scholarly journals Does the recycling of waste streams from drinking water treatment plants worsen the quality of finished water? A case assessment in China

2016 ◽  
Vol 17 (2) ◽  
pp. 597-605
Author(s):  
Zhiquan Liu ◽  
Yongpeng Xu ◽  
Xuewei Yang ◽  
Rui Huang ◽  
Qihao Zhou ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Ammonia Nitrogen ◽  
Raw Water ◽  
Waste Streams ◽  
Filter Backwash Water

The overall purpose was to assess the feasibilities of recycling filter backwash water (FBWW) and combined filter backwash water (CFBWW) in a drinking water treatment plant in south China. The variations of regular water-quality indexes, metal indexes (Al, Mn and Cd), polyacrylamide and disinfection by-product indexes (trihalomethanes and their formation potentials) along with the treatment and the recycling processes were monitored. Results showed the recycling procedure caused increases of turbidity, total solids, ammonia nitrogen (NH3-N), permanganate index (CODMn), and dissolved organic carbon, Al, Mn and Cd concentrations in a mixture of raw water and FBWW or CFBWW compared to those in raw water. However, the recycling procedure had negligible impacts on the qualities of settled water and filtered water because most of the contaminants could be effectively removed by the conventional water treatment process. Although recycling did cause slight increases of NH3-N and CODMn levels in settled water and filtered water, the quality of finished water always conformed to Chinese standards for drinking water quality according to the surveyed indexes in the present study. Thus, it is appropriate to recycle waste streams in water-stressed areas if the source water is well managed and the water treatment processes are carefully conducted.

scholarly journals Use of Acorn Leaves as a Natural Coagulant in a Drinking Water Treatment Plant

Water ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 57 ◽  
Author(s):  
Abderrezzaq Benalia ◽  
Kerroum Derbal ◽  
Antonio Panico ◽  
Francesco Pirozzi
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Distilled Water ◽  
Raw Water ◽  
Turbidity Removal ◽  
Leaf Powder

In this study, the use of acorn leaves as a natural coagulant to reduce raw water turbidity and globally improve drinking water quality was investigated. The raw water was collected from a drinking water treatment plant located in Mila (Algeria) with an initial turbidity of 13.0 ± 0.1 NTU. To obtain acorn leaf powder as a coagulant, the acorn leaves were previously cleaned, washed with tap water, dried, ground and then finely sieved. To improve the coagulant activity and, consequently, the turbidity removal efficiency, the fine powder was also preliminarily treated with different solvents, as follows, in order to extract the coagulant agent: (i) distilled water; (ii) solutions of NaCl (0.25; 0.5 and 1 M); (iii) solutions of NaOH (0.025; 0.05 and 0.1 M); and (iv) solutions of HCl (0.025; 0.05 and 0.1 M). Standard Jar Test assays were conducted to evaluate the performance of the coagulant in the different considered operational conditions. Results of the study indicated that at low turbidity (e.g., 13.0 ± 0.1 NTU), the raw acorn leaf powder and those treated with distilled water (DW) were able to decrease the turbidity to 3.69 ± 0.06 and 1.97 ± 0.03 NTU, respectively. The use of sodium chloride solution (AC-NaCl) at 0.5 M resulted in a high turbidity removal efficiency (91.07%) compared to solutions with different concentrations (0.25 and 1 M). Concerning solutions of sodium hydroxide (AC-NaOH) and hydrogen chloride (AC-HCl), the lowest final turbidities of 1.83 ± 0.13 and 0.92 ± 0.02 NTU were obtained when the concentrations of the solutions were set at 0.05 and 0.1 M, respectively. Finally, in this study, other water quality parameters, such as total alkalinity hardness, pH, electrical conductivity and organic matters content, were measured to assess the coagulant performance on drinking water treatment.

scholarly journals Trophic status, phytoplankton diversity, and water quality at Kafr El-Shinawy drinking-water treatment plant, Damietta

2021 ◽  
Author(s):  
Mohamed Deyab ◽  
Magda El-Adl ◽  
Fatma Ward ◽  
Eman Omar
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Trophic Status ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Raw Water ◽  
Phytoplankton Diversity ◽  
Treated Water

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.

scholarly journals Trihalomethane precursor reactivity changes in drinking water treatment unit processes during a storm event

2019 ◽  
Vol 19 (7) ◽  
pp. 2098-2106
Author(s):  
Chelsea W. Neil ◽  
Yingying Zhao ◽  
Amy Zhao ◽  
Jill Neal ◽  
Maria Meyer ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Plant Performance ◽  
Storm Event ◽  
Source Water ◽  
Treatment Unit ◽  
Source Water Quality

Abstract Source water quality can significantly impact the efficacy of water treatment unit processes and the formation of chlorinated and brominated trihalomethanes (THMs). Current water treatment plant performance models may not accurately capture how source water quality variations, such as organic matter variability, can impact treatment unit processes. To investigate these impacts, a field study was conducted wherein water samples were collected along the treatment train for 72 hours during a storm event. Systematic sampling and detailed analyses of water quality parameters, including non-purgeable organic carbon (NPOC), UV absorbance, and THM concentrations, as well as chlorine spiking experiments, reveal how the THM formation potential changes in response to treatment unit processes. Results show that the NPOC remaining after treatment has an increased reactivity towards forming THMs, and that brominated THMs form more readily than chlorinated counterparts in a competitive reaction. Thus both the reactivity and quantity of THM precursors must be considered to maintain compliance with drinking water standards, a finding that should be incorporated into the development of model-assisted treatment operation and optimization. Advanced granular activated carbon (GAC) treatment beyond conventional coagulation–flocculation–sedimentation processes may also be necessary to remove the surge loading of THM-formation precursors during a storm event.

A Case Study on the Automatic Control of Chemical Dosing Processes for Full-Scale Drinking Water Treatment

2012 ◽  
Vol 209-211 ◽  
pp. 1981-1985 ◽  
Author(s):  
Dong Sheng Wang ◽  
Xing Peng Zhou ◽  
Xiao Ming Mo ◽  
Yi Wang
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Automatic Control ◽  
Water Flow ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Constant Attention ◽  
Operational Conditions ◽  
Quality Water

During drinking water treatment, the chemical dosing processes, such as coagulant dosing process, ozone dosing process and chlorine dosing process are usually manually operated based on the operator knowledge and experience. However, due to the variations of water quality, water flow and process operational conditions and characteristics of large time-delay and nonlinear for the chemical dosing processes, it is difficult to adjust the chemical dosages in time by operators to keep the treated water quality stable, especially during the periods of rapid and frequent variations of water quality, water flow and process operational conditions. Thus, the improvements of control methods for the chemical dosing processes are essential to the operation of drinking water treatment plants. The Xiangcheng Water Treatment Plant in Suzhou, China has been utilizing the automatic control for chemical dosing processes since February 2012. Automatic controllers are designed respectively for the coagulant dosing process, ozone dosing process and chlorine dosing process. After the implementation of automatic control, operators are not necessary to keep constant attention. In addition, due to the improvements of control accuracies for the chemical dosing processes, the chemical dosages are reduced on the premise of ensuring safe water. Thus, both of the human resource costs and material costs can be saved. The practical control results demonstrate the efficiencies of proposed methods.

scholarly journals Long-Term Drinking Water Quality Assessment Using Index and Multivariate Statistical Analysis for Three Water Treatment Plants of Erbil City, Iraq

2018 ◽  
Vol 2 (2) ◽  
pp. 39-48
Author(s):  
Hayder Mohammed Issa ◽  
Reem Ahmed Alrwai
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Water Supply ◽  
Drinking Water Treatment ◽  
Drinking Water Quality ◽  
Total Alkalinity ◽  
Total Hardness ◽  
Water Treatment Plants

Safe source of drinking water is always considered as an essential factor in water supply for cities and urban areas. As a part of this issue, drinking water quality is monitored via a useful scheme: developing drinking water quality index DWQI. DWQI is preferably used as it summarizes the whole physicochemical and bacteriological properties of a drinking water sample into a single and simple term. In this study, an evaluation was made for three drinking water treatment plants DWTPs named: Efraz 1, Efraz 2 and Efraz 3 that supply drinking water to Erbil City. The assessment was made by testing thirteen physicochemical and two bacteriological parameters during a long period of (2003 – 2017). It has been found that turbidity, electrical conductivity EC, total alkalinity, total hardness, total coliform and fecal coliform have more influence on drinking water quality. DWQI results showed that the quality of drinking water supplied by the three DWTPs in Erbil City fallen within good level. Except various occasional periods where the quality was varying from good to fair. The quality of the drinking water supply never reached the level of marginal or poor over the time investigated. The applied hierarchical clustering analysis HCA classifies the drinking water dataset into three major clusters, reflecting diverse sources of the physicochemical and bacteriological parameter: natural, agriculture and urban discharges.

Speciation and seasonal variation of various disinfection by-products in a full-scale drinking water treatment plant in East China

2019 ◽  
Vol 19 (6) ◽  
pp. 1579-1586 ◽  
Author(s):  
Xiang-Ren Zhou ◽  
Yi-Li Lin ◽  
Tian-Yang Zhang ◽  
Bin Xu ◽  
Wen-Hai Chu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Full Scale ◽  
East China ◽  
Raw Water ◽  
Drinking Water Treatment Plant ◽  
By Products

Abstract The objective of this research was to study the occurrence and seasonal variations of disinfection by-products (DBPs), including traditional carbonaceous and emerging nitrogenous DBPs, in a full-scale drinking water treatment plant (DWTP) for nearly 2 years. The removal efficiencies of each DBP through the treatment processes were also investigated. This DWTP takes raw water from the Yangtze River in East China. The quality of the raw water used in this DWTP varied with different seasons. The results suggested that DBP concentrations of the finished water were higher in spring (82.33 ± 15.12 μg/L) and summer (117.29 ± 9.94 μg/L) with higher dissolved organic carbon (DOC) levels, but lower in autumn (41.10 ± 5.82 μg/L) and winter (78.47 ± 2.74 μg/L) with lower DOC levels. Due to the increase of bromide concentration in spring and winter, more toxic brominated DBPs increased obviously and took up a greater proportion. In this DWTP, DBP concentrations increased dramatically after pre-chlorination, especially in summer. It is noteworthy that the removal of DBPs during the subsequent treatment was more obvious in spring than in the other three seasons because the pH value is more beneficial to coagulation in spring.

Objectives for optimization and consequences for operation, design and concept of drinking water treatment plants

2008 ◽  
Vol 8 (3) ◽  
pp. 297-304 ◽  
Author(s):  
A. W. C. van der Helm ◽  
L. C. Rietveld ◽  
Th. G. J. Bosklopper ◽  
J. W. N. M. Kappelhof ◽  
J. C. van Dijk
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Water Cycle ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Operational Parameters ◽  
Regeneration Frequency ◽  
Water Treatment Plants

Optimization for operation of drinking water treatment plants should focus on water quality and not on environmental impact or costs. Using improvement of water quality as objective for optimization can lead to new views on operation, design and concept of drinking water treatment plants. This is illustrated for ozonation in combination with biological activated carbon (BAC) filtration at drinking water treatment plant Weesperkarspel of Waternet, the water cycle company for Amsterdam and surrounding areas. The water quality parameters that are taken into account are assimilable organic carbon (AOC), dissolved organic carbon (DOC) and pathogens. The operational parameters that are taken into account are the ozone dosage and the regeneration frequency of the BAC filters. It is concluded that ozone dosage and regeneration frequency should be reduced in combination with application of newly developed insights in design of ozone installations. It is also concluded that a new concept for Weesperkarspel with an additional ion exchange (IEX) step for natural organic matter (NOM) removal will contribute to the improvement of the disinfection capacity of ozonation and the biological stability of the produced drinking water.

Research on raw water quality assessment oriented to drinking water treatment based on the SVM model

2015 ◽  
Vol 16 (3) ◽  
pp. 746-755 ◽  
Author(s):  
Dongsheng Wang
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Quality Assessment ◽  
Drinking Water Treatment ◽  
Water Quality Assessment ◽  
Assessment Method ◽  
Raw Water ◽  
Control Scheme ◽  
Raw Water Quality

Raw water quality variation has a great effect on drinking water treatment. To improve the adaptivity of drinking water treatment and stabilize the quality of treated water, a raw water quality assessment method, which is based upon the support vector machine (SVM), is developed in this study. Compared to existing raw water quality assessment methods, the assessment method studied herein is oriented to drinking water treatment and can directly be used for the control of the chemical (alum and ozone) dosing process. To this end, based upon the productive experiences and the analysis of the operating data of water supply, a raw water quality assessment standard oriented to drinking water treatment is proposed. A raw water quality model is set up to assess the raw water quality based upon the SVM technique. Based upon the raw water quality assessment results, a feedforward–feedback control scheme has been designed for the chemical dosing process control of drinking water treatment. Thus, the chemical dosage can be adjusted in time to cope with raw water quality variations and hence, the quality of the treated water is stabilized. Experimental results demonstrate the improved effectiveness of the proposed method of raw water quality assessment and the feedforward–feedback control scheme.

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