In full work at Exeter, is a practical application of the biological treatment. It finds favour with practical men. The sewage flows direct into a covered tank holding about eighteen hours* flow, and depositing therein heavy matters in suspension; the lighter matters flow on with the water to coke breeze filter-beds. The discharge is worked automatically by syphons and buckets acting on penstocks, which when one filter is filled turn the flow on to a second empty filter, and empties a third which has had its turn of resting full. The daily amount treated at Exeter is about 60,000 gallons. The amount of deposit left in tank is moderate and is easily removed. The mechanical gear would seem to offer an element of doubt, though it is simple and has worked well under all conditions of weather. No odour of sulphuretted hydrogen comes from the filter-beds, and the filtrate or effluent water is bright and clear. 122 DOMESTIC SANITARY DRAINAGE AND PLUMBING. fit to be turned into any stream, and gives no sign of secondary decomposition. The Septic Tank System thus promises to be of great practical value to villages, small towns, and mansions, where effective sanitary sewage disposal has hitherto proved unattainable at moderate cost. <Callout type="important" title="Important">Adams' patent bacteria bed apparatus is another adaptation of the bacteriological process of sewage disposal which deserves notice; we accordingly give here a plan and section with explanation:</Callout> — With Mr. Dibdin's contact beds it is necessary to fill a bed, shut off the supply, allow the sewage to remain upon the bed for the desired contact, and then to run the bed off and allow it to stand empty for aeration. The illustration shows Messrs. Adams' patented apparatus: the supply to a bed is through a metal casting formed as a trap; liquid passes freely through this ordinarily, but is prevented from doing so when air under pressure is forced into the apparatus, air lock resulting. The necessary air is displaced from an attached air dome by the rising liquid in bed. The filling of the bed thus shuts off its own supply. An added volume of air to the feed forces the trap; this added volume of air is transferred from an air dome in the bed, which it is desired to follow. The supply is thus brought from bed to bed. To discharge the beds a timed syphon is used; this is placed in a small chamber, which is filled by means of a tap from the bed; the rate of filling determines the length of contact. Thus if the tank takes two hours to fill, the sewage is held up for contact in the bed for that length of time; the syphon starting automatically then discharges the contents of its own chamber, and through the overdraw pipe that of the bacteria bed. In this way the contact may be fixed to meet the requirements of the sewage, a thin sewage requiring less and a stronger sewage a longer period. In other modifications the same parts serve for use on the continuous or other systems. <Callout type="tip" title="Tip">Description of Adams' Patent Sewage Lift, — This apparatus for the automatic raising of low-level sewage is actuated by compressed air. The liquid to be raised is ejected from a cylinder — into which it has first gravitated — by this pressure. The illustration shows the lift as installed in a building for raising basement sewage.</Callout> Water enters the flush tank, discharging from it to the air cylinder; air from the latter is thus displaced and sent through the air pipe to the forcing cylinder; from the latter the sewage is ejected by the air pressure thus directly applied. 124 DOMESTIC SANITARY DRAINAGE AND PLUMBING. <Callout type="warning" title="Warning">Adams' original deep trap syphon, invented by Messrs. Adams and Co., depends for its action upon the pressure of the air confined between the deep trap of syphon and the rising liquid in tank; when a sufficient pressure is reached the air is forced out through the water seal and syphonic action follows.</Callout> W'S^^^^'W 1 ""k^ ^ Fio. 17.— Adams' Patent Flush Syphon.
Key Takeaways
- The Exeter method uses a covered tank and coke breeze filter-beds for effective sewage treatment.
- Adams' patent bacteria bed apparatus allows for controlled contact time with air to enhance bacterial action.
- Mechanical gear in sewage disposal can be complex but is necessary for automation.
Practical Tips
- Implementing a septic tank system can significantly reduce the need for expensive municipal services, especially in rural areas.
- Using air pressure systems like Adams' patent flush syphon can automate and streamline the sewage treatment process.
- Regular maintenance of mechanical components is crucial to ensure the effectiveness of sewage disposal methods.
Warnings & Risks
- The mechanical gear used in sewage disposal can be prone to failure, which could lead to untreated sewage discharge.
- Improper installation or operation of air pressure systems can result in odors and secondary decomposition issues.
- Overloading the system with too much sewage at once can overwhelm the bacterial treatment process.
Modern Application
While the specific technologies described may not be directly applicable, the principles of using biological processes for sewage treatment remain relevant. Modern systems have improved efficiency and reliability but still rely on similar foundational concepts. Understanding these historical methods provides a valuable perspective on sustainable sanitation solutions in emergency situations.
Frequently Asked Questions
Q: What is the Exeter method mentioned in this chapter?
The Exeter method involves using a covered tank to hold sewage for about eighteen hours, allowing heavy matters to settle and lighter materials to flow into coke breeze filter-beds. This process ensures effective treatment before discharge.
Q: How does Adams' patent bacteria bed apparatus work?
Adams' bacteria bed apparatus uses air pressure to control the sewage flow through beds, allowing for a fixed contact time with air to enhance bacterial action. The system can be automated and adapted for different types of sewage.
Q: What are some key components of Adams' patent flush syphon?
Adams' original deep trap syphon relies on the pressure of air confined between a deep trap and rising liquid in the tank. When sufficient pressure is reached, the air is forced out through a water seal, initiating syphonic action for sewage discharge.