Water Sampling and Treatment Concepts

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of cation resins in the ion exchange process?

To replace negatively charged ions with hydroxide ions

To filter out organic matter from water

To remove positively charged ions only

To exchange positively charged ions for hydrogen ions (correct)

Which of the following correctly describes the removal of impurities in demineralization?

It primarily targets larger particulate matter

It uses chemical reactions to break down organic substances

It removes nearly all dissolved ionic matter from water (correct)

It removes all non-ionic matter from water

In cross-flow membrane filtration, what is the main purpose of the membrane?

To trap all types of dissolved ions

To remove large suspended solids only

To enhance the chemical reactions of contaminants

To allow only water to pass through (correct)

What is an example of a process that falls under cross-flow membrane filtration?

Reversed osmosis Signup and view all the answers

What does the term 'strong regeneration solution' refer to in the ion exchange process?

A solution that provides highly concentrated ions for exchange Signup and view all the answers

What is a key factor to consider when determining the treatment of polluted water?

The intended use and purpose of the water Signup and view all the answers

Which method is specifically used for removing hardness in water?

Lime softening Signup and view all the answers

What type of contaminants do heavy metals include?

Mercury, arsenic, and lead Signup and view all the answers

What is one of the main categories of water treatment methods?

Water purification for domestic use Signup and view all the answers

Which of the following is NOT a method for removing settable solids?

Evaporation Signup and view all the answers

In wastewater treatment for disposal, which category does agricultural wastewater fall under?

Industrial wastewater treatment Signup and view all the answers

Which contaminant is NOT typically considered when assessing surface water quality?

Genetic mutations in fish Signup and view all the answers

What technological process is commonly used for salt removal from water?

Reverse Osmosis Signup and view all the answers

What is the main purpose of bioremediation?

To reduce the concentrations of contaminants using microorganisms Signup and view all the answers

Which method involves the use of plants to mitigate environmental contamination?

Phytoremediation Signup and view all the answers

What does ISCO stand for in environmental remediation?

In situ-Chemical Oxidation Signup and view all the answers

Which chemical oxidizer is NOT commonly used in ISCO techniques?

Chlorine Signup and view all the answers

What is a common biological treatment method in industrial wastewater treatment?

Activated sludge process Signup and view all the answers

Which of the following best describes phytoremediation?

The use of plants to absorb and detoxify environmental pollutants Signup and view all the answers

Why is ISCO considered effective for organic compounds?

It directly introduces strong chemical oxidizers into the contaminants Signup and view all the answers

Which of the following processes is NOT typically involved in industrial wastewater treatment?

Thermal drying Signup and view all the answers

What is a key consideration when sampling surface water from a depth?

The liquid's consistency may vary with depth. Signup and view all the answers

Why is it important to avoid sampling from the surface layer of water?

Insoluble organics tend to concentrate in the surface layer. Signup and view all the answers

How do liquids flowing in confined boundaries behave?

Flow is fastest in the center and slows at the edges. Signup and view all the answers

What method can create turbulent flow in pipes?

Installing a right angled bend in the pipe. Signup and view all the answers

In the case of a slow-flowing waterway, how should samples be collected?

Across the width of the canal. Signup and view all the answers

What is most likely to lead to errors in sampling operations?

The inherent heterogeneity of bulk matrices. Signup and view all the answers

When is a single sample likely sufficient for analysis?

When dealing with single phase liquids after mixing. Signup and view all the answers

What should be avoided when sampling to prevent metal contamination?

Sampling close to the ship's hull. Signup and view all the answers

What is the main purpose of the biological treatment in sewage treatment plants?

To use microbes to break down organic matter Signup and view all the answers

Which of the following components primarily focuses on removing floating oil and grease?

Clarifiers Signup and view all the answers

What characterizes constructed wetlands in wastewater treatment?

They utilize microorganisms and plants to absorb nutrients. Signup and view all the answers

What is the primary function of the initial physical treatment stage in sewage treatment?

It removes a significant portion of total suspended solids. Signup and view all the answers

In the context of sewage treatment, what does BOD5 stand for?

Biochemical Oxygen Demand over 5 days Signup and view all the answers

Which stage of sewage treatment is aimed at ammonia removal?

Tertiary Treatment Signup and view all the answers

What happens to the biosolids in a sewage treatment plant?

They are treated and stabilized. Signup and view all the answers

Which treatment method is not part of secondary sewage treatment?

Chemical treatment Signup and view all the answers

Study Notes

Sampling Surface Water

Errors occur in sampling operations due to the heterogeneity of bulk matrices
Single phase liquids, following shaking or mixing, are likely to be homogeneous and thus a single sample should be sufficient for analysis
When sampling from a depth of liquid, it is not possible to assume the liquid at the top has the same consistency as that down the column of liquid and thus a single sample is no longer suitable
Liquids flowing in confined boundaries (i.e. pipe, rivers and canals) are subject to principles of laminar flow and as such the liquid flows faster in the centre, with almost zero flow at the edge of the pipe or the bank of the river/canal
Turbulent flow can be created by introducing a right angled bend into the pipe, with sampling just before the flow returns to laminar conditions

Water Treatment

Water treatment should consider: the quality (characteristics) of the source, the reliability/sustainability of the water sources, the intended use and purpose, the level (degree) of treatment (allowable limits), the required volume, location, technology, safety
Water treatment can be classified into: water purification for domestic use, water treatment for industrial use (process water), and wastewater treatment for disposal or recycle
Water purification for domestic use may include surface water, groundwater, and seawater (desalination)
Wastewater treatment may include municipal, industrial and agriculture wastewater treatment

Major Contaminants In Surface Water

Major contaminants include:
- Solids (settleable solids and non-settleable solids)
- Pathogens (bacteria, viruses etc.)
- Sewage (BOD, COD, TOC etc.)
- Dissolved gases (DO, CO2, ammonia)
- Inorganics (cyanide, fluoride, nitrate, nutrients, hardness, salts, acids, alkalinity etc.)
- Organics (hydrocarbons, VOCs/SOCs/NVOC, DBPs, solvents)
- Toxic chemicals (pesticides, PCBS)
- Heavy (trace) metals (mercury, arsenic, lead, copper, cadmium, chromium)
- Radiological constituents

Water Treatment Methods

Treatment methods for settleable solids removal include: sedimentation/settling/clarification and filtration
Treatment methods for non-settleable solids removal include: coagulation/flocculation followed by clarification
Treatment methods for hardness removal (Ca and Mg) removal include: lime softening
Treatment methods for salt removal (anions and cations) include: ion exchange, membrane filtration (ultrafiltration and RO), evaporation for desalting
Treatment methods for organic compound removal include: adsorption, bioremediation, oxidation

Ion Exchange / Demineralization

Impurities dissolve in water dissociate to form ions:
- Cations= positively charged ions
- Anions = negatively charged ions
Ion exchange process uses resin material to exchange one ion for another
Demineralization removes dissolved (ionic matter) impurities from water by ion exchange
Two types of ion exchange resins are used:
- Cation resins remove Ca++, Mg++, Na+
- Anion resins remove SO4--, Cl-

Cross-Flow (Membrane) Filtration

Cross-flow membrane filtration removes both salts and dissolved organic matter
It may include microfiltration (MF), ultra filtration (UF), nano-filtration (NF) and Reversed Osmosis (RO)
MF removes very fine particles (0.1-1.5 μ) or other SS
Bioremediation may occur naturally or through the addition of fertilizers, oxygen, etc.

Phytoremediation

Phytoremediation refers to the use of plants and associated soil microbes to reduce the concentrations or toxic effects of contaminants
Phytoremediation is considered a cost-effective environmental restoration technology

In situ-Chemical Oxidation (ISCO)

A form of advanced oxidation processes, ISCO is an environmental remediation technique used for soil and/or groundwater
ISCO is accomplished by injecting or otherwise introducing strong chemical oxidizers directly into the contaminated medium to destroy chemical contaminants in place
It can be used to remediate a variety of organic compounds, including some that are resistant to natural degradation

Industrial Wastewater Treatment

Processes varies based on the industry type and wastewater generated
Includes:
- Removal of organic wastes by:
  - Biological treatment
  - Adsorption by activated carbon (AC)
- Chemical process: neutralization, precipitation & oxidation/reduction etc.

Onsite Disposal Systems

Drain fields are a discharge system in which wastewater is treated as it flows down grass-covered slopes, designed for soils with low permeability to minimize percolation
Natural wastewater disposal systems include constructed wetlands which act as a plant/soil/organism based system for wastewater treatment

Wastewater (Sewage) Treatment Plants (STPs)

Main components of an STP include stages for large debris removal, grit removal, biological treatment, clarifiers, and biosolids treatment
Treated wastewater is discharged from an STP, while sludge or bio-solids are removed and treated separately
Physical treatment (primary treatment) removes 60% of SS and 30-40% of O2 demanding waste (BOD)
Biological treatment (secondary treatment) removes 90% of dissolved and biodegradable O2 demanding organic waste (BOD)
Tertiary Treatment includes nitrification-de-nitrification for ammonia removal.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers essential concepts in sampling surface water and the principles of water treatment. Understand the importance of sample consistency and the effects of flow dynamics on water quality. Learn how various treatments are influenced by source characteristics and sustainability.