Typically, wastewater from rubber processing plants, fishery, and aquaculture is treated by oxidization, sedimentation, and pre-settling basin before releasing it back to the environment. This method requires energy. If the treatment is not done efficiently, the treated water might still contain harmful residues that could pollute the environment.
Wastewater from rubber processing
Rubber is among the top industries in Thailand. Wastewater from rubber processing plants is a result of various stages of production. Latex production produces wastewater during centrifugation, a process that aims to reach a standard 60% concentration of rubber. The leftover product from this stage is separated then mixed with sulfuric acid before receiving further treatment. The process of making rubber sheet and rubber cup bottom on the other hand involves mixing formic acid to separate rubber from latex prior to any other processing. Water in the rubber becomes wastewater and needs to be treated.
Biological wastewater treatment
If untreated, wastewater from rubber industrial activities would naturally undergo fermentation and decomposition activated by microorganism available in the environment, causing unpleasant odor to the community. Biological wastewater treatment mimics the aforementioned natural process but in a way that responds to the condition of wastewater thus does not yield any adverse effect to the environment. The method begins with the breakdown of large molecules in wastewater by using single-cell algae and plankton. The algae feed on the waste. The last step is when plankton such as Moina terminates the algae. Selection of plankton varies depending on condition of the wastewater. Final result is quality water appropriate to be released back to nature or can be reused for factory cleaning. Plankton could also be repurposed as food for aquaculture or put back in natural water source to enrich and balance the ecology system.
Rubber wastewater to benefit society and environment
Biological wastewater treatment offers variety of benefits including reducing energy and expense per the traditional method, producing treated water that is of quality close to that of natural water, and offering viable ecology for aquatic animals. Water produced can not only be reused to clean factories but also provide plankton beneficial to the environment adding source of protein to feed animal or aquaculture, and to enrich water source and environment.
Asst. Prof. Dr. Chonlatee Cheewasedtham, and Asst. Prof. Dr Wilairat Cheewasedtham
Faculty of Science and Technology, Prince of Songkla University