Frequently Asked Questions
- Is the treatment process is inherently stable and robust?
- Is sludge production low and easy to manage?
- Is it well suited to STEP/STEG effluent sewer collection?
- Is the treatment process passive?
- Are the operation and maintenance requirements low?
- Does the system have a quick start up time?
- Is the system is “fail-safe”?
- How is flow managed?
- Is the technology readily "scalable"?
- Can the system be implemented in "modules"?
- Does the process have a very low energy demand?
- Do you use high quality components?
- Is there low noise?
- Are there any offensive odours?
Is the treatment process inherently stable and robust?
Many treatment processes depend for treatment upon very few trophic levels of organisms, living in concentrations far higher than found anywhere in nature. In contrast, in the AdvanTex®, treatment is accomplished by a diverse ecology, including many trophic levels of organisms, as well as by physical and chemical processes that are inherent to the filtration process. This means it can readily accommodate variability in loading conditions without compromising effluent quality. This is an important consideration in scenarios where seasonal population variability will result in variable loading on the treatment plant, including sudden “shock” loads. Data to support the capability to handle variable and shock loads are presented in the section of this web site under AdvanTex® PBR and within the various case studies. We also recommend that you refer to the independent Rotorua Onsite Effluent Trial conducted by Environment Bay of Plenty and the Rotorua District Council. A copy of this report is available on our web site or at http:/www.ebop.govt.nz.
Is sludge production low and easy to manage?
Because packed bed reactors are designed to limit cell mass growth by controlling the organic loading rate and encouraging endogenous respiration, sludge removal is not required from the PBR itself. Sludge management for this system is not a time-critical operation. Most of the sludge is retained in the septic tank(s) is used for pre-treatment. These can essentially be pumped when convenient. The remainder of the sludge is removed during the bed cleaning process.
Is it well suited to STEP/STEG effluent sewer collection?
The proposed wastewater collection system is an effluent sewer and provides many advantages over alternative collection systems. Unlike other treatment systems which require a high level of BOD or carbon for cell synthesis of the micro-organisms that do the treatment, the AdvanTex® process is ideally suited to treat effluent with the characteristics that exit an effluent sewer. The AdvanTex® has a proven performance record in the treatment of filtered effluent from STEP/STEG effluent sewers.
Is the treatment process passive?
The AdvanTex® does not depend on inputs of energy or adjustments in operating conditions (once the system is set up) to keep the process viable. Pumps merely move water through the system. Naturally occurring micro-organisms naturally populate the textile fibres at population levels similar to those found in nature. This is in contrast to aerobic treatment plants where an unnatural environment must be maintained by input of energy, which is critical to maintaining process integrity, and by close attention to operating conditions over the short term. Thus the aerobic process is prone to "upsets" from many causes, including flow variations, untimely operator intervention, and mechanical problems. Once "off track" it typically takes some time for the process to return to normal, during which poorly treated effluent continues to be produced.
Are the operation and maintenance requirements low?
For both the textile pods, and the "peripheral" equipment, the O&M requirements are fairly simple and straightforward. This means that it is unlikely that there is a high risk of not having personnel with the technical ability to continue operating the plant, though preventative maintenance performed by a trained service agent etc. is recommended at varying intervals depending on the size of the treatment plant.
Does the system have a quick start up time?
This is desirable to avoid potential negative environmental effects during the start-up period of the treatment plant. 80 % removal of cBOD5 within 24 hours of operation, with TSS of less than 15 mg/l has been reported with the AdvanTex®. This is in contrast to aerobic treatment plants where several months are typically required to grow sufficient populations of the micro-organisms that provide wastewater treatment. Further evidence of quick start-up of the AdvanTex® is presented in the section of this web site under AdvanTex® PBR and within the various case studies.
Is the system is “fail-safe”?
The AdvanTex® design does not allow completely untreated sewage to be released since wastewater must pass through the treatment media before discharge. This feature also prevents deliberate attempts to disable the treatment system. Unlike passive gravity-in/gravity-out suspended growth aerobic systems, only the filtrate is discharged, ensuring high effluent quality dispensed for final dispersal. In addition, a pump failure does not immediately compromise the treatment process, and once the failure is corrected, the system continues to operate normally without a start-up period of less than adequate treatment. Furthermore, a well-recognised advantage of packed bed reactors is that the major mode of failure, media clogging, is slow and gradual and can often be identified before criticality. This is further improved with the AdvanTex® where clogging of the textile is even slower, easily identified and very simple to rectify with almost no system down-time.
How is flow managed?
Since the AdvanTex® has a programmable timer in its control panel there is the ability to detect excessive inflow caused by infiltration, leaky plumbing fixtures, or higher-than-normal water consumption by the user. This “flow management” provided by the programmable timer is a fundamental tool that allows operators to detect and diagnose problems that would otherwise go undetected until complete system failure. The programmable controllers also provide improved treatment through frequent “micro-dosing” of the packed bed textile medium.
Is the technology readily "scalable"?
It can be implemented for a single home or for an entire community without compromising the technology.
Can the system be implemented in "modules"?
The expansion of larger systems can be readily accommodated without interrupting the treatment process. These modules can be fairly small, so the system can be expanded in small increments of capacity. The system can therefore be highly responsive to changing needs. This also allows maintenance to be conducted on one module while the rest of the system continues in operation. Properly executed, this modular design also minimises the vulnerability of the system to mechanical failures.
Does the process have a very low energy demand?
The System relies on a mainly passive biological treatment process. Efficient, low-power pumps are the main energy demand, and unlike aerators on activated sludge systems, these run only infrequently. The Rotorua Onsite Effluent Study showed that the AdvanTex® recirculation pump used only 0.5kwh. This equates to about $2.00 per month. With the additional of a discharge pump, the monthly cost of power is around $5.00.
Do you use high quality components?
Only high quality components are used in the manufacture and assembly of the AdvanTex® packed bed reactor. The decreases the risk of component failure and assures the extended lifetime of the plant as well as reducing replacement costs.
Is there low noise?
The AdvanTex® system has no noisy aerators. The noise levels from the treatment plant are so low as to be almost inaudible (less than 15 dB). The small multi-stage turbine pumps used to dose the textile PODs are low noise inherently and when this is coupled with the fact that the pumps are buried under ground in a tank surrounded by liquid, there is no need for further noise control. The ventilation fans and spray nozzles in the POD are enclosed in sealed units and the noise levels are so low that no further noise control is required in this area either. Noise from the discharge pump to the land application system is similar to the dosing pumps and installed in a similar way.