Start-up of bench-scale biofilters for manganese removal under tropical conditions: A comparative study using virgin pumice, silica sand, and anthracite filter media

2021 ◽  
Author(s):  
José Andrés Araya Obando ◽  
Luuk Rietveld ◽  
Andrea Quesada-González ◽  
Andrey Caballero-Chavarría ◽  
Virginia A Pacini ◽  
...  
Keyword(s):  
Comparative Study ◽  
Silica Sand ◽  
Filter Media ◽  
Bench Scale ◽  
Manganese Removal ◽  
Start Up ◽  
Tropical Conditions ◽  
The Tropics

Biofiltration for Mn removal has not been proven in the tropics (18-29°C). Also, the use of pumice as alternative filter media for Mn removal is still poorly known. In this...

Manganese removal in groundwater treatment: practice, problems and probable solutions

2009 ◽  
Vol 9 (1) ◽  
pp. 89-98 ◽  
Author(s):  
R. Buamah ◽  
B. Petrusevski ◽  
D. de Ridder ◽  
T. S. C. M. van de Wetering ◽  
J. C. Shippers
Keyword(s):  
Ferric Hydroxide ◽  
Manganese Concentration ◽  
Filter Media ◽  
Sand Filters ◽  
Operational Conditions ◽  
Treatment Practice ◽  
Bench Scale ◽  
Manganese Removal ◽  
Removal Capacity ◽  
Start Up

Most drinking water production plants use rapid sand filters for the removal of manganese from groundwater. The start-up of manganese removal on newly installed sand media is slow, taking several weeks till months. Reducing this period in order to prevent the loss of water during this phase has become an issue of concern. In this study pilot and bench scale experiments were conducted to investigate the mechanism, influence of operational conditions (e.g. filtration rate, manganese loading) and measures that enhance manganese removal capacity of the sand media. Other filter media were investigated with the objective of finding suitable substitutes for the sand. The development of the adsorptive/catalytic coating the sand media in a pilot plant was very slow, notwithstanding the relatively high pH of 8. Low manganese concentration and more frequent backwashing resulted in a longer start up period of the manganese removal. It can not be excluded, that nitrite has a negative effect as well. Measurements in the lab and bench scale tests show that the rate of adsorption/oxidation of manganese in the top layer of the filter bed is too low to explain the complete manganese removal in the filters. It is likely that the adsorptive catalyst in the top layer has partly been covered with ferric hydroxide. From the Freundlich's isotherms determined for 6 different filter media, a crushed medium consisting of mainly manganese dioxide and some silica, iron and aluminium (Aquamandix) followed by iron oxide coated sand, containing some manganese, demonstrated highest adsorption capacities at pHs 6 and 8. These materials can therefore be potential substitutes for sand in situations of slow start-up of manganese removal.

scholarly journals Properties of catalyst for iron and manganese oxidation in filter materials

2018 ◽  
Vol 59 ◽  
pp. 00014 ◽  
Author(s):  
Joanna Jeż-Walkowiak ◽  
Malgorzata Komorowska-Kaufman ◽  
Zbysław Dymaczewski ◽  
Marek M. Sozański ◽  
Przemysław Zakrzewski
Keyword(s):  
Chemical Composition ◽  
Silica Sand ◽  
Natural Material ◽  
Filter Media ◽  
Manganese Oxidation ◽  
Manganese Removal ◽  
Filter Materials ◽  
Microstructure Parameters ◽  
Filtration Material ◽  
Iron And Manganese

The aim of this work is to determine the properties of contact layers of grain of different type of filter media in term of their suitability for catalytical manganese oxidation and auto-activation for manganese removal from groundwater. The following oxidative filtration materials were investigated: auto-activated silica sand taken from full-scale filters (oxide coated filter media), Pyrolox – manganese ore – natural material and Hydrolit – artificially activated material. As a reference two natural not chemically active materials were tested: clean silica sand and clean chalcedonite. The investigation resulted in chemical composition and microstructure parameters of catalyst contact layers of grains. The modern analytical methods were used: EDAX, Raman spectroscopy, mercury and helium porozymetry. The data indicated that catalyst from autoacivated filtration material has better chemical composition and porosity parameters in comparison to tested catalytic filtration materials, making it more suitable for adsorption and catalytic manganese oxidation.

A simple design and operation for the anaerobic treatment of highly concentrated swine waste in the tropics

1995 ◽  
Vol 32 (12) ◽  
pp. 91-97 ◽  
Author(s):  
P. Y. Yang ◽  
M. Kuroshima
Keyword(s):  
Treatment Process ◽  
Total Solid ◽  
Anaerobic Treatment ◽  
Solid Content ◽  
Total Solid Content ◽  
Treatment Processes ◽  
Tropical Conditions ◽  
Biological Reaction ◽  
The Tropics ◽  
Small Producers

In order to develop a simple operation for an anaerobic treatment process for highly concentrated pig wastewater for small producers, a three-stage anaerobic treatment process was investigated. The system provided a series of mixing, homogenization, biological reaction and final stabilization of concentrated pig waste (total solid content of 8–10%). The process provided a stable operational performance, simple operational procedure and well stabilized sludge effluent. It was also found that the system is economically feasible in Hawaii. Compared to the other treatment processes for highly concentrated pig waste, this process is considered as an appropriate alternative for the application of the small producers in land limited and tropical conditions. Also, the present treatment system can be easily developed into a prefabricated package plant which can minimize the on-site labor and building costs.

scholarly journals Kinetic Modeling and Mechanisms of Manganese Removal from Alkaline Mine Water Using a Pilot Scale Column Reactor

Minerals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 99
Author(s):  
Shigeshi Fuchida ◽  
Shota Tajima ◽  
Takuro Nishimura ◽  
Chiharu Tokoro
Keyword(s):  
Kinetic Modeling ◽  
Mine Water ◽  
Pilot Scale ◽  
Silica Sand ◽  
Edge Structure ◽  
Column Reactor ◽  
Molar Ratios ◽  
Manganese Removal ◽  
Water Ph ◽  
Xanes Analysis

Manganese (Mn) is a major element in various aqueous and soil environments that is sometimes highly concentrated in mine water and other mineral processing wastewater. In this study, we investigated Mn removal from alkaline mine water (pH > 9) with an Mn-coated silica sand packed into a pilot-scale column reactor and examined the specific reaction mechanism using X-ray absorption near-edge structure (XANES) analysis and geochemical kinetic modeling. The kinetic effect of dissolved Mn(II) removal by birnessite (δ-Mn(IV)O2) at pH 6 and 8 was evaluated at different Mn(II)/Mn(IV) molar ratios of 0.1–10. Our results confirmed the positive effect of the presence of δ-MnO2 on the short-term removal (60 min) of dissolved Mn. XANES analysis results revealed that δ-MnO2 was more abundant than Mn(III)OOH in the reactor, which may have accumulated during a long-term reaction (4 months) after the reactor was turned on. A gradual decrease in dissolved Mn(II) concentration with depth was observed in the reactor, and comparison with the kinetic modeling result confirmed that δ-MnO2 interaction was the dominant Mn removal mechanism. Our results show that δ-MnO2 contents could play a significant role in controlling Mn removability from mine water in the reactor.

Rapid Start-Up of Biofilter for Removal of Iron and Manganese from Groundwater

2010 ◽  
Vol 113-116 ◽  
pp. 1316-1319 ◽  
Author(s):  
Hui Ping Zeng ◽  
Dong Li ◽  
Jie Zhang
Keyword(s):  
Removal Efficiency ◽  
Quartz Sand ◽  
Manganese Removal ◽  
Start Up ◽  
Iron And Manganese

“aged” biofilter media was adopted as the inoculum to accelerate the maturation of biofilter for iron and manganese removal in the start-up of filter column. morphology of “aged” biofilter media and new quartz sand was observed with SEM. The results indicate that the “aged” biofilter media coated by a large quantity of bacteria which reduces the start-up time to 30 daysand affords strong Mn-removal efficiency at the beginning of the process. This method probably can be used for the start-up of new filters when there are well-established biofilters around.

The use of diets containing high levels of copra meal for growing/finishing pigs

1997 ◽  
Vol 1987 ◽  
pp. 97-97
Author(s):  
P.J. Thorne ◽  
J. Wiseman ◽  
D.J.A. Cole
Keyword(s):  
Coconut Oil ◽  
Oil Industry ◽  
The Philippines ◽  
Finishing Pigs ◽  
Poor Growth ◽  
Copra Meal ◽  
Potential Source ◽  
Tropical Conditions ◽  
The University ◽  
The Tropics

Copra meal is a by-product of the coconut oil industry and is a potential source of protein and energy in the diets of pigs and poultry in the tropics. However, previous studies with pigs have suggested that its use may be limited because of poor growth performance associated with levels of inclusion above 300 g/kg (Creswell and Brooks, 1971). The experiment reported here and conducted under tropical conditions at the University of the Philippines at Los Banos was designed to study possible ways of feeding copra meal at levels of inclusion greater than 300 g/kg in the diets of pigs while maintaining acceptable animal performance.

scholarly journals Bench-Scale Experiments on Effects of Pipe Flow and Entrapped Air in Soil Layer on Hillslope Landslides

Geosciences ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 138 ◽  
Author(s):  
Yasutaka Tanaka ◽  
Taro Uchida ◽  
Hitoshi Nagai ◽  
Hikaru Todate
Keyword(s):  
Water Supply ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soil Layer ◽  
Silica Sand ◽  
Bench Scale ◽  
Drainage Capacity ◽  
Entrapped Air ◽  
Model Slope

Soil pipes are commonly found in landslide scarps, and it has been suggested that build-up of pore water pressure due to clogged soil pipes influences landslide initiation. Several researchers have also suggested that entrapped air in the soil layer increases the pore water pressure. We carried out bench-scale model experiments to investigate the influence of soil pipes and entrapped air on the build-up of pore water pressure. We installed a water supply system consisting of an artificial rainfall simulator, and used a water supply tank to supply water to the model slope and artificial pipe. We used two types of artificial pipe: A straight pipe, and a confluence of three pipes. Furthermore, we placed a layer of silica sand on top of the model slope to investigate the effect of entrapped air in the soil layer on the build-up of pore water pressure. Silica sand is finer than the sand that we used for the bulk of the model slope. Our results indicate that, although artificial pipes decrease the pore water pressure when the amount of water supplied was smaller than the pipe drainage capacity, the pore water pressure increased when the water supply was too large for the artificial pipe to drain. In particular, the confluence of pipes increased the pore water pressure because the water supply exceeded the drainage capacity. The results also indicate that entrapped air increases the pore water pressure in the area with relatively low drainage capacity, too. Based on these results, we found that although soil pipes can drain a certain amount of water from a soil layer, they can also increase the pore water pressure, and destabilize slopes. Furthermore, entrapped air enhances the trend that the pore water pressure can increase in the area with relatively low drainage capacity, as pore water pressure increases when too much water is supplied, and the artificial pipe cannot drain all of it.

Effect of dietary energy intake during pregnancy on liveweight gain and backfat gain of primiparous sows kept in an outdoor system under tropical conditions

2000 ◽  
Vol 2000 ◽  
pp. 107-107
Author(s):  
R. H. Santos Ricalde ◽  
I. J. Lean
Keyword(s):  
Energy Level ◽  
Energy Intake ◽  
Energy Requirements ◽  
Dietary Energy ◽  
Feeding Management ◽  
Dietary Energy Intake ◽  
Tropical Environments ◽  
Tropical Conditions ◽  
Feeding Resources ◽  
The Tropics

Energy requirements for maintenance in pregnant sows increase when they are kept outdoors under temperate climates in comparison to indoors. However, there is little information on the energy requirements of breeding sows kept outdoors in tropical environments. Knowledge about the correct feeding management for pregnant sows kept outdoors will optimise the utilisation of feeding resources available in the tropics. The aim of this study was to evaluate the effect of energy level supply during pregnancy on backfat change and liveweight change of primiparous sows kept outdoors under tropical conditions.

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