Removal of Musty Odor Compound in Drinking Water by Biological Filter

In order to remove the musty odor compound 2-methyl isoborneol (MIB) from drinking water resources at Lake Biwa, a pilot plant of a biological filtration was installed and operated. In this study, the effects of water temperature, pH and initial concentration of MIB on the MIB degradation potential of the ceramic media packed column in the biological filter were studied. Microorganisms on the surface of the granular media were observed under the scanning electron microscope (SEM). Bacteria which were responsible for the degradation were isolated, studied and identified. From this experiment, the extent of the effect of water temperature on the degradation potential was found to be similar to that on the biochemical oxygen demand (BOD) removal activity by an activated sludge. The optimum pH for the degradation potential was seen to be between 7 and 9. The MIB degradation reaction was seen to be almost a first order reaction. On the surface of the washed granular media, coccoid and rod-shaped bacteria were observed. Eleven out of 34 bacteria isolated from the washed media were judged as biodegraders. Some characteristics of 7 Gram negative biodegraders were studied and two strains of Pseudomonasaeruginosa,one strain of Flavobacteriummultivorum, one strain of Pseudomonas sp. and one strain of Flavobacterium sp. were identified.

Download Full-text

The Relationship between Concentration and Sensory Properties of 2-Methylisoborneol and Geosmin in Drinking Water

Water Science & Technology ◽

10.2166/wst.1988.0218 ◽

1988 ◽

Vol 20 (8-9) ◽

pp. 11-17 ◽

Cited By ~ 4

Author(s):

T. Ito ◽

T. Okumura ◽

M. Yamamoto

Keyword(s):

Drinking Water ◽

Water Temperature ◽

Forced Choice ◽

Residual Chlorine ◽

Mixing Ratio ◽

Consumer Panel ◽

Triangle Method ◽

Musty Odor ◽

The Relationship ◽

Mixed Samples

The study of the relations between the senses of smell and taste and odorant concentration is important for the solution of odor problems. The threshold concentrations of odor and taste (TOC, TTC) of 2-methylisoborneol (MIB) and geosmin were measured by the non-forced choice triangle method using 12-20 panelists. Both TOC and TTC were found to be functions of water temperature and the concentration of residual chlorine. The TOC and TTC of mixed samples were rather lower than the concentrations calculated from the mixing ratio. The sensitivities of the consumer panel and the number of musty odor complaints from consumers are related to MIB or geosmin concentration. The ratio of the number of complaints to MIB (or geosmin) concentration decreased after maximum complaint, but the sensitivity of the consumer panel remained the same.

Download Full-text

Effect of Rainfall and pH on Musty Odor Produced in the Sanbe Reservoir

Water ◽

10.3390/w13243600 ◽

2021 ◽

Vol 13 (24) ◽

pp. 3600

Author(s):

Sangyeob Kim ◽

Shohei Hayashi ◽

Shingo Masuki ◽

Kazuhiro Ayukawa ◽

Shuji Ohtani ◽

...

Keyword(s):

Drinking Water ◽

Water Temperature ◽

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Water Systems ◽

Cyanobacterial Blooms ◽

Field Observations ◽

The World ◽

Musty Odor ◽

Harmful Cyanobacterial Blooms

Harmful cyanobacterial blooms are continuously formed in water systems such as reservoirs and lakes around the world. Geosmin and 2-methylisoborneol (2-MIB) produced by some species of cyanobacteria have caused odor problems in the drinking water of the Sanbe Reservoir in Japan. Field observations were conducted for four years (2015–2019) to investigate the cause of this musty odor. It was found that geosmin was produced by Dolichospermum crassum and Dolichospermum planctonicum (cyanobacteria), and 2-MIB was due to Pseudanabaena sp. and Aphanizomenon cf. flos-aquae (cyanobacteria). Changes in water temperature and pH caused by rainfall were correlated with changes in the concentration of geosmin and 2-MIB. In particular, geosmin and 2-MIB tended to occur under low rainfall conditions. When there was low rainfall, the reservoir changed to an alkaline state because the phytoplankton consumed CO2 for photosynthesis. In an alkaline reservoir, dissolved inorganic carbon mainly existed in the form of bicarbonate (HCO3−). Thus, the results suggest that under such conditions in reservoirs, cyanobacteria grew easily because they could use both CO2 and HCO3− for photosynthesis. Specifically, our study suggests that in order for the musty odor problem in the reservoir to be solved, it is important that the pH of the reservoir be controlled.

Download Full-text

Studies on a biological filter for musty odor removal in drinking water treatment processes

Water Science & Technology ◽

10.2166/wst.1995.0440 ◽

1995 ◽

Vol 31 (11) ◽

pp. 229-235 ◽

Cited By ~ 8

Author(s):

N. Terauchi ◽

T. Ohtani ◽

K. Yamanaka ◽

T. Tsuji ◽

T. Sudou ◽

...

Keyword(s):

Drinking Water ◽

Activated Carbon ◽

Drinking Water Treatment ◽

Powdered Activated Carbon ◽

Biological Filter ◽

Coagulant Dosage ◽

Odor Removal ◽

Musty Odor ◽

Removal Efficiencies ◽

Carbon Additions

Pilot plant studies on biological filter treatment for musty odor in drinking water were conducted. The plant was operated for 2 years at a filtration rate of 170 m/d and the surface water of Lake Biwa was employed as an influent. 2-Methylisoborneol (MIB) produced by Oscillatoria tenuis was the main cause of the musty odor. In the season of natural musty odor generation, total MIB concentration and the insoluble to total MIB concentration ratio in the influent varied to a large extent, but removal efficiencies of MIB by the filter were about 60 to 80%. Out of the season of natural musty odor, reagent MIB was added to the influent and the removal efficiencies obtained were about 70 to 80%. In addition to MIB, color, turbidity, Fe, Mn, NH4-N and KMnO4 consumption value were also effectively removed by the biological filter. Using the effluent from the filter, jar tests for powdered activated carbon treatment and coagulation-sedimentation treatment were conducted. From the results, the biological filter treatment seemed to effectively decrease the powdered activated carbon consumption even in cases where powdered activated carbon additions might be needed. No ill effect on coagulation-sedimentation treatment was seen and the required coagulant dosage was less in water after biological filter treatment.

Download Full-text

Studies on a biological filter for musty odor removal in drinking water treatment processes

Water Science & Technology ◽

10.1016/0273-1223(95)00481-2 ◽

1995 ◽

Vol 31 (11) ◽

Cited By ~ 7

Keyword(s):

Drinking Water ◽

Water Treatment ◽

Drinking Water Treatment ◽

Treatment Processes ◽

Biological Filter ◽

Odor Removal ◽

Musty Odor

Download Full-text

The impact of biological filtration on the proliferation of antimicrobial resistance in drinking water

10.26226/morressier.5f3f8a0d56c61be607c780f1 ◽

2020 ◽

Author(s):

Lena Ciric

Keyword(s):

Drinking Water ◽

Antimicrobial Resistance ◽

Biological Filtration ◽

The Impact

Download Full-text

PTSA (pressure and thermal swing adsorption) method to remove trihalomethanes from drinking water

Water Science & Technology ◽

10.2166/wst.1997.0283 ◽

1997 ◽

Vol 35 (7) ◽

pp. 243-250 ◽

Cited By ~ 1

Author(s):

Shigekazu Nakano ◽

Tomoko Fukuhara ◽

Masami Hiasa

Keyword(s):

Drinking Water ◽

Residual Chlorine ◽

Remarkable Difference ◽

Adsorption Method ◽

Heating And Cooling ◽

Point Of Use ◽

Thermal Swing Adsorption ◽

Long Time ◽

Musty Odor ◽

Vacuum Heating

It has been widely recognized that trihalomethanes (THMs) in drinking water pose a risk to human health. THMs can be removed to a certain extent by the conventional point-of-use (POU) unit which is composed of activated carbon (AC) and microfilter. But it's life on THMs is relatively shorter than on residual chlorine or musty odor. To extent the life of AC adsorber, pressure and thermal swing adsorption (PTSA) was applied by preferential regeneration of chloroform. PTSA was effective to remove THMs, especially chloroform. Adsorption isotherms of chloroform at 25 and 70°C showed a remarkable difference so that thermal swing was considered effective. Chloroform was also desorbed by reducing pressure. By vacuum heating at 70°C, chloroform was almost desorbed from AC and reversible adsorption was considered possible. A prototype of POU unit with PTSA was proposed. Regeneration mode would consist of dewatering, vacuum heating and cooling (backwashing). The unit was maintained in bacteriostatic condition and could be used for a long time without changing an AC cartridge.

Download Full-text

Technologies Developing in Heavy Metals’ Removal from Water

Water ◽

10.3390/w13060860 ◽

2021 ◽

Vol 13 (6) ◽

pp. 860

Author(s):

Konstantinos Simeonidis ◽

Manassis Mitrakas

Keyword(s):

Heavy Metals ◽

Drinking Water ◽

Water Resources ◽

Human Health ◽

Urban Wastewater ◽

Heavy Metals Removal ◽

Metals Removal ◽

Drinking Water Resources

Elevated concentrations of heavy metals in drinking water resources and industrial or urban wastewater pose a serious threat to human health and the equilibrium of ecosystems [...]

Download Full-text

Persistent, mobile and toxic (PMT) and very persistent and very mobile (vPvM) substances pose an equivalent level of concern to persistent, bioaccumulative and toxic (PBT) and very persistent and very bioaccumulative (vPvB) substances under REACH

Environmental Sciences Europe ◽

10.1186/s12302-020-00440-4 ◽

2020 ◽

Vol 32 (1) ◽

Author(s):

Sarah E. Hale ◽

Hans Peter H. Arp ◽

Ivo Schliebner ◽

Michael Neumann

Keyword(s):

Drinking Water ◽

Human Health ◽

Regulatory Decision ◽

Drinking Water Resources ◽

Trade Name ◽

Chemicals Regulation ◽

Range Transport ◽

High Concern ◽

Level Of Concern

Abstract Background Under the EU chemicals regulation REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals EC 1907/2006), registrants are not obliged to provide information related to intrinsic substance properties for substances that pose a threat to the drinking water resources. In 2019, perfluorobutane sulfonic acid (PFBS) and 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoic acid (HFPO-DA trade name GenX) were demonstrated to have an equivalent level of concern (ELoC) to persistent, bioaccumulative and toxic or very persistent and very bioaccumulative (PBT/vPvB) substances owing to their persistent, mobile and toxic (PMT) substance properties and very persistent and very mobile (vPvM) substance properties, respectively. They were both subsequently identified as substances of very high concern (SVHC) applying Article 57(f) in REACH. This work follows up on this regulatory decision by presenting a science based, conceptual level comparison that all PMT/vPvM substances pose an ELoC to PBT/vPvB substances. Using the two cases named above, as well as 1,4-dioxane, 16 categories were developed to evaluate a) serious effects on human health, b) serious effects on the environment and c) additional effects. 1,4-dioxane has recently been proposed to be classified as Carcinogenic 1B by the Committee for Risk Assessment (RAC). The aim was to enable an objective and scientifically justified conclusion that these classes of substances have an equivalent level of concern for the environment and human health. Results In all of the categories related to human health, the environment and other effects, the PMT/vPvM case study substances exhibited comparable effects to PBT/vPvB substances. A difference in the human and environmental exposure pathways of PMT/vPvM and PBT/vPvB substances exists as they vary temporally and spatially. However, effects and impacts are similar, with PMT/vPvM substances potentially accumulating in (semi-)closed drinking water cycles and pristine aquatic environments, and PBT/vPvB substances accumulating in humans and the food chain. Both PMT/vPvM and PBT/vPvB substances share the common difficulty that long term and long-range transport and risk of exposure is very difficult to determine in advance and with sufficient accuracy. Conclusion The registration process of substances under REACH should reflect that PMT/vPvM substances pose an equivalent level of concern to PBT/vPvB substances.

Download Full-text