Papers by Christopher Bellona
Environmental Progress, 2005
The rejection of emerging organic micropollutants is an important issue where sources impaired by... more The rejection of emerging organic micropollutants is an important issue where sources impaired by wastewater discharge are used to augment drinking water supplies. Because previous findings from bench-and laboratory-scale membrane experiments indicated that nanofiltration and to a lesser extent reverse osmosis (RO) membranes can incompletely reject organic micropollutants, this study investigated the efficiency of reverse osmosis membranes in rejecting these compounds at conditions simulating full-scale installations. Compounds investigated were classified by their physicochemical properties. Rejection of solutes was studied using a two-stage laboratory membrane skid and two full-scale RO trains. Full-scale studies did not reveal any quantifiable detects of any target compound, except for low concentrations of caffeine in permeate samples of the second and third stages of one facility. In general, hydrophilic ionic compounds were efficiently removed by steric and electrostatic exclusion. Although there was no evidence that hydrophobic solutes such as steroid hormones partition into permeates, the rejection of chloroform at one facility was rather poor, confirming findings from laboratory-scale experiments. Findings suggest that fouling layers present on membranes in full-scale installations result in an improved rejection of hydrophilic nonionic and especially hydrophobic solutes.
Journal of hazardous materials, Jan 29, 2016
A novel electrical discharge plasma reactor configuration with and without iron ions was evaluate... more A novel electrical discharge plasma reactor configuration with and without iron ions was evaluated for the degradation of 0.02mM Bisphenol A (BPA). The pseudo-first-order reaction rate constant calculated for the plasma treatment of BPA with a stainless steel electrode in the presence of dissolved ferrous ion (Fe(2+)) salts (termed plasma/Fenton treatment) was higher than in the plasma treatment in the absence of iron salts. At the optimal ferrous ion concentration, longer plasma treatment times resulted in higher BPA degradation rates, likely due to increased hydroxyl (OH) radical concentration formed through the decomposition of H2O2. Replacing the stainless steel with a carbon steel grounded electrode resulted in the release of iron ions from the carbon steel thereby increasing the rate of BPA removal and eliminating the need for iron salts. After the plasma/Fenton treatment, >97% of the residual iron salts were removed by coagulation/flocculation/sedimentation. Byproduct iden...
Environmental Science Technology, Aug 12, 2011
Journal of Membrane Science, May 1, 2010
This study investigated membrane fouling during wastewater reclamation by collecting operational ... more This study investigated membrane fouling during wastewater reclamation by collecting operational performance data and employing state-of-the-art techniques for characterization of membrane foulants. Utilizing a pilot-scale membrane unit, two nanofiltration membranes (NF-90 and NF-4040, Dow/Filmtec) and one low-pressure reverse osmosis membrane (TMG10, Toray America) were tested at two wastewater reclamation facilities treating microfiltered non-nitrified secondary effluent and nitrified/denitrified tertiary effluent. The membranes and foulants were characterized by environmental scanning electron microscopy coupled with energy dispersive spectroscopy, attenuated total reflection-Fourier transform infrared spectrometry, zeta-potential measurement, atomic force microscopy, phospholipids analysis, and contact angle measurement.
This study investigated the use of ultra-low-pressure reverse osmosis (ULPRO) and nanofiltration ... more This study investigated the use of ultra-low-pressure reverse osmosis (ULPRO) and nanofiltration (NF) membranes for water reuse applications where lower operating pressures and a high permeate quality are desired. A laboratory-scale investigation was performed to compare the rejection and operational performance of RO, ULPRO, and NF membranes and to select two membranes for testing at a California water facility. A ULPRO membrane and an NF membrane were then tested at pilot and full scale at a water recycling plant and monitored for operational performance and rejection of total organic carbon, total nitrogen, and regulated and unregulated organic micropollutants. Pilot-and full-scale testing of the best-performing membranes demonstrated that both ULPRO and NF membranes could be used to meet potable water quality requirements. The presumed advantage of using ULPRO and NF membranes diminished as fouling occurred, resulting in operating pressures only slightly lower than or similar to those found for traditional RO membranes.
To improve the feasibility of plasma-based water treatment technology and asses the possibility o... more To improve the feasibility of plasma-based water treatment technology and asses the possibility of the technology scale up, a study was conducted to identify and characterize the design parameters that influence treatment effectiveness and the physical phenomena that determine treatment efficiency. The effect of several reactor design parameters, broadly grouped into three categories, on the degradation of 5 mg/L Bisphenol A (BPA) and 5 mg/L Rhodamine B (RhB) was investigated. These parameters include: (1) reactor geometry (e.g., electrode material and shape, electrode spacing, reactor diameter, and ground electrode plate area), (2) electrode configuration, and (3) contact between plasma and the treated solution. Results indicate that changing the reactor geometry, particularly minimizing the distance between the high voltage electrode and the grounded electrode, increasing the reactor radius, and increasing the area of the grounded electrode plate increase the peak current (i.e., i...
To improve the feasibility of plasma-based water treatment technology, a study was conducted to i... more To improve the feasibility of plasma-based water treatment technology, a study was conducted to identify and characterize the design parameters that influence treatment effectiveness and the physical phenomena that determine treatment efficiency. A compound’s octanol-water partition coefficient (i.e., hydrophobicity) has been determined as the major factor that influences the compounds’ relative ability to diffuse into the plasma channel. Experiments conducted with nine different solutes have shown that hydrophilic compounds tend to stay in the bulk liquid whereas hydrophobic compounds such as Bisphenol A (BPA) readily diffuse into the plasma channel where they react with OH and other radicals. Thus the electrical discharge as an advanced oxidation technology appears to be the most effective for the degradation of compounds with limited solubility in water. The effects of several reactor design parameters were investigated, including electrode geometry, electrode spacing, reactor ge...
Chemical Engineering Journal, 2015
ACS Symposium Series, 2010
IDA Journal of Desalination and Water Reuse, 2011
ABSTRACT This article summarizes work recently completed and funded by the WateReuse Research Fou... more ABSTRACT This article summarizes work recently completed and funded by the WateReuse Research Foundation—Predictive Models to Aid in the Design of Membrane Systems for Organic Micropollutant Removal. The project's goal was to develop a model to predict organic contaminant removal during water reuse applications employing high-pressure membranes. Various modeling approaches were evaluated, including a phenomenological model, hydrodynamic model, Donnan steric-pore model, solution-diffusion model, surface force pore model, and quantitative structure property relationship models. In bench-scale experiments, approximately 110 organic compounds and two membranes (one reverse osmosis membrane and one nanofiltration membrane) were used to develop a robust dataset for model development and validation. Modeling approaches developed using bench-scale experimental data were incorporated into mass balance models to describe rejection performance for pilot- and full-scale membrane systems. Developed modeling approaches were subsequently validated using rejection data generated through pilot-scale testing and full-scale sampling campaigns performed at water reuse facilities.
Journal of Cleaner Production, 2015
ABSTRACT Desalination of unconventional water resources is becoming increasingly common for the a... more ABSTRACT Desalination of unconventional water resources is becoming increasingly common for the augmentation of drinking water supplies. Desalination is energy and cost intensive, and concentrate disposal is a significant issue that impedes desalination in many regions of the globe. One possible approach to decrease desalination costs while alleviating concentrate disposal issues is through the extraction of valuable commodities. While past researchers have evaluated the technical feasibility of extracting minerals from both seawater and, to a lesser extent, desalination concentrate, the feasibility of commodity extraction is dependent upon technical, energy, and cost considerations, as well as, market fluctuations of the minerals extracted. Most of the available literature has focused on technical processes used to extract minerals and has not evaluated the feasibility of extraction considering the aforementioned concerns. For this study, the feasibility of material extraction from seawater and desalination concentrate was investigated through three steps: 1) screening for potentially profitable compounds; 2) reviewing literature on extraction methods and market fluctuations for these compounds; and 3) assessing the costs of extracting these compounds. Although the extraction of various compounds from desalination concentrate is technically viable, based on the literature review and the primarily cost analysis, the extraction of the majority would not be profitable considering the current market and available technologies. The results from this study suggest that while the extraction of commodities of sodium, chlorine, potassium, and magnesium from desalination concentrate could be profitable, the feasibility of extraction is highly dependent on commodity pricing and final product purity. Due to the marginally attractive economics of extraction and significant uncertainties associated with producing commodities, this study suggests that extraction from desalination concentrate is unlikely to significantly improve the economics of desalination unless concentrate disposal costs were significantly reduced as a result.
Separation and Purification Technology, 2010
The occurrence of trace organic contaminants in drinking water supplies, wastewater effluents and... more The occurrence of trace organic contaminants in drinking water supplies, wastewater effluents and the environment is amplifying interest in membrane treatment methods due to the removal of a wide variety of organic solutes. During operation, organic matter present in source water accumulates at a membrane's surface. This fouling layer could potentially influence the degree of removal of dissolved constituents including organic contaminants of concern. The purpose of this study was to investigate the effect of organic matter fouling on membrane characteristics and the rejection of non-ionic organic solutes.
Proceedings of the Water Environment Federation, 2005
The scope of this project was to determine if low pressure membranes such as nanofiltration (NF) ... more The scope of this project was to determine if low pressure membranes such as nanofiltration (NF) and ultra-low pressure reverse osmosis (ULPRO) membranes can meet water quality requirements necessary for indirect potable reuse while meeting acceptable operational parameters such as feed pressure, permeate flux, and flux decline. A total of 12 NF and ULPRO membranes were screened in this study and one ULPRO and one NF membrane were selected for a pilot-scale assessment (19 gpm) at a water reuse facility. Results of this study suggest that ULPRO and NF membranes can achieve similar removal efficiencies for the selected trace organics, nitrogen and bulk parameters tested as commonly employed RO membranes. While providing a similar water quality, these membranes can be operated at significantly lower feed pressures. These results suggest that ULPRO and NF membranes are viable for water reuse projects where a high permeate quality is required.
Water Science & Technology, 2015
Nanofiltration (NF) is a relatively recent development in membrane technology with characteristic... more Nanofiltration (NF) is a relatively recent development in membrane technology with characteristics that fall between ultrafiltration and reverse osmosis (RO). While RO membranes dominate the seawater desalination industry, NF is employed in a variety of water and wastewater treatment and industrial applications for the selective removal of ions and organic substances, as well as certain niche seawater desalination applications. The purpose of this study was to review the application of NF membranes in the water and wastewater industry including water softening and color removal, industrial wastewater treatment, water reuse, and desalination. Basic economic analyses were also performed to compare the profitability of using NF membranes over alternative processes. Although any detailed cost estimation is hampered by some uncertainty (e.g. applicability of estimation methods to large-scale systems, labor costs in different areas of the world), NF was found to be a cost-effective technology for certain investigated applications. The selection of NF over other treatment technologies, however, is dependent on several factors including pretreatment requirements, influent water quality, treatment facility capacity, and treatment goals.
ABSTRACT Organic and inorganic micropollutants are rejected by high-pressure membranes, nanofiltr... more ABSTRACT Organic and inorganic micropollutants are rejected by high-pressure membranes, nanofiltration (NF) and reverse osmosis (RO), primarily as a consequence of solute-membrane interactions. These interactions include steric and electrostatic effects that depend on compound properties (e.g., molecular weight (MW) and ionic charge) and membrane properties (e.g., molecular weight cutoff (MWCO) and surface charge (zeta potential)), with the added influence of membrane operating conditions (e.g., recovery). This paper summarizes the rejection trends by several NF and RO membranes for a wide range of organic micropollutants based on hydrophobicity/hydrophilicity (octanol-water partition coefficient, KOW) and charge (neutral or negative), and a more narrow range of inorganic micropollutants in the form of oxyanions (chromate, arsenate and perchlorate) of varying MW and charge. While RO provided greater rejections of micropollutants than NF, observed NF rejections were, in many cases, significant. For oxyanions, rejection was mainly influenced by ionic charge and MW. RO properties generally had little influence while MWCO and zeta potential were both significantly influential for NF. For organic micropollutants, with exception of RO versus NF classifications, membrane properties were less influential than compound properties with greater rejections generally observed with increasing MW, KOw. and (negative) charge.
Environmental Progress, 2005
The rejection of emerging organic micropollutants is an important issue where sources impaired by... more The rejection of emerging organic micropollutants is an important issue where sources impaired by wastewater discharge are used to augment drinking water supplies. Because previous findings from bench-and laboratory-scale membrane experiments indicated that nanofiltration and to a lesser extent reverse osmosis (RO) membranes can incompletely reject organic micropollutants, this study investigated the efficiency of reverse osmosis membranes in rejecting these compounds at conditions simulating full-scale installations. Compounds investigated were classified by their physicochemical properties. Rejection of solutes was studied using a two-stage laboratory membrane skid and two full-scale RO trains. Full-scale studies did not reveal any quantifiable detects of any target compound, except for low concentrations of caffeine in permeate samples of the second and third stages of one facility. In general, hydrophilic ionic compounds were efficiently removed by steric and electrostatic exclusion. Although there was no evidence that hydrophobic solutes such as steroid hormones partition into permeates, the rejection of chloroform at one facility was rather poor, confirming findings from laboratory-scale experiments. Findings suggest that fouling layers present on membranes in full-scale installations result in an improved rejection of hydrophilic nonionic and especially hydrophobic solutes.
Water Science & Technology: Water Supply, 2006
ABSTRACT There has been considerable information reported on rejection of trace organic compounds... more ABSTRACT There has been considerable information reported on rejection of trace organic compounds from pilot-scale and full-scale experiments with reverse osmosis (RO) and nanofiltration (NF), but this information has limited value in predicting the rejection of these compounds by high-pressure membranes. The goal of this research is to define relationships between compound properties, membrane properties, and operational conditions, e.g. pressure, recovery, affecting trace organic compound rejection, comparing bench-scale recirculation tests and bench-scale single-pass tests. In addition, bench-scale results are compared against single element tests to ascertain scale-up effects.
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Papers by Christopher Bellona