Preparation of a New Iron-Carbon-Loaded Constructed Wetland Substrate and Enhanced Phosphorus Removal Performance

Jie Zhao,Junzhao Liu,Jingqing Gao

doi:10.3390/ma13214739

Abstract

Iron-carbon substrates have attracted extensive attention in water treatment due to their excellent processing ability. The traditional iron-carbon substrate suffers from poor removal effects, separation of the cathode and anode, hardening, secondary pollution, etc. In this study, a new type of iron-carbon-loaded substrate (NICLS) was developed to solve the problems of traditional micro-electrolytic substrates. Through experimental research, a preparation method for the NICLS with Fe and C as the core, zeolite as the skeleton, and water-based polyurethane as the binder was proposed. The performance of the NICLS in phosphorus-containing wastewater was analyzed. The results are as follows: The optimal synthesis conditions of the NICLS are 1 g hydroxycellulose, wood activated carbon as the cathode, an activated carbon particle size of 200-60 mesh, and an Fe/C ratio of 1:1. Acidic conditions can promote the degradation of phosphorus by the NICLS. Through the characterization of the NICLS (scanning electron microscope (SEM), X-ray diffractometer (XRD), and energy-dispersive spectrometer (EDS), etc.), it is concluded that the mechanism of the NICLS phosphorus removal is a chemical reaction produced by micro-electrolysis. Using the NICLS to treat phosphorus-containing wastewater has the advantages of high efficiency and durability. Therefore, it can be considered that the NICLS is a promising material to remove phosphorus.

Highlights

With the increases in population, industrialization, urbanization, and agricultural modernization, water pollution is becoming increasingly serious [1]
It can be considered that the new type of iron-carbon-loaded substrate (NICLS) is a promising material to remove phosphorus
The chemical precipitation method is widely used in engineering, but this method has a high cost and a large amount of precipitated sludge

Summary

Introduction

With the increases in population, industrialization, urbanization, and agricultural modernization, water pollution is becoming increasingly serious [1]. A large amount of phosphorus-rich domestic sewage, industrial wastewater, and farmland runoff are discharged into lakes, rivers, oceans, and other water bodies, causing eutrophication of water bodies [2,3,4]. It is very important to remove phosphorus from water. The commonly used phosphorus removal methods mainly include chemical and biological methods [6]. The chemical precipitation method is widely used in engineering, but this method has a high cost and a large amount of precipitated sludge. Coagulant addition can cause equipment corrosion, blockages, and water pollution [7,8]. Biological dephosphorization methods have lower operating costs, but the effectiveness of dephosphorization generally does not exceed 30% [9]

Methods

Results

Conclusion