The influence of agitation on aggregates formed during treatment of water with a content of humic substances

2006 ◽  
Vol 6 (1) ◽  
pp. 211-218 ◽  
Author(s):  
L. Pivokonska ◽  
M. Pivokonsky
Keyword(s):  
Humic Substances ◽  
Velocity Gradient ◽  
Laboratory Tests ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Aluminium Chloride ◽  
Velocity Gradients ◽  
Perforated Baffle ◽  
Wide Size Distribution

This study aims to evaluate the influence of agitation conditions on the efficiency of the aggregation process when treating surface water containing humic substances. Laboratory tests were conducted by the jar tests using a variable speed paddle gang stirrer. Optimization of agitation intensity was determined by a Couette flocculator. Suspension was prepared using aluminium chloride as a destabilising reagent. Aggregation efficiency was evaluated by the determination of the degree of aggregation and by the test of aggregation. For all surface waters treated, the optimum treatability was demonstrated by applying higher velocity gradients (G=200–250 s−1). In addition to the laboratory tests, the plant measurements with water containing increased amounts of humic substances were taken to evaluate the aggregation efficiency. The results obtained by the aggregation efficiency measurements show that the intensity of agitation, with the assistance of perforated baffle-type flocculation chamber, attains a low level of velocity gradient (G=22–113 s−1), in contrast to the optimized velocity gradient level (G=200–250 s−1). The aggregates formed in the water treatment plant have an unsuitably wide size-distribution.

Up-flow roughing filtration: rehabilitation of a water treatment plant in Tarata, Bolivia

1998 ◽  
Vol 37 (9) ◽  
pp. 105-112 ◽  
Author(s):  
Ana María Ingallinella ◽  
Luis María Stecca ◽  
Martin Wegelin
Keyword(s):  
Water Treatment ◽  
Pilot Plant ◽  
Laboratory Tests ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Horizontal Flow ◽  
Design Parameters ◽  
Sand Filters ◽  
Chemical Products ◽  
Made In

This paper presents the methodology used for the rehabilitation of the pretreatment stage in a water treatment plant for a village located in Bolivia which has 3500 inhabitants. The treatment plant was initially composed by horizontal-flow roughing filters and slow sand filters, but due to the high contents of colloidal turbidity of the providing source, it did not work properly. A plan of rehabilitation was made which comprised laboratory tests, pilot tests and proposal of modifications based on the results of previous stages. The laboratory tests were made in order to find the optimum conditions to coagulate the raw water. It was found that horizontal-flow roughing filters must be turned into up-flow roughing filters, so a pilot plant was built and was operated for three months in order to find suitable design parameters. The results obtained obtained during the operation of the pilot plant and the proposal of modifications are presented. The results of operation of the final plant, which are also reported, demonstrated the advantages of the up-flow roughing filtration as a pretreatment stage when it is necessary to add chemical products in small treatment plants.

scholarly journals Improving chemical cleaning of fouled membranes in a drinking water treatment plant

2019 ◽  
Vol 19 (8) ◽  
pp. 2330-2337
Author(s):  
Susumu Hasegawa ◽  
Yasuhiro Tanaka ◽  
Naokazu Wake ◽  
Ryosuke Takagi ◽  
Hideto Matsuyama
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Humic Substances ◽  
Sodium Hypochlorite ◽  
Membrane Fouling ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Chemical Cleaning ◽  
Water Treatment Plants

Abstract Recently, membrane filtration systems have become increasingly common in drinking water treatment plants. In this industry, preventing membrane fouling is of utmost importance. Many studies on the relationship between raw water components and membrane fouling have been performed in laboratory conditions. However, very few studies have analyzed the components of foulants on the fouled membrane as operated in actual drinking water treatment plants. By analyzing these components in plant-conditions, membrane fouling will be more effectively prevented. In this study, we analyzed the components of foulants extracted with 0.1 N NaOH from a fouled membrane operated in a drinking water treatment plant in Japan. Our analysis revealed that the main foulants were humic substances. In order to dissolve the accumulated humic substances, additional chemical cleaning was attempted with 500 ppm sodium hypochlorite. As a result, it was found that humic substances were dissolved and filtration resistance significantly decreased. Additionally, the removal of inorganic foulants was also greater after chemical cleaning with 500 ppm sodium hypochlorite, as inorganic foulants trapped within humic substances were released to the membrane surface as hydroxides by the additional sodium hypochlorite cleaning and were dissolved by the periodic citric acid cleaning.

scholarly journals VALIDATION OF THE METHODS OF Hg DETERMINATION ON WASTE WATER TREATMENT PLANT SAMPLES USING COLD VAPOUR-ATOMIC ABSORPTION SPECTROPHOTOMETER (CV-AAS)TECHNIQUES

2018 ◽  
Vol 16 (1) ◽  
pp. 10
Author(s):  
Rika Anggraini ◽  
Rita Hairani ◽  
Aman Sentosa Panggabean
Keyword(s):  
Atomic Absorption ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Atomic Absorption Spectrophotometer ◽  
Waste Water Treatment Plant ◽  
Cold Vapour ◽  
Repeatability And Reproducibility ◽  
Aas Method

The research about validation of the method of Hg determination on the sample from wastewater treatment plant (WWTP) PT. Badak NGL Bontang, Kalimantan Timur using cold vapour-atomic absorption spectrophotometer (CV-AAS) techniques has been conducted. To obtain a valid measurement result, determinations of the important several parameters that influence the method validation are used. The results of research showed that 20% SnCl2 solution could be used as a reducing agent. The analytic performance of measurement obtain is good, showed with the linearity (r) value ≥ 0.995, LOD was 0.2530 ppb, LOQ was 0.8432 ppb, MDL was 0.6427 ppb and repeatability and reproducibility are shown as % RSD < 2/3 CV Horwitz values. The accuracy of this method is very good with a percentage of recovery value of 114.88%. Based on the results of this research, CV-AAS method can be used in the determination of Hg in WWTP samples with the valid results.

Reagentless-Continuous Flow Method for Determination of Aqueous Ozone with Thin Film Semiconductor and Application to an Advanced Water Treatment Plant

1991 ◽  
Vol 23 (10-12) ◽  
pp. 1961-1968 ◽  
Author(s):  
T. Aoki ◽  
H. Oguro ◽  
K. Fujiyoshi ◽  
M. Yamamoto
Keyword(s):  
Thin Film ◽  
Water Treatment ◽  
Treatment Plant ◽  
Glass Tube ◽  
Water Treatment Plant ◽  
Treatment Processes ◽  
Relative Standard ◽  
Clean Air ◽  
Ultra Trace

A method without any reagent for the determination of ultra-trace aqueous ozone, utilizing a glass tube-separation process and a thin film semiconductor, is proposed. The glass tube was used as the separator to transfer ozone from water into a gas phase. Ozone was transferred into clean air flowing in the tube and then was continuously monitored at the thin film semiconductor. Signals were proportional to concentration of aqueous ozone more than 5 µ g/L. The relative standard deviation (n = 7) las 3.8 % at 7.6 µ g/L. The interference from hydrogen peroxide, mono-chloramine, and dichloramine, was completely eliminated. The present method was applied to an advanced water treatment pilot-plant incorporating two parallel treatment trains and was examined for its potential for monitoring aqueous ozone in treatment processes.

Managing an odour episode in Barcelona's water supply: strategies adopted, the causative agent (diacetyl) and determination of its organoleptic properties

2007 ◽  
Vol 55 (5) ◽  
pp. 209-216 ◽  
Author(s):  
J. Martín-Alonso ◽  
R. Devesa ◽  
A. Bernal ◽  
L. Matia
Keyword(s):  
Treatment Plant ◽  
Sampling Strategy ◽  
Water Treatment Plant ◽  
Paper Mill ◽  
Industrial Area ◽  
Plant Distribution ◽  
Customer Complaints ◽  
Organoleptic Characteristics ◽  
Odour Threshold

The Llobregat River is a basic drinking water resource for the city of Barcelona, meeting 40% of the demand. The river runs through a densely populated industrial area, so that it has in its history experienced various episodes due to industrial spills. The present work deals with a recent episode involving diacetyl. To the best of our knowledge this episode is the first time that this compound has been identified as an odour-causing compound in water. In a previous work the analytical method used for the identification of the compound causing the episode was described. The present work focuses its attention on how the episode was handled: action taken at the Sant Joan Despí water treatment plant and the sampling strategy on the river that led to the identification of the company responsible for the spill, a paper mill. It also deals with the role played by the FPA panel in the resolution of the episode: organoleptic description of samples of the problem in the initial phase of the episode (from the treatment plant, distribution network and customer complaints) and, once the compound responsible was identified, the determination of its organoleptic characteristics (odour threshold, odour descriptors, Weber-Fechner curve).

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