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Questions tagged [environmental-engineering]

5
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8answers
431 views

How to install a wired sensor in a rotating bin without tangling the wires?

I want to insert couple of moisture, temp and humidity sensors in this bin to take readings from the compost. But how do i install it without turning/tangling the wires? Can anyone help me figure a ...
0
votes
0answers
18 views

Why does anaerobic pond system need to have one part aerobic

While reading the book Environmental Engineering, by Howard S peavy in the chapter 5-2 regarding pond and system, is written that the anaerobic pond system need to have aerobic system (shallow pond) ...
2
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0answers
34 views

Hazardous waste packaging

I'd like to ask an environemental question which has to do with waste packaging and the EU regulations that enclosure this subject I'd like to package loads of different hazardous wastes in ...
1
vote
3answers
65 views

Mapping of vehicle to its horn sound

From the "meep meep" of the smallest scooter to the "BLLLAAAAAGGGGGHHH" of the largest seagoing container vessel, vehicles seem to have horn sounds that, in an auditory way, seem to indicate their ...
1
vote
0answers
21 views

Adsorption - what models are used for dry scrubbing?

For scrubbing with activated carbon, air is generally brought through a dry adsorption media, where the contaminant is adsorbed onto the media. I would like to know what mathematical model is used ...
0
votes
2answers
29 views

How to retrofit seed starting trays to prevent root circling

I grow plum trees from pits using seed starting trays: Unfortunately, I have a problem where the roots of the seedlings grow in circles around the bottom of the cavities of the trays. The circling ...
4
votes
2answers
94 views

Solving heat loss equation associated with solar trough concentrators

My project is about finding the efficiency of solar trough (cylindrical parabola) concentrator that will boil water in a pipe located at the focus (check picture please). In the process of doing so (...
3
votes
1answer
61 views

Store seeds at 1°C

I have prunus pits that I stratify in a refrigerator during winter. Normally, the seeds germinate in springtime, which is ideal. However, often some of the seeds germinate prematurely. When this ...
3
votes
4answers
100 views

What colour of tarp will let in the least amount of heat?

Source: Low Tunnel Construction: How to Build a Mini Hoop House I have a small greenhouse that I want to keep as cold as possible in the spring. I plan to cover the greenhouse with a polyethylene ...
1
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0answers
37 views

Design review needed for novel ion trap air scrubber / purifier concept [closed]

As a side kick I came up w/ a wet scrubber / air purifier design using trapped charged water droplets. I'm thinking about building a proof of concept but would like the community's feedback. ...
2
votes
2answers
78 views

Prolong frozen ground conditions (to trick fruit trees into flowering later)

There is a common problem with fruit trees in temperate climates where the trees flower before the last frost. Generally speaking, if the tree has flowered, and the temperature drops below freezing, ...
2
votes
0answers
27 views

How to select a smartphone IR camera for VOC monitoring [closed]

I am currently working on a problem involving volatile organic compounds (VOC) source monitoring on some oil and gas transportation environment. I think using infrared (IR) cameras could be a ...
10
votes
4answers
200 views

Humidity in home is much higher than outside

We have a two year-old, two-story town house with: fiberglass insulation in the walls; a Tyvek vapor barrier under foam board on the exterior walls; blown cellulose insulation in the attic; stucco ...
0
votes
2answers
33 views

Correlating relative humidity outside and inside an enclosure

I am building a device and I tried to Google an answer to this question but I am an electrical person and lack knowledge in this field. I need to know what the relative humidity inside an enclosure (...
0
votes
0answers
21 views

Copying a pond to a different location

In one of my projects there is a pond that is now considered a natural habitat of some species (animal and plants). The pond doesn't seem to have any specific role such as detention however it is not ...
1
vote
2answers
173 views

Why not use Sodium Hydroxide mist to precipitate carbon dioxide from hydrocarbon combustion exhaust

Much of the currently used techniques of scrubbing the carbon dioxide from power plant exhaust uses sophisticated amine and other organic compounds. These compounds are then forced to release the CO2 ...
0
votes
1answer
92 views

Do cars that automatically turn off engines at idle save any significant fuel?

There are many new cars now that automatically turn off their engines when stopped at traffic lights. They then automatically turn them on when moving off. These systems have many names along the ...
2
votes
1answer
2k views

Difference between surface loading rate and surface overflow rate of sedimentation tanks

Can anyone please explain to me the difference between surface loading rate and surface overflow rate when used during the design calculations of sedimentation tanks in water treatment plants?
3
votes
2answers
93 views

Is it better to throw used domestic cooking oil in toilet or within the garbage? [closed]

I recently asked a friend how I should recycle my used deep frying oil because I just don't have enough oil to justify taking my car, drive 20 minutes away to the waste collection site for few liters ...
1
vote
1answer
29 views

How large of an area of the earth's surface would we need to cover in mirrors to negate global warming?

How large of an area of the earth's surface would we need to cover in mirrors to negate current levels of global warming? Let's assume that the reflective component of the mirror is made of aluminium ...
5
votes
2answers
408 views

Can solar panels absorb heat for energy?

Solar panels can absorb sunlight and use it for energy, but can they absorb the heat that is generated from their use and use the heat for energy?
1
vote
0answers
30 views

Why have cascading vessels in the 'B' part of the 'AB' wastewater treatment process?

The AB process is wastewater treatment process that works like this: 'A Stage': Wastewater is (after mechanical treatment) subjected to a high load activated sludge process where also a lot of ...
1
vote
2answers
585 views

Can a retention/detention pond and a parking-lot be constructed in the same site foot-print?

Retention/Detention Ponds are often added to a site-design to mitigate storm-water runoff. Enhanced Porosity Concrete (EPC), aka Pervious Concrete, can be used as a parking-lot pavement that allows ...
1
vote
0answers
50 views

Hazardous Chemicals Waste Recycling company & KOH production, ABANDONED the site [closed]

A Hazardous Chemicals Waste Recycling company & KOH production, ABANDONED the site, they cut (looks like with a diamond saw) the concrete floor (25cm height) at about the middle of the warehouse, ...
1
vote
1answer
71 views

Thermodynamics of an Arctic Greenhouse

QUESTION For a business project, I'm looking into the viability of a greenhouse situated in Canada's far northern town of Iqaluit. The problem is how to mathematically simulate the internal air ...
5
votes
1answer
3k views

How can I calculate the evaporation rate for a hazmat spill?

I was given formulas for general evaporation, for a spill calculator I am building. These are formulas, that are supposed to approximate evaporation, are for a number of different chemicals. ...
3
votes
2answers
44 views

Nuclear wastegate thermal dissipation systems?

How do shoreline nuclear facilities lower the temperature of wastewater generated by their cooling systems before it enters the ocean?
9
votes
2answers
72 views

Inexpensive and moderately accurate (field) method of measuring THC (Total Hydrocarbon Content) in water

I am working in a construction company which is building hydropower plants in Northern Norway. We are monitoring the Total Hydrocarbon Content (THC) of our process waste water. This particularly ...
2
votes
0answers
32 views

In what ways could coastal cities like New York/Boston/Miami mitigate future sea level rises and maintain current dry land area? [closed]

We've all read articles on rising sea levels and the impact it will have on coastal cities in the coming decades. There are even maps that illustrate how varying levels of rising seas will impact the ...
1
vote
0answers
60 views

What is the relation between the Biological oxygen demand and the depth of water tank? [closed]

I need a relation between Biological oxygen demand and depth. The ultimate [BOD] is known, and I need to calculate a [BOD] at any depth of water tank; temperature is constant. The tank is two meters ...
9
votes
2answers
189 views

Why does reducing the amount of emissions control improve the fuel economy of a car?

In addition to power and performance, one of the reasons VW cheated their emissions results was to improve the fuel economy of their cars. Why exactly does this happen? I'm familiar with cars and how ...
3
votes
1answer
356 views

Gas cleaning in activated carbon filters - How much moisture is needed and why?

Biogas and sewage (typically around 60% CH4, rest CO2) gas is typically treated in activated carbon (ac) filters to remove H2S and siloxanes. The ac filters need a small amount of oxygen (>0,4%) to ...
4
votes
1answer
87 views

Oval aeration tanks - what are they called, what are the key differences in operation to circular tanks?

Consider this overview picture of a WWTP: In the back, you see two oval tanks with bridges and walls, separating an inner from an outer area. These are aeration tanks. Is there a specific reason ...
3
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0answers
50 views

SBR-like reactors without decanters?

Sequencing batch reactors let sludge settle before drawing off the supernatant. For this, decanter arms are often used. An example is here. The challenge is to draw off the supernatant without ...
0
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0answers
38 views

Has large scale mono fermentation of sugar beets been achieved?

Sugar beets are an interesting substrate for biogas production due to their high content of easily digested sugars and starches. However, they lack macronutrients to sustain the bacteria population. ...
4
votes
2answers
449 views

How do wastewater sludge degassing systems work?

There are high-rate anaerobic digestion systems where you remove substrate from the digester, let it settle in a tank, and pump back the settled sludge (possibly not all of it) to ensure a higher ...
4
votes
1answer
249 views

Which component of vehicle tailpipe emissions has the greatest social cost?

Emissions Emissions from vehicles have an associated social cost for everyone. We hear a lot about CO2, but CO2 is not the only thing that comes out of a tailpipe. From Wikipedia, emissions ...
4
votes
2answers
1k views

How do cyclonic vacuum cleaners maintain collection efficiency with constant motion and changes in orientation?

Anyone used to doing housework has probably noticed that vacuum cleaners come in both "bagged" and "bagless" varieties. If you're of a certain age, you may have noticed when these "bagless" vacuums ...
6
votes
2answers
208 views

What is a PD pump that I can use as an immersion pump for a slurry?

I need to pump a thick slurry from a tank. The slurry can be pumped, but won't flow well enough that I can use a suction pump from outside the tank. Normally, I'd use a centrifugal immersion pump that ...