Laboratory Testing of Stormwater from Värpinge Wetland Using SiC Membrane

Abstract

Stormwater runoffs have increasingly become a significant issue in urban infrastructure design and environmental management due to problems related to flooding, freshwater stress, and pollutant loading to receiving water bodies. This project investigated the lab-scale performance of silicon carbide (SiC) MF membranes in treating stormwater runoffs from the Värpinge wetland in the western part of the city of Lund, Sweden. The main objective of the study was to assess the operational capability and effectiveness of the membranes in removing potential pollutants from the stormwater and improving the water quality.
A 3-D printed 5 L filtration tank, a flat sheet SiC membrane (0.1 µm pore size and 0.069 m² membrane surface area), and a low-pressure peristaltic pump were used to establish the lab-scale submerged membrane filtration setup. Two stormwater samples collected from different sites i.e., the runoff inlet point (sample 1) and after sedimentation pond (sample 2) were subjected to dead-end filtration under constant pump speed (700 RPM). The results demonstrated that the SiC membrane significantly removed the total suspended solids (up to 93%), turbidity (96%), and particle-bound heavy metals like Fe (95% removal) and Zn (63% removal). However, the membrane exhibited a limited removal capacity for total organic carbon and nutrients like nitrogen and phosphorus which are mainly found in dissolved form. During the 3-hour filtration, flux performance study showed a gradual decline, primarily due to membrane fouling. Compared to filtration flux for sample 1 (runoff inlet point), the flux in the filtration of stormwater sample 2 (post sedimentation pond) was slightly higher, indicating the contribution of the sedimentation pond in creating variations in fouling potential associated with the stormwater samples composition. Moreover, the study also demonstrated that permeate backwashing at a higher pump speed (900 RPM) and water jet flushing could be a convenient and cost-effective cleaning approach to recover the original flux and maintain sustainable operation of the membrane.
Generally, the findings of the study revealed the potential of lab-scale SiC MF membranes in removing major stormwater pollutants, resulting in the enhancement of the water quality to a certain standard, which could then be reused for non-potable purposes or safely discharged to nearby water bodies. The study recommends future work on advanced water quality analysis and the membrane's performance at different seasons and sample locations.

Popular Abstract

Repurposing urban wastewater: Can ceramic membranes help to clean our cities’ runoff?
The increase in population growth and its subsequent urbanization has brought a significant change in our land use, leading to the expansion of impervious surfaces like buildings and roads. This change in landscape is affecting the natural hydrological cycle and is increasing the stormwater runoff, causing several environmental problems like flooding and water pollution. In light of increasing freshwater scarcity, consider the potential benefits of treating and converting urban wastewater into a reusable water source. This treated water could be utilized for various non-potable applications such as irrigation, toilet flushing, and other similar purposes.
This study aimed to investigate the potential of ceramic silicon carbide membrane for the treatment of urban stormwater from Värpinge wetland in the outskirts of the city of Lund, Sweden. Membrane technology with ceramic membranes that can operate under harsh environments has gained attention for replacing the conventional stormwater treatment processes in Värpingedammen, Värpinge wetland. Ceramic silicon carbide membranes are durable membranes with the capacity of filtering out various contaminants such as suspended particles, bacteria, metals, etc.
Using a small-scale submerged filtration lab setup, stormwater samples collected from two different spots of the Värpinge wetland (i.e., from runoff inlet and pre-sedimentation pond outlet points) were filtered through the membrane, and the performance was assessed. Promising results were observed, showing the membrane’s potential in retaining major contaminants (mainly suspended particles, including bacteria and some heavy metals) and improving the water quality to a certain level, which is safer for non-potable purposes and the environment, in compliance to the EU regulation on minimum requirements for water reuse. However, the membrane exhibited some limitations in removing nutrients, organic matter, and some heavy metals, requiring complementary treatment to enhance the water quality of the reclaimed water. Most importantly, this technology could be taken as a sustainable solution due to its longer lifespan and convenient cleaning protocol (backwashing), which addresses the major fouling issue of membranes.
Thus, with future studies conducted on a large scale and long-term operability, ceramic membranes have the potential to emerge as innovative solutions for resilient urban planning and intelligent water ecosystem management.

• author: Brhane, Dawit Zeru
• supervisor: Frank Lipnizki; Tobias Hey
• organization: Chemical Engineering (M.Sc.Eng.)
• course: METM01 20251
• year: 2025
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Silicon Carbide Membrane, Stormwater Management and Treatment, Membrane Fouling and Cleaning, Permeate Flux, Wastewater Reuse, Värpinge Wetland, Membrane Technology
• language: English
• id: 9203595
• date added to LUP: 2025-06-23 11:32:12
• date last changed: 2025-06-23 11:32:12