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.

Performance of Aerated Lagoons in Treating Wastewater from Small Communities

1987 ◽  
Vol 19 (1-2) ◽  
pp. 65-76 ◽  
Author(s):  
K. S. Narasiah ◽  
C. Morasse ◽  
M. Larue
Keyword(s):  
Retention Time ◽  
Treatment Plant ◽  
Extreme Temperature ◽  
Developed Countries ◽  
Point Of View ◽  
Power Requirement ◽  
Small Communities ◽  
Treatment Processes ◽  
Waste Stabilization ◽  
Developing And Developed Countries

Aerated lagoons are used in developing and developed countries to treat domestic and industrial wastewater especially from small communities. They represent a reliable method of biological treatment capable of producing satisfactory effluent throughout the year. They are preferred to several other treatment processes like the activated sludge because of the simplicity of the overall system, less need for trained operator assistance and very competitive overall cost of wastewater treatment. In Québec where there are some 1400 small municipalities this method of treatment is found to perform satisfactorily, notwithstanding the extreme temperature variations. The objective of the present study is to evaluate the performance of this method of waste stabilization from the point of view of organic removal, retention time, power requirement and nutrient removal without chemical coagulation. An existing treatment plant with aerated lagoons was used for the study. The results show that a summer retention time of about 8 days can produce an effluent having 20-25 mg/L of BOD, 20 mg/L of SS and 2-3 mg/L of total phosphates without coagulant addition.

Housing Inflation: Policy Guidelines from Shariah Perspective

2019 ◽  
Vol 16 (1) ◽  
pp. 70-81
Author(s):  
Azrul Azlan Iskandar Mirza ◽  
Asmaddy Haris ◽  
Ainulashikin Marzuki ◽  
Ummi Salwa Ahmad Bustamam ◽  
Hamdi Hakiem Mudasir ◽  
...  
Keyword(s):  
Content Analysis ◽  
Housing Prices ◽  
Construction Materials ◽  
Housing Price ◽  
Developed Countries ◽  
Control Element ◽  
Recent Issue ◽  
Analysis Methodology ◽  
The Government ◽  
Developing And Developed Countries

The soaring housing prices in Malaysia is not a recent issue. It is a global phenomenon especially in developing and developed countries, driven by factors including land price, location, construction materials cost, demand, and speculation. This issue demands immediate attention as it affects the younger generation, most of whom could not afford to buy their own house. The government has taken many initiatives and introduced regulations to ensure that housing prices are within the affordable range. This article aims to introduce a housing price control element from the Shariah perspective, as an alternative solution for all parties involved in this issue. It adopts content analysis methodology on policy from Shariah approved sources.

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.

Improving the biological stability of drinking water by ion exchange

2011 ◽  
Vol 11 (1) ◽  
pp. 107-112 ◽  
Author(s):  
A. Grefte ◽  
M. Dignum ◽  
S. A. Baghoth ◽  
E. R. Cornelissen ◽  
L. C. Rietveld
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Ion Exchange ◽  
Biofilm Formation ◽  
Formation Rate ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Biological Stability ◽  
Biological Activated Carbon ◽  
Pre Treatment

To guarantee a good water quality at the consumer’s tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research is to measure the effect of NOM removal by ion exchange on the biological stability of drinking water. Experiments were performed in two lanes of the pilot plant of Weesperkarspel in the Netherlands. The lanes consisted of ozonation, softening, biological activated carbon filtration and slow sand filtration. Ion exchange in fluidized form was used as pre-treatment in one lane and removed 50% of the dissolved organic carbon (DOC); the other lane was used as reference. Compared to the reference lane, the assimilable organic carbon (AOC) concentration of the finished water in the lane pretreated by ion exchange was 61% lower. The biofilm formation rate of the finished water was decreased with 70% to 2.0 pg ATP/cm2.day. The achieved concentration of AOC and the values of the biofilm formation rate with ion exchange pre-treatment showed that the biological stability of drinking water can be improved by extending a treatment plant with ion exchange, especially when ozonation is involved as disinfection and oxidation step.

Water Treatment Considerations–Aquatic Humus

1983 ◽  
Vol 15 (S2) ◽  
pp. 95-101 ◽  
Author(s):  
E T Gjessing
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Humic Substances ◽  
Health Effects ◽  
Surface Waters ◽  
Cold Climate ◽  
Treatment Processes ◽  
Aquatic Humus ◽  
Treatment Considerations

For several reasons the surface waters in cold climate areas are coloured due to humic substances. There are two major objections against humus in drinking water, the first is concerned with aesthetical and practical problems and the second is due to indirect negative health effects. There are essentially three different methods in use today for the removal or reduction of humus colour in water: (1) Addition of chemicals with the intention of reducing the “solubility”, (2) Addition of chemicals in order to bleach or mineralize the humus, and (3) Filtration with the intention of removal of coloured particles and some of the “soluble” colour. The treatment processes are discussed.

scholarly journals Income, wealth and use of personal protection equipment in the Mekong Delta

2021 ◽  
Author(s):  
Matteo Migheli
Keyword(s):  
Low Income ◽  
Mekong Delta ◽  
Developed Countries ◽  
Household Wealth ◽  
Protective Equipment ◽  
Personal Protection ◽  
Personal Protection Equipment ◽  
Management Techniques ◽  
Using Data ◽  
Developing And Developed Countries

AbstractBoth in developing and developed countries, farmers often do not protect themselves adequately, especially when applying agrochemicals that are dangerous for their health. The issue is relevant because insufficient protection is between the causes leading to intoxication of farmers and workers who handle these products. The literature suggests that both lack of training and information and low income may explain why, especially in developing countries, protective equipment is under-used. Using data from the Mekong Delta, this study addresses the issue of whether income and household wealth may help explaining the use of incomplete protections against pesticides. The results suggest that income, more than wealth, is a reason why Vietnamese farmers operating in the Mekong Delta fail in using adequate protections. In particular, the data suggest that they may prefer to divert resources to increasing the production of their fields or to buying goods that may be used both as protection and as everyday garments. This behaviour leads to underinvestment in some important protective goods. Possible public interventions to mitigate the problem are suggested; in particular, the promotion of integrated pest management techniques could be useful.

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