Impact Of Wastewater Irrigation Research Articles

Soil properties evaluation under different irrigation sources in the Semi-arid Region of Kandahar, Afghanistan

‌Wastewater reuse is a non-conventional source of water containing high amounts of nutrients but also other undesirable components. However, little is known about the impact of wastewater irrigation on farmland soil properties, particularly in Afghanistan. Therefore, this paper reports for the first time a comprehensive understanding of the presence and effect of soil properties under wastewater irrigation and freshwater irrigation in Kandahar, Afghanistan. Accordingly, the properties of soil were evaluated by collecting soil samples from the sites of Haji-Arab (HA), Bala-Karz (BKZ), Mahal-e-Nejat (MN), and Char-Bagh (CB) in Kandahar province. The agricultural fields at the HA, BKZ, and MN sites are irrigated with wastewater, while at the CB site farms are entirely irrigated by freshwater. The results of this study revealed that the lowest pH and maximum EC levels were recorded in the BKZ soil samples, followed by the HA, MN, and CB soil samples. The soil texture class was silt loam and sandy loam at the wastewater-irrigated and freshwater-irrigated sites, respectively. Discoveries from this study have identified implications for informing policymakers on the need for appropriate wastewater treatment systems and regulations to ensure the safe and sustainable use of wastewater for irrigation purposes.

Impact of wastewater irrigation on physical health of soil and yield of marigold (Tagetes patula L. cv. Pusa deep)

A field experiment was conducted to find out the impact of wastewater irrigation on physical and microbiological soil health in marigold (Tagetes patula L. cv. Pusa deep) based on FDR sensor at Water Technology Centre farm of ICAR-Indian Agricultural Research Institute, New Delhi during period of 2020-2021. Eight treatments T-1: Groundwater irrigation scheduled at 25% MAD (v =27%); T-2: Groundwater irrigation scheduled at 50% MAD (v =22.5%) T-3: Groundwater irrigation scheduled at 75% MAD (v= 18%); T4: Groundwater irrigation scheduled as per farmers practice/recommended POP; T-5: Wastewater irrigation scheduled at 25% MAD (v= 27%); T-6: Wastewater irrigation scheduled at 50% MAD (v= 22.5%); T-7: Wastewater irrigation scheduled at 50% MAD (v= 18%); T-8: Wastewater irrigation scheduled as per farmers practice/recommended POP were laid out in a Randomized Block Design (RBD) with three replications. Results indicated that soil physical properties such as bulk density, saturated hydraulic conductivity and porosity at both the sol depths of 0-15 and 15-30 cm in marigold were significantly not changed due to application of wastewater irrigations scheduled at various range of MAD and with the use of FDR sensor. Significantly higher population density of faecal coliform bacteria was observed in treatment plot T-7 where wastewater irrigations were applied at MAD 50% as compared to groundwater irrigations. Moreover, the yield of marigold came to be high in wastewater irrigated plots compared to groundwater. Thus, short-term application of wastewater has less impact and the different ranges of MAD can be used for further studies.

Impact of wastewater irrigation on chemical properties of soil and flower quality of marigold (Tagetes patula L. cv. Pusa deep)

A field experiment was conducted to find out the impact of wastewater irrigation on physical and microbiological soil health in marigold (Tagetes patula L. cv.Pusa deep) based on FDR sensor at Water Technology Centre farm of ICAR-Indian Agricultural Research Institute, New Delhi during period of 2020-2021. Eight treatments T-1: Groundwater irrigation scheduled at 25% MAD (v=27%); T-2: Groundwater irrigation scheduled at 50% MAD (v =22.5%) T-3: Groundwater irrigation scheduled at 75% MAD (v= 18%);T4: Groundwater irrigation scheduled as per farmers practice/recommended POP; T-5: Wastewater irrigation scheduled at 25% MAD (v= 27%); T-6: Wastewater irrigation scheduled at 50% MAD (v= 22.5%); T-7: Wastewater irrigation scheduled at 50% MAD (v= 18%); T-8: Wastewater irrigation scheduled as per farmers practice/recommended POP were laid out in a Randomized Block Design (RBD) with three replications. Results indicated that soil chemical properties such as pH, organic carbon, EC, NPK and heavy metalat depth of 0-15 cm in marigold. As soil pH (7.80), EC (0.24 to 0.31 dS/m), OC (0.38), NPK and the concentration of heavy metals (Ni, Cd, Cr, Pb) were significantly higher in the treatment T6 where wastewater irrigations were scheduled at 50% MADas compared to groundwater irrigations. Moreover, the quality and grade of marigold came to be high in wastewater irrigated plots compared to groundwater. Thus, short-term application of wastewater has less impact over soil and gives better results in crop growth and quality but, the long-term application of wastewater may affect the chemical properties of the soil which can be analysed with different ranges of MAD (maximum allowable deficit) need to be studied.

Impact of wastewater irrigation on chemical composition and heavy metals accumulation in soil (study case: Helwan-El Saff area)

Impact of wastewater irrigation on chemical composition and heavy metals accumulation in soil (study case: Helwan-El Saff area)

Does Irrigation with Treated and Untreated Wastewater Increase Antimicrobial Resistance in Soil and Water: A Systematic Review.

Population growth and water scarcity necessitate alternative agriculture practices, such as reusing wastewater for irrigation. Domestic wastewater has been used for irrigation for centuries in many historically low-income and arid countries and is becoming more widely used by high-income countries to augment water resources in an increasingly dry climate. Wastewater treatment processes are not fully effective in removing all contaminants, such as antimicrobial resistant bacteria (ARB) and antimicrobial resistance genes (ARGs). Literature reviews on the impact of wastewater irrigation on antimicrobial resistance (AMR) in the environment have been inconclusive and mostly focused on treated wastewater. We conducted the first systematic review to assess the impact of irrigation with both treated or untreated domestic wastewater on ARB and ARGs in soil and adjacent water bodies. We screened titles/abstracts of 3002 articles, out of which 41 were screened in full text and 26 were included in this review. Of these, thirteen investigated irrigation with untreated wastewater, and nine found a positive association with ARB/ARGs in soil. Out of thirteen studies focused on treated wastewater, six found a positive association with ARB/ARGs while six found mixed/negative associations. Our findings demonstrate that irrigation with untreated wastewater increases AMR in soil and call for precautionary action by field workers, their families, and consumers when untreated wastewater is used to irrigate crops. The effect of irrigation with treated wastewater was more variable among the studies included in our review, highlighting the need to better understand to what extent AMR is disseminated through this practice. Future research should assess factors that modify the effect of wastewater irrigation on AMR in soil, such as the degree and type of wastewater treatment, and the duration and intensity of irrigation, to inform guidelines on the reuse of wastewater for irrigation.

Biorefinery potential of sustainable municipal wastewater treatment using fast-growing willow

The use of willow plantations can be a sustainable approach for treating primary municipal wastewater, potentially reducing both the environmental and economic burdens associated with conventional treatment. However, the impact of wastewater irrigation upon the willow biorefinery potential has not yet been established. To investigate this effect, three-year-old field grown willows were harvested from plots kept as either controls or irrigated with primary municipal wastewater effluent at 29.5 million L ha−1 yr−1. Biomass compositional analysis, ionic liquid pretreatment and enzymatic saccharification were assessed and differential abundance of persistent extractable phytochemicals was evaluated using untargeted metabolite profiling. Glucan significantly increased by 8% in wastewater treated trees, arabinose and galactose were significantly decreased by 8 and 29%, respectively, while xylose, mannose and lignin content were unaltered. Ionic liquid pretreatment and enzymatic saccharification efficiencies did not vary significantly, releasing >95% of the cell wall glucose and recovering 35% of the lignin. From a total of 213 phytochemical features, 83 were significantly depleted and 14 were significantly enriched due to wastewater irrigation, including flavonoids and lignan derivatives. Considered alongside increased biomass yield from wastewater irrigation (+200%), lignocellulosic bioenergy yields increased to 8.87 t glucose ha−1 yr−1 and 1.89 t ha−1 yr−1 recovered lignin, while net extractives yields increased to 1.48 t ha−1 yr−1, including phytochemicals of interest. The maintenance of glucose accessibility after low-cost ionic liquid pretreatment is promising evidence that sustainable lignocellulose bioenergy production can complement wastewater treatment. Untargeted metabolite assessment revealed some of the phytochemical toolkit employed by wastewater irrigated willows, including accumulation of flooding and salinity tolerance associated flavonoids glabraoside A and glabrene. The extractable phytochemicals underpin a novel high biomass phenotype in willow and, alongside lignocellulosic yields, could help enhance the economic feasibility of this clean wastewater treatment biotechnology through integration with sustainable biorefinery.

Impact of wastewater irrigation on groundwater in the Lahore region and contamination source identification

Abstract Organic pollutants in groundwater samples were analyzed for the very densely populated ‘Lahore’ city and its surrounding ‘Mangamandi’ areas of Punjab-Pakistan, where composite (industrial and urban) wastewater is used for cultivation of crops and vegetables. The samples were pre-concentrated using the Solid Phase Extraction (SPE) technique and analyzed by using High Pressure Liquid Chromatography (HPLC) and a Gas Chromatograph Mass Spectrometer (GC-MS). Organic contaminants like Dichlorodiphenyltrichloroethane (DDT), Dichlorodiphenyldichloroethylene (DDE), Dichlorophenol (DCP), Trichlorophenol (TCP), endrin, and dieldrin were found in certain samples above the permissible limits. Stable isotopes like 13C, 15N and 18O were analyzed to assess the source of shallow groundwater channel contamination. Chemical and isotopic data reveal that contamination of shallow groundwater channels in the area is mainly due to wastewater irrigation and, to some extent, by seepage through unlined wastewater drains in nearby areas. The wastewater containing organic pollutants, used for cultivation, filters through the soil to contaminate the shallow groundwater channels.

Impact of Wastewater Irrigation on Soil Mechanical Properties in the Green Space of Mobarakeh Steel Complex

Impact of Wastewater Irrigation on Soil Mechanical Properties in the Green Space of Mobarakeh Steel Complex

Assessing the impact of wastewater irrigation on cobalt cadmium and lead contents of grains of Sorghum bicolor

The impact of waste irrigation on the concentrations of the metals Cd, Co and Ni contents in grains of Sorghum bicolor was investigated through analyzing (for three seasons 2008-2010s) four different-irrigation sorghum grains samples grown on four different-irrigation soil areas according to the experimental design. Two original soils: Soil, historically and experimentally, irrigated with Wastewater (SHEwastewater), and Soil, historically and experimentally, irrigated with wells water samples were analyzed in the 1st and 2nd seasons. According to the procedures used in the literature, Samples were collected, pretreated, preserved, digested according to the microwave assisted acids digestion procedures, and analyzed for metals by ICP-AES. Quality control was performed and %R(s) we have gotten were good for real samples analysis. Cd and Pb metal contents of the two types of the original soil samples were not significantly different. In addition, these metal contents of the two types of soil samples have not exceeded the upper EU standards. The average means (of 1st and 2nd seasons) levels of Cd and Pb of wastewater were higher than that of wells water. In addition, the average means of these metal ions of both wastewater and wells water was lower than Yemeni standard for irrigation water. Sorghum grains analysis results, for at least two of the three seasons, indicated that: wastewater irrigation resulted in an increase in Cd and Pb contents of grains of Sorghum bicolor. Moreover, there is no significant difference between the effect of wastewater and wells water irrigation on Co content of grains of Sorghum bicolor.

Assessing the impact of wastewater irrigation on some toxic heavy metals concentration in grains of Sorghum bicolor

The impact of waste irrigation on the concentrations of the metals Cu, Fe, Ni, and Zn contents in grains of Sorghum bicolor was investigated through analyzing (for three seasons 2008-2010) four different-irrigation sorghum grains samples grown on four different-irrigation soil areas according to the experimental design. The two original soils: Soil, historically and experimentally, irrigated with Wastewater (SHEwastewater), and Soil, historically and experimentally, irrigated with wells water (SHEwells water), were analyzed in the 1st season. Wastewater and wells water samples were analyzed in the 1st and 2nd seasons. According to the procedures used in the literature, Samples were collected, pretreated, preserved, digested according to the microwave assisted acids digestion procedures, and analyzed for metals by ICP-AES. Quality control was performed and %R(s) we got were in the acceptable ranges for real samples analysis. Fe contents of the two types of soil samples were not significantly different. Cu and Ni contents of SHEwastewater were higher than that of SHEwells water whereas Zn content of SHEwastewater was lower than that of SHEwells water. In addition, not all metal levels of the two types of soil samples have exceeded the upper EU standards except nickel in SHEwastewater. The average means (of 1st and 2nd seasons) levels of Cu, Fe, Ni of wastewater was higher than that of wells water, but for Zn, the case is reversed. In addition, the average means of all metal ions of both wastewater and wells water was lower than Yemeni standard for irrigation water. Sorghum grains analysis results, for at least two of the three seasons, indicated that: wastewater irrigation resulted in an increase of nickel content of grains of Sorghum bicolor. Wells water irrigation resulted in an increase in zinc content. In addition, there is no significant difference between the effect of wastewater and wells water irrigation on copper and iron contents of grains of Sorghum bicolor.

Impact of wastewater-irrigation on in-household water contamination. A cohort study among urban farmers in Ahmedabad, India

This cohort study explores the contribution of wastewater irrigation, in the context of WASH (Water, Sanitation, Hygiene), on in-household water contamination among urban farming households in Ahmedabad, India. Drinking water samples of 204 households in four peri-urban farming communities were collected from the point-of-source (PoS) and point-of-use (PoU) of each household four times over the 12-month follow-up period. Next to the quantification of E. coli, three household surveys (baseline, hygiene and farm) were conducted. Additionally, an observational spot-check was undertaken in bi-monthly intervals throughout the follow-up period. Significant positive differences in water quality between PoS and PoU samples were identified in 78% of households. During the monsoon, the peak of contamination, only 6% of households had access to safe drinking water at PoU. The Average Treatment Effect (ATE) of wastewater irrigation indicates an adverse effect on in-household water contamination, larger in effect size than the mitigation effect of access to sanitation or personal hygiene. To control transmission of fecal pathogens, effective barriers are required for wastewater irrigation similar to the necessity of ensuring access to sanitation and practicing adequate hygiene behavior.

Impacts of Wastewater Irrigation on Growth, Yield and Salts Uptake of Barley

Treated wastewater is promising water resource as alternative or supplementary source for fresh water to be used in agriculture specially for areas of water shortage and crops with good potential of tolerating saline water. In this study long-term irrigation with fresh and wastewater on growth and yield of seven non-local cultivars (S42IL107, BW284, BW281, G400, Scarlett, Bowman and BW290) of Barley (Hordeum vulgare L.) showed that (1) barley cultivars irrigated with both fresh and wastewater had in general the same growth vigor and growth nature, (2) The cultivars irrigated with wastewater gave nearly twice the yield of that irrigated with freshwater. BW290 cultivar showed the best and highest yield among the seven cultivars while S42IL107 had the weakest prostrate growth, (3) The use of wastewater in irrigation increased the nitrogen (N), Phosphorous (P) and potassium (K) contents in soil profiles affecting its texture, (4) barley proved to be a salt-tolerant crop with considerable economic importance, Barley could tolerate saline water until (5µs) without any shortage in the yield of the crop, and (5) barley irrigated with both wastewater and freshwater needed nearly the same time to emergence, stem elongation, flowering and maturity and consequently, wastewater irrigation of barley is a promising water resource as alternatives for fresh water.

Impact of wastewater irrigation on major nutrient status in soil near Bhaluka industrial area of Bangladesh

The population increase has not only increased the fresh water demand but also increased the volume of wastewater generated. Treated or recycled wastewater (RWW) appears to be the only water resource that is increasing as other sources are dwindling. Increasing need for water has resulted in the emergence of domestic wastewater application for agriculture and its relative use. The present study was conducted at the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh during 2013 to evaluate the contribution of wastewater to major soil nutrients (N, P, K, S, Ca, Mg, B and Na) and fluctuation in physicochemical properties of soil (soil pH and Ec) from waste carrying canal at 10 selected sites of Bhaluka Upazila. Three (3) soil samples were collected at 0, 30 and 60 m distances from the waste discharging canals. The pH, EC, N, P, K, S, Ca, Mg, B and Na in soil samples decreased gradually with the increase of distance from waste discharging canal. Maximum concentrations of N at 60 and 0m distance varied from 8400 to 9700, P from 1850 to 5000, K from 4600 to 6000, S from 2000 to 4000, Ca from 7500 to 28800, Mg from 7500 to 7800, B from 90 to 2800 and Na from 2300 to 3100 ?g g-1 in test soil.The results showed better nutrient status of the soil along waste discharge canals. The findings give applicable advice to commercial farmers and agricultural researchers for proper management and use of treated industrial wastewater for agricultural purpose.Asian J. Med. Biol. Res. March 2016, 2(1): 131-137

Effects of industrial wastewater on growth and biomass production in commonly grown vegetables.

In developing countries like Pakistan, irrigation of crops with industrial and municipal wastewater is a common practice. However, the impact of wastewater irrigation on vegetables growth has rarely been studied. Therefore, the present study was conducted to determine the effect of industrial wastewater on the germination and seedling growth of some commonly grown vegetables in Pakistan. Wastewater samples were collected from two different industries (marble industry and match alam factory) at Hayatabad Industrial Estate (HIE) in Peshawar, Pakistan, and their effect on different growth parameters of four vegetables including Hibiscus esculentus, Lactuca sativa, Cucumis sativus, and Cucumis melo was investigated. The obtained results revealed that wastewater from marble industry did not affect seed germination except a minor inhibition in H. esculentus. Effluents from match alam factory stimulated seed germination in C. melo and C. sativus but had no effect on seed germination in the other two vegetables. Wastewater increased root and shoot length in H. esculentus, L. sativa and C. melo, but decreased it in C. sativus. Similarly, differential effects of wastewater were observed on fresh and dry biomass of seedlings in all vegetables. It can be concluded that wastewater may have different effects on different crops, depending upon the nature of wastewater and sensitivity of a plant species to wastewater.

Impact of wastewater irrigation on soil physico-chemical properties, growth and water use pattern of two indigenous vegetables in southwest Nigeria

The indiscriminate use of wastewater for irrigation as a result of freshwater shortage could impair soil functions and cause environmental pollution. The objective of this study was to evaluate soil physico-chemical properties, growth parameters and water use pattern of two indigenous vegetables irrigated with three kinds of wastewater in southwest Nigeria. The study was a 2×4 factorial (wastewater versus vegetable) pot experiment, laid out in randomized complete block design (RBCD) with three replications in a screen house. The tested vegetables were SM — Eggplant (Solanum macrocarpon) and CA — Spinach (Celosia angentea) while the wastewater treatments were abattoir wastewater (AW), bathroom, laundry wastewater (BW) cassava effluent (CE) and rainwater (RW) as control. The wastewaters were analyzed for physical, chemical and biological properties while the soil samples collected from the field at 0–20cm soil layer and pots at 0–10 and 10–20cm layer were analyzed for physico-chemical properties before and after the experiment, respectively. Soil hydrophobicity was determined using the water-droplet penetration time (WDPT) method, plant growth parameters were monitored every 5days while leaf area was determined shortly before harvest. Consumptive water use was determined using the soil water balance technique. The wastewaters had moderate to very high degree of restriction for use in relation to salinity and sodicity. Except for CE treatment, wastewater irrigation increased the soil pH, Mg, K, Ca, TOC, TN and CEC at harvest. SAR surpassed the threshold value of 6 in the surface layer of CA soil irrigated with BW wastewater. Wastewater irrigation caused the occurrence of soil hydrophobicity, with the highest hydrophobic degree from CE treatment. The plant growth indices showed that the SM vegetable performed better under AW treatment while the CA vegetable performed better under BW treatment compared with RW treatment. The vegetables differed in relation to water use and there was no discernible trend among the different wastewater treatments as regards the temporal distribution of the consumptive water use. The CE wastewater had the most negative impact on both soil function and plant growth. The study showed that wastewater resources are valuable because of improvement of soil fertility and enhanced crop growth compared with rainwater, however they need to be managed with caution, preferably treatment, before reused in relation to soil functions and crop quality.

Impact of wastewater irrigation on the dynamics of metal concentration in the vadose zone: simulation with NETPATH--part II.

Understanding and quantification of geochemical processes in vadose zone of sewage-effluent-irrigated soils are helpful in predicting the transference of metals and other ions to food chain and groundwater. Hence, an attempt has been made to simulate various geochemical processes occurring in the flow path of infiltrating sewage water down the vadose zone with the help of Net Geochemical Reaction Along the Flow Path (NETPATH). This study area was located in Western Delhi, India, where sewage effluents originating from Keshopur Sewage Treatment plant have been used for irrigation since 1979. Agricultural lands receiving irrigation through sewage and tube well water were selected for this study. The results indicated that groundwater of 20- and 10-year sewage-irrigated lands was slightly oversaturated in respect of calcite and dolomite, and undersaturated in respect of gypsum. The shallow groundwater of 5-year sewage-irrigated field was undersaturated in case of calcite, dolomite, and gypsum. Among the metals, major focus was given on Fe and Mn as these two metals are redox prone and relatively more mobile than other metals under saturated conditions. There was reduction in concentration of Fe and Mn in groundwater samples of 20-year sewage-irrigated field as compared to that in sewage effluent. Such reduction in concentration of Fe and Mn could be ascribed to the formation of goethite and manganite in vadose zone, respectively, as revealed by simulation with NETPATH. Similarly, in case of 10- and 5-year sewage-irrigated fields, increase in Fe and Mn concentrations in groundwater was due to dissolution of siderite and pyrulusite, respectively. NETPATH software could explain the variation in diethylene triamine pentaacetic acid (DTPA)-extractable Fe and Mn content in vadose zone to the extent of 94 and 65%, respectively.

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.

Impact of wastewater irrigation on the dynamics of metal concentrations in the vadose zone: monitoring: part I.

Agricultural lands in the peri-urban area of New Delhi have been irrigated with treated wastewater from the Keshopur Effluent Irrigation Scheme (KEIS) since 1979. An attempt has been made to study the influence of wastewater irrigation on pH, electrical conductivity, organic carbon, and dynamics of heavy metal concentrations in vadose zone under KEIS. For this study, agricultural lands which have been receiving the sewage irrigation for 20, 10, and 5 years were selected. Adjacent tube well water-irrigated fields were selected and used as reference. Results indicate that there was a significant decrease in soil pH and electrical conductivity (EC) of sewage water-irrigated fields as compared to tube well water-irrigated fields. Organic carbon (OC) content in 20 years sewage-irrigated soil (0-15 cm) increased by 244% over tube well water-irrigated soil. The increases in organic carbon content for 10 and 5 years sewage-irrigated surface soil (0-15 cm) were 138 and 60% over tube well water-irrigated soils. The second-order polynomial model suggested that there is a possibility of accumulation of organic carbon in soil due to sewage irrigation at 1.55 t(-1) ha(-1) year. There was an increase in diethylene triamine pentaacetic acid (DTPA)-extractable Zn content in 20, 10, and 5 years sewage-irrigated soils (0-15 cm) to the extent of 86, 38, and 36% over tube well water-irrigated soils, respectively, while only 20 years sewage-irrigated soils showed a significant increase in DTPA-extractable Cu (289%) in surface layer (0-15 cm) over tube well-irrigated soils. In case of Fe, 127, 88, and 76.6% increases in available Fe content (DTPA-Fe) were recorded under 20, 10, and 5 years sewage-irrigated soils, respectively, over controls. Like Cu, DTPA-extractable Ni also exhibited a significant increase (42.2%) in 20 years sewage-irrigated soil over tube well-irrigated ones. It appears that due to sewage irrigation particularly in surface soil, DTPA-Mn content either remained same or showed a slight decline as compared to tube well-irrigated soils. The assessment of contamination factor (CF) in respect of total metal content in soil indicated the moderate level of metal contamination even after such long-term of sewage irrigation.

Long term impact of waste water irrigation and nutrient rates: I. Performance, sustainability and produce quality of peri urban cropping systems

Farmers in peri-urban areas of developing countries depend on wastewaters for their livelihood but with grave health and environmental risks. An 8-year field experiment compared food grain (FGPS), agroforestry (AFS), fodder (FPS) and vegetable (VPS) production systems and quantified responses to fertilizers (NP 25–100%) when irrigated with sewage (SW; EC 1.3±0.3dSm−1 BOD 82±11, NO3–N 3.2±0.4, NH4–N 9.6±0.5, P 1.8±0.3, K 6.4±0.4mgL−1) vis-à-vis groundwater (GW). Productivity improved with SW by 14–28% while trends were negative with sub-optimal NP under GW. Partial factor productivity (PFP) averaged 18.0, 11.1, 157 and 149kgkg−1 NP with GW in FGPS, AFS, FPS and VPS, respectively. Counter figures were 13.8, 8.8, 96 and 56kgkg−1 NP with SW. Paddy-wheat equivalent yields were 5.5, 1.8 and 19.9 fold under AFS, FPS and VPS with SW. About 40, 33, 75 and 20% of fertilizer NP with SW was sufficient for similar production as with recommended NP and GW in FGPS, AFS, FPS and VPS, respectively. Quality of produce improved in terms of crude protein and the micronutrients in edible parts with SW while toxic metals were within the permissible limits. However, the keeping quality of vegetables was lowered due to faster decay with pathogens contamination (Aerobic bacterial plate counts 5×105–4.2×108cfug−1 and Escherichia coli <2×102–7×105). Thus, the sewage proved as a vital resource in improving productivity, sustainability and saving fertiliser costs but this may pose health risks because of pathogenic infestation that need to be regulated.

Metals Uptake by Wastewater Irrigated Vegetables and their Daily Dietary Intake in Peshawar, Pakistan / Pobieranie Metali Przez Warzywa Nawadniane Ściekami I Ich Dzienne Stężenie W Diecie Ludności Peszawaru, Pakistan

Abstract Vegetables are important source of nutrients for human body. Wastewater irrigation may lead to contamination of these vegetables and cause possible health risk. In the present study impact of waste water irrigation on metals uptake (Fe, Mn, Ni, Co, Zn, Cd, Cr and Pb) by five commonly consumed vegetables (radish, cabbage, lettuce, cauliflower and spinach) grown in the suburbs of Peshawar were investigated using AAS (Atomic Absorption spectrophotometer). The uptake and accumulation of metals for vegetables irrigated with wastewater were significantly (p &lt; 0.05) higher than tube well irrigated vegetables and permissible limits of WHO/FAO. Among the edible parts of vegetables maximum accumulation of Mn, Pb and Cd occurred in radish followed by Ni and Fe in spinach while Cr and Zn were high in cauliflower and cabbage. The estimated daily intake of metals (DIM) revealed that at present the consumption of studied vegetables were under the tolerable limits of (US-EPA, IRIS), however intake of metals in waste water irrigated vegetables were significantly high and can cause health hazards in the long run