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Wastewater Treatment & RecyclingProject 2021 Project Scope Design of treatment processes for water treatment and water recycling

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Wastewater Treatment & RecyclingProject 2021 Project Scope Design of treatment processes for water treatment and water recycling. Background In this course the first 6 weeks focused on the water treatment processes, that are commonly used for water treatment, including coagulation/ flocculation, sedimentation (or settling of particles), filtration, disinfection and adsorption. Atypical flow chart of a water treatment plant is given below (Figure 1) Figure 1: Winneke Process Flow diagram The processes utilised for water treatment are also used for wastewater treatment, especially in water recycling plants. Water recycling plants treat wastewater using preliminary processes, eg grit removal (settling process), primary treatment (settling process), secondary treatment (biological process) and advanced wastewater treatment processes such as coagulation/flocculation, filtration (granular medium or membrane processes), adsorption and disinfection. Advanced water recycling processes utilised vary with the quality of water to be produced. In Melbourne, the Eastern treatment plan, one of the plants run by Melbourne Water, utilises the state of art advanced treatment processes to produce class A water (highest recycled water quality) as shown in Figure 2. Page 1 of 6 Figure Figure 2: Easter Treatment Plant Project Tasks This project focuses on water treatment and water recycling. You will work to complete the following two tasks: 1. design a water treatment plant that produces drinking water from a given resource with a known quality (ie the raw water quality will be provided). The treatment plant is expected to utilise the following processes a. b. c. d. e. ? ? coagulation, flocculation, sedimentation, filtration, disinfection and adsorption (or an equivalent process) (if needed) the design should also include the purpose, description operation and performance of each process guidelines for the treatment of each process is provided with this project brief. See Appendices 2. Concept design of a water recycling facility, that is the tertiary section of the wastewater treatment plant. The quality of the wastewater after it has passed all stages (preliminary, primary and secondary processes) will be provided. The concept design means that you will propose the process and explain how the design and operation of the processes for secondary effluent treatment vary compared to their use for water treatment. Page 2 of 6 The report should be written and presented as formal report (consider it will be submitted for a a water company). As a guide, the report should include (but not limited to the following: 1. Executive Summary 2. Design Problem 3. Introduction / Literature review (brief) : cover water treatment plants, typical processes and water recycling and typical processes 4. Water treatment plant (design and discussion of water treatment processes) 5. Water recycling plant (concept design and discussion) of advanced water recycling processes (advanced wastewater treatment processes) 6. Reflection (briefly compare the two plants (in part 4 and 5 above) ½ - 1 page Note: Assumptions and references used should be stated Example Water Quality Data that will be posted on your TEAMS group. Treatment Plant Capacity Constituent AAAA Raw Water Quality L/day Finished Water Goals Alkalinity (mg/L as CaCO3) Turbidity (ntu) Apparent Color (pcu) pH (s.u.) Total Organic Carbon (mg/L) or BOD and COD Total Dissolved Solids (mg/L) Specific contaminants Note: more information on composition of water may be provided, if needed Page 3 of 6 DESIGN CHECK LIST The following are examples of what need to be included (not a full check list) ? Draw a schematic of each plant and where needed provide a schematic of the process. ? Where solids are produced, show that on a process diagram. You need need to account for streams that are vital for the process operation, e.g. backwashing. ? It’s vitally important to plan for redundancy and maintenance. You must have a system where the peak daily flow can be accommodated such that at least one complete element of the treatment unit can be offline. Thus, if you have two units, one must be capable of handling the entire flow. It usually is cheaper to design a system where there are 3 or 4 units in parallel in which the total flow can be handled by 2 or 3, respectively. ? Summarise the total consumption of all chemicals if applicable (and possible). Page 4 of 6 Design of Sedimentation Tanks – Design of Sedimentation (Clarifier) Tanks (after Coagulation/Flocculation)Guidelines. 1. Use the suggested ranges in Tables 2 & 3 for rectangular and circular clarifiers. For your tanks you should provide ? Number of tanks, ? Layout of tanks, (schematic diagram) ? Dimension of tanks, ? Retention time ? Length and layout of over flow weir, i.e. include in your drawings a depiction of how you will accommodate the required weir length. 2. Discuss how he sludge produced will be handled and managed. 3. Discuss water quality after sedimentation, explain and reference your estimates. Parameter Units Value Minimum number of tanks Unitless 2 Water depth m 3.5 - 5 Length to width Dimensionless 3:1 - 6:1 Surface loading rate (overflow rate), Vo m/h 1.25 - 2.5 (m/d) 30 – 60 Horizontal mean flow velocity (at maximum daily flow) m/min < 0.3 - 1.1 Retention time h 1.5 - 4 Launder weir loading m3/m.h 9 – 13a Parameter Units Value Reynolds number Dimensionless < 20,000 Froude number Dimensionless > 10-5 Bottom slope for manual sludge removal systems m/m 1:300 Bottom slope for mechanical sludge scraper equipment m/m 1:600 Sludge collector speed for collection path m/min 0.3 - 0.9 Sludge collector speed for the return path m/min 1.5 - 3 Page 5 of 6 Design of Coagulation/Flocculation Units The following questions and calculations are a general guide for what should be covered in your report. 1. Design of Coagulation (Rapid Mix) and Flocculation (Slow-Mix) Tanks ? Usually jar tests are used to determine the optimum coagulant dosage. Data obtained using jar tests and coagulants of high purity are provided below. Use the dosage corresponding to your group number Table 1: Optimum coagulant dosage using high purity chemicals Alum FeCl3 Group No. Optimum Optimum Dose Dose 1 30 45 2 60 40 3 40 25 4 70 48 5 55 65 6 45 35 7 35 30 8 40 70 9 45 55 10 25 40 11 35 60 12 85 70 13 65 80 ? Based on the optimum dosage, determine: a. The daily usage of the commercial grade of each coagulant. b. Which coagulant would you use? c. Research the use of coagulants for water treatment. Based on this research, which coagulant would you use? Why? d. What is the total cost of the chemicals required for the coagulation/ flocculation process? 2. Design of rapid-mixing tank and flocculator. Your design should include the following e. Number of tanks (i.e. rapid mixing tanks and flocculation tanks) f. Tanks dimensions g. Diameter of the impeller h. Rotational speed of the impeller i. Power requirement in kW ? Refer to Table 4.15 (Davis and Cornwell text book, on Blackboard), Power requirements p 260 – 263. Other references Metcalf & Eddy chapter 5, sec 5-4 (available on Blackboard). 3. Draw a layout of your tanks, showing the dimensions on the diagram. Page 6 of 6 Project Report 45% Criteria Executive Summary Weigh t 15% Introduction & 10% Design, results and discussion 55% HD Executive summary is well presented and clearly written. The structure of abstract follows the structure of abstracts as outlines and similar to high quality papers. The content of the abstract provides a summary of all project activities and background. Conclusion well written and inline with findings Introduction provides a thorough review of the body of knowledge, the focus is on published literature relevant to the scope of the paper. States the rationale for the project and how this builds on the findings from the review. Outstanding section. The results are well presented, innovative approach for data / results interpretation and presentation. Indepth discussion that Levels of achievement DI CR Executive summary is of Executive summary is good quality, clearly of reasonable quality. written. The structure of It is mostly clear. The abstract follows the structure of abstract structure of abstracts as does not fully follow outlines structure as outlined. The content of the The summary of abstract provides a results and discussion summary of the project reports some findings methodology and findings. and the conclusion is Includes a conclusion not informative, it is inline with results summary of results Introduction provides a good review of the body of knowledge, the review has mostly focused on relevant published literature. Stated the aim and the objectives and rationale for the approach building on the findings from the review t High quality section. The results are well presented, tried to be proactive in terms of data / results interpretation and presentation. High quality discussion that addresses Introduction provides a reasonable review of the body of knowledge. Some review paragraphs are not well aligned with topic / scope of research. The statement concerning the rationale for the approach is satisfactory Good section. Good presentation of data and results. Good discussion that explains well, addresses variation on trends. Explains the PA Executive summary structure does not adhere to the instructions for abstract writing . The content of the abstract does not provide a good summary of the research activities, eg methodology, findings. The conclusion is not inline with project findings. Introduction provides a review of literature on the topic but it is mainly general and does not provide specific reviews relevant to the scope of the research. Knowledge. Rationale is not convincing, not inline with the content Satisfactory section. . The results are satisfactorily presented but the results are not of good quality and hard to see trend. In NN Executive summary is poorly written, there is no clear structure, some aspects of the work are not covered, eg the methodology and it is not clear what were the highlights or findings for this project No conclusion, or poorly written Introduction is poorly written. The review is very general and does not include specific research findings that are inline with the scope of work . No rationale or expected outcomes statement Poorly written section. Results are not presented correctly. Results indicate little work was carried out. No proper discussion Conclusions 10% References 10% addresses the trends and explain the results in the context of hypothesis and fundamental knowledge on the topic. Results are also compared published results where discrepancy is explained Well aligned with contents and meaningful the trends and explain the results well. Compared results obtained with published results. Good attempts to explain the discrepancy between obtained and published results results in the context of fundamental knowledge on the topic. Results are reasonably discussed when compared with published results . Mainly aligned with content and sound of value Reasonably aligned with content and sound meaningful Excellent references and followed a system for references included Mostly excellent references and mostly followed a system for references Included Good references, e.g they used recent publications but also used many web and old book references general there are some points in the discussion that indicate satisfactory ability in terms of results interpretation Very little discussion of published results in the same field Satisfactory conclusions, but do not seem to be of value to the field Satisfactory references, i.e some publications are recent but some are very old, used old books and unverified web resources Very poorly written Poor references. Did not follow a system for referencing Design of Filtration Units The following are guidelines for the design of the sand filters for your water treatment plant 1- As a starting point, review handouts and scan through section 11-4 (chapter 11 in M&E 4th ed). 2- Design parameters are available in M&E , chapter 11, Tables 11-7 to 11-9. Selected parameters are available in Tables 1 to 3 (in this guideline) for the sand filters. 3- The particle size distribution of the sand for your group is provided (on your Group page on CANVAS (under people/ 2021 groups/ project data ) or Google drive. 4- Given the sand particle size distribution (your data), determine (i) The effective size and the uniformity coefficient, UC, for this sand (mono medium) filter. Check if this UC satisfies the design criteria (ii) The number of filters needed and their dimensions (iii) The clean filter head loss (iv) The backwash velocity and the expanded bed depth (the latter is also used for the dimensions of the filter) Note: ? The group can propose modification to achieve a treatment goal to satisfy granular media characteristics and design criteria ? Use the excel spread sheets that you have developed, during the tutorial on week 8, to calculate the head loss and bed expansion. The topic Filtration is well discussed in Metcalf and Eddy, chapter 11 (notes on CANVAS). But if looking for a simpler text refer to Chapter 4 Davis and Cornwell (note that the symbols for the equations are different). Another option is the text by Kiely, Chapter 11, which is also on CANVAS/ text book and references ) Additional Data for all groups The sand bed and additional data are given below Refer to Table 1 filtration rate for single medium shape factor Φ porosity ?? temperature T m/s 0.85 0.4 20 °C water kinematic viscosity at 20 °C depth of filter bed ?? D 1.003E-06 m2/s See Tables below m gravitational gravity g 9.81 m/s2 Sand specific gravity s 2.65 Table 1: Single-Medium Filter Characteristics for Water Treatment VALUE CHARACTERISTIC Range Typical Sand medium : Depth in.