scholarly journals Removal of Pathogens in Onsite Wastewater Treatment Systems: A Review of Design Considerations and Influencing Factors

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1190
Author(s):  
Mian Wang ◽  
Julia Zhu ◽  
Xinwei Mao
Keyword(s):  
Wastewater Treatment ◽  
Microbiological Quality ◽  
Health Concern ◽  
Contributing Factors ◽  
Pathogen Removal ◽  
Operational Conditions ◽  
Onsite Wastewater ◽  
Onsite Wastewater Treatment Systems ◽  
Onsite Wastewater Treatment ◽  
Wastewater Treatment Systems

Conventional onsite wastewater treatment systems (OWTSs) could potentially contribute to the transmission of infectious diseases caused by waterborne pathogenic microorganisms and become an important human health concern, especially in the areas where OWTSs are used as the major wastewater treatment units. Although previous studies suggested the OWTSs could reduce chemical pollutants as well as effectively reducing microbial contaminants from onsite wastewater, the microbiological quality of effluents and the factors potentially affecting the removal are still understudied. Therefore, the design and optimization of pathogen removal performance necessitate a better mechanistic understanding of the hydrological, geochemical, and biological processes controlling the water quality in OWTSs. To fill the knowledge gaps, the sources of pathogens and common pathogenic indicators, along with their major removal mechanisms in OWTSs were discussed. This review evaluated the effectiveness of pathogen removal in state-of-art OWTSs and investigated the contributing factors for efficient pathogen removal (e.g., system configurations, filter materials, environmental and operational conditions), with the aim to guide the future design for optimized treatment performance.

scholarly journals Efficiency of Iron- and Calcium-Impregnated Biochar in Adsorbing Phosphate From Wastewater in Onsite Wastewater Treatment Systems

2020 ◽  
Vol 8 ◽  
Author(s):  
Sahar S. Dalahmeh ◽  
Ylva Stenström ◽  
Mohamed Jebrane ◽  
Lars D. Hylander ◽  
Geoffrey Daniel ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Adsorption Capacity ◽  
Loading Rate ◽  
Maximum Adsorption Capacity ◽  
Phosphate Solution ◽  
Onsite Wastewater ◽  
Onsite Wastewater Treatment Systems ◽  
Onsite Wastewater Treatment ◽  
Iron And Calcium ◽  
Wastewater Treatment Systems

This study evaluated the potential of biochar impregnated with Fe3+ or Ca2+, or mixed with Polonite®, as a filter material for removal of phosphate (PO4-P) from wastewater in onsite wastewater treatment systems (OWTS). Four treatments with biochar were investigated: unimpregnated biochar (UBC), biochar impregnated with iron Fe3+ (FBC), biochar impregnated with calcium oxide (CBC), and biochar mixed with Polonite® (PBC). In a batch experiment using phosphate solution at concentrations 0.5, 3.3, 6.5, 13, and 26 mg PO4-P L–1, adsorption of PO4-P in the different treatments was modeled using Langmuir and Freundlich isotherms. Column filters (5 diameter × 55 cm height) packed with UBC, FBC, CBC, and PBC were then furnished with raw wastewater over 148 weeks. During this experiment, adsorption of PO4-P was investigated in response to increasing hydraulic loading rate (HLR; 56, 74, and 112 L m–2 day–1) and increasing phosphate loading rate (PLR; 195, 324, 653, and 1715 mg PO4-P m–2 day–1). Among the materials, FBC had the highest maximum adsorption capacity (Qm) based on Langmuir isotherms (3.21 ± 0.01 mg g–1). FBC and CBC showed robust performance with increasing HLR, while increasing PLR increased the amount of PO4-P retained in all filters. After 148 weeks of operation, removal of PO4-P (averaged over the last 18 weeks of operation) was 13 ± 16% for UBC, 40 ± 20% for CBC, 88 ± 12% for FBC, and 30 ± 18% for PBC. The PO4-P amount retained in filters over the 148 weeks was 84.75, 221.75, 358.38, and 152.36 g m–2 in UBC, CBC, FBC, and PBC, respectively. The adsorption capacity of the filters after 148 weeks was 1.50, 4.02, 6.41, and 2.75 mg g–1 for UBC, CBC, FBC, and PBC, respectively. The adsorption capacity values and breakthrough curves showed that low concentrations (i.e., <2.6 mg L–1) of PO4-P in wastewater would allow the FBC filter to remain active for 58 months and the CBC filter for 15 months, before PO4-P removal declined to <70%. In conclusion, biochar impregnated with iron and calcium is a promising solution for removal of PO4-P from wastewater in OWTS.

Community management of onsite wastewater treatment systems- what they want in Mount Gambier, South Australia

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
K. S. Alexander ◽  
K. J. Levett ◽  
J. L. Vanderzalm
Keyword(s):  
Wastewater Treatment ◽  
Management Strategies ◽  
South Australia ◽  
Human Consumption ◽  
Wastewater Management ◽  
Consultation Process ◽  
Onsite Wastewater ◽  
Onsite Wastewater Treatment Systems ◽  
Onsite Wastewater Treatment ◽  
Wastewater Treatment Systems

Effective management of onsite wastewater treatment systems (OWTS) is important in preventing contamination of ecologically sensitive receiving environments, such as surface water and groundwater used for human consumption or contact. Householders play a key role in OWTS management, therefore inadequate householder knowledge of system function, inability to recognise signs of system failures and lack of understanding of maintenance requirements can increase the risk of system failure. A householder survey and community consultation process have been undertaken in conjunction with a biophysical effluent sampling program to reveal community understanding of OWTS, opinions on preferred management strategies, institutional arrangements and possible reactions to future financial costs to householders. Opinions from workshop participants and other stakeholders suggested their community wanted knowledge regarding OWTS functioning and maintenance, in particular, information on the use of suitable household chemicals to maintain treatment performance and continued research into contamination of groundwater sources by wastewater systems to better inform wastewater management strategies. Community participants were divided on the preferred administration and cost of maintenance, with some wanting to retain responsibility for maintenance arrangements by contracting specialised personnel and others suggesting local authorities should take responsibility.

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