Use of chitosan in coagulation flocculation of raw water of Keddara and Beni Amrane dams

2011 ◽  
Vol 11 (2) ◽  
pp. 202-210 ◽  
Author(s):  
Hassiba Zemmouri ◽  
Slimane Kadouche ◽  
Hakim Lounici ◽  
Madjid Hadioui ◽  
Nabil Mameri

The effectiveness of chitosan as a coagulant flocculant in surface water treatment has been studied. Tests were carried out in laboratory on treated and raw water. The treated water was mixed with high and low concentrations of bentonite to simulate turbid water. This treated water provides from water treatment plant of Algiers (Boudouaou site) which is supplied by both dams of Keddara and Beni Amrane. The raw water comes directly from these two dams. Chitosan with 85% degree of deacetylation and derived from crab chitin has been used. The performance of coagulation flocculation process has been assessed by measuring the supernatant turbidity for different doses of chitosan, initial turbidity, water quality and pH. The obtained results show that chitosan can be used in a large pH range. Chitosan is effective for coagulation of bentonite suspension and for raw water with high initial turbidity. Otherwise, chitosan is inefficient for raw water with very low initial turbidity. In this case, the use of chitosan as aid coagulant with aluminium sulfate (main coagulant) allows more effectiveness in removing turbidity.

2019 ◽  
Vol 6 (2) ◽  
pp. 121-138
Author(s):  
Imad Ali Omar

Abstract: Water treatment plant (WTP) is essential for providing clean and safe water to the habitants. There is a necessity to evaluate the performance of (WTP) for proper treatment of raw water. The purpose of the present study is to evaluate the quality of treated water by investigating the performance of Ifraz-2 (WTP) units located in Erbil City, Iraq. For assessment of the (WTP) units, samples were taken for a duration of five months from different locations: raw water (the source), post-clarification processes, post-filtration processes, and from the storage tank. Removal efficiencies for the units, and for the whole (WTP) were calculated and presented. Obtained removal efficiencies for the sedimentation unit; filtration unit; and the entire Ifraz-2 (WTP) were 91.51 %, 64.71 %, and 97.29 %, respectively. After the process of disinfection and storage, the valued of the turbidity of the treated water were ranged from 1.2 to 9.7 (Nephelometric Turbidity Units) NTU. Besides, water quality index (WQI) for the (WTP) was studied and calculated for 14 physicochemical water quality parameters. WQI for Ifraz-2 (WTP) was 51.87 and it is regarded as a good level. Also, operational problems have been detected and reported during the research period, especially during sedimentation, filtration, and disinfection. Suitable solutions have been reported to the operational team.


1970 ◽  
Vol 23 (2) ◽  
pp. 133-136 ◽  
Author(s):  
M Alamgir Hossain ◽  
Tahmina Begum ◽  
ANM Fakhruddin ◽  
Sirajul Islam Khan

Bacteriological and physicochemical parameters of the raw and treated water of the Saidabad Water Treatment Plant were analysed during the period January through December 2004. It was found that during dry season Sitalakhya River water was adversely polluted and most of the bacteriological and physicochemical parameters increased to an alarming level. Total coliform and thermotolerant-coliform counts of raw water were highest in months of January through March and lowest during the months of April through November. Ammonia concentration of the raw water was very high (3.08-7.06 mg/l) during the dry months from January to April that coincided with high (2.57-6.08 mg/l) ammonia contamination in the treated water. The others physicochemical parameters like turbidity, conductivity, total dry solid (TDS), hardness and alkalinity were high during the dry months. The residual chlorine in treated water was always below 0.50 mg/l. The study clearly indicated that the load of coliform increased when the concentration of ammonia was high in raw water that, to some extent, influenced the aesthetic properties of the treated water like turbidity, colour, taste, odour, alkalinity, TDS, etc. In spit of that the treated water could be used for domestic and drinking purposes for most of the year. Keywords: Water quality, Total coliform, Thermotolerant-coliform, Ammonia, Physicochemical properties, Residual chlorine   DOI: http://dx.doi.org/10.3329/bjm.v23i2.878 Bangladesh J Microbiol, Volume 23, Number 2, December 2006, pp 133-136


2012 ◽  
Vol 12 (1) ◽  
pp. 56-64
Author(s):  
R. J. Swarts ◽  
J. J. Schoeman

The main aim of this study was to determine a treatment strategy for the Berg River water at the Voëlvlei water treatment plant (WTP). Jar tests were conducted using ferric and aluminium sulphate as coagulants to determine the optimum treatment parameters of the Berg River water and the Voëlvlei WTP raw water. The results for the Voëlvlei WTP raw water and the Berg River water with ferric sulphate as the coagulant showed an optimum Fe3+ dosage of 3.0–4.0 mg/L and 4.0–6.0 mg/L, respectively, with an optimum coagulation pH range of 6.6–9.5 and 5.0–10.0, respectively. The results with aluminium sulphate as the coagulant showed an optimum Al3+ dosage of 2.5–3.0 mg/L and 4.0–5.0 mg/L, respectively, with an optimum coagulation pH of 6.0–7.0 and 6.0, respectively. This study concluded that the Berg River water cannot be effectively treated at the Voëlvlei WTP using the plants treatment parameters, even if it is blended with the Voëlvlei WTP raw water. The best treatment strategy for the Berg River water would be pre-treatment using either ferric sulphate or the MIEX® resin on its own, or in conjunction with one another.


Author(s):  
Mohamed Deyab ◽  
Magda El-Adl ◽  
Fatma Ward ◽  
Eman Omar

Abstract This work aims to study the seasonal fluctuation in physicochemical characteristics, trophic status, and some pollutants influencing phytoplankton diversity, and water quality at a compact Kafr El-Shinawy drinking-water treatment plant, Damietta – Egypt seasonally during 2018. Phytoplankton distribution was affected by the trophic status of water, level of pollutants, and physicochemical treatment processes of water. The predominance of phytoplankton species, especially Aphanizomenon flos aquae (Cyanophyta), Gomphosphaeria lacustris (Cyanophyta), Microcystis aeruginosa (Cyanophyta), Nostoc punctiforme (Cyanophyta), Oscillatoria limnetica (Cyanophyta), Pediastrum simplex (Chlorophyta), and Melosira granulata (Bacillariophyta) in treated water was much less than that in raw water. Trihalomethanes (THMs) levels in treated waters were higher than in raw water, while lower concentrations of heavy metals were recorded in treated water. Intracellular levels of microcystins were lower, whereas the extracellular levels were higher in treated water than raw water, and the former recorded the highest level in raw water during summer. Hence, the levels of dissolved microcystins and THMs in treated water were higher especially during summer, the season of luxurious growth of Microcystis species. Trophic state index (TSI) was relatively high in raw water compared with treated water due to high concentrations of nutrients (total-P, total-N, nitrite, nitrate, and ammonia) in raw water.


Author(s):  
Fuguo Qiu ◽  
Huadong Lv ◽  
Xiao Zhao ◽  
Dongye Zhao

Climate change has often caused failure in water treatment operations. In this study, we report a real case study at a major surface water treatment plant in Alabama, USA. Following a severe winter storm, the effluent water turbidity surged to >15.00 Nephelometric Turbidity Units (NTU), far exceeding the 0.30 NTU standard. As a result, the plant operation had to be shut down for three days, causing millions of dollars of losses and affecting tens of thousands of people. Systematic jar tests were carried out with sediment samples from 22 upstream locations. The coagulation and settleability of sediment particles were tested under simulated storm weather conditions, i.e., low temperature (7 °C) and in the presence of various types and concentrations of natural organic matter (NOM) that was extracted from the local sediments. Experimental results proved that elevated NOM (6.14 mg·L−1 as Total Organic Carbon, TOC) in raw water was the root cause for the failure of the plant while the low temperature played a minor but significant role. Pre-oxidation with permanganate and/or elevated coagulant dosage were found effective to remove TOC in raw water and to prevent similar treatment failure. Moreover, we recommend that chemical dosages should be adjusted based on the TOC level in raw water, and a reference dosage of 0.29 kg-NaMnO4/kg-TOC and 19 kg- polyaluminum chloride (PACl) /kg-TOC would be appropriate to cope with future storm water impacts. To facilitate timely adjustment of the chemical dosages, the real time key water quality parameters should be monitored, such as turbidity, TOC, Ultraviolet (UV) absorbance, pH, and color. The findings can guide other treatment operators to deal with shock changes in the raw water quality resulting from severe weather or other operating conditions.


Author(s):  
Thiago Santos de Almeida Lopes ◽  
Whelton Brito dos Santos ◽  
George Antonio Belmino da Silva ◽  
Thyago Nóbrega Silveira ◽  
Weruska Brasileiro Ferreira ◽  
...  

Abstract The objective of this study was to evaluate the effects of the transfer of the São Francisco River waters on the quality of the water produced by water treatment plant of Gravatá (WTP-Gravatá) using multivariate statistics. Monthly means of the variables pH, apparent color and turbidity of raw, decanted and treated waters were used, in addition to the volume accumulated by the Epitácio Pessoa reservoir, during the period from January 2016 to December 2017. The arrival of the transposition waters abruptly changed the apparent color and turbidity of the raw water. In spite of that, the treated water presented low variability of the mentioned parameters, indicating that the WTP-Gravatá was able to adapt its treatment. From the factor analysis/principal component analysis (FA/PCA) it was found that changes in reservoir volume alter the apparent color and turbidity of the raw water, requiring interventions in the coagulation/flocculation/decantation stages. The increasing of these parameters in the decanted water overloads the filtration step, raising the apparent color of the treated water. The cluster analysis distinguished the different phases experienced by the Epitácio Pessoa reservoir. The information obtained can help decision making in WTPs, considering changes in reservoir volumes.


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