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Biomedical industrial wastewater treatment

By 15 September 2016case, healthcare

The Client
It’s part of one of the most relevant Italian company developing and producing medical units for human blood treatment and purification at a European level. More in detail, units are particularly employed for kidney failure healing through dialysis.
Since the beginning of its activity, the company played a key role for the development of the so-called CRRT (Continuous Renal Replacement Therapies) through the institution and the development of customized solutions. They further developed a full range of polysulfone membranes and hemofilters for dialysis therapy.

The challenge
The core of the production process is the extrusion of capillary veins. Water has here an outstanding employ both for the polymer’s phase inversion process and for membrane washing. Treatment of water solutions for recovery, with quality characteristics preservation, was among the customer’s main targets, especially for N-metil-2-pyrrolidone molecules’ recovery where osmosis processes previously failed.

The Solution provided

The water treatment plant provided offers a modular standard solution to allow both water recovery coming from the production cycle (98%) and its re-introduction within the cycle itself. Concentrate coming from the evaporation and super concentration treatment (2%) is re-employed in the production cycle and allows a consistent cost reduction owing to the high value of the active compound.

Parameters U.M. Effluent Distillate
COD mg/l 2500 <400
Conductivity µS/cm 1100 5
TDS mg/l 1200 <2
N Metil Pyrrolidone mg/l 1000 50
TKN mg/l 200 <30
Flow rate m3/day 50 49.4

Two EVALED® models were employed for this complex biomedical solution. The first vacuum, forced circulation and mechanical vapor recompression evaporator TC 60000 allowed a consistent latent evaporation recovery with a limited power consumption. Distillate produced returned to the process, while concentrate underwent a further treatment through the second EVALED® RW 3000 working discontinuously and equipped with scraping system, heat exchanger and heating jacket.

EVALED® RV series mod. TC 60000
TC models found their technology on forced circulation through shell&tube heat exchangers, positioned outside the boiling chamber. The evaporator guarantees outlet high concentration levels in waste and a drastic decrease in cleaning and maintenance activities. The high circulation speed of the liquid within the exchanger’s pipes allows to keep a high efficiency level in thermal exchange and to decrease scaling and fouling formations on the exchange’s surface. Flash status transition occurs within the boiler, therefore no evaporation phenomenon takes place inside the heat exchanger. Operator’s supervision is least: the whole evaporation process is controlled by a PLC, waste feeding functions, concentrate and distillate discharge are included.

EVALED® AC series mod. RW 3000
RW evaporator working with hot/cold water with natural circulation transferring heat through its heating jacket where hot water is conveyed. This model is designed to treat waste water bearing a high concentration of dissolved or suspended solids. For this purpose a feeding screw scraper constantly mixes waste inside the boiling chamber, in order to prevent surface scaling. Distillate coming from the evaporator can be potentially recycled as it contains no dissolved salts, it also produces a semi-solid, solid concentrate with a water content of less than 15%. RW evaporators are designed to work both continuously, through a pump for concentrate discharge, or in batch, with the interruption of the evaporation cycle, leaving the screw feeder in motion and the discharge door open. RW models can capitalize on vapor as heat source through an intermediate optional heat exchanger.

Results & Benefits

  • Distillation yield 98%
  • Concentration factor 2%
  • Pay back about 4 months
  • Water reuse within the production cycle
  • N-metil-2-pyrrolidone recovery