... **Particulars of sewage thrown:** Qs =620 l/s= $0.62m^3$/sec **Concentrations(Cs):** BOD= 45mg/l Do= 3 mg/l Temperature= $24^o$C K1 at $20^o$C= 0.1 per day **Particulars of river:** Qr = $27 m^3$/sec **Concentrations(Cr):** BOD= 3 mg/l Do= 8.2 mg/l Temperature= $18^o$C **Combined disch ...

... Sewage discharge= $Q_s= \frac{7 \times 10^6}{24 \times 60 \times 60 } = 81.01 \ l/s$ Discharge of river = $Q_r= 160 \ l/s$ BOD of sewage = $C_s= 260 \ mg/l$ BOD of river = $C_r=5 \ mg/l$ BOD of diluted mixture = $C= \frac{C_s.Q_s + C_r.Q_r}{Q_s + Q_r }$ $ C = \frac{260 \times 81.01 + 5 \times ...

... The Physio-chemical methods used for treating Industrial waste water are: 1. Reverse Osmosis. 2. Electrodialysis. 3. Chemical oxidation. 4. Ion exchange. 5. Thermal reduction. 6. Air stripping. When a permeable membrane separates a dilute and a concentrated solution, the osmotic pressure dri ...

... 1. Dewatering is accomplished either by air drying in Sand drying beds or by mechanical means using Vacuum filtration, centrifugation, heat drying etc. 2. Dewatered sludge may some times require further treatment such as incineration to reduce the volume and the organic content of sludge. ...

... 1. Water is used extensively throughout textile processing operations. 2. Almost all dyes, specially chemicals are used. In addition, most fabric preparation steps, including desizing, scouring, bleaching, and mercerizing etc. 3. The quantity of water required for textile processing is lar ...

... 1. The Kraft process of pulp making uses sodium sulphate, sodium hydroxide and sodium sulphide as the digester chemicals. 2. The spent liquor produced is known as Black liquor. The black liquor is treated seperately for the recovery of chemicals. 3. The cellulosic fibre after being seperat ...

... 1. In a sugar mill, for example, cooling oil used in roller mills for tandem cooling can be collected in a sump filled with bagasse, solid waste from the same industry. 2. Bagasse absorbs large quantities of cooling oil which can be later used in boilers. 3. The overflow from evaporators can be co ...

... **Sampling** is necessary to obtain reliable data on chararcterisation and qualification of any type of waste, waste water, stream water etc. Therefore a scientific approach is needed during sampling and analysis to get maximum details. **Factors that can be considered in the design of sampling pro ...

... The treatment of refinery wastes is carried out in three steps: 1)Physical separation of free oil. 2)Chemical coagulation of emulsified oil. 3)Biological treatment for the removal of BOD, phenol and other toxic materials. - The physical separation of oil is accomplished in gravity separator ...

... D.O at $20^0 C$ = $9.17 \ mg/l$ (assume fire value) $\begin{aligned} \text{D.O. content of the stream} &= \text{90 % of saturation D.O.} \\ &= \frac{90}{100} \times 9.17 \\ &= 8.25 \ mg/l \end{aligned}$ $\begin{aligned} \text{Minimum D.O. to be maintained in the stream} \\ \text{Max pe ...