Coagulation monitoring in surface water treatment facilities

1998 ◽  
Vol 38 (3) ◽  
pp. 237-244 ◽  
Author(s):  
Kan Chichuan ◽  
Huang Chihpin
Keyword(s):  
Water Treatment ◽  
Settling Velocity ◽  
Optical Monitoring ◽  
Floc Size ◽  
Surface Water Treatment ◽  
Operation Conditions ◽  
Monitoring Technique ◽  
Coagulation Performance ◽  
Output Ratio ◽  
Treatment Facilities

Coagulant dosing is traditionally determined according to results from jar-tests or operator's experience, which often lead to overdosing or insufficient dosing. In this study, the feasibility of applying an optical monitoring technique to determine chemical dosage and to monitor the coagulation performance in water treatment plants were assessed. To examine the applicability of the monitor under various operation conditions, series of batch trials in the field were conducted to explore the effects of turbidity, pH and rapid mixing intensity on the effectiveness of coagulation. The performance was directly reflected in the output ratio of the monitor, which proved to be an effective index for the floc size and its settling velocity. Therefore, we consider that the optical monitor is an useful instrument in monitoring coagulation in water treatment.

scholarly journals Super-bridging Fibrous Materials for Water Treatment: Impacts on Removal of Plastic Particles, Phosphorus and Natural Organic Matter

2021 ◽  
Author(s):  
Mathieu Lapointe ◽  
Heidi Jahandideh ◽  
Jeffrey Farner ◽  
Nathalie Tufenkji
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Natural Organic Matter ◽  
Emerging Contaminants ◽  
Settling Tank ◽  
Process Unit ◽  
Fibrous Materials ◽  
Floc Size ◽  
Sludge Waste ◽  
Treatment Facilities

Aggregation combined with gravitational separation is the most commonly used method to treat water globally, but it carries a significant economic and environmental burden as the chemicals used in the process (e.g., coagulants) generate ~8 million tons of metal-based sludge waste annually. To simultaneously deal with the issues of process sustainability, cost, and efficiency, we developed materials reengineered from pristine or waste fibers to serve as super-bridging agents, adsorbents, and ballast media. This study shows that these sustainable fiber-based materials considerably increased the floc size (~6630 µm) compared to conventional physicochemical treatment using a coagulant and a flocculant (~520 µm). The fiber-based materials also reduced coagulant (up to 40%) and flocculant usage (up to 60%). Moreover, the unprecedented size of flocs produced using fiber-based materials (up to ~13 times larger compared to conventional treatment) enabled easy floc removal by screening, thereby eliminating the need for a settling tank, a large and costly process unit. Our results show that fiber-based materials can be effective solutions at removing classical (e.g., natural organic matter (NOM) and phosphorus) and emerging contaminants (e.g., microplastics and nanoplastics). Due to their large size (> 3000 µm), some Si-grafted and Fe-grafted fiber-based materials can be easily recovered from settled/screened sludge and reused multiple times for coagulation/flocculation. Our results also show that these materials could be used in synergy with coagulants and flocculants to improve settling in existing water treatment processes. Furthermore, these reusable materials combined with separation via screening could allow global water treatment facilities to reduce their capital and operating costs as well as their environmental footprint.

scholarly journals Sustainable Fiber-Based Materials as Super-bridging Agents, Adsorbents, and Ballast Media

2021 ◽  
Author(s):  
Mathieu Lapointe ◽  
Heidi Jahandideh ◽  
Jeffrey Farner ◽  
Nathalie Tufenkji
Keyword(s):  
Water Treatment ◽  
Emerging Contaminants ◽  
Settling Tank ◽  
Process Unit ◽  
Contaminant Removal ◽  
Floc Size ◽  
Large Size ◽  
Sludge Waste ◽  
Treatment Facilities ◽  
Chemical Usage

Aggregation combined with gravitational separation is the most commonly used method to treat water globally, but it carries a significant economic and environmental burden as the chemicals used in the process (e.g., coagulants) generate ~8 million tons of metal-based sludge waste annually. To simultaneously deal with the issues of process sustainability, cost, and efficiency, we developed materials reengineered from pristine or waste fibers (e.g., cellulose, polyester, cotton, and keratin) to serve as super-bridging agents, adsorbents and ballast media. This study shows that these sustainable materials (fibers, microspheres, and flakes functionalized with Si, Al and/or Fe) considerably increased the floc size (~6630 µm) compared to conventional physicochemical treatment (~520 µm; using alum and polyacrylamide). The fiber-based materials also reduced chemical usage (20–60 %) and improved contaminant removal during settling by increasing floc size and density. Moreover, the unprecedented size of flocs produced using fiber-based materials (13 times larger compared to conventional treatment) enabled easy floc removal by screening, thereby eliminating the need for a settling tank, a large and costly process unit used to treat more than 70% of water globally. Our results show that fiber-based materials can be effective solutions at removing classical (e.g., natural organic matter (NOM) and phosphorus, via electrostatic affinities) and emerging contaminants (e.g., microplastics and nanoplastics). Due to their large size (> 3000 µm), some Si-grafted and Fe-grafted fiber-based materials were easily recovered from settled/screened sludge and reused multiple times for coagulation/flocculation. These reusable materials combined with separation via screening could allow global water treatment facilities to reduce their capital and operating costs as well as their environmental footprint. Finally, our results also show that these materials could be used in synergy with coagulants and flocculants to improve existing water treatment plants for the removal of NOM, phosphorus, turbidity, total suspended solids and microplastics.

scholarly journals Eco-Friendly Coagulant versus Industrially Used Coagulants: Identification of Their Coagulation Performance, Mechanism and Optimization in Water Treatment Process

2021 ◽  
Vol 18 (17) ◽  
pp. 9164
Author(s):  
Nadiah Khairul Zaman ◽  
Rosiah Rohani ◽  
Izzati Izni Yusoff ◽  
Muhammad Azraei Kamsol ◽  
Siti Aishah Basiron ◽  
...  
Keyword(s):  
Water Treatment ◽  
Treatment Process ◽  
Process Time ◽  
Polyaluminum Chloride ◽  
Surface Water Treatment ◽  
Water Treatment Process ◽  
Optimization Study ◽  
Coagulation Performance ◽  
Acidic Conditions ◽  
Complex Organic

The evaluation of complex organic and inorganic coagulant’s performances and their relationships could compromise the surface water treatment process time and its efficiency. In this work, process optimization was investigated by comparing an eco-friendly chitosan with the industrially used coagulants namely aluminum sulfate (alum), polyaluminum chloride (PAC), and aluminum chlorohydrate (ACH) in compliance with national drinking water standards. To treat various water samples from different treatment plants with turbidity and pH ranges from 20–826.3 NTU and 5.21–6.80, respectively, 5–20 mg/L coagulant dosages were varied in the presence of aluminum, ferum, and manganese. Among all, 10 mg/L of the respective ACH and chitosan demonstrated 97% and 99% turbidity removal in addition to the removal of the metals that complies with the referred standard. However, chitosan owes fewer sensitive responses (turbidity and residual metal) with the change in its input factors (dosage and pH), especially in acidic conditions. This finding suggested its beneficial role to be used under the non-critical dosage monitoring. Meanwhile, ACH was found to perform better than chitosan only at pH > 7.4 with half dosage required. In summary, chitosan and ACH could perform equally at a different set of optimum conditions. This optimization study offers precise selections of coagulants for a practical water treatment operation.

The new technology of waste water treatment by using bioreactors with bio membranous movable bed – biochips

2020 ◽  
Vol 10 (3) ◽  
pp. 276-292
Author(s):  
Maria Y. Savostyanova ◽  
◽  
Lidia А. Norina ◽  
Arina V. Nikolaeva ◽  
◽  
...  
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Water Resources ◽  
Waste Water Treatment ◽  
Combined Treatment ◽  
Research Work ◽  
Pollution Level ◽  
Waste Waters ◽  
Treatment Facilities ◽  
Movable Bed

Retaining of water resources quality is one of the global ecological problems of the modern time. The most promising direction in solving the problem of water resources protection is the reduction of negative environmental influence of waste water from production facilities by upgrading the existing water treatment technologies. To treat utility water, technical and rain water from site facilities of Transneft system entities, the specialists developed and approved standard technological diagrams, which are used in producing treatment facilities. The standard technological diagrams provide for all necessary stages of waste water treatment ensures the reduction of pollution level to normal values. However, during operation of treatment facilities it was established, that to ensure the required quality of waste water treatment with initially high levels of pollution, the new technological solutions are necessary. The author presents the results of scientific-research work, in the context of which the best affordable technologies were identified in the area of the treatment of waste water with increased content of pollutants and non-uniform ingress pattern. On the basis of the research results the technical solutions were developed for optimization of operation of existing waste water treatment facilities by means of using combined treatment of technical and rain waters and utility waste waters and applying bioreactor with movable bed – biochips. The use of bioreactor with movable bed allows the increase in the area of active surface, which facilitates increase and retention of biomass. Biochips are completely immersed into waste waters, and biofilm is formed on the entire volume of immersion area, facilitating retention of biomass and preventing formation of sediments. Due to mixing the floating device with biofilm constantly moves along the whole area of bioreactor, and, in doing so, speeds up biochemical processes and uniformity of treatment. The advantages of a bioreactor with movable bed – its active sludge durability against increased and changing pollutant concentrations, change of waste water temperature and simplicity of application – ensured the possibility of its use for blending utility waters, technical and rain waters.

COMPARATIVE STUDY ON SURFACE WATER TREATMENT USING ALUMINIUM SULPHATE AND POLYALUMINIUM CHLORIDES AS COAGULANT REAGENTS

2009 ◽  
Vol 8 (4) ◽  
pp. 859-863 ◽  
Author(s):  
Daniela Simina Stefan ◽  
Cristina Costache ◽  
Viorica Ruxandu ◽  
Monica Balas ◽  
Mircea Stefan
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Comparative Study ◽  
Aluminium Sulphate ◽  
Surface Water Treatment
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