Floc Probe, Spring 2014

Alexandra Green, Tiago Viegas, Paul Vieselmeyer

Abstract

The visualization of the floc blanket in Aguaclara plants has been difficult and limited, so our team has tried to simulate it and create a new apparatus to solve or at least to reduce the problem. We found reports and materials from the turbidimeter team that could help in our task. Research was done on commercial sensors that could help monitor the floc blanket level, but none of the results were feasible. An experimental set up was also created in order to simulate the floc blanket and clear water interface with no success. Finally, a sludge judge apparatus was created to hopefully help with the observation of the floc blanket in San Nicolas.

Turbulent Tube Flocculator, Spring 2014

Felice Chan, Jonathan Christensen, Stephen Jacobs, Ana Oliveira

Abstract

Since the Summer of 2013, the Turbulent Tube Flocculator team has been developing and optimizing a design for a lab scale turbulent tube occulator to better mimic the processes that occur at full scale plants. From this, a vertical occulator of approximately 1.5 m was constructed with 30 coils of exible tubings connected with pieces of metal pipe. Currently, the team is working on the rest of the experimental setup, which involves pumps, turbidimeters, pinch valves, clay stock, temperature and pressure sensors, Settled Water Turbidity analyzer (SWaT), rapid mix, and Process Controller software. Clay will be added directly to the head tank to keep the suspension stable in absence of coagulant. The coagulant, injected immediately following rapid mix, is responsible for aggregation of suspended particles present in the solution. Experiments will measure turbidity reduction as a function of coagulant dosage.

Turbulent Tube Flocculation, Summer 2014

Shreya Jain, Tanya Peifer, Nadia Shebaro, Luke Zhu

Abstract

Over the summer of 2014, the turbulent tube flocculation team has worked to implement and test a SWaT system for analyzing residual turbidity from the flocculator. The group is also working to implement PID control for the turbulent tube occulator to regulate the amount of clay added to the system. The team made minor physical adjustments to the turbulent occulator through the shortening of tubes and the tube settler position. By the end of the summer research period, the team has established a working occulation system to facilitate experiments done by future teams.

Turbulent Tube Flocculator, Fall 2014

Felice Chan, Mingze Niu, William Pennock

Abstract

Over the fall semester of 2014, the Turbulent Tube Flocculator Team improved the turbulent tube flocculation apparatus in terms of flow control, turbidity control and general structure. The objective of this improvement was to prepare the apparatus by the end of the semester for experimentation. The team made a number of updates this semester, including building a support structure for SWaT and the effluent line. In addition, two air releases were installed as well as a diffuser system in the constant head tank to eliminate air from the flocculator. In addition to the structural modifications of the apparatus, the team updated the process controller method file for experimentation. The experiments performed on this apparatus will be used to validate the equation derived by Dr. Monroe Weber­Shirk based on the experimental work of Dr. Karen Swetland.

Fluidized Bed Flocculator -Spring 2014

Felice Chan, Jonathan Christensen, Stephen Jacobs, Ana Oliveira

Abstract:

Novel methods of water treatment, that do not use electricity and only require basic construction materials, are in demand worldwide in remote regions without established centralized water treatment. Gravity-driven unit processes must be developed for these water treatment facilities. Current hydraulic flocculators use baffles with dimensions on the order of meters to generate turbulence and achieve particle aggregation. An alternative approach is to use sand grains, rather than large solid sheets, as flocculator baffles. A fluidized sand bed flocculator occupies much less plan view area, but generates much more head loss. Implementation will depend on a balance of the cost of land and materials against the available hydraulic head.

Sensor Development - Fall 2016

Andrea Pozo, Cheer Tsang, Grace Mitchell, Sidney Lok

Abstract:

The fall semester of 2016 marks the beginning of the Sensor Development subteam to AguaClara, which was created in response to the needs of the Upflow Anaerobic Sludge Blanket (UASB) and Anaerobic Fluidized Bed (AFB) subteams. This semester, the primary goals of this subteam were to develop a gas measurement sensor and a fluidized bed solids concentrator sensor for AguaClara plants. The subteam finalized a method of gas measurement, programmed settings in ProCoDa, and built four final product gas sensors for the AFB subteam. For the fluidized bed solids concentrator sensor, the subteam took measurements of the photosensor output and developed a method to correlate photosensor output to the existing intensity of fluidized solids.

CSFBR - Fall 2016

Jacqueline Dokko, Javier Espada Fraile

Abstract

The countercurrent stacked floc blanket reactor is a system for removing suspended solids or dissolved dyes by coagulating them into larger lumps of particles referred to as flocs using opposing currents to run clean water one way and floc-ridden water the other way. Using two standardized reactors, dye and coagulant concentrations, and flow rates, the team worked towards determining whether multiple reactors in a series is more efficient than a single, long reactor. With the known mechanism and the result of the previous research, this semester’s goal was to intensify dye removal by modifying the design of the reactor, system flow path and flow rates. For the future, the flocculator will be modified to be longer allowing larger flocs to form, increasing efficiency of the system as a whole since the discrepancy in flocculator size prevented comparable performance between the single reactor system and the system of reactors in series.

CSFBR - 2016 Spring

Surya Kumar, Christine Leu, Amlan Sinha, Cindy Dou

Abstract

Floc blankets, which are suspended layers of highly concentrated flocs, have the potential of being a more efficient option for removing arsenic, fluoride, and certain dyes in terms of energy and water consumption than currently employed techniques. For floc formation, a coagulant needs to be added to the water, allowing particles to adsorb to each other when they collide. Previous research has shown that the coagulant, polyaluminum chloride (PACl), has properties that allow arsenic, fluoride, and certain dyes to adsorb to its surface. The first iteration of this research used three floc blankets in series with a counter-current flow of contaminated water and flocs. By feeding flocs from the last reactor into the second, and from the second into the first, the PACl’s surface area can be saturated. To test this theory and apparatus, a dye, Remazol Brilliant Blue R (RBBR), was chosen to be the contaminant due to its less toxic nature and visual component. With this apparatus and contaminant, this semester’s goals were to test dye removal efficiency from water with varying concentrations of clay, PACl, and dye. With a 1:1 ratio of PACl to dye, a dye removal efficiency of roughly 80% was achieved. However, the transportation of flocs from the third reactor to the second and first was not sustanaibly achieved.

Laminar Tube Flocculator - Spring 2015

Luyan Sun, Tanvi Naidu, Kevin Shao

Abstract:

Research on the Laminar Tube Flocculator in Spring 2015 aimed to validate the results obtained by Karen Swetland with the FReTA system and to further investigate factors that affect the overall turbidity removal. The past semester’s team worked to test the new residual turbidity monitoring system, SWaT, in comparison to the FReTA system and to verify that the new system can obtain similar results to those obtained with the old system. However, the actual coagulant tubing size used in the previous SWaT experiment was different from that in the pump control method file. Because of the incorrect input in tubing size, the PACl dosages were not accurate. The Spring 2015 research derived correction factors that would make the previous date usable. Then experiments were conducted in the SWaT system to finish verifying Karen Swetland’s results. Future works includes experiments to determine if there is an optimal floc size which is small enough to combine with small clay particles yet large enough to be separated in the sedimentation tank. Also, future teams should study how dissolved organic matter (DOM) affects the performance of the flocculator and sedimentation tank. These findings will improve the performance of the flocculator and make it more effective for use in water supply.

Floc Size and Count App - Spring 2016

Christian Rodriguez, Anthony Verghese, Deniz Yilmazer

Abstract:

Turbidity measurements provide the primary source of performance monitoring at many water treatment plants. However, turbidity readings of floc suspensions do not provide any insight into the performance of subsequent treatment processes. The Floc Size and Count App team’s aim is to create and easy-to-use personal computer application that could measure floc size distribution using a digital camera with appropriate magnification. The app will be written in LabVIEW. The aim for this semester is to develop coding expertise in the LabVIEW environment and start working on the app that will be used in the AguaClara labs and eventually in AguaClara drinking water treatment plants.

Floc App - Fall 2016

Christian Rodrigues, Anthony Verghese, Deniz Yilmazer

Abstract:

Turbidity measurements provide the primary source of performance monitoring at many water treatment plants. Turbidity provides an excellent way to measure overall plant performance, but it does not provide insight into why the water treatment plants are performing well or poorly. The floc size and count app team’s aim is to create and easy-to-use desktop application that would measure floc size distribution and potentially provide insight as to why a plant is performing well or not. The app will be written in LabVIEW and made available for easy use as a stand alone executable application. The aim for this semester is for the team members to finish the LabVIEW program, integrate the program with a camera system, and have other teams test the camera system and software. By the end of the semester, we hope to have a functional prototype than can be tested by other AguaClara Teams in their experiments.

Sensor Development - Spring 2017

Cheer Tsang, Luna Oiwa, Jingfei Wang

Abstract:

This semester, the Sensor Development subteam modified and recalibrated the fluidized bed solids concentration sensor. This sensor enable the High Rate Sedimentation (HRS) team to determine the concentration of suspended clay particles in a running flocculation recirculator. In addition, the team fabricated a submersible sensor to determine the depth and concentration of the sludge layer in a sedimentation tank. This sensor functions in the same way as the fluidized bed solids concentration sensor, with the added characteristic that the photometer is fixed to the end of a PVC tube.

High G Flocculation - Fall 2017

Roswell Lo, Tanvi Naidu, Luna Oiwa

Abstract:

The High G Flocculation team this semester designed an experimental set-up to test the effects of velocity gradient (G) in a flocculator and to determine the optimal G value based on flocculator performance in terms of effluent turbidity. The G value was varied in different trials by varying flocculator flow rate while controlling for coagulant dosage, influent turbidity, flocculation tube length, and upflow velocity through the sedimentation tank. G_theta was kept constant as around 20,000. The constant sedimentation tank upflow velocity was achieved using a waste stream between the flocculator outlet and sedimentation tank. It was found that for a standard coagulant dose, lower G values were associated with lower effluent turbidity, with 100 Hz being the lowest value tested. The same general relationship was observed for a higher coagulant dose, except that the lowest G values resulted in higher effluent turbidity due to floc blanket collapse. Data from this study will be used in the future to inform the geometry of the flocculator, i.e. the optimal distance between baffles in a full-scale water treatment plant.

Sensor Development - Fall 2017

Grace Zhang, Lois Lee, Srilekha Vangavolu

Abstract:

The Fall 2017 Sensor Development team worked on redesigning and calibrating the fluidized bed solids detector to be used for testing concentration of suspended particles in floc blankets as well as the submersible sensor designed to measure the height of the sludge blanket in the sedimentation tank.

Please note, no research report could be located for this team and the final presentation is linked instead

Sensor Development - Fall 2018

Dana Owens, Lawrence Li, Lois Lee

Abstract:

The objective of the Sensor Development subteam is to develop sensors to monitor water quality during the water treatment process in Aguaclara plants. In previous semesters, the subteam developed a working prototype for an in-lab fluidized bed solids detector and also made progress towards prototyping a submersible sludge blanket detector. This semester the subteam also worked on finalizing a product-level version of the in-lab fluidized bed solids detector with a more intuitive user interface.The subteam will also work on finishing and determining the best prototype for the sludge blanket detector.

Sensor Development - Spring 2019

Lois Lee, Lawrence Li, Srilekha Vangavolu, Sonu Kapoor

Abstract:

The Sensor Development subteam’s goal is to develop low-cost sensors with readily available materials to monitor and report water quality in the water treatment processes in AguaClara plants and labs. In Spring 2019, the subteam worked on four different projects. The subteam started developing a calibration curve for the Fluidized Bed Solids Detector that was fabricated in the previous semester, and also prototyped a Sludge Blanket Detector for the upcoming Honduras trip. Additionally, the subteam began developing the Mobile Application-Processed Endoscope. The subteam also started designing a low-cost turbidimeter that would measure both the transmittance and absorbance of light.

Sensor Development - Fall 2019

Sonu Kapoor, Saul Bernaber, Rishik Zaparde

Abstract:

Sensor Development's goal is to develop affordable sensors with readily available materials to monitor and report water quality in the water treatment processes in AguaClara plants and labs. In Fall 2019, the subteam worked on two different projects that were slight modifications from the previous semester. The subteam worked on a second prototype of the submersible Sludge Blanket Detector. Additionally, the subteam also started designing a low-cost turbidimeter that would measure the amount of dissolved organics as well as turbidity.

Sensor Development - Spring 2020

Sonu Kapoor, Saul Bernaber, Rishik Zaparde

Abstract:

Sensor Development's goal is to develop affordable sensors with readily available materials to monitor and report water quality in the water treatment processes in AguaClara plants and labs. In Spring 2020, the subteam tested two projects from Fall 2019 - the Submersible Sludge Blanket Detector, which is meant for the floc hopper, and the low-cost turbidimeter to measure dissolved organics.