Wastewater For Crop Irrigation Research Articles

Biogeochemical Behavior of Lead and Nickel as Influenced by Phosphatic Fertilizer Applied to Rice (Oryza sativa L.) Cultivars Grown under City Effluent Irrigation

The hydrology of arid to semi-arid regions is substantially different from that in humid regions due to scarce hydrological data distributions with dry climates and strong evapo-transpirative conditions. In the perspective of global water shortage, food security for all of the living beings has become a matter of great concern. Efficient use of water resources both in urban and rural environments and application of non-conventional water resources for irrigation are becoming increasingly important. In order to sustain crop production, the re-use of treated wastewater for irrigation of crops could be a good option. A pot experiment was set up to evaluate effects of different doses of di-ammonium phosphate (DAP) fertilizer on lead (Pb) and nickel (Ni) phyto-availability by two cultivars of rice irrigated with city effluent. Experiment was conducted in a completely randomized design (CRD) each with three replications. The results showed effective immobilization of Pb with applied phosphatic fertilizer. Among all of the tested treatments, the most effective treatment to reduce phyto-availability of Pb was T4 (248 kg P ha−1) due to antagonistic interaction. While Ni showed inconsistent behavior with both synergistic and antagonistic interaction (biphasic) to applied phosphorus (P) rates. Data regarding various growth parameters such as plant height, number of tillers, shoot and root dry weights, straw and grain yields, and physiological attributes such as total chlorophyll contents, photosynthetic and transpiration rates showed significant (p ≤ 0.05) responses to P application. An increasing trend was revealed in determined parameters with increased P application rates, with the exception of decreased plant height. The conclusion of the present remedial approach indicated that addition of P can significantly reduce the risks of rice grown under city effluent irrigation containing high Pb and Ni contents.

Ecotoxicological risk assessment of wastewater irrigation on soil microorganisms: Fate and impact of wastewater-borne micropollutants in lettuce-soil system

The implementation of the new Water Reuse regulation in the European Union brings to the forefront the need to evaluate the risks of using wastewater for crop irrigation. Here, a two-tier ecotoxicological risk assessment was performed to evaluate the fate of wastewater-borne micropollutants in soil and their ecotoxicological impact on plants and soil microorganisms. To this end, two successive cultivation campaigns of lettuces were irrigated with wastewater (at agronomical dose (not spiked) and spiked with a mixture of 14 pharmaceuticals at 10 and 100 µg/L each) in a controlled greenhouse experiment. Over the two cultivation campaigns, an accumulation of PPCPs was observed in soil microcosms irrigated with wastewater spiked with 100 μg/L of PPCPs with the highest concentrations detected for clarithromycin, hydrochlorothiazide, citalopram, climbazole and carbamazepine. The abundance of bacterial and fungal communities remained stable over the two cultivation campaigns and was not affected by any of the irrigation regimes applied. Similarly, no changes were observed in the abundance of ammonium oxidizing archaea (AOA) and bacteria (AOB), nor in clade A of commamox no matter the cultivation campaign or the irrigation regime considered. Only a slight increase was detected in clade B of commamox bacteria after the second cultivation campaign. Sulfamethoxazole-resistant and -degrading bacteria were not impacted either. The irrigation regimes had only a limited effect on the bacterial evenness. However, in response to wastewater irrigation the structure of soil bacterial community significantly changed the relative abundance of Acidobacteria, Chloroflexi, Verrucomicrobia, Beta-, Gamma- and Deltaprotebacteria. Twenty-eight operational taxonomic units (OTUs) were identified as responsible for the changes observed within the bacterial communities of soils irrigated with wastewater or with water. Interestingly, the relative abundance of these OTUs was similar in soils irrigated with either spiked or non-spiked irrigation solutions. This indicates that under both agronomical and worst-case scenario the mixture of fourteen PPCPs had no effect on soil bacterial community.

Socio-economic Impacts of Wastewater Irrigation on Local People in the Outskirts of Chandigarh Urban Areas

The use of wastewater for irrigation is a valuable strategy to maximize available water resources, but the fringe quality of the water can present innumerable challenges. Water scarcity pushes the farmers to use wastewater for irrigation as an available alternate source. The present study was conducted in the peri-urban areas of well-planned city Chandigarh with a primary objective to obtain information about the current status of wastewater use for irrigation and socio-economic reasons for using wastewater from the farmers’ perspective. Therefore, nineteen (19) villages were selected nearby four seasonal choes around the study sites. At the site, we found that 64% of farmers were using freshwater, and the remaining farmers were using wastewater for crop irrigation. In this study, two contrasting perceptions were observed among the farmers about wastewater irrigation. Results indicated that farmers have a piece of relatively good knowledge about the inappropriate quality of wastewater and its adverse effects. Although they were concerned about the health, environmental and social impacts of wastewater yet, they believed that using this water resource is economically profitable for them. Thus, the present study highlighted the need for planning to improve wastewater treatment along with appropriate policies and methods to enhance farmers’ commitment to environmental conservation and human health.

Investigation of Drainage and Waste Water Quality for the Improvement of Technological Treatment Solutions

The purpose of this work is to study the qualitative indicators of drainage and waste water from irrigated areas in order to justify the treatment technology. The research was carried out within the Bagayevskaya irrigation system located in the Rostov Region, the Russian Federation. The location of the well is confined to the second terrace above the floodplain of the Western Manych River. The chemical composition of drainage water allows us to refer this water category to the sulfate class, the sodium group of a partially mixed cationic composition. The type of drainage water is sulfate sodium and sulfate calcium. In drainage runoff, there are no chlorine-magnesium waters, even in the autumn period. The content of biogenic elements during the observation period in the investigated wells was within the following limits: phosphates – from 0.04 to 0.75 mg/dm3, ammonium ions – from 0.07 to 1.35 mg/dm3, and nitrates – from 0.05 to 0.43 mg/dm3. An improved treatment method of drainage and waste water for crop irrigation is proposed. It includes the removal of mechanical impurities and petroleum products (in the first stage) on coalescent modules installed directly on the discharge or drainage channel in the form of a framework module and the release of heavy metal ions, organic substances and excess salts (in the second stage) in the sorption block, which includes three sorption layers – S-VERAD, zeolite and quartz in an equal ratio, placed in a grid of a filter cassette of the cassette-holding device.

Nitrate, phosphate and boron content in wastewater for crop irrigation in Mezquital Valley, Hidalgo

Introduction: Mexico City generates an approximate volume of wastewater of 57 m3 s-1, the wastewater is conduct by the drainage network: main channel-west interceptor-central emitter, and conducted to Hidalgo State, during it course, an important volume is poured into irrigation channels and is used for crop irrigation in the Mezquital Valley.Method: in this study, nitrate (NO3-), phosphate (PO4-3) boron (B3+) and chloride (Cl-) content in 188 wastewater samples was determined. The objective was to assessment the risk of toxicity by specific ions (B3+ and Cl-) and the nutrients content (N, P, K, Ca y Mg) in wastewater used for crop irrigation.Results: the nitrate (NO3-) concentration was very heterogeneous (CV=59.83 %) and this was attributed to the lixiviation of nitrogen fertilizers. The maximum phosphate (PO4-3) value was 65.7 mg L-1, and its concentration was attributed to the discharge of household wastewater. The boron concentration (B3+) was less than 1.88 mg L-1. The risk of toxicity due to the use of wastewater in irrigation may cause a decrease the yield of sensitive crops, such as beans.Conclusion: untreated wastewater used in irrigation in Mezquital Valley, may cause toxicity problems in some crops; the nitrate and phosphate concentrations in wastewater of the Mexico City-Mezquital Valley drainage network were high, and these were attributed to the discharges of domestic and industrial wastewaters and to agricultural drainage, high concentrations of nitrate and phosphate represent a risk for aquatic organisms due to pollution and the possible eutrophication of water bodies. The risk of toxicity by B3+ and Cl-can have a negative effect on the germination and yield of bean crops.

Contaminations of Soil and Two Capsicum annuum Generations Irrigated by Reused Urban Wastewater Treated by Different Reed Beds.

Background: In order to save potable water, this study aims to evaluate the contamination of soil and Capsicum annuum L. (chilli) watered with urban wastewater (sewage) pre-treated by various wetland systems. Methods: The appropriateness of wetland outflow for irrigation when applying reused wastewater with high contamination of minerals and pathogens was assessed. The impact of wastewaters pre-treated by various wetlands on soil and harvest was tested in terms of mineral and biological contamination risk. Results: The wetlands met the standards for irrigation water for most water quality variables. However, the thresholds for key water quality parameters were significantly (p < 0.05) exceeded. The highest values for total coliforms, ammonium-nitrogen, phosphorus and potassium were 157,072 CFU/100 mL, 8.5 mg/L, 5.0 mg/L, and 7.0 mg/L, respectively. The harvest was moderately polluted only by zinc according to vegetable quality standards (threshold of 50 mg/kg). Zinc concentrations for Filters 2, 4, 6, 7 and 8 were 35.8, 60.6, 65.1, 65.5 and 53.2 mg/kg, respectively. No bacterial contamination was detected. Conclusions: Treatment of domestic wastewater applying constructed wetlands and subsequent recycling of the treated wastewater for irrigation of crops is a good substitute to the traditional application of drinking water for irrigation purposes.

Sorption, plant uptake and metabolism of benzodiazepines

Reuse of treated wastewater for irrigation of crops is growing in arid and semi-arid regions, whilst increasing amounts of biosolids are being applied to fields to improve agricultural outputs. Due to incomplete removal in the wastewater treatment processes, pharmaceuticals present in treated wastewater and biosolids can contaminate soil systems. Benzodiazepines are a widely used class of pharmaceuticals that are released following wastewater treatment. Benzodiazepines are represented by a class of compounds with a range of physicochemical properties and this study was therefore designed to evaluate the influence of soil properties on the sorption behaviour and subsequent uptake of seven benzodiazepines (chlordiazepoxide, clonazepam, diazepam, flurazepam, oxazepam, temazepam and triazolam) in two plant species. The sorption and desorption behaviour of benzodiazepines was strongly influenced by soil type and hydrophobicity of the chemical. The partitioning behaviour of these chemicals in soil was a key controller of the uptake and accumulation of benzodiazepines by radish (Raphanus sativus) and silverbeet (Beta vulgaris). Benzodiazepines such as oxazepam that were neutral, had low sorption coefficients (Kd) or had pH-adjusted log octanol-water partition coefficients (log Dow, pH6.3) values close to 2 had the greatest extent of uptake. Conversely, benzodiazepines such as flurazepam that had an ionised functional groups and greater Kd values had comparatively limited accumulation in the selected plant species. Results also revealed active in-plant metabolism of benzodiazepines, potentially analogous to the known metabolic transformation pathway of benzodiazepines in humans. Along with this observed biological transformation of benzodiazepines in exposed plants, previously work has established the widespread presence of the plant signalling molecule γ-amino butyric acid (GABA), which is specifically modulated by benzodiazepines in humans. This highlights the need for further assessment of the potential for biological activity of benzodiazepines following their plant uptake.

Small-scale risk assessment of transmission of parasites from wastewater treatment plant to downstream vegetable farms.

The aim of the present study was to simultaneously investigate parasitic contamination of treated wastewater and downstream vegetable farms that are irrigated with treated sewage, during a year. (Oo) Cysts and eggs of parasites are resistant to most of routine wastewater treatment process. Irrigation of vegetables farms with either treated wastewater or illegally use of raw wastewaters enhances the risk of contamination with enteric pathogens. The treated wastewater samples were taken after chlorination from a wastewater treatment plant located at the south of Tehran. In addition, 60 vegetable samples (5 samples from each farm) were collected from the selected downstream farms that routinely used treated wastewater for irrigation of crops. Parasitological tests were performed using Ziehl-Neelsen, conventional lugol's iodine staining and direct microscopical examination. Parasites including free living larvae, eggs of Toxoascaris leonina, egg of Toxocara sp. Trichuris sp, Trichostrongylus sp and amoeboid trophozoite were seen in 5/12 (41.7%) of vegetable samples gathered during a year. There was no statistically significant correlation between the season and parasitic contamination of the vegetables (P= 1). Furthermore, parasitic contamination was observed in 7/12 (53.8%) of treated wastewater samples. The correlation between season and parasitic contamination of treated wastewater was evaluated that the results showed a higher contamination of treated wastewater in spring and autumn (P<0.05). Fisher's exact test also showed that there was no significant correlation between parasitic contaminations of vegetable samples and treated wastewater according to seasonal change. The results showed parasites in both treated wastewater plant and downstream crops farms that suggests the public health importance of the quality of water resources that routinely used for irrigation of vegetable farms.

Influence of the sewage irrigation on the agricultural soil properties in Tongliao City, China

Increasing shortages of fresh water has led to greater use of treated wastewater for irrigation of crops. This study evaluates the spatial variability of soil properties after irrigation with wastewater and freshwater. Geostatistical techniques were used to identify the variability of soil properties at the different sites. A set of physical and chemical soil properties were measured including total nitrogen (TN), total phosphorus (TP), organic matter (OM) and soil moisture. The TN concentration levels varied from 567 to 700 mg·kg−1, while OC levels ranged from 7.3 to 16.3 mg·kg−1 in wastewater-irrigated zones. The concentration levels of TP were between 371.53 and 402.88 mg·kg−1 for the wastewater-irrigated sites. Wastewater irrigation resulted in higher TN, TP and OM concentrations by 18.4%, 8% and 25%, respectively. The highest TN and OM occurred along the wastewater trunk. It was also observed that nitrogen concentrations correlate with the soil’s organic matter. The increase of salinity may be associated with the increase of pH, which might suggest that a reduction of pH will be beneficial for plant growth due to the decrease of salinity. The average concentrations of nitrogen in topsoil were higher than those in subsurface soils in irrigated areas. Such differences of the N profile might be due to variations in organic matter content and microbial populations. Consistent with TN and OM, soil C:N decreased significantly with an increase of depth. This phenomenon possibly reflects a greater degree of breakdown and the older age of humus stored in the deeper soil layers. The analysis of pH levels at different depths for the three sites showed that pH values for wastewater irrigation were slightly lower than the controlled sites at the same depths.

Estimation of norovirus and Ascaris infection risks to urban farmers in developing countries using wastewater for crop irrigation

A quantitative microbial risk analysis-Monte Carlo method was used to estimate norovirus and Ascaris infection risks to urban farmers in developing countries watering their crops with wastewater. For a tolerable additional disease burden of <or=10(-4) DALY loss per person per year (pppy), equivalent to 1 percent of the diarrhoeal disease burden in developing countries, a norovirus reduction of 1-2 log units and an Ascaris egg reduction to 10-100 eggs per litre are required. These are easily achieved by minimal wastewater treatment-for example, a sequential batch-fed three tank/pond system. Hygiene improvement through education and regular deworming are essential complementary inputs to protect the health of urban farmers.

Soil Nitrogen Balance under Wastewater Management: Field Measurements and Simulation Results

The use of treated wastewater for irrigation of crops could result in high nitrate-nitrogen (NO(3)-N) concentrations in the vadose zone and ground water. The goal of this 2-yr field-monitoring study in the deep silty clay loam soils south of Dodge City, Kansas, was to assess how and under what circumstances N from the secondary-treated, wastewater-irrigated corn reached the deep (20-45 m) water table of the underlying High Plains aquifer and what could be done to minimize this problem. We collected 15.2-m-deep soil cores for characterization of physical and chemical properties; installed neutron probe access tubes to measure soil-water content and suction lysimeters to sample soil water periodically; sampled monitoring, irrigation, and domestic wells in the area; and obtained climatic, crop, irrigation, and N application rate records for two wastewater-irrigated study sites. These data and additional information were used to run the Root Zone Water Quality Model to identify key parameters and processes that influence N losses in the study area. We demonstrated that NO(3)-N transport processes result in significant accumulations of N in the vadose zone and that NO(3)-N in the underlying ground water is increasing with time. Root Zone Water Quality Model simulations for two wastewater-irrigated study sites indicated that reducing levels of corn N fertilization by more than half to 170 kg ha(-1) substantially increases N-use efficiency and achieves near-maximum crop yield. Combining such measures with a crop rotation that includes alfalfa should further reduce the accumulation and downward movement of NO(3)-N in the soil profile.

Preliminary testing of a rapid coupled methodology for quantitation/viability determination of helminth eggs in raw and treated wastewater

The use of raw and treated wastewater for irrigation of crops is a common practice in Mexico. In force since January 1997, the Water Quality Norms for helminth ova refer only to the number of eggs that can be present in the irrigation water, and ignore the assessment of viability because the conventional techniques are not suitable for routine application. However, since viability is of prime importance in the epidemiology of parasitic infections, work was done for the development of a rapid and reliable method to detect a metabolic activity or a physiological characteristic related to viability. As a result, a vital staining procedure was developed and validated, and it was coupled with two rapid quantitative procedures previously assessed, therefore, permitting the determination of the total number of helminth eggs and, simultaneously, the viable and non-viable fraction. The average recovering efficiency of the rapid quantitative methods is 54% for raw wastewater and 77% for treated wastewater; the staining technique for viability is equally reliable (within the 95% confidence limits) as the conventional in vitro procedure; the overall test takes from 4 to6 h to be completed when processing up to four samples at the same time, and the cost per sample (for unrecoverable materials) ranges from US$2.50 to $4.00.

Developing human health-related chemical guidelines for reclaimed wastewater irrigation

We examined the methodology of developing globally applicable human health-related chemical guidelines of using wastewater for crop irrigation. Two approaches may be used to develop pollutant loading guidelines: (a) preventing pollutant accumulation in waste receiving soil and (b) maximizing soil's capacity to assimilate, attenuate, and detoxify harmful chemicals. Pollutant loading rates based on the first approach are in agreement with the fundamental principle of maintaining ecological balances in soil. But numerical limits usually are very stringent and it is difficult for communities to meet these requirements. Recommendations derived with the second approach represent the maximum permissible loadings beyond which pollutant levels in the soil may be harmful to the exposed population. A method employing the second approach was evaluated. Preliminary pollutant loading limits for land application of wastewater are derived by considering the food chain transfer of pollutants via intake of grain, vegetable, root/tuber, and fruit grown on wastewater-affected soils.

Developing human health-related chemical guidelines for reclaimed wastewater irrigation

We examined the methodology of developing globally applicable human health-related chemical guidelines using wastewater for crop irrigation. Two approaches may be used to develop pollutant loading. Guidelines: (a) preventing pollutant accumulation in waste receiving soil and (b) maximizing soil's capacity assimilate, attenuate, and detoxify harmful chemicals. Pollutant loading rates based on the first approach are in agreement with the fundamental principle of maintaining ecological balances in soil. But numerical limits usually are very stringent and it is difficult for communities to meet these requirements. Recommendations derived with the second approach represent the maximum permissible loadings beyond which pollutant levels in the soil may be harmful to the exposed population. A method employing the second approach was evaluated. Preliminary pollutant loading limits for land application of wastewater are derived by considering the food chain transfer of pollutants via intake of grain, vegetable, root/tuber, and it grown on wastewater-affected soils.

Appropriate Wastewater Treatment and Reuse in Morocco – Boujad: A Case Study

Reuse of wastewater for crop irrigation is essential to sustain agricultural growth in a country such as Morocco where water resources are scarce due to the hot, arid climate. However few towns in Morocco have sewage treatment facilities and reuse with untreated wastewater is therefore widespread, and the public health risks from excreta related disease high. A suitable treatment system to provide safe water for irrigation is the use of waste stabilisation ponds, which provide an effluent high in microbiological quality and also high in fertilizer value due to the large amounts of algae which are normally discharged. It was therefore decided to implement an integrated waste stabilisation pond, effluent reuse system as a demonstration scheme of the advantages, both in terms of improved crop productivity and public health of the local community. The town of Boujad in Kouribga Province was selected as a suitable site and this paper describes the background to the development.

Water Regime and Nitrogen Fertilization for Rhodes Grass Irrigated with Municipal Waste Water on Sand Dune Soil

AbstractThe use of municipal waste water for crop irrigation has advantages in increasing water supply and reducing the need for fertilization application. The objective of this research was to develop management for using secondary effluent for crop irrigation while reducing pollution hazards.A field experiment was conducted on a sand dune soil during 1978 and 1979 to determine the water requirement and fertilizer needs of Rhodes grass (Chloris gayana Kunth). There were four irrigation treatments, each at two levels of N fertilizer. The grass was irrigated with municipal effluent that received secondary treatment in settling ponds. The N concentration in the waste water used was about 18 mg/liter, which did not fully supply the needs of the crop. When 250 kg N/ha was added as (NH4)2SO4, an optimum dry matter yield of 12.0 metric tons/ha was obtained when irrigation was applied on the basis of 0.8 pan factor. Higher rates of fertilization and water application resulted in N seepage below the root zone. Any additional water resulted in increased drainage.Rhodes grass proved to be an efficient remover of N from effluent, and also prevented deep seepage and ground‐water pollution.