제지공정 폐수 내에 포함된 리그닌을 재사용하기 위해 같이 포함되어있는 금속이온을 줄여야한다. 본 연구에서는 세라믹 분리막을 이용하여 제지공정 폐수 내의 금속이온을 제거하는 연구를 진행하였다. 분리막은 DMAc 용매에 PESf 고분자를 용해시킨 뒤 α-Alumina 분말을 넣고 PVP 분산제를 첨가하여 평판형 분리막을 제조하였다. FE-SEM으로 분리막의 단면과 표면을 관찰하고 CFP (Capillary Flow Porometer)장치를 통해 기공크기를 측정하였다. 분리막을 이용 한 금속이온제거 실험을 한 뒤 실험 전, 후의 폐수를 ICP-MS분석을 통해 금속 이온량을 측정하였다.
Pulp and paper industry produces large volumes of wastewater and residual sludge waste, resulting in many issues in relation to wastewater treatment and sludge disposal. Contaminants in pulp and paper wastewater include effluent solids, sediments, chemical oxygen demand (COD), and biological oxygen demand (BOD), which should be treated by wastewater treatment processes such as coagulation and biological treatment. However, few works have been attempted to predict the treatment efficiency of pulp and paper wastewater. Accordingly, this study presented empirical models based on experimental data in laboratory-scale coagulation tests and compared them with statistical models such as artificial neural network (ANN). Results showed that the water quality parameters such as turbidity, suspended solids, COD, and UVA can be predicted using either linear or expoential regression models. Nevertheless, the accuracies for turbidity and UVA predictions were relatively lower than those for SS and COD. On the other hand, ANN showed higher accuracies than the emprical models for all water parameters. However, it seems that two kinds of models should be used together to provide more accurate information on the treatment efficiency of pulp and paper wastewater.
We used a conventional activated sludge process to treat a paper wastewater, and then the effluent was treated with an ozone oxidation process as advanced process to remove non-degradable materials. It was found that the removal efficiency rates of the organic matter has been rapidly increased initially, and then it was almost constant after this period. The concentration of ozone should be recommended to maintain approximately 8.3 mg/L during this operation to keep the CODmn value below 100 mg/L and ozone contact time longer than 60 min.
This research was performed to evaluate heavy metal leaching characteristics of the sludge from paper mill process with sintering temperature. Heavy metal leaching of the sludge was characterized with Korean Leaching Test and Toxicity Characteristic Leaching Procedure. The test sludge was composed of 70.72% of moisture, 9.5% of volatile solids and 9.76% of fixed solids. As a result of XRF analysis, Fe was the highest inorganic element in approximately 83%, which implies the recycling possibility of the sludge in reuse of Fenton chemicals and artificial lightweight aggregate. Leaching of heavy metals from sintered sludge was lower than the dry ones. However, there was no significant difference in leaching characteristics between the sludges sintered at 350℃ and 650℃. Zn and Fe were leached more greatly in TCLP and KLT methods respectively.
This work was performed to develop a dip injection wet scrubber (DIWS) system with chlorine dioxide as the oxidant. The exhaust pollutants from a lime kiln of paper-mill were introduced to the system. When NaClO3 was used to oxidize NO into NO2, the oxidation was unsatisfactory and the combination of HNO3 or H2SO4 was required for 100% oxidation. ClO2 is recommended to oxidize NO and SO2 effectively. With the combination of 1st stage of DIWS and ClO2, 57.1% of NOx and 98% of SO2 were effectively removed. In the case of 2nd stage of DIWS and ClO2, 93.5% of NOx and 99% of SO2 were removed. The ClO2+DIWS process was superior to the ClO2+Scrubber process in terms of investment, running cost and NOx removal efficiency.