Woven-Fiber Microfiltration (WFMF) and Ultraviolet Light Emitting Diodes (UV LEDs) for Treating Wastewater and Septic Tank Effluent

Abstract

Decentralized wastewater treatment systems enable wastewater to be treated at the source for cleaner discharge into the environment, protecting public health while allowing for reuse for agricultural and other purposes. This study, conducted in Thailand, investigated a decentralized wastewater treatment system incorporating a physical and photochemical process. Domestic wastewater from a university campus and conventional septic tank effluent from a small community were filtered through a woven-fiber microfiltration (WFMF) membrane as pretreatment for ultraviolet (UV) disinfection. In domestic wastewater, WFMF reduced TSS (by 79.8%), turbidity (76.5%), COD (38.5%), and NO3 (41.4%), meeting Thailand irrigation standards for every parameter except BOD. In septic tank effluent, it did not meet Thailand irrigation standards, but reduced TSS (by 77.9%), COD (37.6%), and TKN (13.5%). Bacteria (total coliform and Escherichia coli) and viruses (MS2 bacteriophage) passing through the membrane were disinfected by flow-through UV reactors containing either a low-pressure mercury lamp or light-emitting diodes (LEDs) emitting an average peak wavelength of 276 nm. Despite challenging and variable water quality conditions (2% < UVT < 88%), disinfection was predictable across water types and flow rates for both UV sources using combined variable modeling, which enabled us to estimate log inactivation of other microorganisms. Following UV disinfection, wastewater quality met the WHO standards for unrestricted irrigation.

Multi-Integrated Systems for Treatment of Abattoir Wastewater: A Review

“…For domestic wastewater from a university campus that they used in their study, the membrane reduced TSS (by 79.8%), turbidity by 76.5%, COD by 38.5%, BOD by 47.8%, and NO 3 by 41.4%. UVT at 254 nm improved by 19.4%, and UVT at 280 nm by 12.4% [1]. Following UV disinfection, wastewater quality met the WHO standards for unrestricted irrigation.…”

“…UVT at 254 nm improved by 19.4%, and UVT at 280 nm by 12.4%. [1]. Following UV disinfection, wastewater quality met the WHO standards for unrestricted irrigation.…”

“…Traditional UV lamps are low-cost and accessible in developing economies, but also contain toxic mercury vapor. On the other hand, UV LEDs are more expensive but mercury-free [1,52].…”

“…Unfortunately, the protein concentrate obtained by the traditional methods cannot be used as animal food because coagulants and flocculants can introduce some harmful compounds and change protein properties. Pressure-driven membrane processes are good at protein The study by Beck, Suwan [1] evaluated a cost-effective, user-friendly, and relatively fast treatment process involving a woven-fiber microfiltration (WFMF) membrane to filter domestic wastewater followed by UV disinfection to disinfect the permeate. With an effective pore size of 1-3 µm [53] the membrane was capable of removing Ascaris lumbricoides eggs (50 mm) and Giardia cysts (10 µm), whereas bacteria (1-2 µm), viruses, and Cryptosporidum oocysts (3 µm), which are small enough to pass through the filter pores, were inactivated by exposure to UV light.…”

“…Relative to other commodities such as winery and car manufacturing, the abattoir industries have also increased and doubled in production in the past decade, increasing water consumption. This increase in water consumption inevitably poses a threat to the environment due to added pollution and increasing water scarcity such that by 2050 global water demand is projected to be 20-30% higher than current levels given both population growth and socio-economic development [1].This is caused by the presence of organic matter such as chemical oxygen demand (COD), which poses a threat to the environment by accelerating the deoxygenation of rivers and contamination of ground water [2]. Abattoir industries consume about of rivers and contamination of ground water [2].…”