What is a Ras waste-treatment plan?
Activated sludge process is a process for treating sewage and waste water commonly referred as effluent using bacteria (to degrade the biodegradable organics) and air (Oxygen for …
How can we reduce the amount of waste generated?
In what way is the RAS waste-treatment plan an example of biomimicry? it depends on bacteria doing what they normally do in nature Approximately 75% of Earth's surface is covered with …
What are the benefits of Ras?
16. In what way is the RAS waste-treatment plan an example of biomimicry? a) It purifies the water with biodegradable filters. b) It depends on bacteria doing what they normally do in …
How do you biodegrade waste?
Biological treatment of organic waste is an age-old practice that in relation to municipal solid waste has had a strong revival during the last decade. This is due to increased efforts to …
Why might bottom trawling fishing techniques make it harder for cod populations to recover even after the ships have left the area?
What is the action that humans engage in when they harvest new species at lower trophic levels after overfishing an upper trophic-level fish?
What is the negative impact of aquaculture on the environment?
What happens to large fish when fishermen start to focus on animals that are lower on the food chain?
In which ways does overfishing lead to decreased biodiversity?
What is aquaculture and why is it important?
How does aquaculture help the environment and what are the concerns of aquaculture?
What are the environmental risks of marine aquaculture?
How aquaculture practices affect biodiversity?
How does overfishing affect the marine food chain?
How does overfishing impact coral reefs?
Why is using fish for fish meal for aquaculture a problem?
Why is bottom trawling important?
Modern fishing methods like bottom trawling allow unsustainable fish harvests, damage ocean ecosystems, and kill nontarget species (bycatch). As supplies of higher-trophic-level fish dwindle, we take fish lower on the food chain, making it hard for the higher-trophic-level fish populations to recover.
What are the advantages of aquaculture?
The following is a list of potential advantages: (1) they can be sized as needed to feed a modern city, or even a country. (2) they can raise large marine species that are declining in the wild, and perhaps ones which are the most beneficial to human health, independent of location of the aquaculture operation.
Why is aquaculture important?
Although the oceans are vast, many fisheries are in serious jeopardy due to overfishing. Aquaculture allows us to raise substantial amounts of fish for harvest, taking some pressure off of wild stocks, but it comes with trade-offs.
What is a simple food web?
A simple food web means that even the loss of one species can have significant consequences for the entire ecosystem as there are fewer other species (or none) to fill in the role of the species in decline. This can be seen in the case of the cod fisheries where the loss of the higher trophic level cod is particularly disruptive ...
What is sustainable fishery?
A sustainable fishery is one that is fished and managed in a way to ensure that fish stocks are maintained at healthy levels, the ecosystem is fully functional, fishing activity does not threaten biological diversity, and the fishery is managed effectively. The rearing of aquatic species in tanks, ponds, ...
What is exclusive economic zone?
exclusive economic zones. Zones that extend 200 nautical miles from the coastline of any given nation, where that nation has exclusive rights over marine resources, including fish. marine protected areas . Discrete regions of ocean that are legally protected from various forms of human exploitation.
What is activated sludge?
Activated sludge refers to a mixture of microorganisms and suspended solids. The bacterial culture is cultivated in the treatment process to break down organic matter into carbon dioxide, water, and other inorganic compounds. The typical activated sludge process has following basic components:
What is the purpose of bacterial culture?
The bacterial culture is cultivated in the treatment process to break down organic matter into carbon dioxide, water, and other inorganic compounds. The typical activated sludge process has following basic components: 1) Primary Clarifier to separate the solids carried along with Sewage/Effluent. 2) A reactor in which the microorganisms are kept in ...
What are the components of activated sludge?
The typical activated sludge process has following basic components: 1) Primary Clarifier to separate the solids carried along with Sewage/Effluent. 2) A reactor in which the microorganisms are kept in suspension, aerated, and in contact with the waste they are treating. 3) liquid-solid separation ; and.
What is primary clarifier?
1) Primary Clarifier to separate the solids carried along with Sewage/Effluent. 2) A reactor in which the microorganisms are kept in suspension, aerated, and in contact with the waste they are treating. 3) liquid-solid separation; and.
Why is oxygen dissolved in water?
The oxygen dissolved in the water allows the bacteria to use the food (BOD) and also to change the ammonia to nitrate. The tank should be big enough to allow sufficient contact time (retention time) between the sewage and the activated sludge for all the chemical changes to take place.
What is biological waste treatment?
Biological treatment of organic waste is an age-old practice that in relation to municipal solid waste has had a strong revival during the last decade. This is due to increased efforts to improve recycling of nutrients and organic matter to soil and in particular to minimise landfilling of biodegradable waste to reduce emission of greenhouse gases. In addition, special attention is given to the possibility of utilising the energy liberated during microbial decomposition of organic matter. Thus, the ultimate objective of biological waste treat-ment is to optimise the resource and energy use and simultaneously minimise the envi-ronmental impacts at the lowest possible in-vestment and operational costs. The ideology behind this is supported at the highest politi-cal levels, e.g., the European Commission has recently proposed a directive with the intent of making biological waste treatment obliga-tory within the next few years.
Is composting more than biogas?
Since composting is more easily downscaled compared to biogas production, composting systems can be placed close and visible to the public and therefore demonstration of the process and engaging people in recycling of organic waste can be accomplished. More-over, due to the aerobic nature of the com-posting process, visitors to composting plants are able to experience the process at closer quarters than at biogas plants where the mate-rial have to be enclosed to maintain anaerobic conditions. Home composting, in particular, offers the possibility to convey a "hands-on" experience to children as well as adults regard-ing recycling of organic waste.
What is waste prevention?
Hence, waste prevention is a basic goal of all the waste management strategies. Numerous technologies can be employed throughout the manufacturing, use, or post-use portions of product life cycles to eliminate waste and, in turn, reduce or prevent pollution. Some representative strategies include environmentally conscious manufacturing methods ...
Can waste be eliminated?
In many cases, wastes cannot be outright eliminated from a variety of processes. However, numerous strategies can be implemented to reduce or minimize waste generation. Waste minimization, or source reduction, refers to the collective strategies of design and fabrication of products or services that minimize the amount of generated waste and/or ...
How can waste be reduced?
In industry, waste can be reduced by reusing materials, using less hazardous substitute materials, or by modifying components of design and processing. Many benefits can be realized by waste minimization or source reduction, including reduced use of natural resources and the reduction of toxicity of wastes.
Is landfill disposal a waste disposal?
Despite advances in reuse and recycling, landfill disposal remains the primary waste disposal method in the United States. As previously mentioned, the rate of MSW generation continues to increase, but overall landfill capacity is decreasing. New regulations concerning proper waste disposal and the use of innovative liner systems to minimize the potential of groundwater contamination from leachate infiltration and migration have resulted in a substantial increase in the costs of landfill disposal. Also, public opposition to landfills continues to grow, partially inspired by memories of historic uncontrolled dumping practices the resulting undesirable side effects of uncontrolled vectors, contaminated groundwater, unmitigated odors, and subsequent diminished property values.
Is tetrachloroethylene toxic?
For decades, dry cleaners used tetrachloroethylene, or “perc” as a dry cleaning solvent. Although effective, tetrachloroethylene is a relatively toxic compound. Additionally, it is easily introduced into the environment, where it is highly recalcitrant due to its physical properties.
What is recycling in manufacturing?
Recycling refers to recovery of useful materials such as glass, paper, plastics, wood, and metals from the waste stream so they may be incorporated into the fabrication of new products. With greater incorporation of recycled materials, the required use of raw materials for identical applications is reduced.
Why is recycling important?
With greater incorporation of recycled materials, the required use of raw materials for identical applications is reduced. Recycling reduces the need of natural resource exploitation for raw materials, but it also allows waste materials to be recovered and utilized as valuable resource materials .