A Review Of Selected Natural Coagulants In Water And Wastewater Treatment

The fashion industry contributes 20% of industrial water pollution  With a high water footprint, massive chemical use and atmospheric, water and greenhouse gas (GHG) emissions, dyehouse operations are the most environmentally damaging component of the apparel supply chain2.Global brands are responding by requiring manufacturers to treat wastewater and reduce effluent. Paradoxically, conventional water treatment systems generate toxic sludge, trading water pollution for solid, chemical discharge that is landfilled and emits GHG – mostly methane.

The United Nations’ Sustainable Development Goal 6 (SDG 6) aims to ensure the availability and management of water and sanitation for all, including an end to open defecation, by 2030.1 Lack of access to clean water and proper sanitation affect all aspects of human life across the globe, having the largest negative effects on least developed countries and marginalized communities. About 36% of the global population live in water-scarce regions, with more than two billion people having no other choice but to consume contaminated water. Water pollution is the greatest culprit in ecosystem destruction, leading to biodiversity loss with often irreversible consequences. Water scarcity is expected to displace 700 million people by 2030, while desertification will put the livelihood of one billion people living in 100 countries across the world at risk by 2050.2 Despite these risks, our society has very few incentives to consume less water, maintain water quality, or allocate funding and resources to ecosystems or social objectives.3 In order to fulfill the objectives of the SDG 6, the High Level Panel on Water called for a “fundamental shift in the way the world looks at and manages water”, noting that a 40% shortfall in water availability by 2030 could be expected if no action is taken.4 An urgent need to develop innovative approaches to solve global water scarcity and quality issues has arisen, as traditional financing solutions and technologies have proven to be insufficient in addressing these challenges.

Hybrid processes combining activated carbon and nanofiltration have been studied to identify the optimum solution for advanced wastewater treatment in high quality water reclamation and reuse. With a focus on the removal of bulk and trace organic compounds the investigation identified three promising process combinations, namely powdered activated carbon followed by nanofiltration (PAC/NF), granular activated carbon followed by nanofiltration (GAC/NF) and nanofiltration followed by granular activated carbon (NF/GAC). The removal potential was examined in lab and pilot scale for a range of refractory pharmaceuticals and industrial chemicals typically detected in effluent in trace concentrations ranging from ng/L to μg/L. Fluorescence excitation emission spectroscopy was employed for the investigation of the fate of effluent organic matter. The optimum strategies for operation of the hybrid processes were determined in pilot scale. The experiments were conducted at the Wastewater Treatment Plant Aachen Soers providing an effluent of high quality with low dissolved organic carbon (DOC) concentrations of about 5 mg/L.

• Identify the source and general types of wastewater odors. • List three potential impacts of odors. • List three factors affecting the existence of odors. • Name a commonly used method to reduce odors from wastewater. • Describe three methods for solving odor problems in air.