Water Treatment Systems and Technology for the Removal of Odor Compounds

1988 ◽  
Vol 20 (8-9) ◽  
pp. 237-244 ◽  
Author(s):  
K. Hattori
Keyword(s):  
Lake Biwa ◽  
Removal Rate ◽  
Space Velocity ◽  
Raw Water ◽  
Filtration System ◽  
Odor Compounds ◽  
Musty Odor ◽  
Removal Technologies ◽  
Low Efficiency ◽  
Purification Plant

Compounds responsible for a musty odor in Lake Biwa have been detected at Isoshima Point in the Yodo river, the intake point of the Murano Purification Plant of Osaka Prefectural Government. 2-Methylisoborneol (MIB) and geosmin have been measured at maximum concentrations in raw water of 103 ng/l and 362 ng/l, respectively (1983–1986). The rapid sand filtration system normally in use has a low efficiency for the removal of such odor compounds, so a study of the following removal technologies: powdered and granular activated carbon (PAC,GAC), ozone and bio-film, was undertaken. The most effective was GAC treatment (linear velocity: 10–22 m/hr, space velocity: 7–16/hr) which completely removed the musty odor compounds. However, when the removal rate of total organic carbon by the GAC system decreased below 30%, the system's ability to remove the odor from the water also decreased.

The relationship between musty-odor-causing organisms and water quality in Lake Biwa

1995 ◽  
Vol 31 (11) ◽  
pp. 153-158 ◽  
Author(s):  
M. Kajino ◽  
K. Sakamoto
Keyword(s):  
Water Quality ◽  
Data Analysis ◽  
Green Algae ◽  
Analytical Methods ◽  
Lake Biwa ◽  
Blue Green Algae ◽  
Odor Compounds ◽  
Musty Odor ◽  
The Relationship

Musty odor has occurred annually in Lake Biwa since 1969. Osaka municipal waterworks, which is located downstream of Lake Biwa, has made many efforts to treat musty-odor compounds produced in Lake Biwa from spring through autumn. With the development of analytical methods for the determination of musty-odor compounds, we have been able to confirm that planktonic blue-green algae are the major causes of the musty-odor occurrences. The relationship between the growth of blue-green algae and the water quality was not so apparent. However, through our data analysis focusing on the relationship between musty-odor occurrences due to Phormidium tenue or Oscillatoria tenuis and some nutrients in Lake Biwa, we found that the concentration of nitrate in water may be an important parameter for the estimation of growth of the algae and the musty-odor behavior.

Effective removal of musty odor in the Kanamachi Purification Plant

1995 ◽  
Vol 31 (11) ◽  
pp. 219-222 ◽  
Author(s):  
S. Muramoto ◽  
T. Udagawa ◽  
T. Okamura
Keyword(s):  
Activated Carbon ◽  
Water Purification ◽  
Powdered Activated Carbon ◽  
Raw Water ◽  
Biological Activated Carbon ◽  
Water Purification System ◽  
Effective Removal ◽  
Purification System ◽  
Musty Odor ◽  
Purification Plant

Since 1972, the Kanamachi Purification Plant has been faced with a “musty odor” problem in water. In 1984, the plant began to treat raw water with powdered activated carbon. However, the concentration of the musty odor substance 2-methylisoborneol (MIB) in raw water varied so markedly that it was difficult to control the dosage of powdered activated carbon. To achieve a more stable and effective removal of the musty odor, the Bureau decided to introduce an Advanced Water Purification system combining ozonation and biological activated carbon (BAC) treatment. On June 25, 1992, we started operation of the facilities. This system, which is the first of these plants in Japan, can remove musty odor to the satisfaction of the customer.

scholarly journals Inflight Transmission of COVID-19 Based on Experimental Aerosol Dispersion Data

2021 ◽  
Author(s):  
Zhaozhi Wang ◽  
Edwin R Galea ◽  
Angus Grandison ◽  
John Ewer ◽  
Fuchen Jia
Keyword(s):  
High Efficiency ◽  
Face Mask ◽  
Generation Rate ◽  
Aviation Industry ◽  
Filtration System ◽  
Dispersion Data ◽  
Low Probability ◽  
Meal Service ◽  
Low Efficiency ◽  
Aerosol Dispersion

Abstract Background An issue of concern to the travelling public is the possibility of in-flight transmission of COVID-19 during long- and short-haul flights. The aviation industry maintains that the probability of contracting the illness is small based on reported cases, modelling and data from aerosol dispersion experiments conducted on-board aircraft. Methods Using experimentally derived aerosol dispersion data for a B777–200 aircraft and a modified version of the Wells-Riley equation we estimate inflight infection probability for a range of scenarios involving quanta generation rate and face mask efficiency. Quanta generation rates were selected based on COVID-19 events reported in the literature while mask efficiency was determined from the aerosol dispersion experiments. Results The MID-AFT cabin exhibits the highest infection probability. The calculated maximum individual infection probability (without masks) for a 2-hour flight in this section varies from 4.5% for the ‘Mild Scenario’ to 60.2% for the ‘Severe Scenario’ although the corresponding average infection probability varies from 0.1% to 2.5%. For a 12-hour flight, the corresponding maximum individual infection probability varies from 24.1% to 99.6% and the average infection probability varies from 0.8% to 10.8%. If all passengers wear face masks throughout the 12-hour flight, the average infection probability can be reduced by approximately 73%/32% for high/low efficiency masks. If face masks are worn by all passengers except during a one-hour meal service, the average infection probability is increased by 59%/8% compared to the situation where the mask is not removed. Conclusions This analysis has demonstrated that while there is a significant reduction in aerosol concentration due to the nature of the cabin ventilation and filtration system, this does not necessarily mean that there is a low probability or risk of in-flight infection. However, mask wearing, particularly high-efficiency ones, significantly reduces this risk.

Removal of Se(VI) from Raw Water by Ion Exchange Process

2012 ◽  
Vol 430-432 ◽  
pp. 941-948 ◽  
Author(s):  
Yong Sheng Shi ◽  
Yu Zhen Shi ◽  
Lin Wang
Keyword(s):  
Ion Exchange ◽  
Removal Rate ◽  
Exchange Process ◽  
Selenium Concentration ◽  
Quality Standard ◽  
Raw Water ◽  
Strong Base ◽  
Ion Exchange Process ◽  
Efficiency Cost ◽  
Easy Operation

Studies have been carried out on removal of Se(Ⅵ) from raw water by ion exchange process. The experiment results indicate that employment of strong-base anion exchange resin of 201×7 can receive a desirable result for Se removal. It is particularly true that the removal rate of Se(Ⅵ) can achieve more than 96% when the Se(Ⅵ) concentration in raw water is 100μg/L. This allows selenium concentration of the supply water in full conformity to the quality standard currently available for drinking water. Ion exchange process for Se removal has been proved to be competent for its efficiency, cost effectiveness and easy operation.

Influence Factors of Denitration Study on Catalyst Mn-Ce/TiO2

2013 ◽  
Vol 634-638 ◽  
pp. 526-530
Author(s):  
Chun Xiang Geng ◽  
Qian Qian Chai ◽  
Wei Yao ◽  
Chen Long Wang
Keyword(s):  
Reaction Temperature ◽  
Catalytic Reduction ◽  
Removal Rate ◽  
Load Capacity ◽  
Fixed Bed ◽  
Influence Factors ◽  
Space Velocity ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Ammonia Gas

Selective Catalytic Reduction (SCR) processes have been one of the most widely used denitration methods at present and the property of low tempreture catalyst becomes a hot research. The Mn-Ce/TiO2 catalyst was prepared by incipient impregnation method. The influence of load capacity, reaction temperature, O2 content, etc. on denitration were studied by a fixed bed catalyst reactor with ammonia gas. Results showed that catalyst with load capacity 18% performed high NO removal rate of 90% at conditions of reaction temperature 160°C, low space velocity, NH3/NO molar ratio 1: 1, O2 concentration 6%.

Distribution and Transformation of Molecular Weight of Organic Matters in a Canal Water Treatment Procedure

2012 ◽  
Vol 610-613 ◽  
pp. 2483-2487
Author(s):  
Xiao Dan Zhao ◽  
Chun Hua Wu ◽  
Zhen Zhou
Keyword(s):  
Molecular Weight ◽  
Activated Carbon ◽  
Water Treatment ◽  
Removal Rate ◽  
Ultrafiltration Membrane ◽  
Raw Water ◽  
Canal Water ◽  
Treatment Procedure ◽  
Organic Matters ◽  
Membrane Method

Distribution and transformation of molecular weight of organic matters in canal raw water, primary coagulated water, secondary coagulated water, enhanced coagulated water and water filtered by activated carbon were monitored by ultrafiltration membrane method. The results show that organics on the fraction of molecular weight less than 2kDa has the largest ratio in total organics of outlets of coagulation and activated carbon tank. Removal rate of total organics is about 73% by secondary coagulation, but which of micromolecule organics of molecular weight less than 2kDa is only 10%, which can be removed by activated carbon more than 80%.

Occurrence of Cryptosporidium oocysts and Giardia cysts in a conventional water purification plant

2001 ◽  
Vol 43 (12) ◽  
pp. 89-92 ◽  
Author(s):  
A. Hashimoto ◽  
T. Hirata ◽  
S. Kunikane
Keyword(s):  
Water Purification ◽  
Water Samples ◽  
Geometric Mean ◽  
Giardia Cyst ◽  
Raw Water ◽  
Observation Level ◽  
Cryptosporidium Oocysts ◽  
Purification Plant ◽  
Mean Concentration ◽  
Giardia Cysts

A one-year monitoring of Cryptosporidium oocysts and Giardia cysts was conducted at a water purification plant. A total of thirteen 50 L samples of river source water and twenty-six 2,000 L samples of filtered water (treated by coagulation-flocculation, sedimentation and rapid filtration) were concentrated using a hollow fibre ultrafiltration membrane module at a purification plant. Cryptosporidium oocysts were detected in all raw water samples with a geometric mean concentration of 400 oocysts/m3 (range 160-1,500 oocysts/m3). Giardia cysts were detected in 12/13 raw waters (92%) with a geometric mean concentration of 170 cysts/m3 (range 40-580 oocysts/m3). Probability distributions of both Cryptosporidium oocyst and Giardia cyst concentration in raw water were nearly log-normal. In filtered water samples, Cryptosporidium oocysts were detected in 9/26 samples (35%) with a geometric mean concentration of 1.2 oocysts/m3 (range 0.5-8 oocysts/m3) and Giardia cysts in three samples (12%) with 0.8 cysts/m3 (range 0.5-2 oocysts/m3). The estimated removal of Cryptosporidium oocysts and Giardia cysts was, respectively, 2.54 log10 and 2.53 log10 on the basis of geometric means, 3.20 and 3.57 log10 on the basis of 50% observation level and 2.70 and 2.90 log10 on the basis of 90% observation level.

Experimental Studies on Enhanced Coagulation of Tail Water

2013 ◽  
Vol 295-298 ◽  
pp. 1478-1481
Author(s):  
Feng Xun Tan ◽  
Jiu Mei Wang ◽  
Dao Ji Wu
Keyword(s):  
Ferric Chloride ◽  
Removal Rate ◽  
Reclaimed Water ◽  
Experimental Studies ◽  
Ammonia Nitrogen ◽  
Raw Water ◽  
Nitrogen And Phosphorus ◽  
Enhanced Coagulation ◽  
Tail Water ◽  
Water Eutrophication

Traditional wastewater treatment methods can no longer remove effectively nitrogen and phosphorus that are the direct murderers of water eutrophication hazard. Enhanced coagulation method was adopted to improve the treatment effect by dosing suitable coagulants and coagulant aids. The raw water was from the reclaimed water in a University. TP and ammonia nitrogen removal of the water had been researched through an enhanced coagulation process with dosing ferric chloride, aluminum sulfate, polymeric ferric chloride, and poly-aluminum chloride (PAC) in this study. The coagulants effects were estimated by determining the removal rate of ammonia nitrogen, TP, COD and turbidity. When dosing the raw water with 80 mg/L PAC, the removal rates of ammonia nitrogen, TP, COD and turbidity are respectively 6.12%, 67.79%, 26.21%, 85.41%. The experimental results can be used as a reference of water treatment in the reclaimed water station.

Biological treatment of ammonia gas at high loading

2004 ◽  
Vol 50 (4) ◽  
pp. 283-290 ◽  
Author(s):  
T. Kanagawa ◽  
H.W. Qi ◽  
T. Okubo ◽  
N. Tokura
Keyword(s):  
Removal Rate ◽  
Space Velocity ◽  
Packed Bed ◽  
Porous Ceramics ◽  
Ammonia Removal ◽  
Ammonium Ion ◽  
Nitrifying Bacteria ◽  
High Concentration ◽  
Ammonia Gas ◽  
Cylinder Diameter

The exhaust gas from compost processing plants contains a large amount of ammonia. To treat ammonia gas at high loads, bench-scale experiments were carried out. First, nitrifying bacteria were enriched from soil and immobilized on porous ceramics. The ceramics were packed in an acrylic cylinder (diameter, 100 mm; packed height, 190 mm) and ammonia gas was introduced to the top of the cylinder. The concentration and flow rate of ammonia gas were gradually increased and finally 85 ppm was introduced at a space velocity of 800 h-1 (empty bed residence time (EBRT), 4.5 sec). The ammonia load was 1.0 kg N/m3 day-1. The exhaust contained 1.5-2 ppm of ammonia. Then the packed ceramics were transferred to another acrylic cylinder (diameter, 50 mm; packed height, 800 mm). A high concentration of ammonia gas (1,000 ppm) was introduced at a space velocity of 96 h-1 (ammonia loading, 1.44 kg N/m3 day-1; EBRT, 37.5 sec). The exhaust contained 2 ppm of ammonia (removal rate, 99.8%). The packed bed was washed with water intermittently or continuously, and the wastewater from the cylinder contained a large amount of ammonium and nitrate ions of at a 1:1 ratio. Stoichiometric analysis showed that half of the introduced ammonia was oxidized to nitrate, and the rest was converted to ammonium ion. Thus, ammonia gas was effectively treated at a high load by biofiltration with nitrifying bacteria.

Performance of PAC/PDM composite coagulants for removal of algae from Lake Taihu waters in summer

2010 ◽  
Vol 62 (2) ◽  
pp. 330-339 ◽  
Author(s):  
Y. J. Zhang ◽  
X. L. Zhao ◽  
X. X. Li ◽  
Ch. Liu ◽  
L. L. Zhu
Keyword(s):  
Water Quality ◽  
Intrinsic Viscosity ◽  
Removal Rate ◽  
Lake Taihu ◽  
Raw Water ◽  
Removal Rates ◽  
Polyaluminum Chloride ◽  
Enhanced Coagulation ◽  
Algae Removal ◽  
Better Than

The enhanced coagulation of algae-rich raw water from Lake Taihu in summer was studied by use of composite coagulants. The composite coagulants were composed of polyaluminum chloride (PAC) and polydimethyldiallylammonium chloride (PDM) with various intrinsic viscosity values (0.55–3.99 dL/g) and different mass percentages (5–20%) in the formulation. For raw water with temperature of 28–29°C and algae content of 3.60 × 104–3.70 × 104 cells/ml, the algae-removal rates of 89.0% and 89.3–93.1% could be realized by using PAC and PAC/PDM (0.55/5%–3.99/20%) with dosages of 8.37 mg/L and 5.93–3.58 mg/L, respectively, when 2 NTU residual turbidity of treated water after sedimentation was required. Compared with using PAC only, the removal rate of CODMn using PAC/PDM increased at least 4.4% when the dosage was 8 mg/L, and increased at least 5.0% when the dosage was 10 mg/L. The composite coagulants could still function well when raw water quality deteriorated and algae content reached 8.00 × 104 cells/ml. The enhanced coagulation efficiency of PAC/PDM (0.55/5%) could be better than that of PAC combined with prechlorination process when the same dosages are used.

Sign in / Sign up

Export Citation Format

Share Document