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本帖最后由 ljaiyj 于 2010-1-12 19:46 编辑
今天看污水处理装置资料，有太多不明白的。那为大虾解释一下，并能说说污水处理装置的详细工作原理，对氧的需求，氯的量控制什么的。。。。。
我附上今天资料里的东西，请一点一点解释 谢谢。 不好意思一张图不知道怎么放进来，就不放了。
Suitable for biological treatment of sewage, "black water" from toilets from maximum 32 persons
up to the maximum hydraulic capacity of the unit calculated on 2.592 litre/day black water and
suitable for disinfecting of all grey water from showers, lavatories etc., without discharge of grind
food waste from maximum 32 persons up to the maximum total hydraulic capacity of the unit
calculated on 5.760 litre/day waste water.（能这样取值，32个人一天只能造2.592 litre/day黑水？ 我不信）
Effluent standards;
Biological Oxygen Demand (BOD5) : < 50 mg/l （不太明白，是生物需氧量（BOD5）小与50 mg/l ？）
Suspended Solids (SS) : < 50 mg/l
Faecal coliforms MPN : < 200/100 ml
Free chlorine : as low as practical.
Design loading of the MSD-II system : normal average 1.1 kg BOD5/m3/day（怎么理解）
maximum 3,5 BOD5/m3/day
Test procedures (10 day witnessed test, with 40 samples analysed by an independent laboratory)
showed BOD5 and SS values average 30% below limit, practically 0 (zero) PPM free chlorine
and same for faecal coliform counts. IMO test requirements oblige to add primary sludge to
simulate peak loads and overload conditions, up to 500 mg/l. The constant fluctuation of influent
quality and sludge concentration makes this addition very difficult to control. Results of influent
analysis organic matters where found to be average above 1.000 mg/l (4 times normal "house
hold" waste water).
2.2 Process & flow diagram
The MSD-II uses micro organisms already present in the waste water to digest the organic pollution.
This is performed by aerobe bacteria, in a single stage process.
Technically, the MSD-II differs from most other aerobe systems in respect to the way that the
bacteria are contained in the system. Conventional systems have the bacteria growth free in the
treated liquid, attaching to sludge particles which circulate in the liquid.
The MSD-II system is fitted with a contact material, also called "packing", "biodeck" or "biofilter",
fully submerged in the liquid. This packing material has a large specific surface on which the
active bacteria and sludge particle will easily attach and grow. This packing is in use with
many municipal waste water plants all over the world, normally used for upgrading of existing
extended aeration systems.
The wastewater flows in to the treatment tank via the inlet (1). The blower (2) takes care of aeration of the sewage and provides circulation over the submerged biofilter (4) by means of a simple
"mammoth-pump" (3). The micro-organisms that grow on the surface of the biofilter are
biologically breaking down the organic matters in the waste water. The water circulates across the
biofilter several times, as the treatment tank volume is designed for beneficiary retention time,
necessary for BOD5 removal. The lower part of the tank is a "still" area, from which the clean
effluent flows over through the spillover connection (6) to the disinfection tank. (7).
The low amount of sludge that is formed, together with small indigestible particles, will settle on
the bottom of the treatment tank (11) for later disposal.
The disinfection pump (8) is metering the liquid disinfectant accurately by simple volumetric means,
to destroy harmful infectious bacteria as faecal coliforms, viruses and worm eggs.
In this way a save quality effluent is produced, suitable for discharge overboard.
The automatic working discharge pump (9) maintains the level within the high and low level
switches (10) optional a high level alarm can be fitted.
2.3 COMPONENTS (HARDWARE)
2.3.1 TREATMENT TANK - Biological oxidation of the sewage organics takes place in the
Treatment Tank. The bacteria naturally grow and attach themselves to the large surface area
provided by the Biodek R.(2.3.2) The Air lifts circulates the sewage to the bacteria and transfers
oxygen into the water. The water level is constant. At the top of the tank is a sufficient air gap
for ventilating the tank.
The tank is a welded steel construction, with necessary connections an inspection hatch.
Although the inner coating is a suitable marine tank coating, not any paint system supplier
will guarantee their products longer than 3 years. Regular inspection is necessary.
2.3.2 BIODECK(专业名字叫什么？） R - (also referred to as "Biofilter", "Packing", or "Plasdek") The biodeck inside the
treatment tank is assembled as blocks from corrugated sheets of PVC. The PVC material used is mainly recycled industrial waste material. The expected life time is 15 years. In case of disposal, the
material is suitable for recycling again.
The corrugated plates are glued together under 60 degrees, forming a cross-pattern of flow channels
and a large specific surface area for microbial growth. The blocks are cut to fit the tank and installed
so that the top of the Biodek is sufficiently below the waterline. The blocks are supported by steel
brackets at the bottom part of the tank. The biodeck material is inert to sewage and seawater, and
normally, needs not to be replaced during the life span of the system.
2.3.3 AIR LIFTS - The Air Lift is a vertical pipe which extends from below the biodeck to the
waterline. (in large systems, two airlifts can be fitted) Compressed air is injected near the bottom
of each Air Lift. The rising air bubbles produce a strong upward flow of the water. In this manner,
the Air Lifts act as high volume pump. This reliable principal is known as "Mammoth pump"
The air bubbles transfer oxygen into the water as does the splashing action above the water
line. The splashing action also stimulates the breaking down of solid particles and toilet paper
present in the waste water. Aeration is critical to the process, as aerobic conditions must be
maintained to achieve proper treatment. The turbulent flow from the Air Lifts also throws foreign
objects to the sides and ends of the Treatment Tank, and prevents clogging of the biofilter surface
with foreign objects.
2.3.4 SLUDGE COMPARTMENT - The lower part of the Treatment Tank is designed to receive
and store the sludge which is a by-product of the biological oxidation of sewage. The sludge
includes inert organic matter as well as inorganic materials such as sand and dirt as cigarette filters.
Sludge is removed periodically, see chapter "Airscoure & pumpout procedure".
2.3.5 AIR SCOUR SYSTEM - For sludge removal, at the bottom of the Treatment Tank there is a pipe
assembly fitted, with holes drilled on the underside at regular intervals. When compressed air is
routed to the Air Scour, the air bubbles break up the accumulated sludge permitting efficient
removal of the sludge from the Biodeck R. The rising airbubbles also strip off excessive growth
of bacteria, and remove foreign particles from the biofilter material.
A more detailed description of this procedure will be found under Section AIR SCOUR
AND SLUDGE PUMP OUT.
2.3.6 SPILLOVER - A standpipe gravity Spillover is installed in the Treatment Tank to feed the
Contact tank. The spillover is situated near the centre of the tank, to reduce the effect of ship's
movements on the level in the tank. As sewage enters the Treatment Tank, an equal volume of
treated water is displaced through the spillover into the Contact tank. The Spillover is equipped
with a water seal to isolate the Contact tank from the Treatment Tank and prevent venting of
Treatment Tank air through the Contact tank into the ships atmosphere.
2.3.7 CONTACT TANK
The Contact tank may be either an independent free-standing tank or a partitioned section of a single
structural tank which comprises both Treatment Tank and Contact tank..
Treated water flows from the Treatment Tank through the Spillover pipe into the Contact tank.
The Contact tank is a retention tank sized for adequate disinfection time (minimal 1/2 hour retention
time) during peak flow periods. The vent connection may be open to the immediate environment.
The Contact tank is discharged overboard by the discharge pump.
2.3.8 DISINFECTANT DOSING SYSTEM
The system is provided with a liquid disinfectant dosing system, that will act as follows ;
Biological treatment takes place as above. The effluent from the media tank discharges
through the spillover into the Contact tank. To produce save effluent, free of life endangering
micro-organisms, the effluent needs to be disinfected.
In automatic operation mode, the effluent level rises to the high level switch in the disinfectant tank.
The discharge pump will start and pump out until low level switch is reached. The low level switch
triggers the action of the disinfectant pump, metering an exact quantity of liquid chlorine, sufficient
for the volume of effluent between the low- and high level switch(看不懂这个关系）. The volume of chlorine is
controlled in two ways; A. the injection pump is adjustable, and B. there is a timer to control the
operational time of the injection pump. Each time the discharge pump is started, the liquid chlorine
dosing pump will charge the disinfectant tank, with an adequate volume of chlorine to disinfect the
following batch of effluent. (manual start of the discharge pump will NOT activate chlorine pump)
The factory setting is based on 15% Sodium-Hypochloride concentration.
Simple adjustment of the injection pump can make your system ready for use of other concentrations,
for instance common household bleach, or other type disinfectant. The dosing and contact time
are calculated in accordance with the IMO/Marpol test requirements.
2.3.8 DISINFECTANT ADJUSTMENT - Depending on the load, a dosage of 10-20 mg/l free chlorine
will be sufficient for adequate disinfection of the effluent. Standard and widely available
15% Sodium Hypchloride is used as disinfectant. The injected volume disinfectant can be adjusted in
two ways (see literature of dosingpump enclosed).
1. The number of strokes per minute is adjustable from 0-60.
2. The volume per stroke is adjustable from 0-100 %
The volume of liquid chlorine is factory set to be 10 mg/l. effluent. After starting up, the residual
free chlorine shall be adjusted to low as practical, about 1-3 mg/l. Effluent samples can be checked
by means of a free chlorine indicator set.
To determine interval of chlorine refill, the level of the container must be regularly checked (weekly)
Optionally a low level switch and testvalve on pump-outlet can be fitted.
It is preferable to set the chlorine pump on 50% capacity and speed, and regulate
the dosing by adjusting the timer in the control box. |
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发表于 2010-1-12 19:36
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