Adsorption/Coagulation/Ceramic Microfiltration for Treating Challenging Waters for Drinking Water Production
Margarida Campinas1, Rui M C Viegas1, Rosário Coelho2
1Water Quality and Treatment Laboratory, Urban Water Unit, Hydraulics and Environment Department, LNEC-National Civil Engineering Laboratory, 1700-066 Lisbon, Portugal.
Membranes
|January 30, 2021
Summary
Powdered activated carbon, coagulation, and microfiltration effectively removed over 75% of microcontaminants from surface water. This combined treatment also reduced natural organic matter and protected against microbial contaminants.
Area of Science:
- Environmental Engineering
- Water Treatment Technologies
- Advanced Oxidation Processes
Background:
- Surface waters often contain low turbidity and natural organic matter (NOM), but can be contaminated with organic microcontaminants.
- Conventional water treatment may not fully remove emerging contaminants like pesticides, pharmaceuticals, and microcystins.
- Assessing integrated treatment systems is crucial for ensuring drinking water safety.
Purpose of the Study:
- To evaluate the pilot-scale performance of powdered activated carbon/coagulation/ceramic microfiltration (PAC/Alum/MF) for treating low-NOM surface waters.
- To assess the removal efficiency of microcontaminants, NOM, and disinfection byproducts precursors.
- To determine the system's efficacy against microbial indicators.
Main Methods:
- Conducted 11 pilot-scale trials using PAC/Alum/MF on surface waters spiked with pesticides, pharmaceuticals, or microcystins.
- Monitored removal of microcontaminants, NOM (A254, DOC), trihalomethane formation potential (THMFP), aerobic endospores, and bacteriophages.
- Varied PAC dosage (4-18 mg/L) and contact time (2 h), assessing impact of water quality parameters like turbidity and NOM levels.
Main Results:
- Achieved 75% to complete removal of total microcontaminants with optimized PAC dosage and contact time.
- Demonstrated reliable particle separation (turbidity < 0.03 NTU) and low aluminum residuals.
- Attained 29-47% median NOM removal, reducing THMFP by 26%, and provided a full barrier against aerobic endospores. PAC dosing was critical for bacteriophage reduction (≥1.1-log).
Conclusions:
- PAC/Alum/MF is a highly effective integrated treatment for removing microcontaminants and microbial indicators from low-NOM surface waters.
- Microcontaminant removal efficiency is influenced by their properties and competition from NOM, necessitating dose optimization.
- The system offers robust protection against pathogens and reduces the potential for disinfection byproduct formation.
Keywords:
THMFPceramic membraneshybrid processmicrocontaminantsmicrocystinspesticidespharmaceuticalspowdered activated carbon/coagulation/microfiltrationprotozoan cystsvirusesMore Related Videos
Related Concept Videos
01:06Coagulation
634
Colloidal solids are solid particles suspended in solution. They are usually negatively charged, attracting a compact primary layer of positively charged ions, which attract more counterions to form an electrical double layer. Electrostatic repulsion between the charged double layers prevents the particles from colliding, stabilizing the colloids. These solids are often undesirable because they can contain toxins that are difficult to remove. Coagulation is a technique that helps aggregate and...
634
01:17Precipitation and Co-precipitation
3.3K
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
3.3K
01:15Dialysis
1.2K
Dialysis is a diffusion-based purification process that separates analyte molecules from a complex matrix. This is accomplished by allowing molecules in the solution to pass through a semipermeable membrane into a liquid on the other side. The membrane is usually made of cellulose acetate or cellulose nitrate, and the second liquid must be miscible with the solution. Ions (e.g., chloride or sodium) or organic molecules (e.g., glucose) can pass through the membrane pores, which generally have...
1.2K
01:25Extracorporeal Removal of Drugs: Hemoperfusion and Hemofiltration
77
Hemoperfusion and hemofiltration are critical techniques in medical treatments to eliminate accumulated drugs, metabolites, and electrolytes from the bloodstream. These methods are particularly vital in cases of accidental poisoning and drug overdose.Hemoperfusion involves passing blood through an adsorbent material to remove unwanted substances. The main adsorbents used in hemoperfusion include activated charcoal and Amberlite resins. Activated charcoal can adsorb both polar and nonpolar...
77
00:53Filtration
2.7K
Filtration is a physical separation process that involves passing a suspension through a porous medium to separate solids from fluids. During filtration, solids collect on the porous medium while liquids, also collectively known as the filtrate, pass through. The filtration medium is selected based on the filtration purpose, quantity, and nature of the precipitate. The general criteria for a suitable filtering medium are that it is inert, mechanically strong, nonabsorbent toward dissolved...
2.7K
04:01Factors Affecting Solubility
35.7K
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Chȃtelier’s principle. Consider the dissolution of silver iodide:
35.7K