Page 541 - Industrial Wastewater Treatment, Recycling and Reuse

Zero Liquid Discharge Solutions 511

ETP treated Ultrafiltration
RO system
effluent system

pH: around neutral RO reject
TDS: 2000–4000
COD: <200
BOD: <30 RO permeate

pH: 6–7
TDS: <100
pH: 7–8 COD: <80
TDS: 1%–2% BOD: <10
COD: 300–400
BOD: 100–150
Figure 13.10 Recycling system for pharmaceutical API effluent.

Mixed solvent

Solvent stripper

Neutralized high
COD effluent High TDS effluent - to
MEE
Figure 13.11 Mixed solvent stripping.

Process condensate to
ETP
COD :2000–3000
Effluent from solvent
stripper (5%–6% TS)

MEE
MEE bottom
TS: 40%–45%
Effluent from ETP RO ATFD
reject (1%–2% TS)

Common salts
moisture: 10%
Figure 13.12 Multiple effect evaporator scheme for pharmaceutical API effluent.