Case Studies

Hospital effluent contains pathogenic microorganisms, pharmaceuticals that have been partially metabolized, and other heavy metals and toxic chemical compounds. Since hospital sewage/wastewater consists of various potentially hazardous components, they will cause many risks to humans and the environment by polluting surface and groundwater.

Problems:

• Using the conventional method, sludge settling was not effective. Owing to that, sludge floats to the surface thus escaping to decanting tank
• This sludge in decanting tank makes filter media in the filter vessels get clogged often resulting in frequent backwashes and even filter media replacement
• This even leads to more functioning filter feed pumps, thereby increasing the power required.
• Being a continuous process, and over functioning of sewage pumps, sludge removal time gets lesser thus leading to accumulation of sludge in settling tank. This often leads to frequent tank cleaning procedures.
• Final treated water quality was less
• Since treated water quality was not up to the level, it was not re-used for flushing / gardening

Solutions:

• Instead of individual sludge settling tank, being combined aeration, settling and decanting in a single tank, most of the sludge will be settled before treated water is taken out.
• No filter vessels will be required in this method of STP
• With the MBR method, the functioning time of almost all electro-mechanical equipment was reduced, thereby reducing overall power consumption.
• With membranes as a filtering medium, only membrane cleaning is required.
• Treated water quality was improved in a dramatic way

Benefits:

• Power Saving Method
• More idle time for electro-mechanical equipment
• Much better-treated water quality
• Re-use of treated water for gardening & flushing

Process used in the industry.

The wastewater from such industries is especially turbid and high in total suspended solids (TSS), chemical oxygen demand (COD), and biological oxygen demand (BOD). Because of these characteristics of these streams, chemical treatment followed by biological treatment systems is the most suitable to recover the waste streams, treating them for discharge within legal limits to reuse them and ensure their safe disposal. Another challenge in the design and construction of wastewater treatment plants is managing space constraints. These plants are usually located close to conurbations.

Problems:

• Effluent generated from industry was not able to be disposed of in natural stream owing to the worst water quality parameters
• During similar processes in ETP, Chemicals such as PAC & Poly were used for effective coagulation & flocculation
• These chemicals generated more sludge when they were used.
• Meanwhile, some of the sludge, if not removed often, gets transferred to the decanting tank causing clogging in the filter vessels, which may lead to frequent media replacement or frequent open backwashes.

Solutions:

• We proposed an effluent treatment plant with chemicals followed by a biological system with UV for disinfection
• This reduced the TSS, turbidity, BOD, and COD ranges in the effluent.
• In order to obtain a Zero Liquid Discharge (ZLD), we provided an ultra-filtration system followed by 2 stages of an RO Plant.
• This in turn a standout prodigy as Dead-end ultra-filtration (DEUF) with 100% permeate recovery
• Introduced a lamella clarifier for the most effective sludge settling
• Given pre-fabricated tanks to reduce the total space available for placing tanks and electro-mechanical equipment.

Benefits:

• Zero Liquid Discharge (ZLD) produced no harm to the environment because no hazardous effluent stream is connected to the sewer
• More sterilized water is best suited for further processing &re-use
• Having 2-stage recovery improved the water quality parameters
• The use of less sludge-generating and more productive chemicals reduced UF & RO membraneclogging and chemical cleaning.