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Response Surface Methodology for Treatment of Paper Mill Wastewater by Using Inorganic Polymeric Coagulant

Ali Mohammed Eid M., Moniem Shimaa M. Abdel, Abdelsalam Hazem, Ammar Nabila S., Ibrahim Hanan S.

Ecological Engineering & Environmental Technology

2022

Vol. 23, iss. 5

153--163

Inorganic polymeric ferric chloride (POFC) coagulant with proposed structure of Fen (Cl2.2OH0.8)n is synthesized using waste materials and characterized by XRD. In the current work scrutinized efficiency of POFC for paper mill wastewater (PMW) treatment using response surface methodology (RSM) with central Composite Design (CCD) modeling. Different factors; dose, rapid mixing speed, and rapid mixing time are used for optimize the coagulation process using POFC for treating PMW. The turbidity and chemical oxygen demand (COD) removals are the indicators for assessing POFC efficiency. The obtained result for XRD confirms the production of new material of inorganic polymeric coagulants. Based on RSM modelling, there is a high correlation between the experimental and predicated removals of turbidity and COD. Subsequently, the model is significantly applied for predicating COD and turbidity removals at different operation condition. Conclusively, the obtained results proposed for practical application of POFC coagulant for treatment of paper mill wastewater for COD and turbidity elimination. Furthermore, the applied RSM with CCD is talented model for optimizing treatment of PMW.

Mixed Pseudo-orthogonal Frequency Coding for SAW RFID Tags

Xu M., Xiao X., Yuan Q., Zong Y.

Archives of Acoustics

2018

Vol. 43, No. 4

681--687

A mixed pseudo-orthogonal frequency coding (Mixed-POFC) structure is proposed as a new spreadspectrum technique in this paper, which employs frequency and time diversity to enhance tag properties and balances the spectrum utilization and code diversity. The coding method of SAW RFID tags in this paper uses Mixed-POFC with multi-track chip arrangements. The cross-correlation and auto correlation of Mixed-POFC and POFC are calculated to demonstrate the reduced overlap between the adjacent center frequencies with the Mixed-POFC method. The center frequency of the IDT and Bragg reflectors is calculated by a coupling of modes (COM) module. The combination of the calculation results of the Bragg reflectors shows that compared with a 7-chip POFC, the coding number of a 7-chip Mixed-POFC is increased from 120 to 144 with the same fractional bandwidth of 12%. To demonstrate the validity of Mixed-POFC, finite element analysis (FEA) technology is used to analyze the frequency characteristics of Mixed-POFC chips. The maximum error between designed frequencies and simulation frequencies is only 1.7%, which verifies that the Mixed-POFC method is feasible.