What are the characteristics of tannery wastewater?

Tannery wastewater is characterized mainly by measurements of Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), suspended solids (SS) and Total Dissolved Solids (TDS), chromium and sulfides etc. (Gower, 1980). Typical characteristics of tannery wastewater are given in Table 1.

What is tannery wastewater?

Tannery wastewater is one of the most pollution sources. It can cause environmental problems related to its high organic matter, suspended solids and chromium. Chromium (III) salts are the most widely used chemicals for tanning processes, causing the tannery wastewater to be highly pollutant with chromium.

What methods are used for the treatment of wastewater?

The treatment of wastewater is accomplished by four basic methods or techniques; physical, mechanical, biological and chemical. Physical methods of treatment include the use of tanks and other structures designed to contain and control the flow of wastewater to promote the removal of contaminants.

What is tannery industry?

Tanning is the process of treating skins and hides of animals to produce leather. A tannery is the place where the skins are processed. Historically this process was considered a noxious or “odoriferous trade” and relegated to the outskirts of town.

Which pollutant is coming from tanning industry?

Tannery Wastewaters Tannery industries are listed as the most polluting activity due to the wide type of chemicals applied during the conversion of animal skins into leather. Chromium salts, phenolics, tannins, organic matter, among others products, are constantly released to the environment in tannery wastewater.

How does a tannery work?

A tannery is the place where the skins are processed. Tanning hide into leather involves a process which permanently alters the protein structure of skin, making it more durable and less susceptible to decomposition, and also possibly coloring it.

How do you dispose of sludge?

Once treated, sludge can be recycled or disposed of using three main routes: recycling to agriculture (landspreading), incineration or landfilling.

What is STP water treatment?

Sewage treatment is the process of removing contaminants from wastewater, primarily from household sewage. It includes physical, chemical, and biological processes to remove these contaminants and produce environmentally safe treated wastewater (or treated effluent).

Which water treatment process is most effective?

Chemical. Chlorine is the chemical most often used in treating sewage and other types of wastewater. The process is called chlorination. This is the most effective means of destroying a variety of viruses and bacteria.

What kind of treatment is needed for tannery wastewater?

Tannery wastewaters are one of the most complex cases of treatment and disposal of industrial effluents. Raw materials are organic, as those coming from food industries, but with a main difference regarding chemical process in with both organic and inorganic reagents are used.

How many lines are in a tannery treatment plant?

Tannery wastewater treatment divided in four line. A typical example of physical-chemical treatment plant is made up of four separate discharge lines: pre-tanning, chrome tanning, fattening, dyeing and washing.

Can a tannery discharge into a public sewer?

In order to discharge into public sewer or receiving waters, a specific and tailored wastewater treatment plant must be carefully designed, considering the type of tanning method adopted, that can be vegetable or chemical (by the use of chrome).

Which is better for tannery wastewater aerobic or anaerobic?

Both aerobic and anaerobic processes are employed for the treatment of tannery wastewater. From the review it can be concluded that physical/chemical processes combined with biological process is the better option for the treatment of tannery wastewater. G. Durai and M. Rajasimman, 2011. Biological Treatment of Tannery Wastewater – A Review.