Evaluation of the effect of untreated wastewater and wastewater on the soil and edible part of the crop

[S1] 

Abstract

Today, Wastewater is usually deployed for crop and land irrigation in the area with limited freshwater supply. Though, using wastewater for agriculture is not legally acceptable in many of the countries. However, the wastewater is a prime source of irrigation in many countries with a shortage of adequate water quality. The research was conducted from two years on the farming field and the crop (potato and okra) irrigated through wastewater and treated wastewater. The crop and file irrigated with wastewater had demonstrated a large amount of heavy metal deposition as compared to the treated wastewater. Further, the effect of two irrigation techniques including drip and flood had been studied. The drip irrigation was beneficial method as there were fewer levels of heavy metals deposited in the soil and crop's edible part.[S2] 

Contents

Abstract 1

Introduction.. 2

Aim.. 3

Results. 3

The year 2015, Evaluation of the effect of Treated wastewater and Wastewater on soil 3

Effect of Treated wastewater on soil (collected at different depth) 3

Effect of Wastewater on soil (collected at different depth) 6

The year 2016, Evaluation of the effect of Treated and wastewater on soil 9

Effect of Treated Wastewater on soil (collected at different depth) 9

Effect of Wastewater on soil (collected at different depth) 11

Evaluation of the effect of Treated wastewater and Wastewater on Crop. 13

Discussion. 16

Conclusion. 18

References. 19

[S3] 

Introduction

Water is the most vital component for living beings, though water is the most limited and inclined source which has assessable limitations and qualitative vulnerability. In accord with Khalid et al. (2018); by 2025, approximately 60 per cent of the world’s population will face the issue due to water scarcity. The untreated water can cause underground water contamination and soil hardening while use as the main source of crop and soil irrigation. The key issue associated with using wastewater as irrigation source is the presence of toxic metal elements (Li et al., 2017). Therefore, it is paramount to undertake a comprehensive study to determine the effect of contaminated and treated water on soil and selected crops.

Aim

In line with the literature, this research would be aimed to evaluate the effect of untreated wastewater (UWW) and treated wastewater (TWW) on soil and crops (potato and okra) in the year 2015 and 2016.[S4] 

Results 

The year 2015, Evaluation of the effect of Treated wastewater and Wastewater on soil

Effect of Treated wastewater on soil (collected at different depth)

The effect of the treated wastewater was estimated, for the same the water was channelized into the field through two processes, flood and drip method. The amount of metal deposition in the soil at a different level, when irrigated with treated wastewater is depicted in Table 1.

Metal deposition in field irrigated through flood

For potato and okra field, when the soil was evaluated at 0-15 cm, 15-30 cm and 30-45 cm, copper levels were 15.7, 18.5, and 14.13ppm respectively. For the potato/okra field, when the soil was evaluated at 0-15 cm, Cr levels were 2.02 ppm. Further, at 15-30 cm and 30-45 cm, the levels were 2.004 ppm and 2.001 ppm respectively. When the soil was evaluated at 0-15 cm, 15-30 cm and 30-45 cm, the Ni level was 2.02 ppm, 2.02 ppm and 3.40 ppm individually. Additionally, when the soil was evaluated at 0-15 cm, Pb levels were 14.09 ppm. Further, at 15-30 cm the level was 14.9. Moreover, at 30-45 cm the metal concentration was 12.3 ppm. Zn levels at 0-15 cm were 16.65 ppm. Further, at 15-30 cm the level was 8.6 ppm. Moreover, at 30-45 cm the metal concentration was 23.2 correspondingly.

Metal deposition in field irrigated through drip

As per the Table1, for potato/okra, when soil sample was taken at 0-15 cm and evaluated for the metal deposition, Cu levels were 20.0 ppm. Further, at 15-30 cm the levels were 11.9 ppm. Moreover, at 30-45 cm the metal concentration was 5.36.  Cr levels at 0-15 cm were 1.087ppm. Further, at 15-30 cm the levels were 1.096 ppm individually. Moreover, at 30-45 cm the metal concentration was 2.0 ppm. The Ni levels at 0-15 cm were 4.04 ppm. Further, at 15-30 cm the levels were 3.4 ppm. Moreover, at 30-45 cm the metal concentration was 2.02 ppm. Additionally, for potato/okra field, when the soil was evaluated at 0-15 cm, Pb levels were 14.09 ppm. Further, at 15-30 cm the levels were 7.8 ppm individually. Moreover, at 30-45 cm the metal concentration was 14.9 ppm. At 0-15 cm, Zn levels were 4.5 ppm. Further, at 15-30 cm the levels were 0.2 ppm. Moreover, at 30-45 cm the metal concentration was 0.01 ppm.

Table 1: Amount of metal deposition in soil (at different levels) after irrigated with treated water in 2015.

Effect of Wastewater on soil (collected at different depth)

The effect of the treated wastewater was estimated, for the same the water was channelized into the field through two processes, flood and drip method. The amount of metal deposition in the soil at a different level, when irrigated with wastewater is depicted in Table 2.

Metal deposition in field irrigated through flood

Soil samples were taken at 0-15 cm and evaluated for the metal deposition, Cu, Cr, Ni, Pb and Zn levels were 27.20, 23.98, 12.42, 88.15 and 80.31 ppm respectively. Further, at 15-30 cm the levels were 24.12, 32.09, 25.42, 92.88 and 35.3 ppm individually. Moreover, at 30-45 cm the metal concentrations were 23.34, 28.10, 2.08, 90.52 and 74.08 ppm correspondingly.

Metal deposition in field irrigated through drip

Soil samples were taken at 0-15 cm and evaluated for the metal deposition, Cu, Cr, Ni, Pb and Zn levels were 55.68, 34.74, 11.62, 68.71 and 35.97 ppm respectively. Further, at 15-30 cm the levels were30.30, 52.20, 20.25, 78.44 and 41.36 ppm individually. Moreover, at 30-45 cm the metal concentrations were 31.06, 52.23, 9.92, 68.71and 5.47 ppm correspondingly.

Table 2: Concentration of metal deposition in soil (at different levels) after irrigated with wastewater in 2015.

The year 2016, Evaluation of the effect of Treated and wastewater on soil

Effect of Treated Wastewater on soil (collected at different depth)

The amount of metal deposition in the soil at a different level, when irrigated with treated wastewater is depicted in Table 3.

Metal deposition in field irrigated through flood

For the potato/okra gourd field, when the soil was evaluated at 0-15 cm, copper levels were 15.9 ppm. Further, at 15-30 cm the levels were 18.6 ppm. Moreover, at 30-45 cm the metal concentration was 14.26 ppm. The chromium, nickel, lead and zinc were also detected in the soil at different levels. Cr and Ni levels at 0-15 cm were 2.01and 2.03 ppm respectively. Further, at 15-30 cm the levels were 2.022 and 2.03 ppm individually. Moreover, at 30-45 cm the metal concentration was 2.001 and 3.42 ppm correspondingly. Additionally, when the soil was evaluated at 0-15 cm, Pb and Zn levels were 14.16 and 16.77 ppm respectively. Further, at 15-30 cm the levels were 15.05 and 8.7 ppm individually. Moreover, at 30-45 cm the metal concentration was 12.3 and 23.4 ppm correspondingly.

Metal deposition in field irrigated through drip

Soil samples were taken at 0-15 cm and evaluated for the metal deposition, Cu, Cr, Ni, Pb and Zn levels were 19.23, 1.09, 4.11, 14.16 and 4.6 ppm respectively. Further, at 15-30 cm the levels were 12.05, 1.1, 3.42, 7.93 and 0.21 ppm individually. Moreover, at 30-45 cm the metal concentrations were 5.41, 2.04, 2.03, 14.16 and 0.018 ppm correspondingly.

Table 3:  Amount of metal deposition in soil (at different levels) after irrigated with treated wastewater in 2016.

Effect of Wastewater on soil (collected at different depth)

The effect of the treated wastewater was estimated, for the same the water was channelized into the field through two processes, flood and drip method. The amount of metal deposition in the soil at a different level, when irrigated with wastewater is depicted in Table 4.

Metal deposition in field irrigated through flood

Soil samples were taken at 0-15 cm and evaluated for the metal deposition, Cu, Cr, Ni, Pb and Zn levels were 32.05, 28.56, 14.72, 103.58 and 95.33 ppm respectively. Further, at 15-30 cm the levels were 28.41, 37.82, 29.96, 109.6 and 41.69 ppm individually. Moreover, at 30-45 cm the metal concentrations were 27.51, 33.12, 2,42, 106.7 and 87.33 ppm correspondingly.

Metal deposition in field irrigated through drip

Soil samples were taken at 0-15 cm and evaluated for the metal deposition, Cu, Cr, Ni, Pb and Zn levels were 65.23, 41.12, 13.78, 80.49 and 43.00 ppm respectively. Further, at 15-30 cm the levels were 35.72, 61.71, 23.87, 92.5 and 48.85 ppm individually. Moreover, at 30-45 cm the metal concentrations were 36.17, 61.86, 11.78, 80.58 and 6.40 ppm correspondingly.

Table4:  Amount of metal deposition in soil (at different levels) after irrigated with wastewater in 2016.

Evaluation of the effect of Treated wastewater and Wastewater on Crop

Table5: Illustrating the effect of treated wastewater and wastewater on crop potato.

Potato and okra crops were evaluated for the metal deposition when the field was irrigated through treated and wastewater. Significantly, a metal deposition was more in case of wastewater irrigation. For instance, in 2016 when the crop was irrigated with wastewater, the lead and zinc values were 21.55 ppm 64.83 ppm respectively (Table 5). Following Table 6, on the evaluation of okra, the metal concentration was high in crop treated with wastewater.

Table 6: Illustrating the effect of treated wastewater and wastewater on crop Okra.[S5] 

Discussion

Numerous soil minerals incorporate in the soil, for instance, carbonates, sulphides, salts or oxides. The concentration of the minerals in any soil is dependent on the soil naturally. Therefore, it is not astounding those soils from a different country or different region with in the country exhibits a substantial range of metals concentration (Avci & Deveci, 2013). As per the above-stated results, the untreated wastewater had deposited the maximum quantity of the metals in the soil.  In 2017, the zinc, copper, chromium, nickel, and lead levels were 1.17, 0.15, 0.11, 0.19 and 1.95ppm respectively, when the soil was irrigated with untreated wastewater. Whereas, the metals deposited by the treated wastewater is less as compared to the wastewater. In 2017 when the soil was irrigated with the treated wastewater, the zinc, copper, chromium, nickel, and lead levels were 0.21, 0.018, 0.0, 0.02 and 0.07ppm correspondingly. The above-stated results of the present study are in accord with the results presented by Singh et al. (2012). The authors had demonstrated that the field irrigated with the sewage water had more deposition of the heavy metals (Zn, Cu, Pb and Cd) as compared to the field irrigated with the ground and domestic water. Further, as per table 1, 2, 3 and 4, it can be demonstrated that the metal deposition was high in flood irrigation technique as compared to the drip irrigation. The same trend is evident with the studies conducted by Varallo et al. (2012), Urbano et al. (2015) and Urbano et al. (2017).

Additionally, the heavy metal deposition was estimated in the edible portion of the crop, as per the table 5 and 6, the heavy metal deposition was high in both the crop, when irrigated with the wastewater. Furthermore, the heavy metal deposition was less in the crops watered with treated wastewater. Moreover, the zinc, lead, nickel and chromium levels were higher than their permissible levels in potatoes, treated with wastewater (highlighted in table 5). The nickel, lead and zinc levels were more than the permissible limits in okra when watered with wastewater (Table 6). Similar results have been documented from the research conducted by Sharma et al. (2007), the author had concluded that wastewater used for the irrigation lead to contamination of heavy metals (lead and nickel) in the edible part of the vegetables. Further, Abaidoo et al. (2010) and Zhuang et al. (2009) had concluded from their study that the edible part of the crop, which is irrigated with the wastewater have more metal and can lead to deleterious effects on the health of the consumer (Jan et al., 2010; Tiwari et al., 2011).[S6] 

Conclusion

It can be concluded that the wastewater as irrigation has various drawbacks. Wastewater consists of various toxic metals; for example, copper, nickel, mercury, lead, chromium and zinc. Moreover, waste-water also consist of various parasites; for instance, bacteria, viruses and worms, that can cause severe health hazards to the environment and human health. The drip irrigation had less deposition of the heavy metal in both soil and crop as compared to the flooded water irrigation. Further, the wastewater has more heavy metal deposition in both edible parts of the crop and soil in contrast to the treated wastewater.[S7] 

References

Abaidoo, R. C., Keraita, B., Drechsel, P., Dissanayake, P., & Maxwell, A. S. (2010). Soil and crop contamination through wastewater irrigation and options for risk reduction in developing countries. In Soil biology and agriculture in the tropics (pp. 275-297). Springer, Berlin, Heidelberg.

Avci, H., & Deveci, T. (2013). Assessment of trace element concentrations in soil and plants from cropland irrigated with wastewater. Ecotoxicology and Environmental Safety, 98, 283-291.

Jan, F. A., Ishaq, M., Khan, S., Ihsanullah, I., Ahmad, I., & Shakirullah, M. (2010). A comparative study of human health risks via consumption of food crops grown on wastewater irrigated soil (Peshawar) and relatively clean water irrigated soil (lower Dir). Journal of Hazardous Materials, 179(1-3), 612-621.

Khalid, S., Shahid, M., Bibi, I., Sarwar, T., Shah, A. H., & Niazi, N. K. (2018). A review of environmental contamination and health risk assessment of wastewater use for crop irrigation with a focus on low and high-income countries. International Journal of Environmental Research and Public Health, 15(5), 895.

Li, Q., Tang, J., Wang, T., Wu, D., Busso, C. A., Jiao, R., & Ren, X. (2017). Impacts of sewage irrigation on soil properties of farmland in China: A review. Solid Earth Discussions, 1-24.

Sharma, R. K., Agrawal, M., & Marshall, F. (2007). Heavy metal contamination of soil and vegetables in suburban areas of Varanasi, India. Ecotoxicology and Environmental Safety, 66(2), 258-266.

Singh, P. K., Deshbhratar, P. B., & Ramteke, D. S. (2012). Effects of sewage wastewater irrigation on soil properties, crop yield and environment. Agricultural Water Management, 103, 100-104.

Tiwari, K. K., Singh, N. K., Patel, M. P., Tiwari, M. R., & Rai, U. N. (2011). Metal