Changing Production Routine to Overcome Waste Difficulty    

-- How does a pharmaceutical company dispose of pollutants in waste water?

By Peter Zong
Since an outbreak of blue algae in Taihu Lake on May 31st, 2007 (CCR 2007 No.23), the related local governments, under the pressures from the central government and public, conducted stricter measures to the companies in the regions adjacent to the lake, particular in pharmaceutical chemical firms. Due to the majority of the lake located in Jiangsu province, the Jiangsu provincial government lifted twice the discharge standards for the firms in the lakeside regions. Meeting the new threshold or not will decide the future of a firm, survival or shutdown. It seems difficult for pharmaceutical manufacturers that always need to clean waste water containing high COD content, high salt concentration and strong acidity. However, Changshu Fushilai Medicine & Chemical Co., Ltd. succeeded in overcoming big difficulties by checking small shortages in production process. It disclosed again devil exists in details.   
   Changshu Fushilai Medicine & Chemical Co., Ltd.(CFMC), built in 2000, is a subsidiary of Jiangsu Fushilai Paper Making Group. It is China's largest producer of 6,8-dichloro ethyl caprylate, alpha lipoic acid (thioctic acid) and their relative pharmaceutical and chemical products. The company has carried out 17 items of renovation since June 2007 and finally reached zero discharge of chemical waste water. It has reduced the usage amount of organic solvent by more than 450 tons in one year through replacing organic solvent by common water. Around 3.4 million tons of waste water was cut per year than before. What is the key?
   The biggest difficult for CFMC is the waste water from the production of alpha lipoic acid, which has high COD content, high salt concentration and strong acidity, and is hard to be degraded by biological technology. Many other alpha lipoic acid producers in China typically dilute this kind of waste water by five times of clean water and then treat with it through traditional treatment technologies so that it can be discharged complied with the related standards. This dilute method will substantially increase the total discharge amount of waste water, which needs a larger facility and causes an increased treatment expense.
   In September 2007 the Jiangsu provincial government approved a new local discharge standard for chemical industry, the maximum discharge permit of COD per liter waste water is reduced from 100 milligram to less than 60 milligram. So the treatment of waste water does not only decide the competitive cost but also decide the survival of the company. CFMC on time organized a research team to overcome the difficulty.
   The team soon found the first problem. Among several production sections, organic solvent is only used as a cooler, and then is mixed with the other waste water, significantly augmenting the COD content in the final waste water. Finding the root of problem, the team decides to reform four production sections, trying to use clean water as cool agent instead of organic solvent. The reform was identified to be successful after thirteen trials.
   Following the first success, the team carried out the clean production scheme for the whole alpha lipoic acid production routine, with an investment of RMB9.35 million. The reformers also reduced the concentration of waster water by pressure filtering and deposit, and then recycle it to the start of the section. Such small reformation reduces pollutants, also helps increase the yielding rate of alpha lipoic acid from 81% to 83%.
   Some waste gases will be generated in the production of alpha lipoic acid. These waste gases can increase the acidity of water when dissolving in water, which will make the treatment of waste water be more difficult. In order to solve this problem, the team neutralizes the acidic sewage before it enters into treatment plant and then returns it back to bump for recycle use. This modification can annually reduce more than 1.8 million tons of waste water.
   For the final procedure, the company selected a set of integrated treatment technologies to deal with the waste water from the production of alpha lipoic acid, reducing the COD from 13 grams per liter to less than 50 milligrams. The cleaned waste water is again reused as the compensate source for cooling water. As an addition gain, the company can extract three tons of sulfites per day from the waste water, which was sold at RMB1 500 per ton.