Units are the vessels or basin that holds wastewater for the treatment by chemical or biological processes. They can be of any shape. Depending upon the flow and operating conditions and the methods of mixing of the wastewater therein, the reactors have the following main types; Continuous-Flow Stirred Tank Reactor (CFSTR) or Completely-Mix Reactor:

PDT is a substructure technique which includes applying slowly varying forces to a structural model. The motions and deformations observed in the test specimens are used to infer the inertial forces that the model would have been exposed to

In coning of wheel the tread or rim of wheels of railway vehicles is made in the shape of a cone with the slope of about 1 in 20. It maintains vehicle in the central position w.r.t. the track. On straight track, portions of wheels running on track have same diameter. While on curved path, the outer wheel has to cover larger distance than the inner wheel. Thus, the

Defined as the "biological decomposition of biodegradable organic constituents of waste under controlled conditions to a state sufficiently stable for nuisance-free storage & handling and for safe use in land applications". About 70% of municipal solid waste is decomposable or compostable.

The physical characteristics of wastewater include those items that can be detected using the physical senses. They are temperature, color, odor, and solids. Sewage contains both organic and inorganic chemicals in addition to various gases like H2S, CO2, CH4, and NH3 etc that are formed due to the decomposition of sewage. The chemical characteristics of wastewater of