Removal of ammonium from rare-earth wastewater using natural brucite as a magnesium source of struvite precipitation

Abstract

This paper presents a study regarding ammonium removal from rare-earth wastewater by struvite precipitation with natural brucite mineral as a source of magnesium. Experimental results indicated that a pH ranging from 8.5 to 9.5 was the optimum for the removal of ammonium using the soluble form of brucite as a magnesium source. Additionally, when solid brucite was used as a magnesium source as well as an alkali reagent, the initial ammonium concentration of 4,535 mg/L decreased to 239-317 mg/L after an reaction time of 12 h in wastewater treated with the S/L (solid brucite/liquid wastewater) ratios ranging from 31.2 to 63.2 g/L. Furthermore, as some non-reacted brucite still remained in the precipitates obtained at the end of reaction, the precipitates were subjected to reuse. The reuse results demonstrated that the reuse of the precipitates obtained with 63.2 g/L was feasible, and almost half of the brucite dose could be saved.Key words 9 9 9 9 ammonium, brucite mineral, phosphorus, rare-earth, struvite precipitation

Energy and nutrient recovery from agro-wastes: Rethinking their potential possibilities

“…It is helpful in recycling of vital nutrients. Different studies suggested that among different agro-waste, cattle manure is very successful in recovery of struvite [113,114], followed by swine manure [108,109,115,116], poultry manure [117], and lastly cattle urine [118]. Generally, farm wastes containing manures are abundant in P and NH 4 + , which is advantageous for struvite recovery.…”

Use of side stream-based MgSO4 as chemical precipitant in the simultaneous removal of nitrogen and phosphorus from wastewaters

“…Due to the relatively high price of these commercial salts, and since magnesium is listed in the European Union's critical raw material list, alternative magnesium sources should be preferred instead of commercial salts [13]. For these reasons, several authors have studied various inexpensive Mg-sources for struvite precipitation, including brucite [14], seawater [12,15], magnesite [16], bottom and fly ash [17,18], dolomite (DOL) [19,20], and MgO-saponification wastewater [21].…”

The Use of Ca- and Mg-Rich Fly Ash as a Chemical Precipitant in the Simultaneous Removal of Nitrogen and Phosphorus—Recycling and Reuse

“…Commonly used precipitants for struvite precipitation are MgCl 2 , MgSO 4 MgO, and Mg(OH) 2 [29,30], but due to the high price of these commercial salts, and since magnesium is listed in European Union's critical raw material list, alternative magnesium containing side streams and industrial waste material should be preferred instead of magnesium salts [1,31]. Therefore, inexpensive magnesium sources such as magnesite [32], brucite [33], a by-product of marine salt manufacturing and by-product of the thermal treatment of meat waste, bone meal, etc. [34], MgO-saponification wastewater [35], seawater [36,37], and bottom ash collected from a small residential fireplace [38] to produce struvite have been tested in several papers.…”