Moving Bed Bioreactor (MBBR) process uses support media which floating in tank to retain an active biomass to reduce the raw sewage BOD Levels. It consists of an aeration tank with special plastic carriers (Pall ring type media) that provide a surface where a biofilm can grow. The carriers are made of a material with a density close to the density of water i.e. (1 g/cm3). The carriers will be mixed in the tank by the aeration system and thus will have good contact between the substrate in the influent wastewater and the biomass on the carriers. To prevent the plastic carriers to escape the aeration it is necessary to have a sieve on the outlet of the tank. In general practice, we provide two stage MBBR systems for better degradation of organic matter thus better reduction of COD & BOD.

ADVANTAGES:

• Easy to maintain
• More surface area available
• Less foot print area required
• Compact design with resistance to shock loads
• As the MBBR system consists of floating carriers, the system is not susceptible to clogging and experience insignificant head loss.
• Higher effective Sludge Retention Time (SRT) which is favorable for nitrification
• Robust operation and resistance to load variations
• Lower sludge production.

Softening is the process of exchange of ions & it is done through cationic resin, the most common and probably the easiest method of removing hardness (that is calcium and magnesium) from water and suitable for utility purpose. As the name implies, it is a process in which undesirable ions are exchanged for more desirable ions. The softening process consists of passing raw water containing hardness through a bed of cation resin in sodium (Na+) form. The hardness contributing major ions Ca & Mg are taken up by resin and in exchange of it, the sodium ions are retained from the resin. This is called the service cycle, where the hard water is softened. In this process of softening of raw water, at one point of time, resin gets exhausted. So to bring back the resin to its original form is called regeneration process. Softener resin is regenerated by Sodium Chloride – NaCl (Common salt) or Brine solution. The common salt solution is stored in the regeneration tank. During the regeneration process, salt solution is injected by the ejector tube into softener & the NaCl (salt solution) replaces Ca, Mg (Hardness) from the resin. Regeneration of the softener is done every day or alternate 1 or 2 days or every week depending upon the usage and design of the water softener plant

Ultra Filtration membrane Technology has been specifically selected and designed as a pre-treatment after Tertiary Treatment (Sand & Carbon filter) for recycling & reusing the Waste water from STP & ETP. Also it is used in WTP as a pre-treatment to Reverse Osmosis system for surface water as well as bore well water etc.

Ultrafiltratoin is a variety of membrane filtration in which forces like pressure or concentration gradients lead to a separation through a semi-permeable membrane. Suspended solids and solutes of high molecular weight are retained in the concentrate, while water and low molecular weight solutes pass through the membrane in the permeate (filtrate). Ultrafiltration membranes are defined by the molecular weight cut-off (MWCO) of the membrane used. Ultrafiltration is applied in cross-flow or dead-end mode. Nominal pore size of the membrane is 0.02 micron.

UF membrane back flushing is done by back flush pumps. Cleaning of membrane is done by using chemicals like Acid, Alkali & Sodium Hychloride once in a day. UF permeate is then collected for further use.

Reverse osmosis (RO) is a water purification technology that uses a semipermeable membrane to remove ions, molecules, and larger particles from drinking water. In reverse osmosis, an applied pressure is used to overcome osmotic pressure, a colligative property, that is driven by chemical potential differences of the solvent, a thermodynamic parameter. Reverse osmosis can remove many types of dissolved (TDS) and suspended (TSS) particulate matter from water, including bacteria, and is used in both industrial processes and the production of potable water. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. The RO system comprises of the membranes along with the pressure tubes. The RO reject water will be drain out and RO (permeate water) treated water is collected to permeate tank. To prevent membrane scaling, Antiscalent chemical is dosed. Also SMBS is used to prevent chlorination or for de-chlorination of intake water or waste water to RO Membranes. RO membrane cleaning is done at a minimum frequency of once in a 3 – 4 months. Membrane Cleaning is carried out at low pressures to minimize permeate production and redeposition of dirt on the membrane element. Little permeate should be produced in order to achieve high cross-flow velocities across the membrane surface, i.e., it should be run at low recovery. High cross-flow velocities are essential to remove foulant effectively from the membrane surface.