Presentations by American Water Chemicals, Inc.
Matches: 23
A Direct Relationship between Calcium Phosphate and Silica Fouling in Wastewater RO Systems
This paper attempts to identify the cause of silica polymerization during formation of calcium phosphate scales at elevated pH, and investigates methods to inhibit this co?precipitation even when ferric ions are present in the feedwater of wastewater RO systems....
Water Chemistry
This paper details the requirement to understand the water quality characteristic of the feed and the filtrate requirement. It talks to the addition of pretreatment chemistry to prevent scaling and fouling without adversely impacting product water quality....
Chemicals for Pretreatment in Texas
This PowerPoint reviews chemical treatment options for Membrane treatment plants with an emphasis on opportunities in Texas....
Optimizing Removal of Scalants and Foulants during Membrane Cleaning
This presentation includes an overview of RO membrane fouling and scaling. It discusses biological, particulate, and inorganic fouling mechanisms and the chemistry driving scaling, antiscalant performance, and membrane cleaning. Complex interactions are discussed, including calcium bridging, chelating, and surfactant behavior....
An Evaluation of Corrosion Control Additives for Potable RO Permeate
Corrosion coupon studies were performed on the finished water of various plants on the East Coast of Florida. Of those plants, three produced finished water consisting of Reverse Osmosis (RO) permeate blended with filtered feedwater, one plant blended RO permeate with lime softened water, and one plant produced only lime softened water. The purpos...
Aluminum Silicate Formation in Membrane Separation Processes: Facts vs. Myths
This paper investigates the types of silica fouling that would occur in the presence of aluminum carryover from coagulant dosing and evaluates multiple types of antiscalants to determine if such fouling can be prevented....
Water Chemistry and Pretreatment Chemicals
This presentation from a preconference workshop in 2014 for Back to Basics on membrane technology discusses pretreatment chemistry for microfiltration, ultrafiltration, nanofiltration and reverse osmosis. Water chemistry is presented and it's influence on the membrane treatment methods....
Case Study: The Impact of Ferrous Ion Oxidation on Silica Scaling In RO Systems
A 6 MGD reverse osmosis plant in South Texas that was using chlorine to oxidize arsenic for improved membrane rejection was experiencing severe membrane fouling. The ferrous ions in the well water were being oxidized by the chlorine, resulting in ferric hydroxide fouling of the cartridge filters and membranes throughout the system. Despite numerous...
Membrane Pretreatment Chemistry
Provdes a detailed overview of membrane pretreatment chemistry design considerations. Includes sections on coagulation and antiscale chemistry....
Development and Application of a Highly Reliable Silica Scaling Prediction Model for Use in Industrial Reuse RO/NF Applications with Complex Feed Waters
This paper describes a new silica scale prediction model and emphasizes the importance of considering cation species and concentrations in any membrane scaling projection. Two case studies are presented, each of which had been used to validate the new silica scaling model and the silica kinetics index....
Validation of an Arsenic Rejection Model for RO/NF Membranes
This paper describes the development and validation of arsenic rejection computer using reverse osmosis ( RO) and/or nanofiltration(NF)....
Predicting Antiscalant Dosages in RO/NF Feedwater With High Ferric Iron Concentrations
This paper discusses certain aspects of iron behavior, the developed computer model, and its application and validation using a pilot system at the Florida RO plant. Speciating the hydrolysis states of ferric iron with respect to pH, ionic strength, and temperature, is essential to predicting the concentration factor as well as the scaling potentia...
Improved Chemicals for Higher Recovery Rates
Innovations in antiscalant technology have allowed for improved scale control under more severe conditions. This presentation discusses the application of a high performance antiscalant for calcium carboante inhibition at a plant in South Florida....
Understanding the Chemistry Behind Membrane Cleaning
This presentation discusses different cleaning chemicals and techniques. It explains the chemistry of membrane cleaning, and how chemicals interact with different foulants under different conditions....
A Novel Calcium Carbonate Scaling Model for Calculating Maximum Recovery and Inhibitor Dosages in Industrial RO Applications
The purpose of this work was to identify a method for determining maximum recoveries in RO systems where calcium carbonate was a concern, and to find a reliable method for antiscalant dosage prediction....
The Use of Chlorine Dioxide as a RO Membrane Cleaning Aid for Natural and Synthetic Organic Foulants
This paper attempts to identify the mechanisms by which chlorine dioxide aided in foulant removal, and to verify the tolerance of polyamide membranes to ClO2 as a cleaning aid....
Permeate Quality and Energy Efficiency Through Membrane Selection
This presentation review the relationship between membrane properties including Surface area and flux and permeability. Salt rejection of various elements and testing procedures is reviewed as is the rejection of non-ionized molecules. Comparing membrane specification sheets is discussed and some recommendations on improving membrane operations is ...
Case Study: Mitigating Severe Organic Fouling in a Brackish Groundwater Reverse Osmosis System
The Torrance Desalter could not be commissioned after a two year expansion because of increases in interstage feed pressure to the 2nd stage. The initial assumption was that scaling was occurring. However, an autopsy and cleaning study determined that the foulant was entirely organic in nature. The approach was to mitigate the problem by resolving ...
Membrane Performance
How to obtain membrane performance data, how to collect, trend and understand the data and how to maintain performance...
Developing and Implementing a Membrane Cleaning Procedure
My RO is producing water, when do I need to clean? How do I clean? This presentation will address the when and how of RO membrane cleaning. We will define the key indicators of when it is time to clean. We will outline the basic procedure to follow to return the membranes to normalized productivity....
The Perils of Using Chloramines for Pretreatment of Water Reuse RO
The use of chloramines has become a standard pretreatment method for biofouling control in water reuse RO. When used in the 2 - 3 ppm range, chloramines have been known to cause only minimal losses in salt rejection, and the benefits are generally believed to far outweigh the risks. However, in recent years, significant irreversible declines in per...
The Perils of Using Chloramines for Pretreatment of Water Reuse RO
The use of chloramines has become a standard pretreatment method for biofouling control in water reuse RO. When used in the 2 - 3 ppm range, chloramines have been known to cause only minimal losses in salt rejection, and the benefits are generally believed to far outweigh the risks. However, in recent years, significant irreversible declines in per...
Effective Membrane Cleaning Tips, Tricks & Procedures
Effective Membrane Cleaning Tips, Tricks & Procedures to optimize membrane system performance and reduce OPEX. - Membrane Cleaning Economics - Membrane Cleaning Basics and Variables - Cleaner Selection & Procedures...