Experimental and modeling evaluation of upward and downward velocities in the coaxial flotation column

2001 ◽  
Vol 43 (8) ◽  
pp. 195-201 ◽  
Author(s):  
K. Park ◽  
J.-M. Cho ◽  
J. Oh ◽  
K. Chung
Keyword(s):  
Removal Efficiency ◽  
Pilot Scale ◽  
Coaxial Cylinder ◽  
Treated Water ◽  
Flotation Column ◽  
Solids Loading ◽  
Solids Concentration ◽  
Upward Velocity ◽  
Solids Removal

This study was conducted to show the influence of upward velocity in the inner column and downward velocity in the outer column of the coaxial cylinder-type flotation column on the solids removal efficiency, solids concentration in the treated water, and so on. The SIMPLE (Semi-Implicit Method for Pressure Linked Equation) solution was applied to the coaxial flotation column to simulate the velocity vectors of the elements of water flowing in the column. The effects of solids loading and residence time in the agglomerate separation zone on the solids removal efficiency were also tested. In the pilot scale coaxial DAF column experiments with solids concentration of 1,000–2,000 mg of SS per liter and solids loading less than 350 kg/m2/day, approximately 90% of the solids removal efficiencies were obtained using the upward velocity of up to 110 cm/min in the contact zone of the inner column and the downward velocity of up to 30 cm/min in the outer column. In the simulation, similar results were observed as in the experiments. The solids loading in the excess of 350 kg/m2/day caused the instability of the sludge float layer and aggravated the quality of the treated water.

scholarly journals Treatment of poultry slaughterhouse wastewater with combined system

10.5219/1147 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 706-712 ◽  
Author(s):  
Kulyash Meiramkulova ◽  
Mikhail Zhumagulov ◽  
Gulnur Saspugayeva ◽  
Zhanar Jakupova ◽  
Мaral Mussimkhan
Keyword(s):  
Removal Efficiency ◽  
Technical Equipment ◽  
Poultry Industry ◽  
Combined System ◽  
Slaughterhouse Wastewater ◽  
Treated Water ◽  
Poultry Products ◽  
Wastewater Samples

With the interest to reuse and recycle the wastewater for technological use, this project aims to test the treatment of wastewater from poultry slaughterhouse industry from three main sections of the poultry slaughtering process, defeathering, eviscerating and cooling processes. The samples for the project were obtained from Izhevskoe a Kazakhstani company. The technology used is a combination of electrocoagulation, ultrafiltration, and photochemical system and its goal is to provide treated water that can be re-utilized in the poultry industry for sterilization of technical equipment without contaminating and affecting the quality of the poultry products. The treatment of wastewater samples lasted in total for 40 min. From the results, it was found that indicators such as BOD, COD, and phosphates had removal efficiency of almost 100%, while the microbiological colonies were all eradicated from then wastewater making the treated water microbes free. Hence, proving this system to be effective for the treatment of poultry slaughterhouse wastewater and safe for technological reutilization.

Suspended Solids Removal Efficiencies of a Barrier Board that Pre-Treats High-Turbidity Raw Water

2012 ◽  
Vol 253-255 ◽  
pp. 969-974
Author(s):  
Jian Liang Chen ◽  
Yi Kuo Chang ◽  
Chin Hsing Lai ◽  
Yun Hwei Shen
Keyword(s):  
Suspended Solids ◽  
Removal Rate ◽  
Initial Period ◽  
Raw Water ◽  
High Concentration ◽  
Solids Concentration ◽  
Gravity Settling ◽  
High Turbidity ◽  
Solids Removal

It tends to produce high-turbidity raw water during the initial period of typhoons or storms and affect the operation of the purifying system. In this research, Raw water suspended solids roughly to 5,000-9,000 mg/l, the removal rate can be to about 70%-90 %, and reduced to 800 mg/l or less, 8 ml/s minimum about 100-400 mg/l. Overall, the quality of effluent water with the overflow water height increased removal rate rose gradually reduce the suspended solids concentration, gravity settling and effective appear, especially the section Ⅳ region (40 cm) removal are more than 80 %, flow 100 ml/s to 84 %, compared with I (10 cm) with 100 ml/s for 74 %, with obvious benefits. The overflow height of the flow of 8 ml/s, and suspended solids by the inlet concentration at 7,400 mg/l to 8,700 mg/l, down to the effluent concentrations are below 300 mg/l, which overflow height of 20, 30, and 40 cm can be reduced to below 200 mg/l, showing that gravitational sedimentation can significantly remove the high concentration of suspended solids.

Sludge accumulation in polishing ponds treating anaerobically digested wastewater

2002 ◽  
Vol 45 (1) ◽  
pp. 75-81 ◽  
Author(s):  
P. Cavalcanti ◽  
A. van Haandel ◽  
G. Lettinga
Keyword(s):  
Pilot Scale ◽  
Important Conclusion ◽  
Solids Concentration ◽  
Volatile Solids ◽  
Useful Life ◽  
One Year ◽  
Uasb Reactors ◽  
Very High ◽  
Sludge Accumulation

When ponds are used for wastewater treatment, settleable solids will form a steadily growing bottom sludge layer, which reduces their effective volume. Eventually this sludge must be removed to ensure that the pond maintains the required retention time to keep performing properly. The settleable solids may either be present in the influent or they are formed during the treatment as a result of algal flocculation. An experimental investigation was carried out to evaluate bottom sludge accumulation in a polishing pond used for treatment of UASB effluent. The mass and composition of the bottom sludge formed in a polishing pond was evaluated after the pilot scale pond had been in operation for 1 year and about 60 m3 of digested wastewater had been treated per m3 of pond. The bottom sludge mass represented a solids accumulation of 70 g per m3 of digested wastewater. About half of these solids were the result of settling of influent solids in the first part of the pond, while the other half was attributable to settling of algae, formed in the pond. It is concluded that the bottom sludge growth in a polishing pond is so low, that desludging during the useful life span of the pond will most likely not be necessary. This leads to the important conclusion that excess sludge discharge from UASB reactors (a major factor in operational costs) may be omitted, if a polishing pond is used for post-treatment. The bottom sludge had a high volatile solids concentration (58%) and the macronutrient fractions were also high (3.9% N and 1.1% P of the TSS mass). The bottom sludge was stable and could be dried directly without problems. The hygienic quality of the bottom sludge was very poor: about half the influent helminth eggs during one year of operation were found in the bottom sludge and the faecal coliform concentration was very high.

Lab-scale testing of a low-loaded activated sludge process with membrane filtration

2009 ◽  
Vol 63 (2) ◽  
Author(s):  
Zuzana Jakubčová ◽  
Petr Hlavínek ◽  
Miloslav Drtil ◽  
Igor Bodík
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Membrane Filtration ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Activated Sludge Process ◽  
Excess Sludge ◽  
Treated Water ◽  
Different Types

AbstractTwo membrane bioreactors (MBRs; volume = 300 L) equipped with different types of immersed membrane modules were operated simultaneously under the same laboratory conditions as a low-loaded activated sludge process without any membrane regeneration and excess sludge uptake (sludge retention time SRT up to 170 d; activated sludge concentration MLSS up to 11 g L−1). The aim was to verify the quality of treated water and to study the properties of "very old" activated sludge. Another aim was to compare different selected membrane types and choose the best one for further pilot-scale testing.

Radon removal by aeration: observations on testing, installation and maintenance of domestic treatment units

2009 ◽  
Vol 9 (4) ◽  
pp. 469-475
Author(s):  
T. Turtiainen
Keyword(s):  
Water Quality ◽  
Water Flow ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Test Protocol ◽  
Household Water ◽  
Medium Flow ◽  
Removal Efficiencies ◽  
Frequent Sampling

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.

Continuing the Development of Municipal Effluent Guidelines for the Northwest Territories

1986 ◽  
Vol 18 (2) ◽  
pp. 179-184
Author(s):  
R. J. Kent
Keyword(s):  
Northwest Territories ◽  
Removal Efficiency ◽  
Municipal Wastewater ◽  
Coliform Bacteria ◽  
Flow Ratio ◽  
Dilution Ratio ◽  
Effluent Quality ◽  
Municipal Effluent

The background to and the rationale for the Guidelines for Municipal Type Wastewater Discharges in the Northwest Territories is discussed. Particu1ar attention is given to the development of Table 2.1, Effluent Quality of Municipal Wastewater Discharges, which was based upon expected lagoon performance. Also included is a discussion of the flow ratio and dilution ratio concepts. The viability of these concepts was assessed against the available data. It appears that the guidelines misjudged both the number of coliform bacteria in northern raw sewage and the removal efficiency for these organisms in lagoons. It appears unlikely that lagoons can consistently meet the guideline requirements. More information and research is necessary before a complete assessment can be performed.

scholarly journals A Comparison of Two-Stage and Traditional Co-Composting of Green Waste and Food Waste Amended with Phosphate Rock and Sawdust

2021 ◽  
Vol 13 (3) ◽  
pp. 1109
Author(s):  
Edgar Ricardo Oviedo-Ocaña ◽  
Angélica María Hernández-Gómez ◽  
Marcos Ríos ◽  
Anauribeth Portela ◽  
Viviana Sánchez-Torres ◽  
...  
Keyword(s):  
Organic Matter ◽  
Product Quality ◽  
Food Waste ◽  
Phosphate Rock ◽  
Pilot Scale ◽  
Two Stage ◽  
Green Waste ◽  
Wet Weight ◽  
Two Phases

The composting of green waste (GW) proceeds slowly due to the presence of slowly degradable compounds in that substrate. The introduction of amendments and bulking materials can improve organic matter degradation and end-product quality. However, additional strategies such as two-stage composting, can deal with the slow degradation of green waste. This paper evaluates the effect of two-stage composting on the process and end-product quality of the co-composting of green waste and food waste amended with sawdust and phosphate rock. A pilot-scale study was developed using two treatments (in triplicate each), one being a two-stage composting and the other being a traditional composting. The two treatments used the same mixture (wet weight): 46% green waste, 19% unprocessed food waste, 18% processed food waste, 13% sawdust, and 4% phosphate rock. The traditional composting observed a higher degradation rate of organic matter during the mesophilic and thermophilic phases and observed thermophilic temperatures were maintained for longer periods during these two phases compared to two-stage composting (i.e., six days). Nonetheless, during the cooling and maturation phases, the two treatments had similar behaviors with regard to temperature, pH, and electrical conductivity, and the end-products resulting from both treatments did not statistically differ. Therefore, from this study, it is concluded that other additional complementary strategies must be evaluated to further improve GW composting.

scholarly journals Mobility and Bioavailability of Metal(loid)s in a Fluvial System Affected by the Mining and Industrial Processing of Pb

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 167
Author(s):  
Unai Cortada ◽  
María Carmen Hidalgo ◽  
Julián Martínez ◽  
María José de la Torre
Keyword(s):  
Total Concentration ◽  
Rare Metal ◽  
Mining District ◽  
X Ray ◽  
Industrial Processing ◽  
Solids Concentration ◽  
Mobile Fraction ◽  
Type Water ◽  
The Impact

The abandoned mining district of Linares (South Spain) is marked with waste from the mining and the processing of metal ores that pose an environmental hazard to watercourses. A combined analysis of waste, sediments and water was carried out to analyse the impact of a smelter on Baños Creek. The composition of the facility waste was determined using X-ray diffractometry and scanning electron microscopy. The total contents of the metal(loid)s in the waters and sediments of the watercourse were analysed, and sequential metal(loid) extraction of solid samples was carried out. The facility wastes consisted mainly of secondary minerals, such as natropharmacosiderite and spertiniite, as well as rare metal salts, such as mopungite and NaPb2(CO3)2(OH). The leachates generated by these wastes were highly alkaline, with a pH of 10 and a total dissolved solids concentration of approximately 9 g L−1. This Na-bicarbonate-type water had an As concentration above 200 mg L−1 and elevated levels of Pb, Sb and Zn (5029 µg L−1, 841 µg L−1 and 525 µg L−1, respectively). This highly contaminated lixiviate had a significant effect on the chemical quality of the waters and the bioavailability of metal(loid)s in the creek sediments, especially in the headwaters. In this zone, the As, Pb, Sb and Zn concentrations in the most mobile fraction of the sediments reached 1035 mg kg−1, 261 mg kg−1, 45 mg kg−1 and 30 mg kg−1, respectively. By comparison, smelter slag and mining waste have a much lower impact on the waters and the mobile fraction of the sediments, while significantly increasing the total concentration of these potentially toxic elements in creek sediments.

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

Sign in / Sign up

Export Citation Format

Share Document