Wastewater Treatment System | Pharmaceutical Wastewater Treatment

1. Background.

The annual output of the world pharmaceutical industry reaches one million tons, and the trade volume is quite high. With the rapid development of the pharmaceutical industry, the problem of pharmaceutical wastewater treatment has become increasingly serious.

According to relevant data, the annual discharge of pharmaceutical wastewater at home and abroad reached 1.25 billion tons. More than half of them have not been treated, which has caused great damage to the ecological environment.

Figure1 Pharmaceutical wastewater.

The pharmaceutical process is extremely cumbersome, and there are many kinds of excipients and complex structures. These organic compounds, including a large number of toxic and harmful substances, lead to many components, toxicity, and poor biochemical performance of pharmaceutical wastewater. The quality and quantity of wastewater produced by different enterprises and processes vary greatly, which increases the difficulty of wastewater treatment. Therefore, the treatment of pharmaceutical wastewater has reached an urgent moment.

2. Classification, Characteristics, and Harm of Pharmaceutical Wastewater.

2.1. Classification and Characteristics.

Pharmaceutical wastewater belongs to refractory industrial wastewater. There are two main classification methods, one is divided according to the production process, and the other is formulated according to the Discharge Standard of Water Pollutants in the Pharmaceutical Industry. The two-division methods complement each other and are generally divided into production process wastewater, cooling wastewater, flushing wastewater, domestic sewage, regeneration wastewater, etc. Fermentation wastewater, chemical synthesis wastewater, extraction wastewater, traditional Chinese medicine wastewater, bioengineering wastewater, and mixed preparation wastewater belong to the types specified in the Discharge Standard of Water Pollutants in the Pharmaceutical Industry.

pharmaceutical wastewater

2.2. Hazards.

No matter what standard is used to distinguish pharmaceutical wastewater, pharmaceutical wastewater is generally characterized by toxicity, high concentration of organic matter, and complex composition. If it is directly discharged into the water without treatment, “Sanzhi” toxic and harmful substances will not only endanger the water environment and destroy the overall ecological security, but also endanger human health through the enrichment of the food chain.

The reverse osmosis membrane-based system developed by NEWater Company can treat pharmaceutical wastewater such as antibiotics, vitamin C, and raw drugs, effectively remove suspended solids and turbidity in wastewater, efficiently desalinate, realize energy saving, and emission reduction, and reduce costs.

3. Application of reverse osmosis treatment of pharmaceutical wastewater.

3.1. Antibiotic Pharmaceutical Wastewater Reverse Osmosis Treatment.

Antibiotic pharmaceutical wastewater has the characteristics of high chroma, high salt content, high organic matter content, and complex components. Pharmaceutical wastewater treated by traditional physical, chemical, and biological methods is often difficult to meet industrial discharge standards. Membrane technology has attracted much attention because of its many advantages and has become a rapidly rising new technology. With the improvement of membrane performance and the decrease of its device cost, it plays an increasingly important role in wastewater treatment and reuse.

NEWater Company adopts the integrated technology of coagulation-sand filtration-microfiltration-reverse osmosis for advanced treatment of antibiotic pharmaceutical wastewater from a certain enterprise. The field test results are good, and the treated wastewater not only meets the discharge standard but also can be reused.

Figure2 Reverse osmosis process flow of antibiotic pharmaceutical wastewater treatment.

The treatment process is coagulation-sand filtration-microfiltration-reverse osmosis, and each treatment unit is described as follows:

  • Coagulation: Adding coagulant, coagulant aid, and fungicide into the outlet pipeline of the original water pump, passing through the pipeline mixer, entering the water tank for slow stirring (reaction stage), then entering the inclined plate settling tank, and hitting the middle water tank through the water pump;
  • Sand filtration: intercepting flocs and suspended solids formed by coagulation;
  • Microfiltration: Two hollow fiber microfiltration membrane modules, made of polyvinylidene fluoride and a single module membrane.

NEWater water filtration method used in the test is external pressure cross-flow filtration, and the backwashing adopts air-water double washing. Carry out chemically enhanced backwashing with sodium hydroxide solution once a day.

  • Reverse osmosis: Roll reverse osmosis components are made of aromatic polyamide composite materials. Reverse osmosis concentrated water is divided into two parts, one part reflows to meet the reverse osmosis influent flow, and the other part is discharged.

The specific process is as follows: Raw Water Pump → Polyferric Sulfate → Polyacrylamide → Sodium Hypochlorite → Mixer → Settling Tank → Water Pump → Intermediate Water Tank → Water Pump → Sand Filter → Scale Inhibitor → Intermediate Water Tank → Booster Pump → Security FilterHigh-Pressure Pump → Ro Assembly → Ro Water Production. RO-concentrated water is produced between the RO component and RO-produced water, which can be circulated through the middle water tank, and the other part passes through the cleaning water tank of the dosing system.

NEWater adopts the integrated technology of coagulation-sand filtration-microfiltration-reverse osmosis to treat pharmaceutical wastewater in-depth and has carried out continuous tests for two months in the field, which comprehensively examines the stability of the test system and the reliability of the equipment.

Figure3 Reverse osmosis treatment equipment for antibiotic pharmaceutical wastewater.

The average removal rates of suspended solids, turbidity, and CODCr by coagulation were 86.6%, 58.6%, and 32.9%, respectively. The average removal rate of turbidity by sand filtration is 46.3%. Appropriate operating pressure and cleaning method were determined. The average removal rates of turbidity, CODCr, and NH3-N by microfiltration were 98.4%, 23.2%, and 31.8%, respectively. The results show that coagulation-sand filtration-microfiltration as the pretreatment of reverse osmosis, the produced water quality meets the requirements of reverse osmosis influent.

The total desalination rate, calcium, and magnesium ion removal rate, CODCr removal rate, and sulfate removal rate of the two components used by NEWater are > 97%, 97%, 95%, and 92%, respectively. The produced water quality meets the requirements of reuse.

3.2. Reverse Osmosis Treatment of Vitamin C Condensate.

The pharmaceutical industry is one of the industries with high consumption and high pollution, which is listed as one of the 12 key industries in environmental protection planning at home and abroad. This industry includes chemical synthetic pharmaceuticals, biopharmaceuticals, ready-for-use traditional Chinese medicine production, etc. Concentration and evaporation operations are often used to increase the concentration of dissolved substances in mother liquor to recover expensive materials. Concentration and evaporation equipment needs to consume a large amount of steam, accounting for 30%  to 60% of the total steam consumption of products. Low-pressure steam is generated in many places in the production process, and a large amount of condensed water is generated after condensation.

At present, most enterprises only use part of condensate water as conventional cleaning water, and the remaining condensate water is directly discharged, which does not realize high-quality water reuse. Therefore, condensate regeneration and reuse technology are some of the common problems to be solved urgently in the pharmaceutical industry.

NEWater The company’s condensate advanced treatment facilities with reverse osmosis technology as the main body show the stability of reverse osmosis system operation and the feasibility of promotion in similar pharmaceutical factories by monitoring and analyzing the pH, conductivity, and TOC of reverse osmosis inlet and outlet water.

Figure4 Condensate treatment flow of vitamin C process.

The condensate treatment flow of the vitamin C process is as follows: Raw Water → Cooling Pool (Adjusting Ph) → Security Filter → Primary Ro → Intermediate Water Tank → Secondary Ro → Produced Water.

Figure5 Vitamin C condensate reverse osmosis treatment equipment.

The reverse osmosis system has a good treatment effect as purified water for the pharmaceutical industry, and the removal rates of salts and TOC are over 99.9% and 99%, respectively. The cleaning of reverse osmosis membranes is also practical and effective, which greatly prolongs the operation cycle of the project and saves the cost. Therefore, it has strong economic and environmental benefits, and it is feasible to use reverse osmosis to treat the condensate reuse process in vitamin C production.

3.3. Reverse Osmosis Treatment of Raw Drug Wastewater.

Many original drug companies are mainly engaged in the production and manufacture of APIs, sterile APIs, and drug intermediates. Their wastewater has the characteristics of complex components, large changes in water quality and quantity, high chromaticity, and difficult biochemical degradation. Originally, it was mainly treated by AOO + MBR process, and the effluent could not meet the reclaimed water reuse standard.

To improve water quality standards and achieve zero wastewater discharge, NEWater chose reverse osmosis as the main treatment solution for reclaimed water reuse according to the characteristics of MBR effluent, and the applicable reverse osmosis membrane is an anti-pollution membrane. After the wastewater is treated by this process, a large amount of high-quality reuse water (about 85%) is produced, which can be used for workshop water, and a small amount of concentrated water (about 15%) is produced, which can be used for slag flushing, thus realizing “zero emission” and energy-saving and emission reduction of raw drug wastewater.

After the reverse osmosis reuse process, the SS, COD, and conductivity of the original pharmaceutical wastewater from MBR effluent are well controlled, and SDI < 3 can be ensured. The concentrated water from the second stage of reverse osmosis is used to flush slag, which realizes zero discharge of wastewater.

Figure6 Process flow of reverse osmosis reuse of raw drug wastewater.

The process flow of reverse osmosis reuse of raw pharmaceutical wastewater is as follows: MBR Effluent → Mbr Clear Water Tank → Ozone Generator → Activated Carbon Filter  → Clear Water Tank → Activated Carbon Filter → Filter Tank → Primary Reverse Osmosis → Intermediate Water Tank → Secondary Reverse Osmosis → Pure Water Tank → Reuse. One section of reverse osmosis can directly pass through the pure water tank, during which the second section of reverse osmosis produces concentrated water for slag flushing.

After a long-term operation, the reverse osmosis membrane will accumulate some fouling that is difficult to wash, such as organic matter and inorganic salt fouling, which will cause the performance of the reverse osmosis membrane to decline. This kind of dirt must be cleaned with chemicals to restore the performance of the reverse osmosis membrane.

The reverse osmosis system consists of two stages, and the recovery rate of the system is 85%. The main parameters are:

  • Front middle, booster pump, and filter water supply pump;
  • Security filter, which mainly intercepts suspended solids in filter effluent to ensure the safe operation of reverse osmosis membrane;
  • Reverse osmosis unit to remove most salt in water. Anti-fouling membrane element, the system recovery rate is 85%. Effluent quality: SDI ≤ 3, influent turbidity ≤ 1 NTU, desalination rate > 95%.

Figure7 Reverse osmosis treatment equipment for raw drug wastewater.

NEWater After debugging, the zero-emission system with reverse osmosis as the main process runs normally. After normal operation, entering the cleaning cycle, the water yield decreased by 8%. After replacing the corresponding fillers, the pretreated water quality is stable. The second-stage system has a longer cleaning cycle because the amount of scale inhibitor is relatively increased when treating the concentrated water of the first-stage system. During this period, the water quality is stable, which can meet the industrial water standards and requirements and realize zero-emission.

NEWater The developed wastewater advanced treatment system can achieve zero emission of wastewater treatment for original drug production, which can not only reduce wastewater discharge pollution, but also save a lot of water resources, achieve energy conservation and emission reduction, and at the same time reduce costs.

If you encounter any difficulties in pharmaceutical wastewater treatment, please contact NEWater Company, we will provide you with a comprehensive reverse osmosis treatment system for pharmaceutical wastewater, effectively removing suspended solids and turbidity in wastewater, efficiently desalinating, realizing energy saving and emission reduction, and reduce costs!

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