Physico-chemical characteristics of paper industry effluents--a case study

This paper presents the characteristics of wastewater from a small paper mill which is using wastepaper as a raw material. After analysis it was found that the raw wastewater consisted of 202-294 mg/l and 2010-3200 mg/l of suspended and dissolved solids respectively while pH varied from 6.7-7.3. The BOD and COD values ranged from 210-310, 1680-2340 mg/l respectively. Due to the treatment of raw effluent, the SS and TDS of treated effluent were significantly decreased and the values ranged in between 118 mg L(-1) to 154 mg L(-1) and 645 mg L(-1) to 925 mg L(-1), respectively. The pH values of the treated effluent were higher than the raw effluent. The nitrogen, phosphorous and potassium content of treated effluent were found to be higher after the treatment of paper mill raw effluent. The low amount of nutrient content may be because of the use of chemicals in process section which do not contain such elements. The sodium, calcium and magnesium were found higher in treated effluent, which may be due to addition of chemicals during the pulping and production section.