Fabrication and evaluation of an attapulgite membrane as the filter for recycling blowdown water from industrial boilers

Abstract

Continuous blowdown water (CBW) from industrial boilers is of great quantity and energy, and therefore worth recycling. According to the data from a long period of monitoring, carbonate and sulfate were documented as the main contaminants in CBW. Herein, an attapulgite (ATP) membrane was prepared on a macroporous Al 2 O 3 support through solid state sintering. The prepared membrane (attapulgite membrane (ATM)) was characterized by mercury porosimetry, scanning electron microscope, X-ray diffraction, and permselectivity analysis in dead-end mode. The optimal sintering temperature was 800 W C based on the morphology of the sintered active layer and its adhesive strength with support. The active layer exhibited a pore size distribution concentrated on 12.7 nm with a thickness of about 80 μm. In addition, crystal structures of ATP were retained in powder form after sintering. ATM obtained a pure water permeability of 1,411.87 L mwith the effective retention of carbonate and sulfate through electrical-related interactions. Several ATM filters were also developed and mounted on the boiler blowdown pipe, which had a high rejection rate of alkalinity and dissolved solids in CBW. The volume of wastewater emitted from the low-pressure boiler was reduced, since the filtrate could be recycled as part of the make-up water.

Optimized Anticorrosion of Polypyrrole Coating by Inverted-Electrode Strategy: Experimental and Molecular Dynamics Investigations

“…In comparison, the CA value of the PPy-I-coated counterpart (inset of Figure 2 f) attains up to 79.4°, indicating the formation of a layer with inferior wettability on the copper surface. However, the obtained CA value of PPy-I was less than that reported by Akula et al (106.1°) [ 13 ], which may be caused by the capillarity effect due to coating defects [ 27 ].…”

Synergetic Anticorrosion Mechanism of Main Constituents in Chinese Yam Peel for Copper in Artificial Seawater

“…Meanwhile, plentiful pits and crevices are seen in Figure d caused by severe corrosion, which is also supported by the elevated O content on the copper surface (Table ). Due to the capillary effect of a deteriorated surface, , the water contact angle of the corroded sample is lowered to 38.3°. In sharp contrast to Figure c, a well-protected surface is shown in Figure e, which furthest retains the primal gloss of copper compared with that imaged in Figure a.…”

Efficient corrosion inhibition by sugarcane purple rind extract for carbon steel in HCl solution: mechanism analyses by experimental and in silico insights

“… 4 Furthermore, the release of rust in the ecosystem also poses a heavy environmental burden. 5 Thereby, research efforts have been devoted to controlling the deterioration of C-steel in various corrosive media. Consequently, corrosion inhibitors, especially organic species, have attracted significant scientific and industrial attention owing to their low cost, convenience and efficiency.…”