Wastewater Use In Agriculture Research Articles

Groundwater Quality and Pollution Index for Heavy Metals in Saïs Plain, Morocco.

Background.Heavy metals contamination threatens groundwater resources in many areas around the world. Various methods to evaluate groundwater quality have been used to characterize sources of contamination and associated parameters. For assessment of heavy metals contamination, calculation of pollution indices is an effective tool for assessing water quality.Objectives.The purpose of the present study was to assess heavy metal concentrations and determine distributions in Saïs plain, Morocco using multivariate analysis.Methods.A total of 144 groundwater samples were collected from twelve stations in Saïs from January 2018 to January 2019, and were analyzed for heavy metals (arsenic, cadmium, total chromium, lead, copper, iron, manganese and zinc) using atomic absorption spectrophotometry.Results.Chromium was found to be a major contaminant affecting water quality in Station 2 (0.057 mg/l) and Station 8 (0.065 mg/l), while elevated levels of iron were found in Station 7 (1.4 mg/l) and Station 11 (0.45 mg/l), and elevated levels of copper (2.9 mg/l) and zinc (3.39 mg/l) were found in Station 11, relative to other heavy metals. The high concentrations of these elements are related to anthropogenic pollutants. The factor analysis showed two components controlling groundwater chemistry. The results of the present study demonstrate that the concentrations of toxic metals, like Fe and Cr, are present in slight excess in one or two stations during one season. The calculated heavy metal pollution level for the groundwater of Saïs plain was below the index limit of 100.Conclusions.The results show that groundwater is not polluted with respect to heavy metals and is acceptable for drinking. However, precautionary measures, such as managing the use of agricultural inputs and avoiding the use of wastewater in agriculture, are recommended in this area.Competing Interests.The authors declare no completing financial interests

Wastewater-irrigated urban vegetable farming in Ethiopia: A review on their potential contamination and health effects

In response to rapid urbanization and increase in population, there is water scarcity and growing demand for water for irrigation. Nowadays, use of wastewater in agriculture for production of veget...

Impact of climate change on raw and untreated wastewater use for agriculture, especially in arid regions

Impact of climate change on raw and untreated wastewater use for agriculture, especially in arid regions

Survey of Listeria monocytogenes contamination of various environmental samples and associated health risks

Listeria monocytogenes is the causative agent of listeriosis, one of the most important foodborne infections. Pre-harvest contamination of ready to eat crops constitutes a potential source of Listeria infections. The aim of this study was to investigate the presence of Listeria spp. and L. monocytogenes via molecular methods in wastewater effluent, sewage sludge (SS) and livestock manure as potential sources of Listeria. The presence of L. monocytogenes in wastewater-irrigated soil and crops was also investigated. Quantitative microbial risk assessment (QMRA) was performed for analysis of Listeria infections for SS workers and farmers. The results of survey showed no presence of L. monocytogenes in wastewater effluent and wastewater-irrigated soil and crop samples, whereas L. monocytogenes was detected in SS (50%) and manure (8%) samples. QMRA analysis using exponential model showed that the likelihood of Listeria infections from direct ingestion of SS to be very low. In contrast, Beta-Poisson dose-response model showed an annual risk of Listeria infections higher than the proposed value of 10−4 per person per year (pppy) by EPA, with the highest risk (4.41 × 10−1 pppy) for SS workers. Based on our results, the agricultural use of wastewater doesn't seem to present risk of Listeria infections for consumers of wastewater-irrigated crops. However, direct ingestion of SS may pose a risk for exposed individuals. The estimated risk values could be further improved by obtaining accurate insights into the prevalence of Listeria infections especially at national or regional level. Further studies are also needed to determine inactivation rate of Listeria in SS-amended soils in arid and semi-arid areas.

Determine the Required Log Reductions of Human Intestinal Helminth Eggs by Waste Stabilization Pond: A Simulation for Wastewater Recycling in Agriculture

Abstract This paper investigates the determined the required log reductions for human intestinal helminth eggs by waste stabilization ponds as simulation as assessing of mitigating health risk to satisfy practice WHO, 2006 guidelines for the safe use of wastewater in agriculture (≤ 0.1 helminth egg/L) to protect the health of children under 15 years was the development of MATLAB, a computer program based waste stabilization ponds design based on parameter uncertainty and 10,000-trial Monte Carlo simulations were developed for a series of anaerobic, facultative and maturation ponds based on 95%-ile of effluent (≤ 0.1 helminth egg/L) which the result in a health-based target. Whereas the influent of the helminth eggs (Nematode) was (932.500 eggs/L). While the treatment provided (100 % reduction/removal) for the overall treatment process with total hydraulic retention time in climatic conditions of Libya it took 36.207 days in the anaerobic pond, facultative pond, first maturation pond and one of the subsequent maturation pond.

Removal of escherichia coli using waste stabilization pond: A simulation in climatic conditions of Libya

The most important determinant when recycling of wastewater for agriculture is that related to public health. This paper investigates the removal of Escherichia Coli/coliform in the waste stabilization pond as simulation as assessing of mitigating health risk. A case study in climatic conditions of Libya. As a result of a computer program based waste stabilization pond design based on parameter uncertainty and 10,000-trial Monte Carlo simulations, were developed for a series of anaerobic, facultative and maturation ponds to produce on a 95%-ile value <1000 E. Coli per 100 ml. While a number of influent of E. Coli bacteria was (156.732×106E. Coli /100ml). Where it decreased was a number of the effluent (10 E. Coli /100ml). Where the efficiency of removal E. Coli bacteria was (99.999 %). And the overall hydraulic retention time it took 89.548 days in the anaerobic pond, facultative pond, first maturation pond and twelve of the subsequent maturation ponds. To satisfy practice 2006 WHO guidelines for the safe use of wastewater in agriculture.

Helminth Eggs Parameter of Water Spinach Agriculture Field in Bandung

The high prevalence of helminth infection in Indonesia had encouraged the government to issue the Regulation of the Minister of Health concerning the Prevention of Soil-transmitted Helminths in 2017. Researches on the presence of helminth eggs in the environment, in soil and water as a media for transmitting the disease, are very few. Aim: The aim was conducted to investigate the potential presence of helminth eggs causing STH infections in two urban agricultural areas in northern and southern part of Bandung City. Methodology and results: Samples of water from the inlet and plantation area, as well as soil and water spinach produced by both regions, were collected and analyzed for the presence of helminth eggs using modified Bailinger methods. The number of helminth eggs of 1–119 eggs/L in water, soil, and vegetable samples. Conclusion, significance, and impact study: The results confirmed that the irrigation water used in both areas has been contaminated by feces. The average number of fecal coli exceeds the allowable value for the irrigation water source based on the Grade 4 of water quality criteria in Indonesia. Variations in the number of helminth eggs found in the samples can be caused by environmental conditions such as temperature, humidity, and soil types. The presence of helminth eggs in irrigation water and land samples exceeds the value recommended by WHO (2006) in the guidelines for the safe use of wastewater for agriculture. It can lead to an increased risk of helminth infection to consumers, agricultural workers, as well as residents around the farmland.

Policy Note: "Addressing Trade-offs to Promote Safely Managed Wastewater in Developing Countries"

Policy Note: "Addressing Trade-offs to Promote Safely Managed Wastewater in Developing Countries"

The Impact of Climate Change on Raw and Untreated Wastewater Use for Agriculture, Especially in Arid Regions: A Review.

Climate change is one of the major challenges of our time that pose unprecedented stress to the environment and threats to human health. The global impacts of climate change are vast, spanning from extreme weather events to changes in patterns and distribution of infectious diseases. Lack of rainfall associated with higher temperatures has a direct influence on agricultural production. This is compounded by a growing population forecasted to expand further with increasing needs for food and water. All this has led to the increasing use of wastewater worldwide. In this review, we more specifically discuss the use of untreated wastewater in agriculture in the Middle East and North Africa (MENA) countries, the most arid region in the world. This presents challenges for agriculture with respect to water availability and increasing wastewater use in agri-food chain. This in turn exerts pressures on the safety of food raised from such irrigated crops. Current practices in the MENA region indicate that ineffective water resource management, lack of water quality policies, and slow-paced wastewater management strategies continue to contribute to a decline in water resources and an increased unplanned use of black and graywater in agriculture. Radical actions are needed in the region to improve water and wastewater management to adapt to these impacts. In this regard, the 2006 WHO guidelines for the use of wastewater contain recommendations for the most effective solutions. They provide a step-by-step guide for series of appropriate health protection measures for microbial reduction targets of 6 log units for viral, bacterial, and protozoan pathogens, but these need to be combined with new varieties of crops that are drought and pest resistant. More research into economic local treatment procedures for wastewater in the region is warranted.

Wastewater Reuse in Agriculture: A Review about Its Limitations and Benefits

For centuries, wastewater has been improperly used in agriculture, presenting potential risks to public health and the environment. In the context of scientific development, and confronted by an increasing water crisis, wastewater reuse merits consideration because the practice helps decrease water use pressure and moderates water pollution. Thus, this article presents a literature review that addresses the effects, both positive and negative, of wastewater use in agriculture, emphasizing the effects on the soil environment. The literature review reveals that, until the 1990s, research studies promoted the use of wastewater for irrigation purposes from a treatment approach, while proposing “end of pipe” conventional solutions. However, more recent research studies (2012–2016) reveal that agricultural reuse significantly affects soil texture properties, while also causing possible alterations of the biomass and microbiota. In addition, research in this period has been oriented to the quantitative evaluation of microbiological risk.

Obstruction and uniformity in drip irrigation systems by applying treated wastewater

ABSTRACT The use of wastewater in agriculture is an alternative to control surface water pollution, and helps to promote the rational use of water. Therefore, the objective of this study was to evaluate the obstruction and uniformity of application of treated wastewater in drip irrigation systems. The study was conducted in a greenhouse at the Universidade Federal de Campina Grande. The treatments were composed by the factorial combination of two factors: three types of water (supply water-ABAST, effluent of a constructed wetland system -WETLAND and upflow of anaerobic reactor effluent followed by constructed wetland system -UASB + WETLAND), and two drip irrigation systems (surface and subsurface), set in a completely randomized design, with four replications. The results indicated that the pH, suspended solids, total iron and coliforms of the WETLAND and UASB + WETLAND treatments represented a severe risk of clogging of drippers; the flow of the emitters increased as the service pressure was increased; values of CUC and CUD in surface and subsurface drip were classified as excellent in ABAST and WETLAND treatments. The degree of clogging reduced as pressure under surface and subsurface drip was increased.

The use of wastewater in livestock production and its socioeconomic and welfare implications.

Although epidemiological studies have found a significant amount of toxins in surface water, a complex link between animals' access to wastewater and associated animal and human welfare losses needs to be explored. The scarcity of safe water has put stress on the utilization of wastewater for crops and livestock production. The access of animals to wastewater is related to the emergence of dangerous animal's diseases, hampering productivity, increasing economic losses, and risking human health along the food chain. This review explores use of wastewater for agriculture, epidemiological evidence of microbial contamination in wastewater, and animal and human welfare disruption due to the use of wastewater for crop and livestock production. More specifically, the review delves into animals exposure to wastewater for bathing, drinking, or grazing on a pasture irrigated with contaminated water and related animal and human welfare losses. We included some scientific articles and reviews published from 1970 to 2017 to support our rational discussions. The selected articles dealt exclusively with animals direct access to wastewater via bathing and indirect access via grazing on pasture irrigated with contaminated wastewater and their implication for animal and human welfare losses. The study also identified that some policy options such as wastewater treatments, constructing wastewater stabilization ponds, controlling animal access to wastewater, and dissemination of necessary information to ultimate consumers related to the source of agricultural produce and wastewater use in animal and crop production are required to protect the human and animal health and welfare.

Métodos de valoración ambiental aplicados a la regeneración y reutilización de aguas residuales en agricultura

El análisis económico y financiero de los proyectos de sistemas de regeneración y reutilización de aguas residuales se ha concentrado frecuentemente en los costes y beneficios privados, tanto por las dificultades metodológicas relacionadas con la estimación de las externalidades, como por la disponibilidad de datos necesarios para su valoración. La consideración de los costes y beneficios ambientales permite una mejora sustancial en el diseño y gestión de los sistemas de regeneración y reutilización de aguas residuales, ya sean públicos o privados. Como consecuencia, también se produce una mejora en la gestión de las inversiones en estos sistemas de tratamiento. El objetivo de este trabajo es presentar unos fundamentos básicos para los principales métodos de valoración ambiental. Y muy especialmente, cuando estos son aplicados en actividades relacionadas con el uso de aguas residuales en agricultura.

A faecal exposure assessment of farm workers in Accra, Ghana: a cross sectional study.

BackgroundWastewater use in urban agriculture is common as a result of rapid urbanisation, and increasing competition for good quality water. In order to minimize risks to farmers and consumers of wastewater irrigated produce the World Health Organization (WHO) has developed guidelines for the safe use of wastewater in agriculture. These guidelines are based on a Quantitative Microbial Risk Assessment (QMRA) model, though the reliability of this model has been questioned due to a lack of primary data. This study aimed to assess the ability of the WHO guidelines to protect farmers’ health, by identifying and quantifying key exposures associated with the transmission of faecal pathogens in wastewater irrigated agriculture.MethodsEighty farmers were observed and interviewed during the dry and wet seasons, and water and soil samples were analysed for the presence of E. coli. STATA 12 was used for descriptive analyses of farmers’ exposure and risk practices, and also to determine risk factors for soil and irrigation water contamination, while the WHO QMRA model and @Risk 6 were used to model farmers’ infection risk to pathogens.ResultsThe results showed that although irrigation water was highly contaminated (5.6 Log E. coli/100 ml), exposure to farm soil (2.3 Log E. coli/g) was found to be the key risk pathway due to soil-to-mouth events. During the observations 93 % of farmers worked barefoot, 86 % experienced hand-to-soil contact, while 53 % experienced ‘soil’-to-mouth events, while no ‘water’ to mouth contacts were observed. On average, farmers were found to have 10 hand-to-mouth events per day. From the indicator based QMRA model the estimated norovirus infection risk to farmers was found to be higher than guidelines set by the WHO.ConclusionsThis study found exposure to soil as the critical pathway of pathogen risk in wastewater farmers, and that this risk exceeded recommended health targets. The study recommends the incorporation of hand-to-mouth events, the use of actual pathogen concentrations, and the use of direct exposure frequencies in order to improve the reliability of risk estimates from QMRA models.

Microbial contamination along the main open wastewater and storm water channel of Hanoi, Vietnam, and potential health risks for urban farmers

The use of wastewater in agriculture and aquaculture has a long tradition throughout Asia. For example, in Hanoi, it creates important livelihood opportunities for >500,000 farmers in peri-urban communities. Discharge of domestic effluents pollute the water streams with potential pathogenic organisms posing a public health threat to farmers and consumers of wastewater-fed foodstuff. We determined the effectiveness of Hanoi's wastewater conveyance system, placing particular emphasis on the quality of wastewater used in agriculture and aquaculture. Between April and June 2014, a total of 216 water samples were obtained from 24 sampling points and the concentrations of total coliforms (TC), Escherichia coli, Salmonella spp. and helminth eggs determined. Despite applied wastewater treatment, agricultural field irrigation water was heavily contaminated with TC (1.3×107colony forming unit (CFU)/100mL), E. coli (1.1×106CFU/100mL) and Salmonella spp. (108 most probable number (MPN)/100mL). These values are 110-fold above Vietnamese discharge limits for restricted agriculture and 260-fold above the World Health Organization (WHO)'s tolerable safety limits for unrestricted agriculture. Mean helminth egg concentrations were below WHO tolerable levels in all study systems (<1egg/L). Hence, elevated levels of bacterial contamination, but not helminth infections, pose a major health risk for farmers and consumers of wastewater fed-products. We propose a set of control measures that might protect the health of exposed population groups without compromising current urban farming activities. This study presents an important example for sanitation safety planning in a rapidly expanding Asian city and can guide public and private entities working towards Sustainable Development Goal target 6.3, that is to improve water quality by reducing pollution, halving the proportion of untreated wastewater and increasing recycling and safe reuse globally.

English

The use of wastewater in agriculture is an alternative means of reducing wastewater release into water sources. This process, known as fertigation is an opportunity to make use of organic matter and other nutrients in wastewater for agricultural productivity. The presence of organic matter in these effluents serves as biofertilizer. Since 19th century in Britain, fertigation had been widely accepted due to the scarcity of water, the large amount of sewage produced and the concern about the final destination of wastewater. However, salinization, contamination of soil and agricultural products with the microbial pathogens and presence of heavy metals may limit the use of wastewaters in agricultural system. Thus, the plantation of agronomic varieties that do not have direct use as human food are optional cultivars, which may not have implications of fertigation with domestic wastewater. Fertigation with wastewater will be a nutritive support for the cultivation of Brachiaria brizantha cv Marandu in cerrado soil that is considered as low fertility soil. Soil microorganisms are fertility indicators. For example, nitrogen fixing bacteria (NFB) and arbuscular mycorrhizal fungi (AMF) has great potential to assist in the development of plant varieties under irrigation with domestic wastewater. These microorganisms are good parameters to be used in the analysis of changes that occur when sewage is applied into the soil. Furthermore, microbes contribute to the structuring of the soil, degradation of organic matter and nutrient availability to the biotic component of soil. Despite the limitations of fertigation with domestic sewage, it is a great alternative to use wastewater for nutritional enrichment to the soil that will be used for planting of agricultural crops of commercial interest. Key words: Brachiaria brizantha, agriculture, salinization, diazotrophic bacteria, mycorrhizal fungi.

Wastewater use in agriculture and potential effects on meso and macrofauna soil

ABSTRACT: The use of wastewater in agriculture has been practiced on an increasing scale over the past decades because of its fertilizing potential and the reduction in demand for surface water and groundwater. However, this practice may bring harm when performed without planning, not respecting the capacity of the soil to recycle organic waste. The most common problems are contamination of surface and groundwater via leaching and runoff, as well as accumulation of nutrients and potentially polluting elements that compromise chemical, physical and biological characteristics of the soil. The biological compartment, represented by the micro, meso and macrofauna, plays an important role in nutrient cycling, decomposition of organic matter, particle movement and transport of materials at different depths, helping to maintain soil physical and chemical characteristics. In this sense, this paper aims to discuss the effect of using different kinds of wastewater in agriculture on soil biology, highlighting strengths and weaknesses, as well as emphasizing the need to conduct investigations that enhance the positive aspects of wastewater use associated with edaphic processes.

A Review of Health Risks and Pathways for Exposure to Wastewater Use in Agriculture.

Background:Wastewater is increasingly being used in the agricultural sector to cope with the depletion of freshwater resources as well as water stress linked to changing climate conditions. As wastewater irrigation expands, research focusing on the human health risks is critical because exposure to a range of contaminants must be weighed with the benefits to food security, nutrition and livelihoods.Objectives:The goal of this paper was to review research examining health risks and exposure pathways associated with wastewater irrigation to identify research trends and gaps.Methods:We conducted a review of the literature and identified a total of 126 studies published from 1995 to 2013. Findings were summarized based on several themes including types of exposure pathways, wastewater contaminants, methodological approaches and the geographical distribution of research.Results:Only 23 studies used epidemiological methods, while most research applied alternative methods to estimate risk, such as quantitative risk assessment models or comparisons of crop contamination to established guidelines for wastewater reuse. A geographic breakdown demonstrated a focus on microbiological contaminants in specific regions such as sub-Saharan Africa and Southeast Asia, despite growing chemical risks associated with rapid urbanization and industrialization that may change the types and distribution of wastewater contaminants.Conclusions:To provide a more comprehensive understanding of the health risks of wastewater use in agriculture, future research should consider multiple exposure routes, long-term health implications, and increase the range of contaminants studied, particularly in regions heavily dependent on wastewater irrigation.Citation:Dickin SK, Schuster-Wallace CJ, Qadir M, Pizzacalla K. 2016. A review of health risks and pathways for exposure to wastewater use in agriculture. Environ Health Perspect 124:900–909; http://dx.doi.org/10.1289/ehp.1509995

A Farm to Fork Risk Assessment for the Use of Wastewater in Agriculture in Accra, Ghana.

The need to minimise consumer risk, especially for food that can be consumed uncooked, is a continuing public health concern, particularly in places where safe sanitation and hygienic practices are absent. The use of wastewater in agriculture has been associated with disease risks, though its relative significance in disease transmission remains unclear. This study aimed at identifying key risk factors for produce contamination at different entry points of the food chain. Over 500 produce and ready-to-eat salad samples were collected from fields, markets, and kitchens during the dry and wet seasons in Accra, Ghana, and over 300 soil and irrigation water samples were collected. All samples were analysed for E. coli, human adenovirus and norovirus using standard microbiological procedures, and real time RT-PCR. Finally, critical exposures associated with microbial quality of produce were assessed through observations and interviews. The study found that over 80% of produce samples were contaminated with E. coli, with median concentrations ranging from 0.64 to 3.84 Log E. coli/g produce. Prepared salad from street food vendors was found to be the most contaminated (4.23 Log E. coli/g), and that consumption of salad exceeded acceptable health limits. Key risk factors identified for produce contamination were irrigation water and soil at the farm level. Storage duration and temperature of produce had a significant influence on the quality of produce sold at markets, while observations revealed that the washed water used to rinse produce before sale was dirty. The source of produce and operating with a hygiene permit were found to influence salad microbial quality at kitchens. This study argues for a need to manage produce risk factors at all domains along the food chain, though it would be more effective to prioritise at markets and kitchens due to cost, ease of implementation and public health significance.

Wastewater use in agriculture in Djibouti: Effectiveness of sand filtration treatments and impact of wastewater irrigation on growth and yield of Panicum maximum

In the arid climate of Djibouti, salt concentrations of up to 1200mgL−1 have been recorded in well water, attributed to the overexploitation of aquifers. Farmers are therefore turning to untreated wastewater as a source of water for crop irrigation. The authors undertook a study in two phases. In the first phase they tested the field transposition of an experimental water treatment method previously laboratory-tested on a small scale. The pilot device was composed of an adaptor basin for the wastewater, a filter basin filled with sand and a storage basin to collect and hold the treated water. Transfer of waters from basin to basin was gravitational. The physicochemical and microbiological sleek raw water parameters were determined weekly for 7 weeks. Monitoring of chemical oxygen demand concentrations decreased from 445±5.76mgL−1 O2 on the first day of the experiment to 101±1.34mgL−1 O2 on the 21st day. The removal of total coliforms attained more than 99.6% as of day 21. The performance of the microbiological treatment of waters obtained through sand filtration is therefore of definite interest in agriculture. In the second phase the effect of different irrigation waters (untreated wastewater (WW), treated wastewater (TW), saline well water (SW), mixed water (MW) and potable water (PW)) on growth and yield of the grass Panicum maximum were also compared. The use of WW and TW in irrigation effectively increased stem height and aerial part dry matter compared to other treatments, while irrigation with SW and PW showed the lowest measured values. Depending on their performance, the effectiveness of the treated waters can be ranked in the following increasing order: TW; WW>MW>PW; SW. The performance of the TW treatment can be explained by its higher nutritive content, especially in N.