Technology

Constructed wetland System

Constructed Wetland Technology, based Waste Water Treatment Plant

  • Constructed Wetland Technology based Water Treatment Plant for treating raw and untreated Water daily.
  • The Plant will make use of selective plant species, Biomedia and engineered filters to reduce the biological parameters to following levels.
  • The space requirements have been elated in the designs provided.
  • Technical Parameters.

Constructed Wetland/DEWATS system for Sewage Treatment

  Inlet Parameters [mg/ltr] Outlet[mg/ltr] Tertiary
BOD 200-400 10-20 4-5
COD 300-500 20-30 10-5
pH 5-8 7  
Nitrogen 10-40 1-2  
Phosphorus 10-40 1-2  
TSS 150-350 10-15  

Note: The above mentioned parameters of treated water very well meet the CPCB and NGT norms, regarding the same.

Working of the Constructed Wetland based Waste Water Treatment Plant

  • The Constructed Wetland technology treatment is a subsurface flow type in which wastewater is applied to cell / system filled with porous media such as crushed bricks, gravel and stones. The hydraulics is maintained in such a manner that wastewater does not rise to the surface retaining a free board at the top of the filled media.
  • The system consists of the following three zones: (i) inlet zone comprising of crushed bricks and different sizes of stones, (ii) treatment zone consisting of the same media as in inlet zone with plant species, and (iii) outlet zone.
  • The reduction in the treated effluent for the total suspended solids (TSS) varied from 70% to 80, BOD from 78% to 84%, nitrogen from 70% to 75%, phosphorus from 52% to 64% and fecal coliform from 90 % to 97%.
  • The treated effluent is useful for municipal gardens, fountains and irrigation.
  • The total area required for the system is approximately 21 sq. m. for 20 m3/day.
  • This technology has been has already been installed at various projects such as Omega Greens, Lucknow (500 kld), Rudra Heights, Varanasi (100 kld), NRI City, Kanpur (100 kld), and many other places and is working very well.

Advantages

  • Odorless.
  • Minimal Consumption of Electric.
  • Easiest and Simplest Maintenance.
  • Life of STP analogous to Life of Property.
  • Treated Water meeting norms on a daily basis.
  • Working range – 5 %- 110 % of capacity installed.
  • Aesthetically beautiful.

Effluent Treatment Systems

Tertiary Treatment : ACF & SPF

ACF : Granular activated carbon (GAC) is commonly used for removing organic constituents and residual disinfectants in water supplies. This improves taste and minimizes health hazards; Activated carbon is a
favored water treatment technique because of its multifunctional nature and the fact that it adds nothing detrimental to the treated water.

However, different raw materials produce different types of activated carbon varying in hardness, density, pore and particle sizes, surface areas, extractables, ash and pH. These differences in properties make certain carbons preferable over others in different applications.

SPF : Raw water is passed through thepressure sand filter, the filter media (Fine quartzsand) is supported on gravel & pebbles bed of progressively larger sizes. During the filtration cycle the filter bed retains the dirt and suspended particles from the water and accumulates within the filter bed.

Tertiary Treatment : Ozonator

Ozone has a greater disinfection effectiveness against bacteria and viruses compared to chlorination. In addition, the oxidizing properties can also reduce the concentration of iron, manganese, sulfur and reduce or eliminate taste and odor problems. Ozone oxides the iron, manganese, and sulfur in the water to form insoluble metal oxides or elemental sulfur. These insoluble particles are then removed by post-filtration. Organic particles and chemicals will be eliminated through either coagulation or chemical oxidation. Ozone is unstable, and it will degrade over a time frame ranging from a few seconds to 30 minutes. The rate of degradation is a function of
water chemistry, pH and water temperature.

Electro-Coagulation Based ETP

EFFLUENT QUALITY GUIDELINES AND PARAMETERS

PARAMETER Design for ETP
Guideline Values Average Maximum
pH, pH units 6.00-9.00 4.8 11.1
Conductivity, μS/cm 40 1500 2100
Appearance clear Unclear Unclear
Colour, Hz 200 200 400
Turbidity, NTU 5.0 900 2700
Flouride 1.5max <0.005 <0.005
Total Dissolved Solids (TDS) 500mg/l 1200 1500
Biochemical Oxygen Demand (BOD) 30.0mg/l 1200 2900
Chemical Oxygen Demand (COD) 60.0mg/l 4500 6600
Oil/Grease 5.0mg/l 12 780
Total Phosphate 2.0mg/l 1 3
Ammonia- Nitrogen (NH3-N) 1.00 55 70
Nitrate-Nitrogen (NO3 -N) 10mg/l 0.3 26.4
Alkalinity 150mg/l 175 350
Sulphide 1.50 <0.005 0.35
Chloride 250 250 560
Total Coliform (cfu/100ml) Nil/Negative 124 x 104 155 x 104
E-coli cfu/100ml Negative/Nil 69 x 103 95 x 103
Dissolved Oxygen > 2mg/l 2.55 2.86

Flow Chart