Part 2 Flashcards
Identify the primary waste emitted by the pulp and paper industry
bleaching and finishing processes,
sludge from wastewater treatment, and
air emissions from combustion of fossil fuels and biomass.
Describe the general process of how the pulp and paper industry operates
. Bark is separated from the rest of the wood
2. Production of pulp
3. Treatment of pulp to give paper qualities
4. Pulp goes into a paper machine where it is formed into paper and dried
There are two ways to produce pulp
− The Sulfite Process
− The Sulfate/Kraft Process
More BOD : Sulfite
Acidic = sulfite
Greater variety of wood types= sulfate
water treatment for pulp and paper pollutants
pre-treatment, primary treatment, secondary treatment, tertiary treatment
Tertiary treatment:
further reduce BOD and SS, lower toxicity, and mitigate color, odor, and taste problems
How to reduce the toxic chemical in industrial effluents ( Solution )
Remove the toxic chemical from manufacturing process
Recover and recycle the toxicants before discharge
Remove toxicant from wastewater and dispose of it an environmentally friendly manner
2 processes that influence oxygen levels
Respiration of microbes that consume organics matter in the wastewater ( decreasing oxygen saturation%)
Reaeration of water with oxygen from atmosphere ( increasing oxygen saturation %)
What would the conditions of the wastewater to be in order to create such a curve
Wastewater high in organisms that consume oxygen
Organic matter that is food decomposers
Define pesticides
kill or control insects, or other unwanted organisms
Classification of Pesticides ( Target species ) Herbicides
designed to kill plant growth
Selective herbicides kill only one type of plant
Non-selective herbicides kill all plants
Fungicide
designed to kill fungi growth
Insecticide
designed to kill insect
Chemical nature
(i) Chlorinated Organics
chemically stable and can accumulate in fatty tissues, leading to bioaccumulation and biomagnification
Some chlorinated organics like DDT are highly toxic to fish and birds
DDE, DDD, and methoxychlor are alternatives to DDT
Chlordane, heptachlor, aldrin, and dieldrin have been banned due to their carcinogenic
Chemical nature
(ii) Organophosphates
They are less stable, do not bioaccumulate/biomagnify as readily
classified as the most toxic of all pesticides to most animals, including humans
Examples of organophosphates are malathion and parathion
Malathion is less toxic to humans and can be found in garden store pesticides
Parathion is highly toxic to humans and has caused most of the human pesticide poisonings worldwide due to improper use
Chemical nature
(iii) Carbamates
They are all derivatives of carbamic acid
they don’t bioaccumulate/biomagnify
not very toxic to fish but are highly toxic to birds and bees
Two common carbamates are aldicarb and carbofuran
Chemical nature
(iv) Pyrethroids
Pyrethroids are synthetic relatives of natural pyrethrin esters obtained from Chrysanthemum flowers
pyrethroids require lower application rates and are generally less toxic to animals
Pyrethroids are highly toxic to beneficial insects and extremely toxic to fish
Examples of pyrethroids are allethrin and dimethrin.
Pesticides Use
Public Health:
Animals can act as a carrier for infectious diseases, making it easier to attack the animal instead of the disease itself.
Mosquitoes are an example of a vector that can transmit diseases
DDT is a pesticide used to control mosquitoes that carry malaria
Pesticides use
2. Agriculture
The Green Revolution increased agricultural production worldwide, especially in developing countries..
High-yielding varieties (HYV) have a larger proportion of their structure usable for food, increasing the harvest index.
HYVs require large amounts of fertilizer, water, and pesticides to perform well.
Pesticides use
3) Forestry
Damage to forests from pests is difficult to estimate, but losses include:
* Reduced growth rates
* Loss of reproductive ability
* Direct mortality of trees
* Loss of recreational value
Pesticide Effects on Aquatic Communities
They impact fish species (non-target organisms)
They contaminate groundwater (due to their persistence)
They bioaccumulate and biomagnify (food chain magnification)
Pesticide Effects Non-Target Species
Pesticides can cause death in aquatic ecosystem when they runoff
DDT was sprayed in large amounts in New Brunswick forest in 1952
Low levels of chronic exposure to pesticides can lead to health risks such as cancer
Frogs are especially susceptible to pesticides due to their thin skins
Human are a non-target species for pesticide use
Pesticide Persistence in the Biosphere
The persistence of a pesticide depends on the environment
Pesticide persistence can contaminate groundwater
Pesticide Food Chain Magnification
Persistence of pesticides is related to food chain magnification.
The study found higher DDT residues at higher trophic levels.
It is unclear whether the higher concentration is from the water or from consuming food rich in DDT.
Pest Resistance
certain pesticides become virtually worthless for controlling pests,
a large amount of money must be spent to achieve a satisfactory level of pest control
Alternatives to Synthetic Pesticide Use Biological control
Ladybugs reduced the pest population,
is the introduction of natural pest predators, competitors or pathogens to a cropland