Wastewater Reuse For Irrigation Research Articles

Treated wastewater reuse for irrigation: A feasibility study in Portugal

In an increasing water scarcity and climate-vulnerable global context, treated wastewater represents a vital alternative water source, thereby enhancing resource sustainability. Despite its potential, only roughly 2.5 % of the treated wastewater is reused in the European Union, with Portugal's reuse rate being only 1.2 % in 2022. Considering this framework, this study evaluates the feasibility of increasing wastewater reuse in Portugal by focusing on the Tagus River and Ribeiras do Oeste Basins. The regional assessment identified eight key wastewater treatment plants (WWTP) with significant potential for irrigation reuse in the agriculture and tourism sectors. Analysing costs, quality requirements, and technological options, this study considered five treatment lines, incorporating filtration and disinfection methods. The findings indicate that reclaimed water costs may range from 0.02€/m3 to 0.83€/m3, being competitive with other water sources and significantly lower than desalination processes (up to 1.66€/m3). Distribution investments and energy consumption are primary cost drivers, suggesting a relocation of WWTP closer to end-users as a cost-saving strategy. The proposed reuse projects could quadruple regional reuse rates and double the national rate, mitigating water needs for over 2000 ha of agricultural land and golf courses. This study underscores the importance of treated wastewater reuse in addressing water scarcity, advocating for WWTP decentralisation, strategic investments and policy interventions to achieve cost-effective goals. The methodologies and insights presented offer valuable guidance for other regions facing similar challenges, promoting a paradigm shift towards circular water resource management.

Assessment of Urban Wastewater Reuse for Irrigation – Environmental Feasibility and Sustainable Development – A Case Study in El Jadida

Assessment of Urban Wastewater Reuse for Irrigation – Environmental Feasibility and Sustainable Development – A Case Study in El Jadida

Process Performance and Nutrient Removal in Fish Processing Wastewater Using a Membrane Bioreactor (MBR) Unit for Reuse for Irrigation

This study investigated the removal of nitrogen and phosphates in fish processing wastewater through process optimization of a membrane bioreactor (MBR) treatment unit. Raw process wastewater was collected from the Makindi fish farm and was pre-filtered through a mesh of 0.8 mm. The experiment was conducted at a lab scale using commercial Polyethersulfone (PES) membranes submerged in the MBR unit. The pre-filtered wastewater sample was added into a denitrification (anoxic) tank. The process was conducted through continuous recirculation between the aeration and the anoxic tank to enhance the removal of nitrogenous compounds. The recirculation flow rate was 10L/h. A hydraulic residence time (HRT) of approximately 22-25h was maintained, and the aeration rate in the aerobic tank was 100L/min. Aluminum sulphate AI2(SO4)318H2O was added continually into the anoxic tank and with constant stirring to enhance the removal of phosphates. A removal rate of 85±2% for NH4+-N, 84±1% for NO3- -N, and 69±3% for PO43--P was obtained. The nutrient concentration in the effluent was successfully reduced to an acceptable level with both nitrogenous compounds and phosphate concentrations obtained within the range of < 30 mg/L and ≤ 5 mg/L as per the WHO guidelines for wastewater reuse for irrigation. The results showed a successful process optimization that can be applied to ensure optimized performance of the MBR unit thus improve its effectiveness for the treatment of fish processing wastewater. The study therefore recommends process optimization as a tool for effective removal of nutrients in the MBR system thus making it a potential recycling approach for treatment of fish processing wastewater for reuse for irrigation purposes.

Progress on the Use of Hydroponics to Remediate Hog Farm Wastewater after Vermifiltration Treatment

Hog farm wastewater may require novel biological treatment techniques to improve efficiency and reduce costs. Previous studies combining vermifiltration with downstream hydroponics showed the need for a balanced wastewater nutrient content, particularly the nitrogen-to-phosphorus ratio. Here, a deep-water culture hydroponic system, growing lettuce as model culture, was used to remediate hog farm wastewater after an initial vermifiltration stage, aiming to produce an effluent suitable for irrigation. Supplemented vermifiltered wastewater (SVW) with added nutrients was tested against unsupplemented vermifiltered wastewater (VW) over 35 days, using a synthetic nutrient solution (NS) as a control. Supplementation was shown to improve lettuce growth, light use efficiency, and water use efficiency. Nutrient analysis over time showed a better-balanced phosphorus and nitrogen removal in SVW than in VW; in all treatments nitrogen and phosphorus content was reduced to legally acceptable levels for treated wastewater reuse in irrigation: nitrate 5 mgN L−1 in VW and undetectable in SVW and NS; ammonia undetectable in all treatments; and total phosphorus 2.4 mg L−1 in SVW, 0.9 mg L−1 in NS and undetectable in VW. Coliforms increased in VW and SVW during hydroponic treatment, which should be solved by disinfection. Overall, combining vermifiltration with downstream hydroponic culture proved to be a promising treatment to remediate nutrients in hog farm effluent to make it suitable to be reused for irrigation.

Influence of Swine Wastewater Irrigation and Straw Return on the Accumulation of Selected Metallic Elements in Soil and Plants

Treated livestock wastewater reuse for irrigation and straw return in arid regions have become common practices worldwide. However, many uncertainties still exist regarding the effects of the returning straw sizes on heavy metal accumulation in soil and plants under treated livestock wastewater irrigation. In a pot experiment growing maize and soybean, large (5–10 cm), medium (1–5 cm), and small (<1 cm) sizes of wheat straw were amended to assess the changes in Cu and Zn distribution in the rhizosphere, bulk soils, and plants. Groundwater and swine wastewater were used as irrigation water resources. The results showed that irrigation with swine wastewater significantly reduced soil pH and increased the concentration of soil-available potassium. Concentrations of Cu in soil were more sensitive to swine wastewater and straw application than those of Zn in soil. Swine wastewater irrigation increased the accumulation of Cu and Zn in plants with higher concentrations of Zn, while straw return tended to inhibit this increase, especially when a small size of straw was employed. In addition to providing a reference for revealing the interaction mechanism between swine wastewater irrigation and straw return, this study proposes feasible solutions to improve the efficiency of agricultural waste recycling and realize sustainable agricultural development.

A Numerical Study of the Efficiency of the Sono Galvano-Fenton Process as a Tertiary Treatment Technique for the Wastewater Reuse in Agriculture

In the present study, the Sono-Galvano-Fenton process is studied numerically as a tertiary treatment process for treated wastewater reuse in irrigation, with in situ generation of the Fenton’s reagent and catalyst, i.e., H2O2 and Fe2+. The sonochemical pathway is examined as a source of hydrogen peroxide under the pre-optimized condition of acoustic frequency, 200 kHz. The macroscopic model accounting for the performance of the single acoustic cavitation bubble and the bubble population density is combined with the Fe/Cu galvanic cell operating in acidic conditions (pH 3), following a cumulative and instantaneous production approach in terms of Fenton’s reagent. The combination is optimized based on the rate of hydroxyl radicals generated by the Galvano-Fenton process, as a non-selective powerful oxidant against recalcitrant pollutants, then considering the synergetic effect of the hybrid process in terms of HO● pumped sonochemically and via the Fenton based pathway, treated using simulations of the isolated processes then their combined configuration following both aforementioned approaches.

Navigating quality, health and environmental risk: A novel framework for wastewater resource recovery products

The aim of this study is to establish a universal framework for the quality monitoring and risk evaluation of resource recovery products. This innovative framework addresses challenges inhibiting the uptake of wastewater resource recovery products by addressing quality, health, and environmental concerns. In contrast to the current European regulations, which primarily govern wastewater reuse for irrigation and limited nutrient recovery cases, this framework has a broader scope that includes various recovery scenarios, such as cellulose fibers, biocomposites, building materials and biochar. The framework is structured as three pillars: (i) ensuring access to a product of good quality, (ii) safeguarding public health, and (iii) environmental protection. It applies quantitative microbial risk assessment (QMRA) and quantitative chemical risk assessment (QCRA) to enable transparent monitoring and reporting for different actors across resource recovery value chains. The framework offers a means to cluster and leverage existing regulations, bridging gaps to ensure comprehensive oversight across various unregulated resource recovery scenarios and products.

Evaluating the potential of treated municipal wastewater reuse in irrigation and groundwater recharge; 5-year contaminant transport modeling

Evaluating the potential of treated municipal wastewater reuse in irrigation and groundwater recharge; 5-year contaminant transport modeling

Reuse of wastewater for irrigation of coriander in Morocco: Evaluation of effects on crop growth parameters

AbstractCurrently, the convergence of climate change, population growth, and deteriorating water quality has triggered a scarcity of freshwater resources, presenting substantial hurdles for agricultural endeavors. Consequently, repurposing treated wastewater for agricultural use is gaining prominence. This strategy offers a noteworthy advantage by furnishing an alternative water source, distinct from conventional freshwater, for agricultural irrigation. The considered irrigation water categories encompass treated wastewater, sewage treated with supplementary fertilization, treated water of a specific quality, and treated water quality fortified with fertilizer. An assessment of the treated wastewater extracted from the Imzouren‐Bni Bouayach treatment facility was undertaken, encompassing scrutiny of its physical, chemical, and bacteriological attributes. This analysis yielded measurements for a range of parameters, including pH, temperature, electrical conductivity, dissolved oxygen, suspended matter, biochemical oxygen demand, chemical oxygen demand, total phosphorus, nitrate, nitrite, total coliforms, fecal coliforms, and fecal streptococci. These measurements align with acceptable thresholds for direct discharge and are following Morocco's established water quality standards tailored for irrigation. In light of the soil analysis, the soil is classified as alkaline, with a pH of 8.2, and displays low salinity, evidenced by an electrical conductivity of 2.42 mS/cm. Furthermore, the soil exhibits deficiencies in organic matter and essential nutrients, with carbon content measuring 0.84%, organic matter at 1.45%, nitrogen at 0.07%, phosphorus at 10.6 mg/L, and potassium at 56.5 mg/L. The utilization of treated wastewater for irrigation purposes bestows the crop with a dependable water supply, ensuring stability in its growth.

Numerical modeling of groundwater flow and nitrate transport in karst and wastewater irrigated agricultural and forest landscapes, PA, USA

AbstractUnderstanding the influence of treated wastewater reuse for irrigation on nitrate groundwater contamination in karstic landscape is critical for developing long‐term management plans and assessing the sustainability of these practices. The Pennsylvania State University has been operating a secondary treated wastewater effluent irrigation site—the “Living Filter”—since the 1960s. The objective of this study is to develop a regional groundwater flow and nitrate transport model to assess the impact of treated wastewater and disposal of large volumes of wastewater for irrigation of agricultural and forested lands on nitrate groundwater contamination in a karst landscape in the Spring Creek Watershed in central Pennsylvania. The modular three‐dimensional finite‐difference ground‐water flow model (MODFLOW) was used to construct the groundwater flow model of the local aquifer and simulate three‐dimensional regional changes in the water table over time. The simulation of nitrate fate and transport in the aquifer was conducted by developing a groundwater mass transport model using MODFLOW and a modular three‐dimensional transport multi‐species model (MT3DMS). The calibrated groundwater model yielded a root mean square error of 5.41 ft for the area of irrigation and 24.67 ft for the entire modeled area. Results of the calibrated model show the extension of a nitrate plume over most of the study area with concentrations below 10 mg·L−1 under the current 2015 setting and the long‐term 2035 scenario of increased irrigation rates. The nitrate migration was dominated by the presence of two high conductivity groundwater troughs adjacent to the study area resulting in a near steady‐state total mass since the 1990s.

Mitigating risks and maximizing sustainability of treated wastewater reuse for irrigation

Scarcity of freshwater for agriculture has led to increased utilization of treated wastewater (TWW), establishing it as a significant and reliable source of irrigation water. However, years of research indicate that if not managed adequately, TWW may deleteriously affect soil functioning and plant productivity, and pose a hazard to human and environmental health. This review leverages the experience of researchers, stakeholders, and policymakers from Israel, the United-States, and Europe to present a holistic, multidisciplinary perspective on maximizing the benefits from municipal TWW use for irrigation. We specifically draw on the extensive knowledge gained in Israel, a world leader in agricultural TWW implementation. The first two sections of the work set the foundation for understanding current challenges involved with the use of TWW, detailing known and emerging agronomic and environmental issues (such as salinity and phytotoxicity) and public health risks (such as contaminants of emerging concern and pathogens). The work then presents solutions to address these challenges, including technological and agronomic management-based solutions as well as source control policies. The concluding section presents suggestions for the path forward, emphasizing the importance of improving links between research and policy, and better outreach to the public and agricultural practitioners. We use this platform as a call for action, to form a global harmonized data system that will centralize scientific findings on agronomic, environmental and public health effects of TWW irrigation. Insights from such global collaboration will help to mitigate risks, and facilitate more sustainable use of TWW for food production in the future.

Wastewater quality index (WWQI) as an indicator for the assessment of sanitary effluents from the oil and gas industries for reliable and sustainable water reuse

With the development of numerous industries, the increasing use of water resources and the discharge of pollutants into the environment, particularly industrial wastewater, has become extremely important. The purpose of this study was the assessment of sanitary wastewater treatment plants attributed to the oil and gas industries as reliable and sustainable water resources based on the wastewater quality index (WWQI). The findings revealed that the facilities under investigation effectively process and discharge their effluents following the Environmental Protection Organization's standards. Springtime has the maximum removal in wastewater treatment plants (WWTPs), with typical removal values of COD and BOD5 of 96.1% and 97.1%, while pH in the effluent of these WWTPs was 7.22, and DO in the range of 1–6.3 mg/L throughout this period. In addition, fecal coli removal efficiencies were 98.6%, respectively. Finally, the wastewater treatment system in the four refineries investigated has resulted in a considerable decrease in microbiological and organic pollutants in conformity with environmental regulations permitting wastewater reuse for irrigation and agriculture, as well as discharge into adsorption wells. However these treatment plants perform poorly in terms of cumulative and WWQI models (13.86–16.05), it is clear from the results and discussion of this research that the results of the treated wastewater from the under-investigation plants comply with the Environmental Protection Organization of Iran's standards required for discharge to surface water or reuse in agricultural land irrigation. Still, the treatment system should be constantly audited and improved to reach a higher rank according to the WWQI.

Evaluation of the operation of the stabilization pond for agricultural irrigation purposes

Improving the quality of residual water and increasing agricultural production is necessary to achieve food sovereignty in water deficit conditions. The research was carried out to evaluate the operation of the precision lagoon for agricultural irrigation purposes by determining the geometric and hydraulic parameters, kinetic coefficients and dissolved Oxygen using the Streeter & Phelps model. The main results indicate the presence of a facultative lagoon with a hydraulic retention time of 6.7 days, flow rate of 1 641,6 m3 day-1 contributed by 41 312 inhabitants, solar penetration of 0.20 m, presence of green algae, 0,36 day-1 deoxygenation coefficient, 0,60 day-1 reaeration coefficient, 0,09 day-1 sedimentation coefficient, 0,45 day-1 total removal coefficient, dissolved Oxygen of the effluent of 2 mg L-1, initial dissolved oxygen deficit of the influent and effluent of 8,4 mg L-1 and 2,43 mg L-1 respectively. These indicate that the effluents can be used as wastewater reuse for irrigation of cooked food crops according to the recommendations of the World Health Organization. Keywords: wastewater, kinetic coefficients, dissolved Oxygen, hydraulic parameters, reuse.

An Assessment of Irrigation Water Quality with Respect to the Reuse of Treated Wastewater in Al-Ahsa Oasis, Saudi Arabia

Irrigation water quality is important to sustain agricultural productivity. The primary irrigation water sources in Al-Ahsa Oasis, KSA, are groundwater wells, mixed with treated wastewater and agricultural drainage. This study sought to evaluate irrigation water quality in Al-Ahsa Oasis with the aid of using irrigation water quality indices (IWQIs). One hundred and forty-eight different water samples were collected from various irrigation water resources throughout Al-Ahsa Oasis. The investigated physiochemical characteristics include pH, temperature, TDS, EC, turbidity, free chlorine, total hardness, cations (Na, K, Ca, Mg), anions (Cl, CO3, HCO3, SO4), organic matter indices (DO, BOD, COD), and nutrients (NH4, NO3, PO4). The IWQIs used in this study include salinity hazard, sodium adsorption ratio (SAR), Kelly’s ratio (KR), soluble sodium percentage (SSP), Permeability index (PI), residual sodium carbonate (RSC), and magnesium hazard (MH). The results indicated that treated wastewater mixed with groundwater is acceptable for irrigation. Spatial variations in irrigation water quality throughout Al-Ahsa are associated with water resources. For instance, groundwater mixed with agricultural drainage has the highest values of TDS, cations, and anions, whereas the lowest values were reported for treated wastewater, reflecting the good efficiency of wastewater treatment plants. The IWQI results revealed that 4.1% and 62.1% of the investigated irrigation water samples were considered good (class III) and satisfactory (class IV) for irrigation, respectively, whereas 33.8% of the collected water samples fall within the severe irrigation restrictions. Moreover, 79.7% of the investigated water samples were classified to have high to very high salinity hazards (C3, C4) and medium to high sodium hazards (S2, S3). Regular monitoring and assessment of treated water quality and wastewater treatment plant efficiency are important factors in achieving the sustainability of treated wastewater reuse in irrigation and consequently food security.

Occupational Health Risk Assessment for Wastewater Treatment and Reuse in Kanpur, India.

The treatment and reuse of wastewater for irrigation can lead to occupational health risks for sewage treatment plant (STP) workers and farmers. Sanitation Safety Planning (SSP) is an approach which can be used to measure and mitigate these risks. This paper explores what impact a novel secondary treatment process, consisting of an integrated permeate channel (IPC) membrane combined with a constructed wetland plus, has on the occupational health risks compared with the existing activated sludge wastewater treatment process and reuse system in Kanpur, Uttar Pradesh. A mixed methodology was used, which included key informant interviews, structured observations, and E. coli analysis. This data was used to undertake semi-quantitative risk assessments following the SSP approach. The novel secondary treatment increased the number of health risks which the STP workers were exposed to, but the severity of the risks was lower. This was due to the differences in treatment processes and infrastructures. The number of health risks for the farmers decreased both in number and severity. For their children, the severity of the health impacts decreased. These changes were due to the increase in the microbiological quality of the irrigation water. This study highlights the potential of using a semi-quantitative risk assessment to assess the occupational health impacts of using novel treatment technologies.

Wastewater reuse in agriculture: A review of soil and crops parasitic contamination, associated health risks and mitigation approach

Background: Wastewater reuse in agriculture can potentially result in adverse health implications including parasitic diseases spread. Trichuris, Ascaris, and Giardia are major pathogenic parasites of concern associated with this practice. This review investigated their occurrence in wastewater, and environmental components reached through wastewater application, including irrigated soil and grown crops. Exposure pathways and evidence for health risks were also explored. Methods: Several databases (Google Scholar, PubMed, Science Direct, Scopus, Web of Science, and ResearchGate) and other sites were searched for published literature up to 2021. The searched keywords include wastewater reuse, soil-transmitted helminths (STHs), Ascaris, Trichuris, Giardia, crop contamination, soil contamination, health risk, epidemiological studies, exposure pathways, and risk mitigation. Overall, 160 papers have been yielded. After screening for relevance, 60 studies were considered for inclusion. Results: Giardia, Ascaris, and Trichuris were frequently detected in wastewater with up to 5×105 cysts/L and 5.73×103 eggs/L. Concentrations of 750 eggs/100 g and 2.8×104 cysts/100 g were reported in wastewater irrigated soil. Ascaris was reported in irrigated crops with up to 70 eggs/kg versus 6.6×103 cysts/kg for Giardia, depending on the type of crops. Epidemiological studies provided evidence supporting the increase of ascariasis, trichuriasis, and giardiasis diseases related to the exposure to wastewater irrigated soil and crops. Conclusion: The findings suggest that wastewater reuse in agriculture leads to contamination of soil, and crops with pathogenic parasites, increasing health risks in the exposed groups. To remedy this issue, protection measures, including a multi-barrier approach, can be applied to mitigate the health risks engendered by wastewater reuse for irrigation.

The role of regular evaluation of wastewater quality in minimizing health consequences due to wastewater reuse in irrigation

The role of regular evaluation of wastewater quality in minimizing health consequences due to wastewater reuse in irrigation

Impact of urban wastewater reuse for irrigation on hydro-agro-ecological systems and human health risks: A case study from Musi river basin, South India

Use of wastewater for irrigation remains a disagreement among policymakers and researchers. However, it is fact that wastewater may contains many contaminants including heavy metals that can negatively impact ecosystem health. The present study is an attempt to assess the impact of wastewater use on soil, crop, and water and associated health risks based on exposure risk model where wastewater irrigation is more prominent in Hyderabad city, South India by analyzing physical (pH, EC, turbidity, oil and grease, TSS), chemical (Zn, Cr, Pb, Mn, Cu and Ni) and biological (BOD, COD, DO) parameters. The results indicated that biological contamination and the presence of heavy metals with the rising groundwater salinity. Low to moderate cancer risks are also inferred if humans are exposed to these waters for a long time. However, the study suggests continuous monitoring of the water and soil quality in wastewater irrigated areas to take remedial actions for sustainable agriculture development and protect ecosystems.

Impact assessment of treated wastewater reuse for irrigation: growth potential and development of lettuce in Al Hoceima province, Morocco

The reuse of treated wastewater for agricultural practices is becoming increasingly important due to the growing demand for the transition to a circular economy. It has the major advantage of providing an alternative resource to the conventional water used for agricultural irrigation. The main objective of this work is to study, through tests on experimental installations, the effect of the type of irrigation water on the growth and development of lettuce. The types of irrigation water were prepared from purified wastewater, treated wastewater plus fertilizer, conventional water, and conventional water plus fertilizer. The physicochemical analyzes of wastewater from the Imzouren-Bni Bouayach WWTP resulted in different values of the parameters measured (pH, temperature, electrical conductivity, oxygen below, suspended matter, BOD5, COD, nitrate, nitrite and phosphorus) which fall within the limited range of direct discharges and comply with Moroccan standards for the quality of water intended for irrigation. The results of the characterization of the soil showed that it is a basic soil (pH= 8.5), unsalted (electrical conductivity = 2.43 ms/cm) and poor in organic and nutrient elements (Carbon 0.8%, organic matter 1.46%, nitrogen 0.06 mg/l, phosphorus 10.5 mg/l, potassium 56.4 mg/l.) The main results of the plant analysis show that the production level of this study crop irrigated with conventional water is similar to that of this study crop irrigated with treated wastewater. In other words, irrigation with treated wastewater allows lettuce to guarantee irrigated production at least at the level of conventional water. Another motivated addition of nitrogen, phosphate and potash mineral supplement in the treated wastewater improves the production potential of lettuce.

Antibiotic resistance genes and bacterial diversity: A comparative molecular study of treated sewage from different origins and their impact on irrigated soils

Present study aims to investigate how is soil affected following irrigation with treated effluents of different origins by analysing the bacterial diversity, metabolic diversity and antibiotic resistance genes (ARGs). Comparative analysis with previously reported ARGs in effluents was performed to understand the mobility of ARGs from treated wastewater to the irrigated soil with respect to the control soil regimen. Acinetobacter, Burkholderia and Pseudomonas were observed as the most abundant genera in all the samples. The metabolic gene abundance of all the samples suggests a prominent contribution to natural mineral recycling. Most abundant ARGs observed encode resistance for clindamycin, kanamycin A, macrolides, paromomycin, spectinomycin and tetracycline. Treated effluent reuse did not appear to enhance the ARG levels in soils in most cases except for institutional treatment site (M), where the ARGs for aminoglycosides, β-lactams and sulfonamides were found to be abundantly present in both treated effluent and the irrigated soil. This study finds the importance of wastewater treatment from different origins and the impact of treated wastewater reuse in irrigation. This study also emphasises on the better understanding of ARGs mobility from water to soil.