Rapid Organic Waste Stabilizer (ROWS)

IN Patent No. 373169

 
Introduction

Accelerated growth in urbanization and industrialization in concurrence with lack of awareness and non-availability of suitable technologies has led to generation of huge quantities of municipal solid waste (MSW). The management of MSW is considered an important public health, economic and environmental concern, especially in developing countries. Presently, India is generating about 64 million tonnes MSW per year, which is expected to increase to 165 million tonnes by 2031. Compositional analysis revealed that solid organic waste (SOW) constitutes to about 40 - 60% of the total waste generated from the society. Nowadays, there is a paradigm shift towards looking at SOW, and it is globally recognized as resources than the waste. The nutrient contents such as nitrogen (N), phosphorus (P), and potassium (K) in the SOW make it an ideal feedstock for producing organic fertilizer. The traditional biological conversion techniques require months of time for completing the humification process. In this context, thermal digestion offering quick removal of moisture, eliminating the pathogens and converting organics to produce nutrient rich end product, could prove to be a viable technique.
The Swachh Bharat Mission (2.0), under the aegis of the Ministry of Housing and Urban Affairs (MoHUA) encourages the bulk waste generator to use mechanized organic waste composter to promote decentralize treatment of the waste. This invention i.e., the rapid organic waste stabilizer is also in line with the GoI regulatory framework “Solid Waste Management Rule, 2016” which instructs waste generators to adopt suitable technique(s) to modify the physical, chemical, or biological characteristics of any waste to reduce its volume, potential to cause harm, and minimize the burden on landfill.

 
About the Technology:

The working of the rapid organic waste stabilizer (ROWS) is based on novel thermal digestion technique in which the waste is shredded into a particle size < 10mm and then uniformly heated at a temperature around 150oC through convection mode of heating. This process digests the organics and coverts the nutrients into a simpler and plant available form which can directly be used for agricultural purposes. ROWS takes around 4 - 6 hours to convert the solid organic waste into a completely dried nutrient rich end product of powder form consistency. Around 20 - 25 kg of organic fertilizer could be produced by feeding 100 kg of the SOW.

Characteristics of the Organic Fertilizer:

Sources of greywater include, sinks, showers, baths, clothes washing machines or dish washers and are free from pathogenic contamination. This water can be used directly for flushing of toilets. IIT(ISM) has constructed a pilot scale plant for treating 40 KLD of grey water generated from Sapphire hostel. We are now using the treated grey water for flushing the toilets of Sapphire hostel. The photograph of the installed ETP is shown in Fig 3. IIT(ISM) Dhanbad is planning to install such ETP plants for all the hostels in near future. Moreover, in the new buildings it has been instructed to the CPWD to construct dual piping system and the flushing cisterns will be connected to the treated grey water which will reduce the load on fresh water for flushing purposes. On completion of segregation of grey water and sewage water discharge from all the buildings a total of 680 KLD of grey water will be used in flushing of toilets.

Management and Storage of storm water at IIT(ISM) Dhanbad

The detailed fertilizing characteristics of the organic fertilizer generated from the process (Fig.1), is given in Table1. The total NPK value of the organic fertilizer is much higher than the standard recommended values required for organic fertilizer (FAI, 2019). Moreover, a lower C:N ratio revealed the maturity of the fertilizer.

 
Image 1
Image 2
Salient features of the ROWS:
  • Rapid treatment of the solid organic waste (within 4 - 6 hours).
  • Onsite reduction in the waste volume (>75%)
  • Produces soil conditioner rich in macro and micro nutrients.
  • Requires less space and ease in operation.
  • Requires minimal maintenance.
  • No effluent is generated during the process.
  • Eco-friendly modular plants can be designed for various capacities as per the end user’s requirement.
 
Well suited for:
  • Apartments & Residential Societies
  • Hostels
  • Hotels, restaurants, canteens, mess
  • Vegetable & fruit/Meat markets
  • Agricultural waste
  • Municipalities & Nagar Palikas of big cities and metros
  • Bio reclamation of degraded lands