Water Treatment Plant i.e. STP and ETP By Eroz Environ Engineer Pvt. Ltd.,

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capacity:15 kl/day to 500 kl/day

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Product Details

Effluent Treatment Plant for Acid Neutralization

About Effluent Treatment Plant

When Lead Acid Batteries are replaced, they contain spent acid with some lead dissolved in it. These used batteries are sold in the open market to lead recyclers where they are drained before being put into the process of recycling. Further in many units, plastic containers of the batteries, after cutting and opening, are washed to remove any lead in them. The drained acid along with any washing effluent of the plastic scrap comprises of the effluent that needs treatment at the Effluent Treatment Plant (ETP). This ETP is also commonly called Acid Neutralisation System.

If unchecked, these untreated effluent will seep in to land and would lead to soil contamination, pollution in ground water table and their runoff may also lead to pollution of nearby water sources. Hence, their proper treatment before disposal is necessary.

Description of Process

Effluent from such used batteries mainly consist of sulphates and sulphates of lead, small quantity of lead and diluted sulphuric acid. Further effluent from container washing which mainly contains small quantity of lead is also fed to the ETP. This effluent has low pH values. pH balancing agent (caustic or lime in this case) is added to adjust the pH and also for coagulation. The effluent is then mixed for Flocculation. The floccs so formed are settled and dewatered on a Sludge Bed (or through Filter Press). Treated effluent after this is further polished using filters. While treated water may be disposed or used as permitted by law, sludge is recharged into furnaces for recycling and reclamation of lead*.

Characteristics of Effluent before and after Treatment:

Parameter Before Treatment Approved Range

PH ****0 6.5 - 8.5
Suspended Solids ******0 mg/l < *0 mg/l
Lead ****0 mg/l < 0.1 mg/l

(*However, where only spent acid is fed into the ETP, sludge generated is in the form of sodium sulphate or calcium sulphate with lesser quantities of lead will be dewatered and stored as hazardous waste instead)

Description of Plant

An Effluent Treatment Plant for Acid Neutralization can be designed as a Batch Type unit or as a Continuous Unit. This mainly depends on the quantity of effluent to be handled. While smaller quantities can be treated in batches, quantities above *0 kl/day are to be treated in Continuous Operating Units.

• Batch Type Unit
• Continuous Treatment Unit

Batch type Unit

Effluent from used batteries and from container washing is stored in a receiving tank. It is then lifted with the help of an acid proof pump and fed to a Clari-flocculator. Required dosing of alkaline additive is mixed in fresh water in a separate dosing tank and also fed to this Clari-flocculator. The Clari-flocculator is a PVC lined cylindrical tank in mild steel construction. It has an electro-mechanized stirrer for mixing of the effluent with dosing chemical. It has conical bottom with drain valve. Effluent is fed from the top and after requisite dosing, is agitated and mixed. This leads to neutralization, coagulation and thereafter flocculation. Once mixing is stopped and floccs are formed they are allowed to settle at the bottom of the conical tank. After some time, treated effluent is drained from the side of the tank. Sludge is disposed through the bottom of the tank for dewatering to either Sludge Beds or to Filter Press.

Treated effluent is passed through a series of Polishing Filters (a set of Pressure Sand Filter & Activated Carbon Filter) before disposal. This improves upon the characteristics of the treated effluent.

This is called a Batch type unit as the Clari-flocculator is designed to process effluent of a particular capacity in one operation cycle and no more. After it is completely treated and drained, a second batch of effluent can be treated.

Continuous Treatment Unit

In a Continuous type unit, effluent is consistently fed into the system and is treated continually. Hence, it is suggested for treatment where higher capacities of effluent is involved.

Effluent from used batteries and from container washing is stored in a receiving tank. It is then lifted with the help of an acid proof pump and fed to a Flocculator. Required dosing of alkaline additive is mixed in fresh water in a separate dosing tank and also fed to this Flocculator. The Flocculator is a PVC lined tank in mild steel construction. It has an electro-mechanized stirrer for mixing of the effluent with dosing chemical. It has conical bottom with drain valve. Effluent is fed from the top and after requisite dosing, is agitated and mixed. This leads to neutralization, coagulation and thereafter flocculation.

Effluent with floccs is passed to a Tube Settler. It is a PVC lined tank in mild steel construction. Hexagonal PVC settling media is fitted in this tank. Effluent is allowed to settle here and as a result, the floccs settle on the PVC media provided and are passed to the conical bottom of the settler. Sludge is disposed through the bottom of the tank for dewatering to either Sludge Beds or to Filter Press.

Treated effluent is passed through a series of Polishing Filters (a set of Pressure Sand Filter & Activated Carbon Filter) before disposal. This improves upon the characteristics of the treated effluent.

Sewage Treatment Plant for Domestic Waste

Sewage and its Treatment

Sewage is the spent water stream generated after use of fresh water in various activities of domestic, non industrial nature, such as washing water, food preparation waste, laundry waste, and other waste products of normal living including sanitary
waste water.

This sewage, if discharged untreated into water bodies, leads to their pollution and degradation of the most valuable resource of all water. Sewage hence needs to be treated before its discharge and after that, can also be reused for some
applications such as toilet flushing and gardening etc.

Requirement of Sewage Treatment Plants :

Sewage Treatment is not only important for preserving our natural resources, it is also required by the law. Hence, following require treatment of sewage generated, before its discharge, as mandated by law :

1 Residential Colonies, Apartments etc.
2 Educational Institutions
3 Hospitals
4 Hotels, Marriage Palaces, Commercial Malls etc.
5 Industrial Units (apart from effluent treatment, if applicable)
6 Other kinds of institutional or community buildings like large Temples etc.

Apart from this, city municipal units are required to set up treatment units for treatment of complete sewage generated in their areas before disposal into any water body.

Village level organizations can be benefitted by use of sewage treatment; sewage which otherwise is disposed off in village ponds or nearby rivulets can be recycled for irrigation with appropriate level of treatment.

Sewage Treatment Plant and its Process

A Sewage Treatment Plant, commonly called as STP, is domestic waste water treatment plant used to achieve the end of making spent water pollution free before its disposal or re-use. It mainly consists of 3 stages :

Preliminary, Biological and Tertiary :

Depending upon the intended end use of treated water, a fourth stage of advanced treatment may also be considered.

Preliminary Treatment
consists of screening and removal of oil and grease (if applicable) for which mostly physicomechanical processes are used. The purpose of this stage is to remove external large solid/ floating material as well as floating oils in the stream so as to make it suitable for biological treatment stage.

Biological Treatment
is the stage where organic impurities in the waste stream are treated by the use of microbial organisms. These organisms metabolize the pollutants as their food either in presence or absence of air, called aerobic or anaerobic processes respectively. The sludge so generated is settled and ultimately flushed out from the system.

It is thus, the Biological Reactor which is the HEART of any Sewage Treatment Plant and it is on the basis of the same, that all processes are classified into different groups. Other than this, different stages of all processes are similar.

Tertiary Stage consists of disinfection and filtration. Disinfection is required for the purpose of removal of any residual harmful bacteria in the water stream. Filtration is used to remove any TSS in the stream and also for polishing the treated water clean.

Various Technologies Available

During the evolution of this discipline through decades, various technologies of treatment have been developed. Most of them provide desired results when properly applied. Difference mainly lies in the advancement of the biological treatment
part which has been consistently making treatment more effective, economical and treatment units easier to operate and maintain.

Broadly, Sewage Treatment processes can be classified as :

1 Aerobic (Biological Treatment takes place in presence of air)
2 Anaerobic (Biological Treatment takes place in absence of air)

From above processes, the major emphasis is on Aerobic process only.

Aerobic processes can be further segregated into Suspended and Attached Growth processes. However, through numerous installations and years of experience, it has been found the below two as mostly suitable for handling complete range of requirements :

1. EA (Extended Aeration) , Suspended growth based
2. MBBR (Moving Bed Biofilm Reactor) , Attached growth based

EA Based STP- Process and Its Features

Extended Aeration (EA) is a variant of suspended growth based Activated Sludge Process (ASP). Waste Water after preliminary treatment is fed to a Reactor where air is provided using diffusers at the bottom of the tank. Microbial growth takes place in suspended form in the reactor. MLSS (Mixed Liquor Suspended Solids), in layman language the bacterial mass, in the reactor is recycled from a settler placed after the reactor. This is used to maintain the MLSS count in the process, required for effective treatment. Excess quantities are discarded from the system.

Sewage Treatment Plant & Process:

1 Resistant to shock loads
2 Widely used and accepted
3 Properly digested sludge
4 Low maintenance cost
5 Recycling of Sludge into the reactor
6 Low retention times of ****6 hrs.
7 No External Media
8 Easy to operate and maintain.

MBBR Based STP- Process and its Features

MBBR (Moving Bed Biofilm Reactor) is a variant of attached growth based processes. Waste Water after preliminary treatment is fed to a Reactor which is packed with specially designed PVC biological media with large surface area/ volume ratio and of certain pre-determined density. Microbial Growth takes place in attached form on this media. A thin film of microbes called the biofilm develops on the media and this media remains in continuous motion due to air supplied from the bottom of the tank. No sludge is required to be recycled into the system and is discarded after settling.

MBBR Based STP has following Features :

1 Very Low space requirement compared to all other treatment processes
2 Most popular for small and package type units
3 Properly digested sludge
4 Low operation and maintenance costs
5 No recycling of sludge into the reactor
6 Easy in operation

Description of Equipments in a Typical Sewage Treatment Plant

1. Bar Screen : Waste water is passed through a mesh type or rack type screen to remove large sized material like plastic, paper, rags, wood etc. In smaller units it is replaced by strainers. In larger units, mechanical bar screens are also employed.

2. Storage or Equalization Sump : The waste water used for various purposes is collected through various channels into a common storage sump. This is also called equalization sump, because the flow of waste water is not steady state, hence,
equalization of the flow takes place here.

3. Waste Water Lift Pump : It is used to lift the sewage water into the Bio-Reactor.

Pays:	India
N Â° de modÃ¨le:	STPETP1
Prix FOB:	(Negotiable) Obtenir le dernier prix
LocalitÃ©:	-
Prix de commande minimale:	-
Commande minimale:	1 Set
Packaging Detail:	export worthy
Heure de livraison:	4 to 6 weeks
Capacité de Fournir:	-
Payment Type:	T/T
Groupe de produits :	Water Treatment Plant