Ops and Procedure Guide
Southern Section: Grey Water Treatment
Current as of 04/07/2004
Version 1 by Katie Harris* & Tara Ruttley** *MDRS-11 / **MDRS-12 (1/5/03-2/1/03)
Version 2 by James Russell & Peter Collins MDRS-27 (04/07/2004)
The GreenHab is divided into two sections with a biological wastewater management facility in the southern end and a greenhouse for plants in the northern end. This system relies on a combination of solar and generator power in addition to crew interaction to maintain proper function. This following discussion provides a general overview of the GreenHab systems and covers the crew operation and maintenance procedures
Southern Side: Grey Water Treatment
Introduction: The biological wastewater treatment system combines bacteria and plants to break down the Oasis soap, sweat solids, and food leavings. This system consists of 2 storage tanks, 2 trickling filters, and 5 alternating non-aerated and aerated tanks. These tanks should contain several different species of aerobic bacteria which cleave the carbon chains to produce CO2 and nitrify the ammonia (NH3) into nitrate (NO3). The nitrate is then utilized by the plants or denitrified into nitrogen, which on Mars would help offset air leaks.
Note: The system is currently inundated with Algae and the normal bacteria have been out competed. Currently we are trying to reinnoculate the system.
Habitat Water Flow: As shown in our following general flow diagram, potable water flows from a large outside tank into a 55 gallon tank located in the 2nd floor loft. Water is then drawn from the tank into a hot water tank or as cold water for use in preparing meals, filling water bottles, washing dishes, personal hygiene, showers, or science experiments. Of these uses, Crew 27 has estimated the water used and the corresponding grey water input for each of these uses (Note: the range of values includes previous crew findings based on crews of 6 people).
Preparing Meals: Water used depends on the meal [0 to 4 cups per meal]. No grey water load Crew water: No values recorded however estimated 3 gallons per day. No grey water load Washing Dishes: 5 gallons once per day at night (20:00) with all going out as grey water Personal Hygiene: 8 to 16 ounces for washing hands, face, and brushing teeth. All goes as grey water. Showers: 2.5 to 3 gallons per shower all goes as grey water. [Range: 1 (sponge) to 10 gallons] Science Experiments: Water usage is science specific; however, every few days you will use 3 to 5 gallons to wash laboratory ware which all goes as grey water.
Per current Mission Support recommendations, a daily grey water flowrate of 25-35 gallons per day is desired due to the size of the system. Currently we produce less grey water than recommended (~20 GPD) due to water savings.
Gray water from the sinks and shower drains via gravity through the piping which exits the hab into two holding tanks. The first tank is a double coned 100 gallon grease and sediment trap where the water exits the bottom of the tank into the 110 gallon outdoor holding tank, which are both in the ground and located to the northeast of the habitat. This grey water is then pumped from the 110 gallon tank into the southern GreenHab treatment area.
|The southern green habitat contains a series of two trickling filters with reservoirs and five tanks with several different points for potential recycling. The grey water enters the system into the 55 gallon barrel reservoir of the first trickling filter. Water in the reservoir is continuously pumped up to the trickling filter barrel filled with bioballs. The bacteria (or algae if not properly covered) on the bioballs aerobically oxidizes the grey water components.|
This process continues until the water in the reservoir reaches the overflow level which allows the water to travel to the second trickling filter. In the second trickling filter the process continues in a same fashion, with the exception that the water either flows from the overflow port into Tank 1 or flow can be directed after one pass of the upper filter directly into Tank 1.
The water now enters five 100 gallon aquatic tanks, with water flowing by gravity from 1 to 5 via overflow ports at the top of the tanks. Tanks 1, 3 and 5 are not aerated, which allows for denitrification while Tanks 2 and 4 are aerated for nitrification and additional carbon breakdown. On top of the water in Tanks 2 and 4 plants, such as water hyacinths and water lettuce grow by taking up the nitrate and other nutrients from the water. To continue water moving through the system in order to limit algae growth, the recirculation pump transfers water from Tank 4 back to Tank 1 based upon the GreenHab operators discretion.
Finally, the treated water is pulled by a pump when switched on by an operator from Tank 5 through a 5 micron filter (and a 1 micron filter) into the toilet supply tank (a large blue trash can). (Note: It is important to verify that a filter is operational).
The TST currently resides inside the main hab [but will be moved to the Greenhab for the 2004-2005 season]. This filtered water is subjected to a UV filter unit for sterilization until it fills the toilet tank by gravity. This water is then used to flush the toilet which flows through a septic tank to a nearby leach field.
Grey Water Composition: Grey water contains Oasis soap, food leavings, and shower waste (sweat solids & hair). Each gram of Oasis soap contains approximately 3 grams of NH3 and 10 grams of NO3. The bottle recommends 1 TBSP which is approximately 3 grams per gallon, but actual usage varies greatly. Based on grey water measurements from the outlet of the 110 gallon tank, the combination of these wastes and the local water normally produces a pH between 7.8 and 8.2.
Water Treatment Procedures for Grey and Black Water
Personal Protective Equipment (PPE): Wear gloves and face shield when inside the GreenHab. Wash hands thoroughly when you return to the hab.
Daily Readings: GreenHab system status must be noted daily and temperature readings must be taken three times daily (recommended 8 am, noon, and 8 pm) from the gauge on the southern door, (circled below).
General Wiring Around South Door
Send the readings to Mission Support as well as system status notes as shown below:
- Verify that the covers are in place over tanks 1 to 5, the trickling filters and around the trickling filter reservoirs.
- Verify that the southern fan and trickling filter pumps are working. If you find the system completely off, these items have been disconnected by the Solar Panel Pod controller to allow the battery to recharge. If you see this, turn switch to Hab Power and next time you visit the GreenHab (a few hours) flip the switch back to Solar Power in order to reactivate the system.
- Turn on recycle pump for 15 minutes to a 1/2hr to remove algae from the top of Tank One
- Check that TST water filter flowrate is still acceptable
- Record trickling filter #2 temperature. Thermometer suspended in reservoir.
- Aerators working in tanks 2 and 4.
- Tank 2 bubbles. If Tank 2 suds become out of control, scoop the excess suds into a nearby bucket. Suds are the by-product of aeration due to the surfactants from the soaps.
- Evening Reading Only: Maximum and minimum temperatures off of Channel 1 from the Oregon Scientific base station in the upper level of the Main Hab. The actual thermometer is located on the outer wall to the left of the rear airlock. After you take the reading, clear the memory for channel 1 by holding "Memory" for 3 seconds.
- Evening Reading Only: [Currently Not Done] Light levels of tanks 2, 3 and 5. Use the light meter and place the light sensitive end just above the plants in the respective tanks. The meter should be on the middle setting.
- Verify that the sump pump is connected to a timer which activates the system at 12:00 hours and 00:00 hours
- Digital photos of plants. Once per week, take digital pictures of the plants in the tanks. Upload these pictures in as part of your daily pictures to Mission Support
- Take Nutrient Readings: pH, NH3/NH4, NO2, and NO3 readings with the Hach water strip test kit. These tests are very simple and provide immediate results (but not very high resolution). Use the Pond Care test kits for pH, ammonia, nitrite, and nitrate. Detailed instructions are provided in each kit, but essentially they are simple test strips which you dip in the water. Wear gloves, as with any procedure involving the Greenhab water.
- On the first and fifteenth of each month, pour 40ml of the "Odorlos" green solution from under the sink in the shower room into the toilet bowl
- On the first and fifteenth of each month, check to make sure the toilet supply inlet port is not clogged. Do this by turning the inlet line valve by the TST to the off position and removing the four screws with a Philips head screwdriver
Cleaned hole in toilet supply inlet port
- Add a chlorox tablet as needed to the toilet tank and the toilet supply tank when the previous tablets have disappeared.
- Twice a month, clean the shower stall while wearing gloves. Pull the 3 black mats out of the shower and put them outside in the sun to dry fully. Use the squeegee (or a sponge) to direct all standing water down the drain and then use the Orange Kleen cleaner to clean all the surfaces of the shower.
Acronyms:Questions to think about or for use by Teachers:
- How much water does the MDRS use daily?
- What is the biggest use of water?
- What amount of water do you think would be required for a Mars mission?
- Are there any missing water users from this list?
- Can you estimate the amount of NH3 and NO3 added to the system from the soap? If so, how much?
- If you were to add urine to this system, what would happen to the levels of pH, NH3 and NO3 in the water? Would you still call it grey water?
Greenhab Ops and Procedure Guide Revised: Part 2 of 2
General Overview: The GreenHab is divided into two sections with a biological wastewater management facility in the southern end and a greenhouse for plants in the northern end. This system relies on a combination of solar and generator power in addition to crew interaction to maintain proper function. This following discussion provides a general overview of the Greenhab systems and covers the crew operation and maintenance procedures
Northern Side: Plants
Introduction: The northern section of the GreenHab provides a humid and temperature controlled environment for growing plants. These plants are mostly vegetables, such as radishes, carrots, tomatoes, and more. For example, on today, April 7, 2004, we are growing radishes, carrots, and beans. These are all being grown in soil. However, there are other ways to grow these plants, such as in a hydroponic system which Crew 28 will be starting again. If done hygienically, these plants can be eaten by the crew.
Procedures For Plant Care: Personal Protective Equipment (PPE): None required at this time.
Daily Tasks: Water plants in the GreenHab with clean tap water, NOT grey water from the southern GreenHab.
Monthly Tasks: Verify the northern fan opens at the correct temperature for the types of plants being grown.
Some pictures of plants being grown during Crew 27's increment.