Pesticides, inorganic and organic pollutants AQA A-Level Environmental Science| Primrose Kitten

Pesticides

Chemicals deliberately released into the environment to kill pest species, with properties that benefit farmers but can be harmful to the environment.

Systemic pesticides

Pesticides absorbed by crop roots and present within the crop's cells.

Contact pesticides

Pesticides sprayed onto the exterior of crops.

MDAF (Minimum Dose Always Fatal)

The lowest dose of a pesticide that will kill all members of a population.

MDNF (Maximum Dose Never Fatal)

The highest dose of a pesticide that will not kill any members of a population.

Neonicotinoids

Pesticide group with high insect toxicity, persistence, and potency at low dosages, but low specificity and neurotoxicity.

Organophosphates e.g. malathion

Pesticide group with high insect toxicity, neurotoxicity, and high mammalian toxicity, but low persistence and not lipid soluble.

Organochlorines e.g. DDT

Pesticide group with high insect toxicity and persistence, but harmful effects on bees, butterfly species, and bird populations.

Pyrethroids

Pesticide group with high insect toxicity, biomimetic properties, low mammal toxicity, low persistence, and insolubility in water.

Systemic Pesticides

Pesticides remaining within plant tissue to reduce dispersion

Contact Pesticides

Pesticides dispersing easily, affecting non-target organisms

How does the timing of application impact pollution?

Strategic application timing to minimize negative impacts

Buffer Strips

Uncultivated land around fields to prevent chemical leaching

Cultural Pest Control

Using methods like crop rotation and biological control

Inorganic Pollutants

Pollutants without carbon, e.g., nitrates and phosphates

Organic Pollutants

Pollutants containing carbon, e.g., glucose and sewage

Eutrophication

Deoxygenation due to inorganic material input in water bodies

Oligotrophic Lakes

Low nutrient concentration, low plant diversity

Eutrophic Lakes

High nutrient concentration, high plant diversity

Nitrate Vulnerable Zones (NVZ)

Areas extremely vulnerable to nitrogen fertiliser use

Blue-Baby Syndrome

Condition from nitrite reacting with haemoglobin in infants

Organic Fertilisers

Less water-soluble alternatives like manure and green manure

Legumes

Plants with nitrogen-fixing bacteria in root nodules

Iron Sulphate

Reactant used to remove phosphate from sewage

Organic Nutrients

Carbon-containing pollutants like carbohydrates, proteins

Heterotrophic Organisms

Organisms needing external food sources

Aerobic Digestion

Oxygen-consuming breakdown of organic matter

Inorganic Nutrients

Non-carbon-based nutrients like phosphates

Pathogens

Disease-causing agents like bacteria

Turbidity

Cloudiness in water reducing light penetration

What are the sewage treatment stages

Pre-treatment, primary, secondary, tertiary, sludge treatment

What is the benefit of pre-treatment?

Removing large solids and debris from sewage

Primary Treatment is ...

Sedimentation to settle suspended solids

Secondary Treatment is ...

Aerobic breakdown of remaining organic matter

Tertiary Treatment is ...

Phosphate removal and sterilization of effluent

Sludge Treatment is ...

Anaerobic digestion of sludge to reduce volume

Anaerobic Digestion

Microbial breakdown of sludge without oxygen

What is a cheap but unsustainable sewage disposal method?

Landfill Disposal

Incineration

Burning sewage to ash, releasing greenhouse gases

Agricultural Use

Safe sludge use as crop fertilizer after testing

Methane Production

Release during anaerobic digestion of sludge

Monitoring Methods

Techniques to assess air and water pollution levels