Domestic
Domestic wastewater comprises of organic and inorganic wastewater produced in a household, comprising of the following sources : Bathroom, Toilet, Laundry, Kitchen and Car wash
Out of these, only wastewater from toilet is considered as black waste water while wastewater generated from other sources is considered as grey wastewater. The aim is to treat this wastewater and convert it into reusable water with production of minimum sludge in the process. It can be done in 2 ways :
- Aerobic (with the help of oxygen)
- Anaerobic (no-supply of oxygen)
Both the black and grey wastewater can be fed in the treatment system together while our approach is to provide and tailor a solution that meets the requirement of the consumer in the best way possible.
Civil work under progress
Civil work under progress
Design of plumbing work
DEWATS Vortex in the making
A DEWATS Vortex site
A DEWATS Vortex site
A DEWATS Vortex site
A DEWATS Vortex site
DEWATS (Decentralised Wastewater Treatment System) plus Vortex is a combination of Anaerobic digestion plus Oxidation where wastewater is made to move up and down in the settler tank and baffled reactors resulting in maximum sludge settlement and creation of anoxic zone which results in elimination of biological nutrients. Further to this, wastewater is then made to pass through filtration media which is present in Anaerobic filter tanks where bacteria colony removes (digests) the remaining nutrients and compounds present in water.
Finally, through vortex action, done in a cylindrical tube with the help of a single and only pump of the system, oxidation is induced in the water resulting in its polishing and odour removal. The output water is disinfected with the help of chlorine or UV and has various non-potable utilities (read more in key features) The entire process requires minimum Operation and Maintenance of the plant (read more in comparison) A DEWATS + Vortex system can be installed in a single household and can also be easily installed for a group pf households. It is easily integrable with surroundings resulting in aesthetical harmony.
Schematic diagram of DEWATS + Vortex
Key Features of DEWATS + Vortex
- A proven technology with installations in over 17 countries and 350 plant setups in India alone
- Up to 80% Lower O&M costs than aerobic treatment systems
- No chemicals added
- Minimal electricity and day to day activity
- Integrable with landscaping
- Treatment Capacity from 1,000 litres per day (1m3) to 10 Lakh litres per day (1,000 m3)
- Water utility in garden, agriculture, flushing, fisheries, recreational activities.
A decanter used in RW-SBR
RW-SBR site
RW-SBR site
Aerobic systems are those treatment systems which require supply of air (oxygen), mixture of activated sludge to initiate treatment. A kind of Aerobic treatment system is RW-SBR. SBR comprises of a distribution tank, two or more aeration tanks cum settlement tanks, a filter feed sump, a clear water tank and a sludge holding tank.
As the name suggests, the treatment happens in various cycles which also helps mitigate the risk of overloading, where 2 aeration tanks are connected via an automatic valve which controls the distribution of wastewater to both the aeration tanks. With one of the least retention period for wastewater, around 12-14 hrs, among various treatment systems, SBR is one of the efficient ways of treatment of domestic wastewater.
Key Features of RW - SBR
- Small Footprint
- PLC Control System Provides High Degree of Reliability and Flexibility
- Decanting rate of 10-50 mm/min. ensures low TSS (Total Suspended Solids)
- Consistent removal of Nitrogen and Phosphorous
- Avoidance of sludge bulking
- Achievement of Biological treatment and secondary clarification in a single reactor vessel.
- Potential capital cost savings by elimination of clarifiers and other equipment.
- Low electricity consumption compared to other aerobic systems
Schematic Diagram of RW – SBR
| Parameters (100 KLD plant as reference) | Aerobic (RW – SBR) | Anaerobic (DEWATS + Vortex) |
|---|---|---|
| Technical Aspects ** | ||
| Extra Sewage Load Capacity | 70 - 100% | 40% - 50% |
| Number of tanks | 5 | 5 |
| Area usage (m2) | 55 | 125 |
| Depth from inlet pipe (m) | 4 | 2.6 |
| Total volume of tanks / Total excavation (m3) | 220 | 325 |
| Outcome Quality ** | ||
| BOD (mg/l) | < 10 | < 10 |
| Total suspended solids (mg/l) | < 10 | < 10 |
| COD (mg/l) | < 50 | < 50 |
| Oil & Grease (mg/l) | < 10 | < 10 |
| Outcome Quantity (as a percent of feed volume) | 80 - 85 % | > 90% |
| Whether it meets the new norms of PCB | Yes | Yes |
| Cost Aspect in (Rs.) | ||
| Initial Cost (100 KLD) * | 9 Lakhs | 7 Lakhs |
| Repair & Maintenance (yearly) | 1 Lakh | 0.3 Lakh |
| Operator (yearly)*** | 1.7 Lakhs | 0.5 Lakh |
| Electricity Cost (yearly) (Rs 6 per unit) | 1.75 Lakhs | 0.4 Lakh |
| Cost at purchase (tentative) | 10 Lakhs | 7 Lakhs |
| Cumulative Cost after 5 years | 32 lakhs | 13 Lakhs |
| Cumulative Cost after 20 years | 99 Lakhs | 31 Lakhs |
Note : Standard Inflation rate and Depreciation of equipment has not been taken into account.
Cost of Civil work is not taken into account but can be deduced from the technical aspects
Numbers are put in reference with a 100 KLD system.
* May vary from region to region
** The Performance evaluation of sewage treatment plants was published under NRCD by CPCB, August, 2013
***semi-skilled Labour (Rs. 7000 pm x 2 shifts);
For DEWATS- unskilled (Rs. 4000 pm x 1 shift)