Treatment of wastewater from a handmade paper (HMP) mill to reduce pollution load

In the Philippines and other developing countries, hand-made papermaking is one of the small and medium enterprises (SMEs) with relatively significant triple impacts: economic, environmental, and social. Environmentally, there is no available report of any local HMP mill contributing to environmental pollution. Visits to some of the mills, however, do indicate generation of pollutants, specifically in their wastewater. Hence, to assess the quality of wastewater generated in a typical HMP mill, Mari et al. (FPRDI) studied the treatment of wastewater from a HMP mill. Specifically, the study assessed the potential of a charcoal-based treatment system in treating HMP mill wastewater; designed and fabricated a wastewater facility model; evaluated the technical and economic viability of the technology on a pilot scale; and monitored and evaluated the immediate impact of the technology on the cooperator's business and the nearby community. Wastewater samples from HMP mills varied in degree of pollution depending on the raw material used, material preparation, and design of product. But generally, all were potential environmental pollutants. Treating HMP mill wastewater with spent liquor, bleach, and sheet forming effluents that settle and pass the supernatant liquid through two aerated charcoal bed (ACBs) for about 5 days each, reduced biochemical oxygen demand (BOD) and total suspended solids (TSS) to acceptable limits. However, chemical oxygen demand (COD) and color were not reduced. This indicated that the treated wastewater can be recycled or allowed for discharge to inland bodies of water. Treatment of the sheet forming or sheet forming plus bleaching effluents with alum coagulant, followed by settling and passing the supernatant liquid through an ACB for about 2 days reduced the pollution loads to acceptable limits. The treated wastewater can also be safely dispensed through draining. The results of the pilot runs indicated the technical viability of the wastewater treatment system for HMP mill effluent, particularly of sheet forming and bleaching effluent, preferably the COD level should be below 600 mg/L. Cost of treatment before interest was P89.00/cu m of wastewater. In terms of added cost to the HMP producer, the treatment facility entailed an additional cost of P107.00/day or an additional cost of P0.13/sheet. However, the cooperator earned positive views from its clients and neighbors, as well as fellow industry players, concerning the wastewater management in the mill. Prior to treatment of wastewater, it was observed that the segregation of the less polluted sheet forming and bleaching effluents can be treated and possibly recycled back into the process, except for the pulping effluent which has to be handled separately. Since clean production technologies are favored over pollution control technologies, the present pulping process in HMP making may have to be extensively modified, if not completely changed. This is to minimize or prevent the discharge of excessive Na plus ions to the environment. Otherwise, spent liquor may have to be treated for use in concrete or hollow block manufacture and also diluted several times for irrigation purposes. The treatment technology is recommended for promotion to assist the HMP industry.