The City of Springfield, Missouri was recently recognized with a Peak Performance Award by the National Association of Clean Water Agencies (NACWA). The award was given to Springfield's Northwest Clean Water Plant (CWP) in recognition of five years of complete and consistent compliance of their treated effluent discharge permit.
In a world where high-quality water resources are becoming increasingly scarce, developing safe new measures for keeping up with soaring water demand is of paramount importance. One such option is to recycle water by treating wastewater to a standard that is suitable for drinking, a practice known as potable reuse. Several categories of potable reuse can be defined, including direct potable reuse, indirect potable reuse, and de facto potable reuse. De facto potable reuse represents the most common of the three forms.
Steinle-Darling, E. "The Many Faces of DPR in Texas."JAWWA, Vol 107, No. 3, March 2015.
Most water resource recovery facilities (WRRFs) using biological nutrient removal (BNR) processes are required by permit to reduce significantly the total nitrogen (TN) and total phosphorus (TP) concentrations discharged in reclaimed water.
Consistently meeting low permit limits for nutrients can sometimes challenge even the most experienced facility personnel. Optimizing TN and TP removal requires an understanding of the chemical species of each nutrient, their expected concentrations throughout the process, the basic concepts of the processes designed to reduce them, and the interaction of components within the treatment facility. Having knowledge of process controls, and understanding how to apply them to daily facility operations, is essential for achieving low concentrations of nutrients — and doing so consistently.
Stone, E., Walker, S., Reardon, R., and Pretorius, C. "Nutrient Removal Remedies: Troubleshooting BNR Processes Requires a Holistic Review."WE&T Water Environment and Technology, Volume 27, Number 4, pp: 42, 2015.
The treatment of oil and gas (O&G) exploration wastewaters by forward osmosis (FO) could make water management in the O&G industry more sustainable. Specifically, recovery of pit water from well drilling operations and hydraulic fracturing could reduce the impacts associated with wastewater transportation, deep well disposal, and fresh water procurement for subsequent hydraulic fracturing operations. This study evaluates the environmental and economic impacts of FO for treatment of O&G pit water through comparative life cycle impact and costing assessments; the FO technology is evaluated when operated as an engineered osmosis system and as a stand-alone osmotic dilution process. Cradle-to-grave life cycle inventories are developed for each FO process and evaluated using ten environmental impact categories. The relative environmental impacts of FO are found to be comparable to the transportation and pumping energy alone required for deep well injection. At the current state of the technology, the energy demand of the FO systems when operated with no upstream pretreatment is the single greatest contributor to the negative environmental impacts. At 75% water recovery, FO can potentially reduce pit water management costs by nearly 60% compared to deep well disposal, and pit water transportation requirements can be reduced as much as 63%.
Coday, B. D., Miller-Robbie, L., Beaudry, E. G., Munakata-Marr, J., and Cath, T. Y. "Life cycle and Economic Assessments of Engineered Osmosis and Osmotic Dilution for Desalination of Haynesville Shale Pit Water."Desalination, 369, pp:188-200, 2015.
Water treatment technologies that employ sustainable driving forces for treatment of high ionic strength, complex feed streams and have the capacity to separate a broad range of contaminants are needed for economical treatment of flowback and produced waters in the oil and gas industry. This is especially true given the surging interest in treatment of oil and gas wastewaters for reuse in hydraulic fracturing or discharge to the environment in lieu of deep well injection. Forward osmosis is a robust membrane separation technology that can provide superior rejection of a broad range of feed stream contaminants and dissolved ions, thus providing a brine stream suitable for reuse in hydraulic fracturing or excellent pretreatment for downstream desalination processes. In this work, the impacts of membrane selection (asymmetric cellulose triacetate versus polyamide thin-film composite) and system operating conditions on the performance of FO membranes for desalination of produced water for the Niobrara shale formation are investigated. Specifically, water flux, contaminant rejection, membrane fouling, and chemical cleaning were evaluated using a combination of standard methodology and operating conditions analogous to those employed when operating industrial spiral wound FO membrane modules. Membrane autopsy was conducted to determine what effect(s) membrane physiochemical properties might have on system performance and to interpret the potential molecular level interactions occurring near the membrane-feed stream interface. Results from this study indicate that FO can achieve high rejection of organic and inorganic contaminants, membrane fouling can be mitigated with chemical cleaning, and long-term FO system performance might be better controlled with optimized hydrodynamic conditions near the membrane surface (i.e., feed flow velocity, module design, membrane packing) and not by membrane selection.
Coday, B. D., Almaraz, N., and Cath, T. Y. "Forward Osmosis Desalination of Oil and Gas Wastewater: Impacts of Membrane Selection and Operating Conditions on Process Performance."Journal of Membrane Science, 488, pp: 40-55, 2015.
As the first step in the regulatory development process, the US Environmental Protection Agency (USEPA) is required by the Safe Drinking Water Act to publish a list of contaminants known as the Drinking Water Contaminant Candidate List (CCL) every five years. The purpose of the CCL is to provide the requisite information needed for subsequent regulatory decisions (regulatory determinations). This article briefly describes the purpose and approach of the contaminant identification research and its results.
Robertson, A., Adams, C., Bench, R., and Rosen, J.S. "Development of Recommendations for the Fourth Contaminant Candidate List."Journal of the American Water Works Association. 107 (10), pp: 76, 2015.
Prolonged drought conditions in California have brought about unprecedented reforms in both statewide and regional policies on water usage, including a recent Executive Order which mandates a statewide 25 reduction in water usage. Additionally, $7.12billion will be authorized for state water supply infrastructure projects. As a result, stormwater is being identified more than ever as a valuable water resource, overcoming its long-hold stigma as wastewater that runs down sidewalks, roads and driveways before entering the storm drains and flowing in to the river. This article describes groundbreaking projects underway in partnership with the City of Los Angeles, the City of Oxnard, and local agencies, and shows how managing urban storm is showering benefits in this area.
Rammohan, P., and West T. "Urban Stormwater: New Water Supply for Drought-Stricken California."World Water. Vol 38(5), pp: 14-15, 2015.
Many unwanted constituents can be found in groundwater, No silver bullet exists that can solve all groundwater treatment challenges. This article presents five strategies that can be used to determine economical and effective groundwater treatment options.
Each option is explained in detail in this article.
He, Charlie. "Take a Holistic Approach to Groundwater Treatment."American Water Works Association Opflow. Vol. 41 No. 11, pp: 22-25, 2015.
At a 2013 AWWA Symposium on biological treatment of drinking water, presentations covered a full spectrum of topics. Speakers outlined different processes, dispelled misconceptions, introduced new research, and summarized the regulatory aspect of biotreatment. This article provides a summary of those presentations.
Brown, J., Summers, R. S., LeChevallier, M., Collins, H., Roberson, J. A., Hubbs, S., Dickenson, E. "Biological Drinking Water Treatment? Naturally."Journal of the American Water Works Association. 107(12), pp: 20-30, December 2015.
Nanoparticles (NPs) are becoming prevalent in consumer goods, including foods and cosmetics. Understanding the interactions between NPs and bacteria in an engineered model colon can indicate potential impacts of NP exposure on the gut, and therefore overall human health. Human microbiome health has important implications to overall individual health. This work aims at quantifying the phenotypic response to NP ingestion of a model microbial community within a model colon. Three NPs at environmentally relevant concentrations (0.01 lg/L ZnO, 0.01 lg/L CeO2, and 3mg/L TiO2) were individually introduced into a model colon to identify the subsequent impact on the gut microbial community. Results indicate that NPs cause the microbial community's phenotype to partition into three distinct phases: initial conditions, a transition period, and a homeostatic phase, with the NP-exposed community displaying significant differences ( p < 0.05) from the unexposed community in multiple phenotypic traits. Notably, phenotypes, including short-chain fatty acid (SCFA) production, hydrophobicity, sugar content of the extracellular polymeric substance, and electrophoretic mobility, which indicate changes in the community's stability, were affected by the NPs. TiO2 NPs led to extended phenotypic transformations for hydrophobicity when compared with the other NPs, likely due to its lack of dissociation and greater stability. Overall, the NPs caused nonlethal, significant changes to the microbial community's phenotype, which may be related to overall health effects.
Taylor, A., Marcus, I. M., Guysi, R. L., and Walker S. L. " Metal Oxide Nanoparticles Induce Minimal Phenotypic Changes in a Model Colon Gut Microbiota."Environmental Engineering Science. July 2015, 32(7) pp: 602-612, 2015.
This study evaluated the feasibility of replacing acetic acid with a commercial carbohydrate-based electron donor (CBED) for removal of nitrate and perchlorate (ClO4-) from drinking water. Bench-scale biologically active carbon fixed-bed and fluidized-bed reactors (FXBR and FLBR, respectively), with an initial empty bed contact time (EBCT) of 42.8 min, were fed simulated groundwater containing 15 mg/L nitrate as nitrogen and 200 µg/L ClO4-. EBCT in the FLBR after final expansion was 80.5 min. During the first 100 days using acetic acid at 125 mg/L chemical oxygen demand (COD), complete nitrate removal was achieved in both systems, whereas perchlorate in the FXBR and FLBR effluents remained below 3 and 6 µg/L ClO4-, respectively. For comparable removals, influent COD requirement was higher with the CBED. Biomass yields with acetic acid and the CBED were 0.54 to 0.58 and 0.59 to 0.74 mg CODbiomass/mg CODsubstrate, respectively. The higher yield with the CBED resulted in more frequent maintenance requirements.
Upadhyaya, G., Kotlarz, N., Togna, P., Raskin, L., "Carbohydrate-Based Electron Donor for Biological Nitrate and Perchlorate Removal From Drinking Water." Journal of the American Water Works Association. 107 (12), pp: E674-E684, December 2015.
Walnut Creek, Calif. – Carollo Engineers has recently been selected as winner of the American Public Works Association’s Public Works Project of the Year Award for Small Cities/Rural Communities. The West Sacramento Bridge District Water Storage and Park Project (The Project) was recognized for its innovative approach to structures – which includes municipal facilities, parks, and more.
Walnut Creek, Calif.–Carollo Engineers is proud to announce it is now ranked as the largest Consulting Engineering/Design firm in the country focused exclusively on water projects.
Walnut Creek, Calif.– Carollo Engineers is pleased to announce that Susan Gilbert has joined the firm as a Senior Vice President. Susan will assist with implementing Carollo’s strategic plan, working with clients across the country to implement, procure and execute solutions to their water needs.
Walnut Creek, Calif.– The American Public Works Association’s Oregon Chapter has recently selected the City of Gresham as winner of the Public Works Project of the Year Award in the Environmental category (including Water, Wastewater, and Stormwater). The Gresham Wastewater Treatment Plant (WWTP) was recognized for its Cogeneration (Cogen) Expansion Project – which allowed the plant to go energy net zero. Carollo Engineers served as the primary consultant on the project.
The application of semipermeable membranes for dewatering of complex oil and gas wastewaters continues to be a topic of increasing interest. Several studies have explored the fouling propensity and contaminant rejection of osmotically driven membranes during forward osmosis (FO) treatment of produced waters; however, none have investigated changes in membrane transport and physiochemical properties after exposure to these feed streams. In this study we discuss the impacts of produced water exposure on the transport and active layer surface properties of cellulose triacetate (CTA) and polyamide thin-film composite (TFC) FO membranes. While produced water exposure yields some, albeit minor changes to the membrane performance and surface characteristics of the CTA and the traditional TFC membranes, close to 50% reduction in reverse salt flux and contaminant transport was observed for a surface-modified TFC FO membrane; only minimal changes in water permeability were recorded. Results of this study demonstrate the chemical and physical robustness of FO membranes for treatment of oil and gas wastewaters, and they highlight a knowledge gap that exists in membrane polymer selection and contaminant interactions with the membrane polymer matrix that should be further addressed in future membrane fouling studies.
Coday, B. D., Hoppe-Jones, C., Wandera, D., Shethji, J., Herron, J., Lampi, K., . and Cath, T. Y. "Evaluation of the Transport Parameters and Physiochemical Properties of Forward Osmosis Membranes after Treatment of Produced Water."Journal of Membrane Science, 499, pp: 491-502, 2016.
If you’re interested in advances in water technology (and who isn’t?), you’ll want to catch Carollo’s desalination expert Tom Seacord’s upcoming webcast, called “Guidelines for the Use of Stainless Steel in the Water and Desalination Industries.”
The webcast will take place on Tuesday, February 23 from 3‒4 pm ET
Bookmark this link, and watch this space for further registration information.
Metals Accumulation and Release Within the Distribution System: Evaluation of Mechanisms and Mitigation
Developed in conjunction with the International Ultraviolet Association, this is a guide for consultants, wastewater utilities, and operators that provides introductory information on the advantages—and disadvantages—of UV disinfection compared to other commonly used technologies.
Using specific case studies to illustrate concepts, UV Disinfection for Wastewater fills a gap in the design guidance that is available for UV disinfection for low-dose applications, including disinfection of secondary and tertiary wastewater effluent discharges to meet NPDES compliance Chapter 5, Process Design and System Sizing, discusses all of the factors that affect UV system sizing. These factors include permit requirements, wastewater quality, upstream processes, reactor selection criteria, and dose control strategies. A UV system sizing example is also provided.
Salveson, A., Bourgeous, K., Fontaine, N., Noibi, N., and Sotirakos, B. “Chapter 5 – Process Design and System Sizing.” WEF Manual of Practice “Ultraviolet Disinfection for Wastewater – Low-Dose Application Guidance for Secondary and Tertiary Discharges.” Water Environment Federation, Alexandria, VA, and International Ultraviolet Association, Washington, DC, 2015.
Developed in conjunction with the International Ultraviolet Association, this is a guide for consultants, wastewater utilities, and operators that provides introductory information on the advantages—and disadvantages—of UV disinfection compared to other commonly used technologies.
Using specific case studies to illustrate concepts, UV Disinfection for Wastewater fills a gap in the design guidance that is available for UV disinfection for low-dose applications, including disinfection of secondary and tertiary wastewater effluent discharges to meet NPDES compliance.
Chapter 3, Bioassay Methods to Determine the Ultraviolet Dose (Fluence) Delivery of an Ultraviolet System, discusses the three most prevalent biodosimetry tests (bioassays) in use for wastewater applications. It also provides a bioassay validation exemplar.
Whitby, G.E., and Sotirakos, B. "Chapter 3 – Bioassay Methods to Determine the Ultraviolet Dose (Fluence) Delivery of an Ultraviolet System." WEF Manual of Practice "Ultraviolet Disinfection for Wastewater – Low-Dose Application Guidance for Secondary and Tertiary Discharges."Water Environment Federation, Alexandria, VA, and International Ultraviolet Association, Washington, DC, 2015.
The American Society of Civil Engineers, Region 9 (representing more than 18,000 members in California) has selected Carollo’s Yazdan (Yaz) Emrani as its 2015 Outstanding Civil Engineer in the Private Sector. This award is given annually to an ASCE member who has demonstrated outstanding engineering achievement and has made significant impacts to the field of civil engineering. This impact may be through professional activities, ASCE involvement, research and innovative engineering solutions.
Yaz will be honored during the Region 9 Awards dinner on March 18, 2016 in Sacramento. We at Carollo congratulate Yaz on being selected for this prestigious award!Yaz Emrani
