Industrial Waste Water Management
Board paper mill refers to a factory that manufactures paper. It has a capacity of producing 25 board paper tons every day. This factory produces board paper using waste paper. The first step of the production process entails pulping waste papers. It takes the factory one hour to pulp an 18m3 paper. This step is followed by coarse screening. Coarse screening also takes one hour per every 35m3 paper.
After coarse screening, the pulp moves to the next step of high-density cleaning. This step leads to fine pulp screen. The pulp moves to the next step of low-density screening where it is prepared to be thickened, dispersed, deflaked and refined (Abou-Elela et al., 2008). After the pulp is refined and deflaked, it is now ready for use in forming sheet. The sheet is later pressed and eventually dried in order to come up with a board paper.
There is so much waste that is produced in the factory during paper processing. The first three paper processing stages produce effluent. At the stage where sheet is formed, effluent is produced again. The other wastes that are produced during the process include water which mostly has contaminants that include suspended solids and organic pollutants (Abou-Elela et al., 2008). The factory produces an alarming volume of water. 1000m3 of waste water is dumped into the pond that is near the factory without being treated.
A case study done on board paper factory aimed at accomplishing two major goals. One was to determine economically and technically, end-of-pipe approaches that would enhance Environmental Legislations in Egypt compliance. The other goal was to determine cleaner production and pollution prevention methods that could be used against the end-of-pipe treatment. Despite having these goals, the main reason why pollution prevention research was conducted was to find out and to offer information regarding the probability of reducing the produced waste, reusing and recycling water, reusing and recovering materials while improving efficiency in the operations.
Different quantities and qualities of water that the factory produced necessitated the establishment of a monitoring program that would identify waste sources throughout the production process. The established monitoring program took about two weeks during which composite samples were collected and analyzed with adherence to standard methods (Abou-Elela et al., 2008).
Waste reduction targets were set once waste had been characterized. Initially, the waste was characterized as effluent, water, solids and organic pollutants. Therefore, the targets were fiber recovery, white waters reuse in appropriate areas, some not clarified and others clarified and minimizing fresh water consumption without damaging operability and quality of the factory and paper respectively (Abou-Elela et al., 20008).
According to the study’s findings, the reduction targets were achieved. Fiber was recycled to stock chest once sand and plastic particles were removed. This led to L.E. 1, 350, 000 benefits per year during the 10-day payback duration. On the other hand, treating whitewater allowed water to be used in different processes after which it could be used by the subsequent processes. This eliminated chemical use in treating water. As such, L.E 30, 000 were saved every year over the 2-day Payback duration. Fresh water reduction improved DAF process performance. This meant that the uses of fresh water were reduced. Fresh water was only used in trimming nozzles, wire showers and felt showers. This led to 270,000 L.E savings per year during the 3-day payback duration (Abou-Elela et al., 2008).
Abou-Elela, S. I. et al. (2008). Pollution prevention pays off in a board paper mill. Journal of Cleaner Production, 16:330-334