The performance of an ozonation-biological activated carbon process under long term operation

1998 ◽  
Vol 38 (6) ◽  
pp. 163-169 ◽  
Author(s):  
Wataru Nishijima ◽  
Woo Hang Kim ◽  
Eiji Shoto ◽  
Mitsumasa Okada
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Supply ◽  
Water Temperature ◽  
Seasonal Changes ◽  
Pilot Scale ◽  
Raw Water ◽  
Biological Activated Carbon ◽  
Term Operation

The objective of this study is to evaluate removal of DOC and THMFP during long term operation of an ozonation-biological activated carbon (BAC) process. A pilot scale plant with raw water in an eutrophic reservoir for drinking water supply was operated for 910 days. High DOC and THMFP removal were maintained at 36% and 57%, respectively, in the ozonation-BAC process even after saturation of BAC by DOC. DOC and THMFP removal by ozonation were only 8% and 24%, respectively. High DOC and THMFP removal after saturation was due to the increase in biodegradable DOC by ozonation from 7% to 32% and the subsequent biodegradation by bacteria attached on BAC. Although water temperature changed in the range from 5 to 30°C, seasonal changes in DOC and THMFP removal were not observed in the ozonation-BAC process.

scholarly journals Removal of oxidative stress and genotoxic activities during drinking water production by ozonation and granular activated carbon filtration

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Maria Yu ◽  
Elin Lavonen ◽  
Agneta Oskarsson ◽  
Johan Lundqvist
Keyword(s):  
Oxidative Stress ◽  
Drinking Water ◽  
Activated Carbon ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Full Scale ◽  
Raw Water ◽  
Treatment Efficiency ◽  
Drinking Water Production ◽  
Treatment Technologies

Abstract Background Bioanalytical tools have been shown to be useful in drinking water quality assessments. Here, we applied a panel of in vitro bioassays to assess the treatment efficiency of two pilot-scale treatments: ozonation and granular activated carbon (GAC) filtration at a drinking water treatment plant (DWTP). The pilot-scale systems were studied alongside a full-scale treatment process consisting of biological activated carbon (BAC) filtration, UV disinfection, and monochloramine dosing. Both systems were fed the same raw water treated with coagulation/flocculation/sedimentation and sand filtration. The endpoints studied were oxidative stress (Nrf2 activity), genotoxicity (micronuclei formations), aryl hydrocarbon receptor (AhR) activation, as well as estrogen receptor (ER) and androgen receptor (AR) activity. Results Nrf2, AhR, and ER activities and genotoxic effects were detected in the incoming raw water and variability was observed between the sampling events. Compared to most of the samples taken from the full-scale treatment system, lower Nrf2, AhR, and ER bioactivities as well as genotoxicity were observed in all samples from the pilot-scale systems across all sampling events. The most pronounced treatment effect was a 12-fold reduction in Nrf2 activity and a sixfold decrease in micronuclei formations following ozonation alone. GAC filtration alone resulted in sevenfold and fivefold reductions in Nrf2 activity and genotoxicity, respectively, in the same sampling event. Higher bioactivities were detected in most samples from the full-scale system suggesting a lack of treatment effect. No androgenic nor anti-androgenic activities were observed in any sample across all sampling events. Conclusions Using effect-based methods, we have shown the presence of bioactive chemicals in the raw water used for drinking water production, including oxidative stress, AhR and ER activities as well as genotoxicity. The currently used treatment technologies were unable to fully remove the observed bioactivities. Ozonation and GAC filtration showed a high treatment efficiency and were able to consistently remove the bioactivities observed in the incoming water. This is important knowledge for the optimization of existing drinking water treatment designs and the utilization of alternative treatment technologies.

pH and Mg/Ca control for biological treatment of an offensive flavour (2-MIB)

1998 ◽  
Vol 37 (10) ◽  
pp. 101-106
Author(s):  
H. Sumitomo
Keyword(s):  
Activated Carbon ◽  
Water Supply ◽  
Biological Treatment ◽  
Raw Water ◽  
Removal Rates ◽  
Biological Activated Carbon ◽  
Effects Of Ph ◽  
Carbon Filtration

From a series of experimental observations, it was found that removal rates of the offensive flavor 2-methyl-isoborneol(2-MIB) and ammonia by a biological treatment for water supply were rather unstable and that the removal rates of them often became reverse such as low removal in 2-MIB and high removal of ammonia. One reason for the reverse phenomenon was found that the affinities of sludge around bacteria with 2-MIB and ammonia often became reversed. The affinities of sludge with 2-MIB and ammonia were found to be changeable depending upon pH along with magnesium (Mg) and calcium (Ca) concentrations in sludge. From these findings, control of pH and magnesium calcium ratio (Mg/Ca) of raw water was recommended for simultaneous and stable removal of 2-MIB and ammonia. From plant scale experiments equipped with automatic pH controller, the effects of pH and Mg/Ca control for biological treatment of 2-MIB and ammonia were observed in a biological activated filtration. Here, a biological activated carbon filtration means a longer filtration than 40 to 50 days from the beginning. The obtained results were almost as expected, showing high removal rates of both 2-MIB and ammonia.

Comparison of biological activated carbon (BAC) and membrane bioreactor (MBR) for pollutants removal in drinking water treatment

2009 ◽  
Vol 60 (6) ◽  
pp. 1515-1523 ◽  
Author(s):  
J. Y. Tian ◽  
Z. L. Chen ◽  
H. Liang ◽  
X. Li ◽  
Z. Z. Wang ◽  
...  
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Activated Carbon ◽  
Water Treatment ◽  
Membrane Bioreactor ◽  
Drinking Water Treatment ◽  
Raw Water ◽  
Moderate Amount ◽  
Biological Activated Carbon ◽  
Hydrophobic Acids

Biological activated carbon (BAC) and membrane bioreactor (MBR) were systematically compared for the drinking water treatment from slightly polluted raw water under the same hydraulic retention time (HRT) of 0.5 h. MBR exhibited excellent turbidity removal capacity due to the separation of the membrane; while only 60% of influent turbidity was intercepted by BAC. Perfect nitrification was achieved by MBR with the 89% reduction in ammonia; by contrast, BAC only eliminated a moderate amount of influent ammonia (by 54.5%). However, BAC was able to remove more dissolved organic matter (DOM, especially for organic molecules of 3,000 ∼ 500 Daltons) and corresponding disinfection by-product formation potential (DBPFP) in raw water than MBR. Unfortunately, particulate organic matter (POM) was detected in the BAC effluent. On the other hand, BAC and MBR displayed essentially the same capacity for biodegradable organic matter (BOM) removal. Fractionation of DOM showed that the removal efficiencies of hydrophobic neutrals, hydrophobic acids, weakly hydrophobic acids and hydrophilic organic matter through BAC treatment were 11.7%, 8.8%, 13.9% and 4.8% higher than that through MBR; while MBR achieved 13.8% higher hydrophobic bases removal as compared with BAC.

scholarly journals ROBUST DECISION MAKING (RDM) INVESTIGATION IN WATER RESOURCES PLANNING AND DISASTER MITIGATION IN MAKASSAR CITY, INDONESIA

2020 ◽  
Vol 6 (3) ◽  
pp. 429
Author(s):  
Zakir Sabara ◽  
Rahmad Junaidi ◽  
Rofiqul Umam
Keyword(s):  
Climate Change ◽  
Drinking Water ◽  
Water Resources ◽  
Water Supply ◽  
Disaster Mitigation ◽  
Drinking Water Supply ◽  
Raw Water ◽  
Management Planning ◽  
Resources Management

The Kota Makassar water utility serving (<em>Perusahaan Daerah Air Minum</em> - PDAM) faces a significant problem in managing water resources for their drinking water supply. The problems comprise raw water supply, the vulnerability of water quality, infrastructures, costs, and climate change uncertainty. The availability of clean water is one of the problems in the field of national defense. Because water is the main source of life in all sectors, be it agriculture or livestock. This study is aimed at assisting officials in making an adaptive and resilient decision. It involves inter-and cross-disciplinary studies within Robust Decision-Making (RDM) in water resources management planning for drinking water supply and disaster mitigation in Makassar. This research applies a qualitative approach in data analysis; reviewing strategies used by the utility management to anticipate all uncertainty, long-term strategies feasibility from simulation models, analyzing potential vulnerability scenarios, and the trade-off for an adaptive and robust decision in water resources management planning for drinking water supply in Makassar through RDM. The novelty lies in the raw water management policy that is more adaptive toward potential vulnerability and presents a variety of raw water supply alternatives in the long term. Reviews against the document of drinking water Master Plan found that the absence of harmony along with a high level of anticipation towards the threat of climate change along with their impact, as well as the threat of the raw water supply limitations due to the exogenous problems beyond the reach of human beings capacity, will result in global and long-term impact.

Pilot plant study on ozonation and biological activated carbon process for drinking water treatment

1997 ◽  
Vol 35 (8) ◽  
pp. 21-28 ◽  
Author(s):  
Woo Hang Kim ◽  
Wataru Nishijima ◽  
Eiji Shoto ◽  
Mitsumasa Okada
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Contact Time ◽  
Drinking Water Treatment ◽  
Suspended Solid ◽  
Residual Chlorine ◽  
Raw Water ◽  
Activated Carbon Adsorption ◽  
Biological Activated Carbon

A study on advanced drinking water treatment was conducted in a pilot scale plant taking raw water from Minaga Reservoir, Japan. Ozonation-biological activated carbon process (O3-BAC), BAC process (BAC) and chlorination-granular activated carbon adsorption process (Cl2-GAC) were evaluated based on the following parameters; dissolved organic carbon (DOC), adsorbable DOC (ADOC) and biodegradable DOC (BDOC). The raw water used was pre-treated by biofiltration for suspended solid removal and biological treatment. Contact time for ozonation and chlorination was 24 min. Empty bed contact time of activated carbon column was 15 min. Ozone dosage was 3 mg • 1−1. Chlorination was carried out to maintain a residual chlorine concentration of 0.2 mg • 1−1. Effluent DOC from biofiltration consisted of mainly ADOC (90%) and BDOC (10%). Therefore, DOC was mainly removed by adsorption in all processes. However, biodegradable DOC increased by 20% after ozonation in O3-BAC and was removed effectively by the attached bacteria on the activated carbon. Significant differences in DOC removal were not noted among the three processes during 8 months of operation. After the saturation of activated carbon, the effluent DOC from the O3-BAC was lower than that from BAC and Cl2-GAC. Ozonation improved biodegradability of organic substances and effluent water quality by the following biodegradation of biodegradable DOC by biological activated carbon.

The use of particle monitoring in the performance optimisation of conventional clarification and filtration processes

1997 ◽  
Vol 36 (4) ◽  
pp. 191-198
Author(s):  
G. Standen ◽  
P. J. Insole ◽  
K. J. Shek ◽  
R. A. Irwin
Keyword(s):  
Activated Carbon ◽  
Water Supply ◽  
Laser Diffraction ◽  
Raw Water ◽  
Particle Distributions ◽  
Upper Limit ◽  
Start Up ◽  
On Line ◽  
Particulates Removal ◽  
Particle Monitoring

The application of laser diffraction particle monitoring to the performance optimisation of a pilot clarifier and full-scale rapid gravity filters (RGF), operating on water supply works in Hampshire, is described. Furthermore the dosing of powdered activated carbon (PAC) into the works' clarifiers has been evaluated in terms of RGF performance. A costly proposal to install a third filter medium was subsequently abandoned when it was found that particle numbers in the filtered water were consistently below 1×102/ml. Various combinations and doses of coagulants and flocculant aids, shown to give optimum particulates removal during intensive jar testing trials, were transferred to the pilot clarifier. Particle monitoring enabled a more accurate derivation of suitable blanket chemistry and optimum blanket heights than turbidity changes. Raw water turbidities were 10-15 NTU at start-up with corresponding counts beyond the upper limit of the particle monitor. An on-line dilution system was developed to overcome this problem. Latex bead (4.33 μm) and Lycopodium spore (4-5 μm) suspensions (about 1 × 109 particles) were injected into the pilot clarifier to assess the removal efficiency of Cryptosporidium-sized particles. Reductions of about 1.7 log and 2.6 log were achieved for the beads and spores, respectively. Particle distributions of various PAC's and a bentonite were obtained in order to assess their potential effects on the coagulation process during clarification. Bentonite was also beneficial as an on-line means of checking particle monitor response and calibration. The works' filters achieved 1.5 to 2.0 log removals of 2-5 μm particles without media addition or operational changes. Combined clarification and filtration gave better particulates removal than two-stage microfiltration.

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