AFFORDABLE WATER QUALITY ANALYSIS: A PROPOSED FRAMEWORK FOR THE DEVELOPMENT AND REGULATION OF LOW-COST WATER QUALITY MONITORING DEVICES

Access to adequate supplies of potable water is a key driver of human health. Physical and chemical treatment processes are frequently necessary to make water safe to drink. Monitoring of water before, during, and after treatment is an essential component of the provision of potable water, and most aspects of water quality monitoring require electronic devices to augment human senses. Every nation sets rules governing the treatment and monitoring of drinking water, in an attempt to continuously ensure potability of drinking water supplies. Presently, however, the regulations governing the design of common electronic devices for water quality monitoring are developed and published by just two organizations – the US Environmental Protection Agency (EPA) and the International Organization for Standardization (ISO). The implications of this regulatory situation on drinking water quality monitoring, particularly in low-resource settings, are largely (perhaps completely) unaddressed in existing literature. Turbidity, which may be summarized as cloudiness in a body of liquid due to the scattering of light by particles suspended in that body, is internationally recognized as a simple and useful monitoring parameter for drinking water treatment. Using turbidity as an exemplar, this dissertation examines the structure of regulations governing the design of water quality monitoring devices, and the potential impact that regulatory structure has on the design, fabrication, and marketing of water quality monitoring devices, including both closed-source and open-source technology. National turbidity monitoring requirements for several nations, and the turbidity guidelines promulgated by the World Health Organization, are compared. The EPA and ISO turbidimeter regulations are also examined in relation to these national and international turbidity monitoring requirements. Design variables and requirements are identified which are generally necessary to ensure a properly functioning turbidimeter, but which are not explicitly stated in EPA and ISO turbidimeter regulations. Aspects of the commercial turbidimeter market, and EPA and ISO turbidimeter regulations, which are likely burdensome for water quality monitoring efforts in low-resource settings (such as rural communities in developing countries), are explored – perhaps chief among these being cost. While production of open-source turbidimeter designs provides a potential solution for turbidity monitoring in low-resource settings, open-source turbidimeter design efforts are currently far from able to meet global needs. To provide supplementary regulatory requirements for EPA and ISO turbidimeter standards, and to spur the development of market-ready open-source turbidimeter designs, a framework titled the Affordable Water Quality Analysis (AWQUA) device development is proposed. It consists of a turbidity-specific regulatory section, and a general water quality monitoring device development guidance section. Proper use of this guidance section is intended to strengthen open-source water quality monitoring device development efforts and encourage the production of device documentation suitable to demonstrate compliance with the regulatory section. An important contribution of this dissertation effort is the development and detailed description of four different examples of novel, low-cost, open-source water quality monitoring devices that motivated the proposed supplementary framework, informed its design, and serve to illustrate its application. First, a low-cost, open-source handheld turbidimeter based on a simple digital light detection sensor is detailed and discussed. The design, fabrication, and testing of this device served as a motivator for the development of the proposed supplementary turbidimeter development guidelines proposed. The turbidimeter nearly meets international regulatory guidelines, was fully described in a peer-reviewed publication, and is believed to be the most detailed open-source design of a digital turbidimeter publicly available (at the time of this writing) and yet contains several subtle but critical design flaws that are unaddressed in current national and international turbidimeter regulations. This prototype thus motivated and informed the design of the proposed new regulatory framework. Subsequently, three other promising open-source water quality monitoring designs were developed, fabricated, and evaluated under the AWQUA Framework: (1) a second low-cost open-source handheld turbidimeter, based on a highly precise light-to-voltage analog sensing setup; (2) a highly compact low-cost open-source inline turbidimeter, designed for continuous immersive monitoring of turbidity in surface waters; and (3) a low-cost open-source jar tester – a device used to evaluate certain physical and chemical treatments employed in drinking water treatment to reduce turbidity. These designs and the associated framework that grew from them are contributions toward the provision of “Affordable Water Quality Analysis” (AWQUA) capabilities for communities in low-resource settings

Web based water turbidity monitoring and automated filtration system: IoT application in water management

Water supplied to residential areas is prone to contaminants due to pipe residues and silt, and therefore resulted in cloudiness, unfavorable taste, and odor in water. Turbidity, a measure of water cloudiness, is one of the important factors for assessing water quality. This paper proposes a low-cost turbidity system based on a light detection unit to measure the cloudiness in water. The automated system uses Intel Galileo 2 as the microprocessor and a server for a web-based monitoring system. The turbidity detection unit consists of a Light Dependent Resistor (LDR) and a Light Emitting Diode (LED) inside a polyvinyl chloride (PVC) pipe. Turbidity readings were recorded for two different positionings; 90° and 180° between the detector (LDR) and the incident light (LED). Once the turbidity level reached a threshold level, the system will trigger the filtration process to clean the water. The voltage output captured from the designed system versus total suspended solid (TSS) in sample water is graphed and analyzed in two different conditions; in total darkness and in the present of ambient light. This paper also discusses and compares the results from the above-mentioned conditions when the system is submerged in still and flowing water. It was found that the trends of the plotted graph decline when the total suspended solid increased for both 90° and 180° detector turbidimeter in all conditions which imitate the trends of a commercial turbidimeter. By taking the consideration of the above findings, the design can be recommended for a low-cost real-time web-based monitoring system of the water quality in an IOT environment

Development of a LAMP assay for detection of Leishmania infantum infection in dogs using conjunctival swab samples

Background: Leishmania infantum infections in dogs play a crucial role in the transmission of pathogens causing visceral leishmaniasis to humans in the Gansu province, northwest China. To be able to control zoonotic transmission of the parasite to humans, a non-invasive loop-mediated isothermal amplification (LAMP) assay to specifically detect L. infantum infections in dogs was developed. Methods: The primers used in the LAMP assay were designed to target kinetoplast DNA minicircle sequences of the L. infantum isolate MCAN/CN/90/SC and tested using DNA isolated from promastigotes of different Leishmania species. The LAMP assay was evaluated with conjunctional swab samples obtained from 111 and 33 dogs living in an endemic and a non-endemic region of zoonotic visceral leishmaniasis in the Gansu province, respectively. The LAMP assay was also compared with conventional PCR, ELISA and microscopy using conjunctional swab, serum and bone marrow samples from the dogs, respectively. Results: The LAMP assay detected 1 fg of L. infantum DNA purified from cultured promastigotes which was 10-fold more sensitive than a conventional PCR test using Leishmania genus-specific primers. No cross reaction was observed with DNA isolated from promastigotes of L. donovani, L. major, L. tropica, and L. braziliensis, and the L. infantum reference strain MHOM/TN/80/IPT1. The L. infantum-positive rates obtained for field-collected samples were 61.3%, 58.6%, 40.5% and 10.8% by LAMP, PCR, ELISA and microscopy, respectively. As only one out of the 33 samples from control dogs from the non-endemic region of zoonotic visceral leishmaniasis was positive by the LAMP assay and the PCR test, the observed true negative rate (specificity) was 97% for both methods. Conclusion: This study has shown that the non-invasive, conjunctional swab-based LAMP assay developed was more sensitive in the detection of leishmaniasis in dogs than PCR, ELISA and microscopy. The findings indicate that the LAMP assay is a sensitive and specific method for the field surveillance of domestic dogs, particularly of asymptomatic canines, in ZVL-endemic areas in western China

The Effect of Granular Activated Carbon Pretreatment and Sand Pretreatment on Microfiltration of Greywater

Around the world, water scarcity is driving people to practice water reuse. One form of water reuse is the recycling of greywater, which is household wastewater excluding toilet waste. With adequate treatment, greywater may be recycled onsite for applications that do not require potable water, such as irrigation or toilet flushing. Membrane filtration (including microfiltration (MF)) is one option for greywater treatment. The small footprint, modular nature, and predictable performance of MF make it an attractive option. However, direct MF of greywater can lead to rapid membrane fouling. This thesis investigated two possible pretreatments for reducing membrane fouling and improving effluent water quality: granular activated carbon (GAC) and silica sand. To test these pretreatments, synthetic greywater (representing effluent from bathroom sinks and showers) was prepared using a recipe from NSF/ANSI Standard 350 and then treated using a pressure-driven MF membrane in a dead-end configuration. Samples were taken before pretreatment, after pretreatment, and after microfiltration and analyzed for four parameters: turbidity, total organic carbon (TOC), chemical oxygen demand (COD), and surfactants. Membrane flux was also monitored. The results indicate that for the given experimental conditions, GAC and sand pretreatments improved effluent water quality but did not significantly reduce membrane fouling. GAC was more effective than sand at removing surfactants, while sand was more effective than GAC at removing turbidity. GAC and sand were comparable in their ability to remove TOC and COD once the flows through the columns had stabilized (i.e., within one minute). After microfiltration (MF), samples that had been pretreated with GAC exhibited the lowest level of contamination in all categories. Nevertheless, according to guidelines published by the US Environmental Protection Agency the final treated effluent was unsuitable for direct reuse because it exceeded the recommended threshold for TOC. (Currently there is no recommended threshold for water reuse regarding surfactants.) These results imply that physical treatment alone may be insufficient to remove contaminants from greywater, especially dissolved contaminants such as surfactants, which are prevalent in greywater. Future research could investigate the effect of different operating conditions (e.g., longer pretreatment contact time, upflow configuration through GAC, different membrane types), different pretreatment setup (e.g., dual layer pretreatment media with both GAC and sand), and incorporation of a biological component (i.e., allowing biofilm to develop on filter media or using a membrane bioreactor instead of strict membrane filtration)

Development of an Integrated Algal/Seed Clam Unit Using Recirculation, Computer-Control, and Fluidization Technologies.

Computer-control, recirculation, and fluidized-bed technologies were utilized in the integration of a land-based seed clam nursery system with an algae production system to improve northern quahog seed production (6-10 mm). The components of the integrated system included: a seawater treatment system; an algae production system; a seed clam nursery system; and a computer-control system. Treatment of the incoming seawater for the integrated system included filtration (20, 1, and 0.5 micron), chlorination, UV sterilization, and ozonation. During the summer months a chiller was used to maintain the treated seawater at approximately \rm 20\sp\circ C. The diatom, Chaetoceros muelleri, was cultured in an algae production system which consisted of two 550 L tanks, covered with clear lexan to prevent the entrance of airborne contaminants. An air pump aerated and mixed the cultures and \rm CO\sb2 was injected into the airline to maintain pH. The biomass of the algal cultures was estimated using a HACH 1720C turbidimeter. Cultures were harvested when the estimated biomass concentration was greater than the control program set point. Harvest volume was set at 90% tank volume (450 L). After harvesting, the tanks were refilled with the treated seawater and resupplied with nutrients. The harvested algae was the food source for the land-based nursery seed clam system. The nursery system consists of six clear cylindrical upweller units (5 cm diameter, 76 cm in height); a 400 L feed reservoir, a solids separator, a bead filter \rm (0.03\ m\sp3) and a chiller. A high water flow velocity was maintained in the upweller units to fluidize the seed mass. Fluidizing the seed mass allows for the high density culture of seed by providing a more uniform distribution of food, and transporting waste material away from the seed mass. Individual upweller units obtained a biomass density of approximately 5.5 g whole wet weight clam per \rm cm\sp2 and greatest growth rates were observed when provided an effective daily algal ration of approximately 2% g dry weight algae per g whole wet weight clam

Influence of Human Activities on the Water Quality of Ogun River in Nigeria

The quality of Ogun River in south-west, Nigeria was investigated by a field survey; covering the dry season and rainy season. Water samples were collected from seven sites (including an Abattoir, a market, residential community and a brewery); analysis of the physico-chemical parameters using standard methods and their environmental effects on the river were investigated. Generally, the value/degree of dissolved oxygen, phosphate, BOD, COD, pH, temperature, hardness from the sites during the rainy and dry seasons were compared with the World Health Organization (WHO) standards for domestic and commercial water. The traces of some hazardous physical and chemical impurities in the river were above the acceptable limits; and thereby pose a health risk to several rural communities who rely heavily on the river primarily as their source of domestic water. The study revealed a need for continuous pollution monitoring and management program of surface water in Nigeria. Keywords: surface water, water quality, water pollution, field survey, physico-chemical analysi

Marine Citizen Science: Current State in Europe and New Technological Developments

Marine citizen science is emerging with promising opportunities for science, policy and public but there is still no comprehensive overview of the current state in Europe. Based on 127 projects identified for the North Sea area we estimate there might be as much as 500 marine and coastal citizen science projects running in Europe, i.e., one marine citizen science project per 85 km of coastline, with an exponential growth since 1990. Beach-based projects are more accessible and hence most popular (60% of the projects), and the mean duration of the projects is 18–20 years. Current trends, topics, organizers, aims, and types of programme in terms of participation are presented in this overview. Progress in marine citizen science is specially enabled and promoted through technological developments. Recent technological advances and best practise examples are provided here, untapping the potential of smart mobile apps, do-it-yourself (DIY) technologies, drones, and artificial intelligence (AI) web servicesVersión del edito

Drinking Water Quality and Sanitation Issues: A Survey of a Semi-Urban Setting in Nigeria

An assessment on the drinking water quality from major source (borehole) and household in a semi-urban setting in Nigeria was carried out. Structured questionnaire was administered to randomly selected households in seven zones of the municipality to determine the common method of collection and transportation, storage, and sanitation practices. Water samples collected were subjected to laboratory analyses for physico-chemical and microbial properties. The result of the physico-chemical analysis when compared against the World Health Organization (WHO) and Standard Organization of Nigeria (SON) drinking water quality benchmark revealed that the water samples were within standards for consumable water except for the presence of feacal contamination. The result revealed that before water can be totally considered safe for drinking, further treatment is required at the household level due to fecal contamination, and water safety concerns are also highlighted. The result translates to the fact that compliance assessment with standards and impact assessment studies in determining the fate of pollutants is necessary at all level

Modification of a Biosand Water Filter for Household Treatment of High Turbidity Water

One billion of the poorest people in the world today do not have access to improved drinking water. Without treatment, fecal contamination results in an overwhelming disease burden. A long term best practice solution will take decades to implement. In the meantime, approximately 5 million children under five die each year from gastrointestinal diseases. This tragedy can be alleviated by household water treatment. Household Water Treatment and safe Storage systems (HWTS) provide an interim solution. While many low cost and simple technologies exist, none of them are effective against high suspended solids concentrations (\u3e50 NTU). Previous short-term field research by others has considered modifying a BioSand water Filter (BSF), to include pretreatment through an upper sand layer in order to extend the run cycle of the primary filter, enabling complete ripening to occur. In this research program, one control and twelve configurations of modified filters were setup in the laboratory. Water was chemically conditioned to provide worst case scenario treatment by adjusting pH, TDS, and particle dispersion. Sample water was passed through each filter daily, and monitored for DO, turbidity, flow rate, and E. coli concentrations. The results indicate that pretreatment is not necessarily beneficial under all water quality conditions. Recommendations include a description of conditions under which the modification may be beneficial, and optimized pretreatment design criteria. Regardless of water quality conditions, it was found that changing the operational guidelines for filter use can significantly improve treatment efficiency, without complicating the filter design. Design guidelines for an unmodified filter coupled with operational guidelines are provided, in order to obtain sufficient quantities of the best possible water quality under high turbidity conditions. This will enable the BSF to be used in high turbidity conditions and still significantly improve the drinking water quality. It is hoped that this will decrease the disease burden and loss of life in many of the world\u27s poorest communities