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Environmental Engineering

With more than three decades of experience in the field of construction, we are now putting our foot forward in the field of environmental consultancy. Our valued consultancy services on Environmental Engineering broadly includes adequacy and treatability studies for existing wastewater treatment plants, basic and detailed engineering for onsite sewage and effluent treatment plants, turnkey execution of proposed sewage and effluent treatment plants, supply of packaged sewage treatment plants, consultancy services for rainwater harvesting as well as liaison with government authorities for environmental clearance. We undertake detailed engineering works for design, manufacture, supply, erection, testing and commissioning of Water and Wastewater Treatment Plants and Projects of Water Distribution as well as Wastewater Collection and Stormwater Disposal Systems.

Our Services

Detailed Engineering for Setting

  • Basic and detailed engineering for installation of new STP/ETP including tender documentation.
  • Provision of packaged sewage treatment plants.
  • Treatability and Feasibility studies related to Sewage and Effluent treatment plants.
  • Modifications and up-gradations in existing ETP/STP.
  • Rainwater harvesting systems.
  • Turnkey execution of RCC/MS sewage treatment plant with zero discharge concepts.
  • Environmental clearance services for building projects.
  • Cholamandlam Finance Ltd.
  • Annual Operation and Maintenance contract for STP/ETP.
  • Structural consultancy for water retaining structures.

Completed Projects

  • Pramukh Villa, Valsad
  • Amul, Virar
  • Kakrapar atomic power project, Kakrapar
  • Navin Fluorine, Surat.

Package Sewage Treatment Plant

What is Package Sewage Treatment Plant?
Residential complexes, commercial buildings, institutional buildings and infrastructure development projects need to install the sewage treatment plants (STPs) for treatment of sewage generated in premises. The concept of the modern buildings with the sewage treatment units are required to reduce the possible carbon footprints. The Packaged STPs are designed in a way that they fit in places such as basements, parking slots or landscaping area which generally have height restrictions and requires no odour or noise problems. The sewage treatment plant provides highest degree of treatment to sewage so that it can be reused for various purpose such as gardening, flushing, car washing etc.

Packaged Sewage treatment Plant from ‘OPTIMA ENGINEERS & DEVELOPERS’ is a type of biological treatment for domestic waste using the extended aeration process. The extended aeration process is found to be more effective as compared to the conventional municipal activated sludge type systems under low flow and high BOD5 loadings. With the extended aeration technology; a high quality effluent could be achieved with smaller plants. The basic design includes extended aeration system (approx. 18-24 hours) in combination with a defined settling tank (approx. 4 hours) for sewage treatment.

Extended Aeration Process
Theoretically, the extended aeration process purifies the wastewater by consumption of the organic compounds using air to oxidize the volatile material (both solid & liquid) into inert gases, water & sludge. By continued aeration of these concentrated solids, biological organisms are produced and grow in colonies. The colonies will attach themselves to the volatile materials breaking it down into water, carbon dioxide and ash, the result being a clear and odour free effluent.
Extended aeration packaged plants can be divided into four main treatment stages as given below : 

Block Diagram of STP

1. Pre-treatment
In case of Packaged STPs, provision of septic tank cum collection tank of raw sewage is fundamentally essential for avoiding the shock load through equalization process. In most of the cases one can avoid the provision of screen for packaged plants as the effluent gets filtered with the provision of jali trap at source. Bar screens are used to trap large particles (i.e. plastic and paper) and prevent them from entering the packaged sewage treatment plant. One can observe 25% of treatment efficiency in pre-treatment processes.
2. Aeration
The next step in the process takes place in the settling compartment called settling tank. Here there is no circulation of effluent so any remaining solids can settle to the tank bottom and can be returned to the aeration chamber for maintaining active biomass. Extra sludge can be disposed off through sludge drying beds of other sludge disposal methods.
3. Settling
In the aeration tank, “Aerobic digestion” or “Wet burning” takes place. Here the pre-treated incoming wastewater is mixed and aerated by air diffusers, located in the bottom of the tank. These diffusers inject ample air to meet the oxygen demand of the aerobic digestion process as well as mix the entire tank contents.
4. Disinfection and Filtration
The last stage before discharging the effluent is Disinfection through different chemicals or Ozone Gas and filtration through activated carbon and sand filters for removal of colour and overflowed suspended particles.

Advantages Of Package STP

  • Small footprint.
  • Short delivery time.
  • Minimum field assembly.
  • Multiple sludge returns for the flexibility of operation in any season.
  • Extended aeration systems have a relatively low sludge yield due to long sludge ages, can be designed to provide nitrification, and do not require a primary clarifier.
  • Consistent quality of treated effluent which can be reused.
  • Low maintenance and easy operation.
  • Low noise, no odour, no nuisance.
  • Auto operation and does not requires specially trained skilled operators to operate the unit.
  • Easy access to all parts of the plant for cleaning and adjustments.
  • Packaged sewage treatment plants can constructed with RCC on site (if pre-planned)

Suitable for

  • Small Communities
  • Schools
  • Resorts & Hotels
  • Housing Developments
  • Hospitals
  • Shopping Malls
  • Industrial Parks & Factories
  • Large Construction sites


Packaged Sewage Treatment Plant

Package STP Presentation

Our Offices

Surat Office

409/410, Titaanium The Business Hub, Bhimrad Rd, Checkpost, Surat, Gujarat 395017

Vadodara Office

Office No. 12, 13 ,Second Floor,Vrund Complex,
BPC Road, Vadodara – 390020, Gujarat, India.

Vapi Office

353, 3rd Floor, Govinda Complex, Nr GIDC Char Rasta, Vapi 396191, Gujarat, India.

Bharuch Office

Office G 14, Aditya Complex, Near Kasak Circle, Bharuch, 392 001

Bardoli Office

205, 2nd Floor, Maa Krupa Complex, Gandhi Road, Bardoli 394 601

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