, 기존의 active 처리시설에서 망가니즈가 철 및 알루미늄에 의해 공침 및 흡착 기작으로 제거되므로 처리를 위해 필요한 pH가 낮아지는데, pH 재조정조의 반영 여부 등을 판단해 효율적인 active 처리시설을 설계하기 위하여 Fe, Al 및 Mn 농도로부터 처리 pH를 추정하는 관계도 관련 연구로부터 제안하였다.

Convective Drying Kinetics of Faecal Sludge from Vip Latrines

In striving to achieve sustainable sanitation, one challenge is to ensure hygienic disposal of faecal sludge from on-site sanitation facilities. In order to safely dispose of the sludge, drying can be carried out to reduce the volume and mass of the waste for transportation, to deactivate pathogens making the sludge safer to handle and reuse, and finally to increase the calorific value of the sludge for potential fuel use. Improved understanding of the drying process and kinetics are crucial for the design of treatment facilities for faecal sludge and the quickest way to do this is to perform drying analysis of faecal sludge in laboratory small scale set-up. In this study, faecal sludge from ventilated improved pit (VIP) latrines from the Durban area in South Africa were dried in a convective drying thermobalance by varying the drying temperature from 40 to 80oC, the relative humidity from 0 to 25% and the velocity of the supplied air from 0.3 to 1.2 mm/s. The faecal sludge samples were in the form of a thin layer or pellets with different diameters from 8 to 14 mm. Drying curves were plotted from the experimental data and used to determine the drying rates, critical moisture content and effective diffusivities of moisture through the faecal sludge with their respective activation energies. The drying curves data were then fitted to various common models from literature, and a faecal sludge drying model was developed from this analysis. Drying rates were in the range between 1 and 40 g/min/m2, increasing as temperature and air velocity were increased, and pellet diameter and relative humidity decreased. Temperature and pellet diameter had the greatest influence on the drying rate, whereas the drying kinetics were affected in a moderate way by the relative humidity, and insignificantly by the air velocity under the explored conditions. The effective diffusivities increased from 7.81 x 10-8 to 1.97 x 10-7 m2 /s by increasing temperature from 40° to 80°C, with an activation energy of humidity. The experimental data fitted most closely to the Page model and, based on the latter, a new model was proposed for the prediction of drying times across a range of temperatures and pellet diameters. The results of the proposed model fitted the experimental data with acceptable accuracy, so that the developed model could be employed as an analytical tool for the design, operation and optimisation of drying equipment.

Determination of design layer of rainfall for design of treatment facilities of surface runoff

The article assesses the influence of the initial data and the duration of observations on the calculated value of the sediment layer, which determines the performance of treatment facilities of surface runoff. At design of these constructions drain volume from a settlement rain is found. The error introduced by the grouping of initial data depending on the accepted gradation of intervals is determined. The daily layer of precipitation from low-intensity frequent rains with a period of a single excess of the calculated intensity of 0.05-0.1 years was determined (for the conditions of Samara). Recommendations on the choice of initial data in the design are given.

Cancer Treatment Facilities: Using Design Thinking to Examine Anxiety and the Patient Experience

Worldwide, 14 million people were diagnosed with cancer, and 8.8 million victims of cancer died in 2015 (Cancer, 2017). There is no doubt that cancer is a traumatic experience. Using design–thinking strategies, the purpose of this qualitative study was to examine if the built environment in cancer care facilities influences anxiety in patients and to generate patient–driven solutions to reduce stress. Due to its human–centered and codesign emphasis, design thinking is uniquely qualified to explore cancer treatment facility design. Yet, little research using a design–thinking approach examines how the built environment influences stress among patients in an oncology unit. Eight stakeholders ( n = 8), including cancer survivors, patients, caregivers, and staff, participated in three design–thinking workshops generating ideas for oncology units. In Workshop One, participants identified issues that caused anxiety through journaling and experience diagramming, including amount of travel within the facility, small uncomfortable waiting rooms, smells, and institutional spaces. Using prioritizing strategies, participants concluded with, “How can we optimize patients’ time and movement within a facility?” This question informed subsequent workshops where participants brainstormed and prototyped ideas. The final solution addressed patient time and movement through the creation of individualized Patient Treatment Pods (PTP) that provided control, privacy, comfort, and minimal travel within oncology units. Participants clustered the PTPs around a restroom, patient lounge, nurse's station, and nutrition. Utilizing participants’ personal experiences along with design thinking led to a prototype that creates a cancer treatment facility that may better suit patient needs while potentially reducing anxiety.

The influence of particle size on the first flush strength of urban stormwater runoff.

The presence of a first flush (FF) of suspended solids (SS) in stormwater runoff has important implications for the design of treatment facilities, as does the particle size of solids. Whilst numerous studies have examined the FF behaviour of SS, few have disaggregated FF trends by particle size. In this study, the FF behaviour of SS was investigated in five size ranges, sampled from an urban stormwater drainage system located in Dublin, Ireland. A weak FF was exhibited in the gross fraction of SS, with just two events from 14 transporting more than 50% of the SS mass in the first 25% of runoff, implying that treatment structures should be capable of removing SS throughout the storm event. In the majority of rain events, the FF strength increased with decreasing particle size, probably related to the lower intensities required to dislodge solids at the onset of rainfall. Although FF strength was correlated with rain event characteristics, prediction intervals were too broad to confirm FF presence based on rainfall data alone. Therefore, the design of smaller treatment volumes based on an assumption of FF must be justified by local monitoring data.

Manganese Removal from Drinking Water Sources

Manganese (Mn) in drinking water can cause aesthetic and operational problems. Mn removal is necessary and often has major implications for treatment train design. This review provides an introduction to Mn occurrence and summarizes historic and recent research on removal mechanisms practiced in drinking water treatment. Manganese is removed by physical, chemical, and biological processes or by a combination of these methods. Although physical and chemical removal processes have been studied for decades, knowledge gaps still exist. The discovery of undesirable by-products when certain oxidants are used in treatment has impacted physical–chemical Mn removal methods. Understanding of the microorganisms present in systems that practice biological Mn removal has increased in the last decade as molecular methods have become more sophisticated, resulting in increasing use of biofiltration for Mn removal. The choice of Mn removal method is very much impacted by overall water chemistry and co-contaminants and must be integrated into the overall water treatment facility design and operation.

Management of BWRO systems using long-term monitoring of feed water quality to avoid future membrane process failure

Pumping of wells from aquifers that are used to supply brackish-water reverse osmosis (BWRO) treatment systems commonly causes increases of water salinity in time. Some key aspects of assuring operational security are the magnitude of the water quality changes to assure that treatment can continue without failure of the process, reduction in installed capacity, or the necessity to modify the process by increasing the operational pressure and changing the membranes. An example of a BWRO system that uses a leaky aquifer system as a source of feed water located in Florida shows that careful monitoring of the well water quality and individual well pumping rates over a 10-year operating period can be used to assess the projected long-term changes in water quality with regard to the treatment facility design. The total dissolved solids concentration of the wellfield began with an average TDS of 2,461 mg/L which changed over 10 years to an average of 2,855 mg/L. The variation in time is linear and the projected average change for the next 20 years shows that the average TDS for the current pumping rate will increase to 3,611 mg/L which is well below the design maximum TDS treatment ability of 8,129 mg/L.

A systematic approach to projecting industrial solid waste generation by industrial sector in Shanghai

The increasing volumes of industrial solid wastes (ISW) generated have become a serious issue in Shanghai, China. Knowing the volume of ISW that is to be generated in the future is considered a prerequisite for an effective reduction policy and the successful design of treatment facilities. It has been verified that the prediction of ISW generation has an inherent relationship with industrial restructuring caused by economic growth. This study contributes its efforts to develop a systematic approach involving a regional input–output analysis for the forecasting of ISW generation, taking into account the probable industrial restructuring developments. In the process, changes in the consumption patterns, export structure, and technical change are considered to be the important drivers. Further, a sensitivity analysis is carried out as well to investigate the influence of change in consumption on ISW generation. The case study of Shanghai provides for a feasible application of our model on a regional level until the year 2020.

A knowledge management methodology for the integrated assessment of WWTP configurations during conceptual design

The current complexity involved in wastewater management projects is arising as the XXI century sets new challenges leading towards a more integrated plant design. In this context, the growing number of innovative technologies, stricter legislation and the development of new methodological approaches make it difficult to design appropriate flow schemes for new wastewater projects. Thus, new tools are needed for the wastewater treatment plant (WWTP) conceptual design using integrated assessment methods in order to include different types of objectives at the same time i.e. environmental, economical, technical, and legal. Previous experiences used the decision support system (DSS) methodology to handle the specific issues related to wastewater management, for example, the design of treatment facilities for small communities. However, tools developed for addressing the whole treatment process independently of the plant size, capable of integrating knowledge from many different areas, including both conventional and innovative technologies are not available. Therefore, the aim of this paper is to present and describe an innovative knowledge-based methodology that handles the conceptual design of WWTP process flow-diagrams (PFDs), satisfying a vast number of different criteria. This global approach is based on a hierarchy of decisions that uses the information contained in knowledge bases (KBs) with the aim of automating the generation of suitable WWTP configurations for a specific scenario. Expert interviews, legislation, specialized literature and engineering experience have been integrated within the different KBs, which indeed constitute one of the main highlights of this work. Therefore, the methodology is presented as a valuable tool which provides customized PFD for each specific case, taking into account process unit interactions and the user specified requirements and objectives.

Residence time distribution analysis of an intermittently operating truck fill facility to determine effective contact time

Two tracer studies were performed on a First Nations water treatment plant (WTP) reservoir in order to determine the reactor mixing pattern as well as the effective contact time, or t10, value. A unique characteristic of the reservoir in question was that the major outlet from the tank was a truck fill station that operated intermittently throughout the day as water haul trucks filled up for delivery. Almost three times the flowrate was removed as was added, and coupled with the undersized reservoir resulted in major short-circuiting in the unbaffled contact chamber. The reservoir showed an almost ideal completely mixed flow regime, and the lowest t10 value determined from 2 days of testing was 14 min, much lower than what was required for chlorine Ct compliance. The residence time distribution curves also showed a unique step shape that resulted from the intermittent operation of the truck fill. With the introduction of a lagged time factor a generalized approach for analysis of existing truck fills and the design of new facilities was developed using easily quantifiable variables. An alternative approach for the design of new truck fill facilities was also provided and is somewhat more conservative than the lagged time factor method but allows for a more flexible water delivery schedule. Given the prevalence of truck fill stations in northern communities and the upcoming need for infrastructure upgrades to comply with new standards and guidelines this approach will help ensure the continued protection of public health through the potable water system. Key words: truck fill, residence time distribution, Ct concept, tracer study, water treatment facility design, public health.

Redundancy and Reliability – The 5<SUP>th</SUP> Generation of Membrane Bioreactor Design

Membrane bioreactor (MBR) facility designs have progressed through four generations of development (Crawford et al, 2001). The four generations are generally described as evolving from long Solids Retention Time (SRT) package plants, to the inclusion of nutrient removal (total nitrogen and/or phosphorus), to equipment and facility design optimization by reducing both the SRT and the Mixed Liquor Suspended Solids (MLSS) concentrations, and finally to the fourth generation characterized by larger plant designs with the Owner/Engineer assuming increased risk and design responsibility. The small MBR installations of the first three generations, as well as most fourth generation plants, were not required to operate with full reliability and redundancy – most MBR plants to date have included very large flow equalization or flow diversion basin capabilities, or withdraw their influent wastewater from a collection sewer that continues to a larger downstream plant. At these plants, reliability and redundancy is desirable but not essential – system shutdowns can occur without causing a raw wastewater bypass. Some recent MBR designs however are of the 5 th generation of design; characterized by the inclusion of fully reliable and fully redundant design features that are essential for end-ofpipe treatment facility design. Detailed design information from operating MBR installations showing the unique reliability and redundancy requirements of end-of-pipe MBR system designs will be presented.

An alternative to open burning treatment of solid propellant manufacturing wastes

Chemical Systems has selected base hydrolysis treatment to replace open burning of solid propellant manufacturing wastes. This treatment approach was adapted from several technologies. Reclaim/reuse and experimental treatment technologies were combined into the selected treatment process. Adoption of this change in treatment technology requires characterization and minimization of waste streams and alternate product development. The treatment facility design and permitting are discussed. Experiments performed on three representative types of solid propellants demonstrate the process feasibility and characterize the products of the hydrolysis. The products of the propellant treatment are ammonia, hydrogen, nitrogen oxide gasses, soluble inorganic and organic salts, and insoluble polymeric and metallic materials. Materials contaminated with propellant are cleaned and separated from the hydrolysate. The products of the process will be treatable in conventional waste treatment facilities.

Environmental Radiolysis for Soil and Sediment Treatment: A Review of Chemistry, Design, and Economic Issues

AbstractRadiation processing is a mature industrial technology widely utilized in the manufacture of an extensive assortment of products. In addition, there have been many successful demonstrations of the use of radiolysis for environmental application. The purpose of this article is to illustrate that the use of ionizing radiation to remediate contaminated media should be seriously considered as an innovative alternative to conventional techniques, especially in the case of chlorinated pollutants such as dioxins and PCBs. A thorough review of the principles of radiolysis and the practice of radiation processing is presented. A comparison of gamma and high-energy electron radiation sources is made in order to delineate the type and scale of application best suited for a particular system. Since the quantities of contaminated soils, sediments, and sludges are enormous and the required radiation doses are large, the economies of scale favor the use of high power and high energy electron beams. A cost estimate is presented to illustrate that a contaminated soil can be treated at a dose of 1 MGy with a 150 kW, 10 MeV IMPELA electron beam at a rate of approximately 3000 metric tons/year and at a total amortized cost of $720/ton, a sum substantially less than incineration costs. A novel soil treatment facility design is presented and various strategies in which it can be employed to reduce overall treatment costs are discussed.

The SIMTAR CAD/CAE system for the interactive computer aided design of wastewater treatment facilities

It can be stated that the development and application of CAD/CAE systems in engineering have evolved in parallel with the evolution of computers. However, in the technological field of wastewater treatment there is so far a considerable gap between capability of hardware and software available for simulation and the design of treatment facilities. SIMTAR, a CAD/CAE system, implies an effort to adjust this situation. It is a handy tool for the design and evaluation of wastewater treatment plants -WTP's-. In this system the whole of the stages involved in the design of WTP's (calculation of equipment sizes, cost estimation, and drawing of equipment plants) can be accomplished. The input is done interactively by means of menus and a graphical interface, which allows the user to generate the simulation diagram and the treatment process flowsheet. Results computed by SIMTAR fit quite well with those calculated by several engineering firms for the Manresa and Martorell's plants (Catalonia, Spain).

Environmental concerns associated with the design of genetic engineering facilities.

Recombinant DNA technology is being used to produce a wide spectrum of products, such as vaccines, interferon, insulin, and growth hormones. In the design of facilities employing this technology, critical consideration must be given to the protection of the environment, both in the prevention of releases of recombinant DNA organisms into the environment and in the treatment of wastes originating from the production facilities. The design requirements for containment of large-scale systems are complex and require detailed analysis to insure that the containment system can handle both the normal and emergency releases of recombinant DNA organisms. This must include the prevention of releases through either liquid discharges or air emissions. The "killing" method used in the process for either the cells (extracellular product) or the broth (intracellular product) is an important step and can have significant implications in downstream treatment of wastewaters. Since fermentation is the primary process used in the production of recombinant DNA products, wastewater characteristics from this area of the process are basically similar to those of other fermentation processes. They differ, however, because of the "killing" step in the process, which can introduce compounds not normally found in fermentation wastewaters. This can complicate the treatment process by requiring additional treatment operations. Characteristics of wastewaters from other areas of the process can be very diverse, and no general characterization can be made. Techniques for recovery and purification can vary from product to product or even from plant to plant, making characterization difficult. It is important, therefore, that each process be examined in detail so that waste characterization is meaningful and useful in the design of treatment facilities. Because of the complex nature of the processes involved in the production of recombinant DNA products, wastewater treatment can also become a very complex problem. Systems to treat these wastewaters can include many diverse unit operations, from pretreatment of selected streams to tertiary treatment of the combined streams to meet stringent effluent criteria. While biological treatment is almost always applicable, waste loads are very high, and multiple-stage systems could be required. Early and ongoing interface between the process development scientists and engineers and the environmental disciplines allows for the early recognition of potential environmental problems. With early recognition, many of these problems can be economically and efficiently addressed in the design of the facility.(ABSTRACT TRUNCATED AT 400 WORDS)

Tailoring design off treatment plants to local conditions

A description and comparison of five water treatment systems and supply sources—located in Sydney, Australia; Manila, Philippines; Springfield, Mass.; Rochester, N.Y.; and Long Island, N.Y.—are used as the basis for a discussion of tailoring the design of treatment facilities to local conditions. Water quality, existing treatment facilities, the supply source and method of regulation, climatic conditions, labor intensive design versus automation, equipment maintenance, cost of chemicals, emergency measures, and waste‐solids disposal are considered as they relate to the process train and other considerations relevant to the system.

Recent developments in water pollution control

Following a brief outline of the status of pollution control in Ontario, the paper examines recent developments in wastewater technology as applied to plant performance, secondary treatment, and sludge processing.Modelling, automatic control, addition of pure oxygen, land disposal, and sludge dewatering are among the new approaches to the design of treatment facilities that are described; their limitations are noted and their application in Canada is considered.Increasing public concern and decreasing resources will force serious consideration of new methods to improve treatment reliability and efficiency. Technology, judiciously employed, can be one of the most effective ways of protecting our environment.

Design of treatment facilities for the control of phosphorus

Design of treatment facilities for the control of phosphorus

Design of treatment facilities for the control of nitrogenous materials

IN ~tAN'~ receiving waters of the United States, it is becoming increasingly important to control either the qualitative or quantitative composition of efltuents in regard to nitrogenous substances. Due to the high oxygen demand of ammonia nitrogen, it is desirable to produce a nitrified effiuent, before discharge, in a great many watersheds. To a much lesser extent, it is necessary to provide for nitrogen removal in those cases where eutrophication or health hazards are a problem. From pilot plant (BAR~ et al., 1968) and field evaluation studies (MU'LBARGER, 1970), a multiple-stage, combined chemical-biological process is being designed for several large United States facilities. The general design of such a process is shown on Fro. 1. The essential features of design are the stage concept, which essentially isolates each biological system so that optimum design conditions can be employed to maximize efficiency of each biological transformation. Secondly, experience has shown that