scholarly journals Small scale water recycling systems - risk assessment and modelling

2001 ◽  
Vol 43 (10) ◽  
pp. 83-90 ◽  
Author(s):  
C. Diaper ◽  
A. Dixon ◽  
D. Butler ◽  
A. Fewkes ◽  
S. A. Parsons ◽  
...  

This paper aims to use quantitative risk analysis, risk modelling and simulation modelling tools to assess the performance of a proprietary single house grey water recycling system. A preliminary Hazard and Operability study (HAZOP) identified the main hazards, both health related and economic, associated with installing the recycling system in a domestic environment. The health related consequences of system failure were associated with the presence of increased concentrations of micro-organisms at the point of use, due to failure of the disinfection system and/or the pump. The risk model was used to assess the increase in the probability of infection for a particular genus of micro-organism, Salmonella spp, during disinfection failure. The increase in the number of cases of infection above a base rate rose from 0.001% during normal operation, to 4% for a recycling system with no disinfection. The simulation model was used to examine the possible effects of pump failure. The model indicated that the anaerobic COD release rate in the system storage tank increases over time and dissolved oxygen decreases during this failure mode. These conditions are likely to result in odour problems.

2008 ◽  
Vol 62 (6) ◽  
pp. 700-703
Author(s):  
Makoto Matsushita ◽  
Yoshiharu Numata

2001 ◽  
Vol 43 (10) ◽  
pp. 287-294 ◽  
Author(s):  
S. Hills ◽  
A. Smith ◽  
P. Hardy ◽  
R. Birks

Thames Water is working with the New Millennium Experience Company to provide a water recycling system for the Millennium Dome which will supply 500m3/d of reclaimed water for WC and urinal flushing. The system will treat water from three sources:rainwater - from the Dome roofgreywater - from handbasins in the toilet blocksgroundwater - from beneath the Dome site The treatment technologies will range from “natural” reedbeds for the rainwater, to more sophisticated options, including biological aerated filters and membranes for the greywater and groundwater. Pilot scale trials were used to design the optimum configuration. In addition to the recycling system, water efficient devices will be installed in three of the core toilet blocks as part of a programme of research into the effectiveness of conservation measures. Data on water usage and customer behaviour will be collected via a comprehensive metering system. Information from the Dome project on the economics and efficiency of on-site recycling at large scale and data on water efficient devices, customer perception and behaviour will be of great value to the water industry. For Thames Water, the project provides vital input to the development of future water resource strategies.


2021 ◽  
Author(s):  
Seogchan Kang ◽  
Rhea Lumactud ◽  
Ningxiao Li ◽  
Terrence H Bell ◽  
HyeSeon Kim ◽  
...  

Heavy reliance on synthetic pesticides for crop protection becomes increasingly unsustainable, calling for robust alternative strategies that do not degrade the environment and vital ecosystem services. There exist numerous reports of successful disease control using various microbes in small-scale trials. However, their inconsistent efficacy has hampered large-scale applications. An enhanced understanding of how beneficial microbes interact with plants, other microbes, and the environment and which factors affect their efficacy of disease control is crucial to deploy microbial allies as effective and reliable pesticide alternatives. Diverse metabolites produced by plants and microbes participate in pathogenesis and defense, regulate the growth and development of themselves and neighboring organisms, help maintain cellular homeostasis under varied environmental conditions, and affect the assembly and activity of plant and soil microbiomes. However, research on the metabolites associated with plant growth/health-related processes, except antibiotics, has not received adequate attention. This review highlights several classes of metabolites known or suspected to affect plant health, focusing on those associated with biocontrol and belowground plant-microbe and microbe-microbe interactions. The review also presents how new insights anticipated from systematically exploring the diversity and mechanism of action of bioactive metabolites can be harnessed to develop novel crop protection strategies.


Author(s):  
Huasong Peng ◽  
Muhammad Bilal ◽  
Hafiz Iqbal

Herein, we reviewed laboratory-acquired infections (LAIs) along with their health-related biological risks to provide an evidence base to tackle biosafety/biosecurity and biocontainment issues. Over the past years, a broad spectrum of pathogenic agents, such as bacteria, fungi, viruses, parasites, or genetically modified organisms, have been described and gained a substantial concern due to their profound biological as well as ecological risks. Furthermore, the emergence and/or re-emergence of life-threatening diseases are of supreme concern and come under the biosafety and biosecurity agenda to circumvent LAIs. Though the precise infection risk after an exposure remains uncertain, LAIs inspections revealed that Brucella spp., Mycobacterium tuberculosis, Salmonella spp., Shigella spp., Rickettsia spp., and Neisseria meningitidis are the leading causes. Similarly, the human immunodeficiency virus (HIV) as well as hepatitis B (HBV) and C viruses (HCV), and the dimorphic fungi are accountable for the utmost number of viral and fungal-associated LAIs. In this context, clinical laboratories at large and microbiology, mycology, bacteriology, and virology-oriented laboratories, in particular, necessitate appropriate biosafety and/or biosecurity measures to ensure the safety of laboratory workers and working environment, which are likely to have direct or indirect contact/exposure to hazardous materials or organisms. Laboratory staff education and training are indispensable to gain an adequate awareness to handle biologically hazardous materials as per internationally recognized strategies. In addition, workshops should be organized among laboratory workers to let them know the epidemiology, pathogenicity, and human susceptibility of LAIs. In this way, several health-related threats that result from the biologically hazardous materials can be abridged or minimized and controlled by the correct implementation of nationally and internationally certified protocols that include proper microbiological practices, containment devices/apparatus, satisfactory facilities or resources, protective barriers, and specialized education and training of laboratory staffs. The present work highlights this serious issue of LAIs and associated risks with suitable examples. Potential preventive strategies to tackle an array of causative agents are also discussed. In this respect, the researchers and scientific community may benefit from the lessons learned in the past to anticipate future problems.


Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 124 ◽  
Author(s):  
Mthembu ◽  
Zishiri ◽  
Zowalaty

Livestock are an important source of protein and food for humans, however opportunistic pathogens such as Salmonella spp. turn livestock into vehicles of foodborne diseases. This study investigated the prevalence of virulence genes in Salmonella spp. isolated from livestock production systems in two provinces of South Africa. During the period from May to August, 2018, a total of 361 faecal (189), oral (100), environmental (soil (36) and water (27)) and feed (9) samples were randomly collected from different animals (cattle, sheep, goats, pigs, ducks and chickens) that were housed in small-scale livestock production systems from Eastern Cape and KwaZulu-Natal Provinces in South Africa. Salmonella spp. were isolated and identified using microbiological and DNA molecular methods. Salmonella spp. were present in 29.0% of the samples of which 30.2% belonged to the Salmonella enterica species as confirmed by the positive amplification of the species specific iroB gene. Virulence genes that were screened from livestock-associated Salmonella were invA, iroB, spiC, pipD and int1. Statistically significant associations (p < 0.05) were established between the virulence genes, sampling location, animal host as well as the season when samples were collected. Furthermore, statistically significant (p < 0.05) positive correlations were observed between most of the virulence genes investigated. This is one of the recent studies to detect and investigate livestock-associated Salmonella spp. in South Africa. This study highlights the importance of continuous monitoring and surveillance for pathogenic salmonellae. It also demonstrated the detection and prevalence of virulent Salmonella spp. harbored by livestock in South Africa. This study demonstrated the potential risks of pathogenic Salmonella enterica to cause foodborne diseases and zoonotic infections from farm-to-fork continuum using the global one-health approach.


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