Effective treatment of high phosphorus pharmaceutical wastewater by chemical precipitation

Abstract

The conditions for the treatment of high phosphorus pharmaceutical wastewater using chemical precipitation were determined to achieve high efficiency on the removal of total phosphorus (TP). The key factors affecting the TP removal efficiencies of four metal salts (FeCl3, AlCl3, MgCl2, and CaCl2), such as molar ratio, initial wastewater pH, and reaction time, were investigated. The optimal metal mole ratios of FeCl3, AlCl3P, MgCl2, and CaCl2 for the TP removal were 1.8:1, 1.8:1, 1.6:1, and 1.6:1 in the initial pH range, respectively. The TP removal efficiencies obtained by FeCl3, AlCl3, MgCl2, and CaCl2 were 99.8 %, 98.3 %, 96.9 %, and 99.2 % at the optimal mole ratio and pH conditions with 30 min reaction time, respectively. FeCl3 and AlCl3 had better removal performance on COD, wherein the removal rates of COD by FeCl3 and AlCl3 were 38.6 % and 27.6 %, respectively. FeCl3 and CaCl2 were selected for the combined process of removing TP and overcoming the aforementioned problem. The final effluent quality was better than the one only used on one of the four metal salts, in which the removal rates of TP and COD were as high as 99.8 % and 46.9 %, respectively. The combined process with FeCl3 and CaCl2 was an effective method for the pretreatment of high phosphorus pharmaceutical wastewater to reduce the processing cost and to decrease the chemical oxygen demand (COD) and TP.

Application of TiO2 and ZnO nanoparticles immobilized on clay in wastewater treatment: a review

“…Different methods have been developed and used for the treatment of wastewater. Some of the adopted techniques are centrifugation (Peeters 2015), filtration (Cardenas et al 2016), flotation (de Oliveira da Mota et al 2015), evaporation (Li et al 2016), distillation (Ji 2018), ion exchange (Tan et al 2017), precipitation (Sun et al 2017), electrolysis (Huang et al 2016), electrodialysis (Akhter et al 2018), adsorption (Guillaume et al 2018;You et al 2019), crystallization (Lu et al 2017), micro and ultra-filtration (Pinto et al 2017), sedimentation and gravity separation, reverse osmosis (Venzke et al 2017), and coagulation (Mousa and Hadi 2016). However, these prevailing technologies have some setbacks such as being time-consuming and costly and leading to the generation of toxic sludge.…”

Potential of using kaolin as a natural adsorbent for the removal of pollutants from tannery wastewater

“…Different methods have been developed and used for the treatment of wastewater. Some of the adopted techniques include centrifugation (Peeters, 2015), filtration (Cardenas et al., 2016), flotation (de Oliveira da Mota et al., 2015), oxidation and evaporation (Li et al., 2016), distillation (Ji, 2018), ion exchange (Tan et al., 2017), precipitation (Sun et al., 2017), electrolysis (Huang et al., 2016), electrodialysis (Akhter et al., 2018), adsorption (Guillaume et al., 2018), crystallization (Lu et al., 2017), micro and ultra-filtration (Pinto et al., 2017), sedimentation and gravity separation, reverse osmosis (Venzke et al., 2017) and coagulation (Mousa and Hadi, 2016). Adsorption is a process which is widely used to remove pollutants from fluids.…”

Simultaneous Removal of Phosphate and Nitrate on Calcined Mg-Al Layered Double Hydroxides

“…Therefore, it is important to remove phosphate, but difficult because of markedly low concentrations [1]. Various techniques, including chemical precipitation [2], electrocoagulation [3], and adsorption [4] have been used for phosphate removal. Nitrate is one of the three nutrients of fertilizers, but it is also a potential hazard for human heath, especially to infants, causing blue baby syndrome [5].…”