Pre-Treatment of Algal-Laden Water using Volcanic Ash in a Dual Media Filtration System

2010 ◽  
Author(s):  
H.M. Kalibbala ◽  
E. Plaza ◽  
O. Wahlberg ◽  
R. Kaggwa
Keyword(s):  
Volcanic Ash ◽  
Filtration System ◽  
Pre Treatment

Use of volcanic ash and its impact on algae proliferation in drinking water filtration

2013 ◽  
Vol 3 (2) ◽  
pp. 199-206
Author(s):  
Kalibbala Herbert Mpagi ◽  
Kaggwa Rose ◽  
Plaza Elzbieta
Keyword(s):  
Drinking Water ◽  
Volcanic Ash ◽  
Developed Countries ◽  
Intact Cells ◽  
Treatment Processes ◽  
Filtration System ◽  
Sustainable Water Supply ◽  
Water Supply And Treatment ◽  
Pre Treatment ◽  
Developing And Developed Countries

With increasing pollution of the available water resources, development of safe drinking water supplies is increasingly becoming a challenge, both for developing and developed countries. To alleviate the prevailing difficulties, approaches should focus on sustainable water supply and treatment systems that require minimal maintenance and operator skills. In this study, a pre-treatment of water containing algae using a combination of volcanic ash (VA) and sand in a filtration system was assessed. The results indicated that a combination of VA and sand performed better in the removal of algae than sand alone. However, it was noted that different algae genera were removed at different rates within the two types of media arrangement. In addition, there was an increase in the filtration run length of the ash-sand columns with VA on top of sand of about two and half times compared with the sand columns. It is therefore anticipated that pre-treatment of raw water laden with algae using ash-sand would probably improve on the performance of the subsequent conventional processes in removing intact cells of algae and thus reduce the threat of releasing toxins into the water that may not be removed by the subsequent conventional treatment processes.

Low-pressure membrane filtration with unconventional coagulation regimes

2005 ◽  
Vol 5 (5) ◽  
pp. 1-8 ◽  
Author(s):  
K.Y. Choi ◽  
B.A. Dempsey
Keyword(s):  
Activated Carbon ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Cross Flow ◽  
Chemical Cleaning ◽  
Sand Filters ◽  
Charge Neutralization ◽  
Floc Size ◽  
Filtration System ◽  
Pre Treatment

The objective of the research was to evaluate in-line coagulation to improve performance during ultrafiltration (UF). In-line coagulation means use of coagulants without removal of coagulated solids prior to UF. Performance was evaluated by removal of contaminants (water quality) and by resistance to filtration and recovery of flux after hydraulic or chemical cleaning (water production). We hypothesized that coagulation conditions inappropriate for conventional treatment, in particular under-dosing conditions that produce particles that neither settle nor are removed in rapid sand filters, would be effective for in-line coagulation prior to UF. A variety of pre-treatment processes for UF have been investigated including coagulation, powdered activated carbon (PAC) or granular activated carbon (GAC), adsorption on iron oxides or other pre-formed settleable solid phases, or ozonation. Coagulation pre-treatment is often used for removal of fouling substances prior to NF or RO. It has been reported that effective conventional coagulation conditions produced larger particles and this reduced fouling during membrane filtration by reducing adsorption in membrane pores, increasing cake porosity, and increasing transport of foulants away from the membrane surface. However, aggregates produced under sweep floc conditions were more compressible than for charge neutralization conditions, resulting in compaction when the membrane filtration system was pressurized. It was known that the coagulated suspension under either charge-neutralization or sweep floc condition showed similar steady-state flux under the cross-flow microfiltration mode. Another report on the concept of critical floc size suggested that flocs need to reach a certain critical size before MF, otherwise membranes can be irreversibly clogged by the coagulant solids. The authors were motivated to study the effect of various coagulation conditions on the performance of a membrane filtration system.

scholarly journals Comparative environmental impact evaluation using life cycle assessment approach: a case study of integrated membrane-filtration system for the treatment of aerobically-digested palm oil mill effluent

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Yeit Haan Teow ◽  
Meng Teck Chong ◽  
Kah Chun Ho ◽  
Abdul Wahab Mohammad
Keyword(s):  
Activated Carbon ◽  
Life Cycle ◽  
Palm Oil ◽  
Membrane Filtration ◽  
Electricity Consumption ◽  
Sand Filters ◽  
Unit Operations ◽  
Filtration System ◽  
Pre Treatment ◽  
Aerobically Digested

AbstractAiming to mitigate wastewater pollution arising from the palm oil industry, this university-industry research-and-development project focused on the integration of serial treatment processes, including the use of moving bed biofilm reactor (MBBR), pre-treatment with sand filters and activated carbon filters, and membrane technology for aerobically-digested palm oil mill effluent (POME) treatment. To assess the potential of this sustainable alternative practice in the industry, the developed technology was demonstrated in a pilot-scale facility: four combinations (Combinations I to IV) of unit operations were developed in an integrated membrane-filtration system. Combination I includes a MBBR, pre-treatment unit comprising sand filters and activated carbon filters, ultrafiltration (UF) membrane, and reverse osmosis (RO) membrane, while Combination II excludes MBBR, Combination III excludes UF membrane, and Combination IV excludes both MBBR and UF membrane. Life cycle assessment (LCA) was performed to evaluate potential environmental impacts arising from each combination while achieving the goal of obtaining recycled and reusable water from the aerobically-digested POME treatment. It is reported that electricity consumption is the predominant factor contributing to most of those categories (50–77%) as the emissions of carbon dioxide (CO2), sulfur dioxide (SO2), nitrogen oxides, and volatile mercury during the combustion of fossil fuels. Combination I in the integrated membrane-filtration system with all unit operations incurring high electricity consumption (52 MJ) contributed to the greatest environmental impact. Electricity consumption registers the highest impact towards all life cycle impact categories: 73% on climate change, 80% on terrestrial acidification, 51% on eutrophication, and 43% on human toxicity. Conversely, Combination IV is the most environmentally-friendly process, since it involves only two-unit operations – pre-treatment unit (comprising sand filters and activated carbon filters) and RO membrane unit – and thus incurs the least electricity consumption (41.6 MJ). The LCA offers insights into each combination of the operating process and facilitates both researchers and the industry towards sustainable production.

scholarly journals Laboratory analysis of a system for catchment, pre-treatment and treatment (SCPT) of runoff from impervious pavements

2010 ◽  
Vol 61 (7) ◽  
pp. 1845-1852 ◽  
Author(s):  
A. H. Fernández-Barrera ◽  
J. Rodriguez-Hernandez ◽  
D. Castro-Fresno ◽  
A. Vega-Zamanillo
Keyword(s):  
High Capacity ◽  
Regression Equations ◽  
System Configuration ◽  
Treatment Efficiency ◽  
Online System ◽  
Filtration System ◽  
Pre Treatment ◽  
Inflow Conditions ◽  
Laboratory Prototype ◽  
Pollution Loads

This article reports the development and construction of a 1:1 scale laboratory prototype of a System for Catchment, Pre-treatment and Treatment (SCPT) of runoff polluted by contaminants washed from impervious pavements. The concept of the SCPT is an online system with an up-flow filter. The filter is composed of geotextile layers and limestone. The laboratory tests carried out were focused on determining the SCPT prototype behaviour under different working conditions. The variables studied were: inflow, pollutant loads and filtration system configuration. The results show that the system designed has a high capacity for treatment of solids and oil, with an average efficiency of 85% and 97% respectively. Moreover, the regression equations of the treatment efficiency were determined for each of the pollutants studied, for different inflow conditions and pollution loads.

Hybrid filtration method for pre-treatment of stormwater

2010 ◽  
Vol 62 (12) ◽  
pp. 2937-2943 ◽  
Author(s):  
M. A. H. Johir ◽  
S. Vigneswaran ◽  
J. Kandasamy
Keyword(s):  
Removal Efficiency ◽  
Suspended Solids ◽  
Hybrid Filter ◽  
Filtration Method ◽  
Zinc Removal ◽  
Filtration System ◽  
Lead Zinc ◽  
Pre Treatment ◽  
Modified Fouling Index ◽  
Solids Removal

In this study the hybrid filtration process (combining fibre filter with deep bed dual media filtration) was investigated as pre-treatment to stormwater. This process was investigated in-terms of reduction in turbidity, dissolved organic carbon (DOC), colour, headloss development across the filters, suspended solids removal, organic matter removal, nutrients and heavy matter (such as iron, copper, lead, zinc) removal efficiency. A comparison was made between the hybrid filter with single media (sand) deep bed filter and fibre filter. It was found that the hybrid filtration system successfully removed turbidity (98%), colour (99%), suspended solids (99%), and DOC (55%). The removal efficiency of heavy metal was relatively low as the concentration of heavy metals present in stormwater was low. The removal efficiency of nitrate, nitrite and phosphorous (as orthophosphate) was 27, 35 and 72% respectively. Hybrid filtration processes showed a better reduction of Modified Fouling Index (MFI) value (from 15.500 s/l2 to 9 s/l2) compared with single media sand, anthracite and fibre filter which were 35 s/l2, 13 s/l2and 14 s/l2 respectively when operated at FeCl3 dose of 15 mg/l.

scholarly journals Cellulose Acetate Textile Fiber Filtration System Applied for Pre-Treatment of Surface Water

2022 ◽  
Vol 45 ◽  
Author(s):  
Ana Silvia De Lima Vielmo ◽  
Ailton Borges Rodrigues ◽  
Eduardo Volkart da Rosa ◽  
Dayane Gonzaga Domingos ◽  
Juliana Barden Schallemberger ◽  
...  
Keyword(s):  
Surface Water ◽  
Cellulose Acetate ◽  
Surface Waters ◽  
Cigarette Butts ◽  
Filtration System ◽  
Apparent Color ◽  
Cellulose Acetate Fiber ◽  
Pre Treatment ◽  
And Performance ◽  
True Color

This study aimed to evaluate a nonwoven (NW) production and performance from cellulose acetate fiber from cigarette butts andapplied to a filtration system for surface water pre-treatment. The system had a surface area of 692 cm³, cellulose acetate from cigarette butt as filter media, was used and was fed with surface water from a pond. In order to evaluate the treatment performance of the filtration system were evaluated in the raw water (RW) and the filtered water (FW) the classical parameter of water quality as turbidity, total suspended solids (TSS), apparent color, true color, and total organic carbon (TOC) and heavy metals (iron, copper, and cadmium). Moreover, the presence of nicotine was investigated in the FW. The results showed a mean removal efficiency in order to 62.01%, 54.42%, 50.36 %, 6.73%, and 5.20% for turbidity, TSS, apparent color, true color, and TOC, respectively. The removal of metals varied in the order of 72.26%, 9.61%, and 2.12% for cadmium, iron, and copper, respectively. The presence of nicotine in RW and FW was not identified. In this way, besides reducing the negative environmental impacts caused by cigarette butts present in the environment, the developed technology showed potential for removing pollutants present in surface waters.

EELS characterization of “Smut” layer films on steel surface prepared for chrome plating by anodic etching

1995 ◽  
Vol 53 ◽  
pp. 538-539
Author(s):  
E Y. Wang ◽  
J. T. Cherian ◽  
A. Madsen ◽  
R. M. Fisher
Keyword(s):  
Steel Surface ◽  
Surface Preparation ◽  
Treatment Method ◽  
Chrome Plating ◽  
Transmission Electron ◽  
Alloy Steels ◽  
Pre Treatment ◽  
Hard Chrome ◽  
Electron Energy Loss

Many steel parts are electro-plated with chromium to protect them against corrosion and to improve their wear-resistance. Good adhesion of the chrome plate to the steel surface, which is essential for long term durability of the part, is extremely dependent on surface preparation prior to plating. Recently, McDonnell Douglas developed a new pre-treatment method for chrome plating in which the steel is anodically etched in a sulfuric acid and hydrofluoric acid solution. On carbon steel surfaces, this anodic pre-treatment produces a dark, loosely adhering material that is commonly called the “smut” layer. On stainless steels and nickel alloys, the surface is only darkened by the anodic pre-treatment and little residue is produced. Anodic pre-treatment prior to hard chrome plating results in much better adherence to both carbon and alloy steels.We have characterized the anodic pre-treated steel surface and the resulting “smut” layer using various techniques including electron spectroscopy for chemical analysis (ESCA) on bulk samples and transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) on stripped films.

Evaluating the effect of a group pre-treatment chemotherapy psycho-education session for chemotherapy-naive gynecologic cancer patients and their caregivers

2021 ◽  
Vol 160 (1) ◽  
pp. 234-243
Author(s):  
Diana Samoil ◽  
Nazek Abdelmutti ◽  
Lisa Ould Gallagher ◽  
Nazlin Jivraj ◽  
Naa Kwarley Quartey ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Gynecologic Cancer ◽  
Education Session ◽  
Pre Treatment
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