scholarly journals Pilot-scale electrochemical disinfection of surface water: assessing disinfection by-product and free chlorine formation

2016 ◽  
Vol 17 (2) ◽  
pp. 526-536 ◽  
Author(s):  
Charles E. Schaefer ◽  
Graig M. Lavorgna ◽  
Todd S. Webster ◽  
Marc A. Deshusses ◽  
Christina Andaya ◽  
...  
Keyword(s):  
Surface Water ◽  
Energy Demand ◽  
Heterotrophic Bacteria ◽  
Pilot Scale ◽  
Electrochemical Treatment ◽  
Mixed Metal Oxide ◽  
Electrochemical Disinfection ◽  
Subsequent Exposure ◽  
Low Levels ◽  
Chlorine Generation

Electrochemical disinfection of surface water using mixed metal oxide anodes was evaluated in a pilot-scale demonstration. Disinfection rates, chlorine generation, energy demand, and generation of disinfection by-products were monitored over the 190-day study. Particular attention was given to the generation of trihalomethanes (THMs) and haloacetic acids (HAAs) during the electrochemical treatment cycle. In addition, the potential for generation of THMs and HAAs during post-treatment storage of the water was assessed. The electrochemical treatment system resulted in a 2- to 3-log removal of total heterotrophic bacteria, with values below detection (<1 CFU/mL) often observed. Disinfection occurred with only very low levels of observed chlorine generation (<0.1 mg/L), suggesting that alternate disinfection mechanisms likely played a significant role in the observed removal of bacteria. THM and HAA concentrations after treatment were consistently well below regulatory levels. Results also showed that electrochemical treatment significantly reduced the formation of bromoform when the water received subsequent exposure to hypochlorite. Removal of naturally occurring bromide in the water by the electrochemical system may have been the cause (in part) for this observed mitigation of bromoform formation. The formation of calcium scale on the cathode surface over time was the primary operational challenge.

scholarly journals Endogenous respiration process analysis between aMBR and UV/O3-aMBR for polluted surface water treatment

2019 ◽  
Vol 68 (8) ◽  
pp. 793-802 ◽  
Author(s):  
Lu Li ◽  
Kang Song ◽  
Chettiyappan Visvanathan
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Energy Demand ◽  
Advanced Oxidation Process ◽  
Biological Process ◽  
Heterotrophic Bacteria ◽  
Process Analysis ◽  
Endogenous Respiration ◽  
Respiration Activity ◽  
Pva Gel

Abstract The microbial endogenous respiration process is very important in biological water treatment processes. This study analyzed and compared the endogenous respiration process in an attached growth membrane bioreactor (aMBR) system and a UV/O3 integrated aMBR system (UV/O3-aMBR) in treating polluted surface water with CODMn around 10 mg/L. The endogenous respiration activity of heterotrophic microbes and autotrophic nitrifiers activity in both systems was analyzed and compared. Results show that heterotrophic bacteria and autotrophic nitrifiers enter endogenous respiration at 6 h aeration in an aMBR and 0 h in a UV/O3-aMBR system. Biomass amount on PVA-gel in aMBR was higher than in UV/O3-aMBR in terms of specific respiration rates SOURt, SOURH, and SOURA. Substrate remained on PVA-gel in the aMBR system, but no substrate remained on PVA-gel in the UV/O3-aMBR system. Higher species of microbes, including recoverable and irrecoverable components, existed in the aMBR system as compared to the UV/O3-aMBR system. The UV/O3-aMBR system could make full use of the advanced oxidation process (AOP) and biological process, leading to a higher treatment performance, and has the potential to mitigate total energy demand. Thus, the UV/O3-aMBR system can be used as a new technology for treating polluted surface water with the co-contribution of biological process and AOP treatment.

Depressed filtration ripening enhances removal of Cryptosporidium parvum

2002 ◽  
Vol 2 (3) ◽  
pp. 159-168 ◽  
Author(s):  
V. Gitis ◽  
R.C. Haught ◽  
R.M. Clark ◽  
E. Radha Krishnan
Keyword(s):  
Surface Water ◽  
Cryptosporidium Parvum ◽  
Pilot Scale ◽  
Kaolin Clay ◽  
Clay Particles ◽  
Physico Chemical ◽  
Cryptosporidium Parvum Oocysts ◽  
Granular Filtration ◽  
Electrostatic Adhesion ◽  
Innovative Concept

Pilot-scale experiments were conducted to investigate removal of Cryptosporidium parvum by contact granular filtration. The research demonstrated enhanced removal of Cryptosporidium parvum in the presence of kaolin particles. This is believed to be due electrostatic adhesion of Cryptosporidium parvum oocysts to the kaolin clay particles. The elementary physico-chemical interactions between filter granules and suspension particles will be discussed. This innovative concept was successfully implemented to reduce the ripening sequence of subsequent filtration experimental test runs by the addition of large surface area particles to slurry of kaolin and Cryptosporidium parvum in surface water.

Nanofiltration of colored surface water: Quebec's experience

2003 ◽  
Vol 3 (5-6) ◽  
pp. 15-22
Author(s):  
P. Kouadio ◽  
M. Tétrault
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Membrane Fouling ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Quebec City ◽  
Water Regulation ◽  
Eastern Canada

Three colored surface water nanofiltration pilot-scale projects were conducted in the province of Quebec (eastern Canada), between November 2000 and March 2002, by the company H2O Innovation (2000) inc., for the municipalities of Lac Bouchette, Latulipe-et-Gaboury and Charlesbourg (now part of Quebec City). Results indicated that nanofiltration permeate quality has an advance on present drinking water regulation standard in Quebec, but important membrane fouling occurred. Fouling can be controlled by pretreatment and optimization of the operating conditions.

Treatment of highly-colored surface water by a hybrid microfiltration membrane system incorporating ion-exchange

2018 ◽  
Vol 19 (3) ◽  
pp. 855-863 ◽  
Author(s):  
T. Miyoshi ◽  
Y. Takahashi ◽  
T. Suzuki ◽  
R. Nitisoravut ◽  
C. Polprasert
Keyword(s):  
Surface Water ◽  
Hybrid System ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane System ◽  
Pilot Scale ◽  
Manganese Concentration ◽  
Moderate Increase ◽  
Coagulant Dosage ◽  
Filtration System

Abstract This study investigated the performance of a hybrid membrane filtration system to produce industrial water from highly-colored surface water. The system consists of a membrane filtration process with appropriate pretreatments, including coagulation, pre-chlorination, and anion exchange (IE) process. The results of the pilot-scale experiments revealed that the hybrid system can produce treated water with color of around 5 Pt-Co, dissolved manganese concentration of no more than 0.05 mg/L, and a silt density index (SDI) of no more than 5 when sufficient coagulant and sodium hypochlorite were dosed. Although the IE process effectively reduced the color of the water, a moderate increase in the color of the IE effluent was observed when there was a significant increase in the color of the raw water. This resulted in a severe membrane fouling, which was likely to be attributed to the excess production of inorganic sludge associated with the increased coagulant dosage required to achieve sufficient reduction of color. Such severe membrane fouling can be controlled by optimising the backwashing and relaxation frequencies during the membrane filtration. These results indicate that the hybrid system proposed is a suitable technology for treating highly-colored surface water.

scholarly journals Development of an Electrochemical Process for Blackwater Disinfection in a Freestanding, Additive-Free Toilet

2017 ◽  
Author(s):  
Katelyn Sellgren ◽  
◽  
Christopher Gregory ◽  
Michael Hunt ◽  
Ashkay Raut ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Electrochemical Process ◽  
Mixed Metal Oxide ◽  
Boron Doped Diamond ◽  
High Effectiveness ◽  
Electrochemical Disinfection ◽  
E Coli ◽  
Boron Doped ◽  
Improved Sanitation ◽  
Conventional Wastewater Treatment

Electrochemical disinfection has gained interest as an alternative to conventional wastewater treatment because of its high effectiveness and environmental compatibility. Two and a half billion people currently live without improved sanitation facilities. Our research efforts are focused on developing and implementing a freestanding, additive-free toilet system that treats and recycles blackwater on site. In this study, we sought to apply electrochemical disinfection to blackwater. We compared commercially available boron-doped diamond (BDD) and mixed metal oxide (MMO) electrodes for disinfection efficiency in E. coli–inoculated model wastewater. The MMO electrodes were found to be more efficient and thus selected for further study with blackwater. The energy required for disinfection by the MMO electrodes increased with the conductivity of the medium, decreased with increased temperature, and was independent of the applied voltage. Fecal contamination considerably increased the energy required for blackwater disinfection compared to model wastewater, demonstrating the need for testing in effluents representing the conditions of the final application.

Nanocomposite hollow fiber nanofiltration membranes: Fabrication, characterization, and pilot‐scale evaluation for surface water treatment

2019 ◽  
Vol 136 (45) ◽  
pp. 48205 ◽  
Author(s):  
Gulsum Melike Urper‐Bayram ◽  
Burcu Sayinli ◽  
Reyhan Sengur‐Tasdemir ◽  
Turker Turken ◽  
Enise Pekgenc ◽  
...  
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Hollow Fiber ◽  
Pilot Scale ◽  
Nanofiltration Membranes ◽  
Scale Evaluation ◽  
Surface Water Treatment

Effect of PAC dosage in a pilot-scale PAC–MBR treating micro-polluted surface water

2014 ◽  
Vol 154 ◽  
pp. 290-296 ◽  
Author(s):  
Jingyi Hu ◽  
Ran Shang ◽  
Huiping Deng ◽  
Sebastiaan G.J. Heijman ◽  
Luuk C. Rietveld
Keyword(s):  
Surface Water ◽  
Pilot Scale

scholarly journals Synergistic Recapturing of External and Internal Phosphorus for In Situ Eutrophication Mitigation

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 2 ◽  
Author(s):  
Minmin Pan ◽  
Tao Lyu ◽  
Meiyi Zhang ◽  
Honggang Zhang ◽  
Lei Bi ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Pilot Scale ◽  
P Adsorption ◽  
Control Approach ◽  
P Concentration ◽  
Water Ph ◽  
Low Levels ◽  
P Removal

In eutrophication management, many phosphorus (P) adsorbents have been developed to capture P at the laboratory scale. Existing P removal practice in freshwaters is limited due to the lack of assessment of the possibility and feasibility of controlling P level towards a very low level (such as 10 μg/L) in order to prevent the harmful algal blooms. In this study, a combined external and internal P control approach was evaluated in a simulated pilot-scale river–lake system. In total, 0.8 m3 of simulated river water was continuously supplied to be initially treated by a P adsorption column filled with a granulated lanthanum/aluminium hydroxide composite (LAH) P adsorbent. At the outlet of the column (i.e., inlet of the receiving tanks), the P concentration decreased from 230 to 20 µg/L at a flow rate of 57 L/day with a hydraulic loading rate of 45 m/day. In the receiving tanks (simulated lake), 90 g of the same adsorbent material was added into 1 m3 water for further in situ treatment, which reduced and maintained the P concentration at 10 µg/L for 5 days. The synergy of external and internal P recapture was demonstrated to be an effective strategy for maintaining the P concentration below 10 µg/L under low levels of P water input. The P removal was not significantly affected by temperature (5–30 °C), and the treatment did not substantially alter the water pH. Along with the superior P adsorption capacity, less usage of LAH could lead to reduced cost for potation eutrophication control compared with other widely used P adsorbents.

Frameworks for assessing reliability of multiple, independent barriers in potable water reuse

1998 ◽  
Vol 38 (6) ◽  
pp. 1-8 ◽  
Author(s):  
Charles N. Haas ◽  
R. Rhodes Trussell
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Formal Specification ◽  
Water Reuse ◽  
Potable Water ◽  
Failure Modes ◽  
Formal Analysis ◽  
Careful Attention ◽  
Low Levels ◽  
Human Health Effects

The development of potable water reuse systems (systems for the treatment of wastewater to quality adequate to augment other surface water supplies) requires careful attention to the consistent production of product water which has low levels of contaminants, such as infectious pathogens, capable of causing human health effects from acute exposure. Little consideration has been given to the formal specification of the degree of reliability of such systems. In this paper we present two ways to approach the problem. The first is a formal extension of the ‘multiple barrier’ concept often cited in the water treatment literature. The second is an application of probabilistic analysis. With either method, it is clear that much more information should be obtained with respect to the failure modes, and the frequency with which individual processes achieve a particular level of performance. However the conceptual framework presented here should enable a formal analysis of the problem to be conducted.

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