scholarly journals Nexus between sanitation and groundwater quality: case study from a hard rock region in India

2019 ◽  
Vol 9 (4) ◽  
pp. 703-713 ◽  
Author(s):  
S. Murty Bhallamudi ◽  
R. Kaviyarasan ◽  
A. Abilarasu ◽  
Ligy Philip
Keyword(s):  
Groundwater Quality ◽  
Hard Rock ◽  
Oxygen Demand ◽  
Shallow Groundwater ◽  
Fecal Coliforms ◽  
Septic Tank ◽  
Effluent Quality ◽  
Deep Aquifers ◽  
Top Soil ◽  
Shallow Groundwater Table

Abstract Groundwater quality in the towns of Namakkal and Erumaipatti in India was studied to understand the nexus between surface sanitation and groundwater quality in hard rock regions. In total, 32 wells, both shallow open and deep bore wells, were monitored over a two-year period. The presence of fecal coliforms (FCs) up to 600 CFU/100 mL in wells as deep as 100 m showed that bacteriological contamination had reached deep aquifers through fractures and fissures. Statistical analyses showed that bore wells located in Namakkal were bacteriologically more contaminated than those in Erumaipatti (p = 0.017 for FC) because of urbanization, the type of top soil and the shallow groundwater table. Wells in densely toileted areas of Namakkal were more contaminated than those located in open defecation areas. After replacing a soak pit with a septic tank, concentrations of FC and chemical oxygen demand (COD) in the leachate at a depth of 2.1 m reduced from 2,500 to 1,000 CFU/100 mL and from 200 to 50 mg/L, respectively, after 150 days of the construction of septic tanks. To improve the hygiene and sanitation, the provision of toilets along with on-site waste management systems, capable of achieving required effluent quality, are essential.

Performance of a biofilter system with agave fiber filter media for municipal wastewater treatment

2013 ◽  
Vol 68 (3) ◽  
pp. 599-607 ◽  
Author(s):  
Juan Manuel Vigueras-Cortés ◽  
Ignacio Villanueva-Fierro ◽  
Marco Antonio Garzón-Zúñiga ◽  
José de Jesús Návar-Cháidez ◽  
Isaías Chaires-Hernández ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Fecal Coliforms ◽  
Municipal Wastewater Treatment ◽  
Operational Parameters ◽  
Filter Media ◽  
Effluent Quality ◽  
Us Epa ◽  
Removal Efficiencies ◽  
By Products

Agave plants grow in semi-arid regions and are used for mescal production. However, agave fiber by-products are considered waste materials. Thus, we tested agave fiber as a filter media and biofilm material carrier for removing pollutants from municipal wastewater. Three laboratory-scale biofiltration reactors were used in two trials with five hydraulic loading rates (HLRs = 0.27, 0.54, 0.80, 1.07 and 1.34 m3 m−2 d−1). One series was conducted using mechanical aeration (0.62 m3 m−2 h−1). To prevent compaction, decreasing pressure and clogging of the filter media, 4, 8 and 12 internal divisions were evaluated in the biofilter column. After 17 months of continuous operation at an HLR of 0.80 m3 m−2 d−1, the removal efficiencies of the aerated biofilters were 92.0% biochemical oxygen demand, 79.7% chemical oxygen demand, 98.0% helminth eggs, 99.9% fecal coliforms and 91.9% total suspended solids. Statistical analysis showed that the chosen operational parameters significantly influenced the removal efficiencies of the biofilters. The effluent quality obtained under these conditions complied with the Mexican and US EPA standards for agricultural irrigation and green spaces, except for coliforms, which is why the effluents must be disinfected. Thus, agave fiber is a favorable choice for use as a packing material in biofiltration processes.

scholarly journals Shallow groundwater quality assessment: use of the improved Nemerow pollution index, wavelet transform and neural networks

2017 ◽  
Vol 19 (5) ◽  
pp. 784-794 ◽  
Author(s):  
Q. Yang ◽  
J. Zhang ◽  
Z. Hou ◽  
X. Lei ◽  
W. Tai ◽  
...  
Keyword(s):  
Neural Network ◽  
Groundwater Quality ◽  
Back Propagation ◽  
Oxygen Demand ◽  
Shallow Groundwater ◽  
Pollution Index ◽  
Quality Standard ◽  
Total Hardness ◽  
Back Propagation Algorithm ◽  
National Quality

Shallow groundwater is generally of great interest to the community due to its easy availability. However, it is very sensitive to external stimulus. In this paper, shallow groundwater quality is assessed and classified with improved Nemerow pollution index, multi-layer perceptron artificial neural network (MLP-ANN) optimized with a back-propagation algorithm and wavelet neural network (WNN) methods in a coastal aquifer, Fujian Province, South China. The data used in three models were collected during the pre-monsoon over the period 2004–2011. The eight parameters, total dissolved solids, total hardness, chemical oxygen demand, chloride, sulphate, nitrate, nitrite and fluorides, were selected to characterize groundwater quality classification based on the National Quality Standard for Groundwater (GB/T 14848-93). The results of MLP-ANN and WNN are interpreted by mean absolute error, root mean square error and R2 (determination coefficient) criteria. The results obtained from three methods demonstrate that WNN has a higher accuracy compared with the other two methods. The study reveals that these methods are efficient tools for assessing groundwater quality.

Role of saturated and unsaturated zone in soil disposal of septic tank effluent

1988 ◽  
Vol 15 (4) ◽  
pp. 709-716 ◽  
Author(s):  
K. R. Johnson ◽  
J. W. Atwater
Keyword(s):  
Oxygen Demand ◽  
Ground Surface ◽  
Pilot Scale ◽  
Scientific Basis ◽  
Separation Distance ◽  
Saturated Soil ◽  
Fecal Coliforms ◽  
Septic Tank ◽  
Absorption System ◽  
Septic Tank Effluent

The guidelines for the use of the septic tank – soil absorption system (ST–SAS) in the Province of British Columbia are very specific in regard to the separation distance between the ground surface and the groundwater table (minimum 1.2 m), and between the tile field and perimeter drains or ditches (minimum 3.0 m). A pilot-scale experiment employing waterproof channels filled with a saturated soil was used to evaluate the scientific basis for these guidelines. Septic tank effluent was applied to unsaturated columns and the inlet end of the channels and samples were taken at different points in the channels. Measurements were made of total and fecal coliforms, chemical oxygen demand, ammonia, nitrate, and orthophosphate. Coliform reductions within the channels were at least 30 000-fold with total coliform numbers generally lying below 200 coliforms/100 mL and fecal coliforms generally less than 50 coliforms/100 mL. Varying degrees of nitrification occurred in the unsaturated columns, resulting in relatively high concentrations of nitrate in some of the channel sections (1–7 mg/L in channels filled with sand and 0.1–1.0 mg/L in channels filled with loamy sand). The removal of orthophosphate was greater than 90% in all of the channel sections, independent of the saturated or unsaturated zones. Reductions in measured influent parameters were substantial in all of the channels. This suggests that the guidelines may be conservative with respect to these particular soils. Of concern are the high nitrate values observed in some of the channels, therefore consideration of nitrification potential should be made in conjunction with the potential for reduction of other contaminants. Key words: septic tank, soil absorption system, saturated soil, unsaturated soil, coliforms, nutrients.

scholarly journals Hydrogeochemical Characterization and Quality Assessment of Groundwater in a Long-Term Reclaimed Water Irrigation Area, North China Plain

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1209 ◽  
Author(s):  
Xiaomin Gu ◽  
Yong Xiao ◽  
Shiyang Yin ◽  
Qichen Hao ◽  
Honglu Liu ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Groundwater Quality ◽  
Reclaimed Water ◽  
Shallow Groundwater ◽  
Deep Groundwater ◽  
Irrigation Area ◽  
Deep Aquifers ◽  
Drinking And Irrigation ◽  
Reclaimed Water Irrigation

Water scarcity has led to wide use of reclaimed water for irrigation worldwide, which may threaten groundwater quality. To understand the status of groundwater in the reclaimed water irrigation area in Beijing, 87 samples from both shallow and deep aquifers were collected to determine the factors affecting groundwater chemistry and to assess groundwater quality for drinking and irrigation purposes. The results show that groundwater in both shallow and deep aquifers in the study area is weakly alkaline freshwater with hydrogeochemical faces dominated by HCO3-Na·Mg·Ca, HCO3-Mg·Ca·Na, HCO3-Ca·Na, and HCO3-Na. The chemical composition of groundwater in both shallow and deep aquifers is dominantly controlled by the dissolution of halite, gypsum, anhydrite, and silicates weathering, as well as ion exchange. Geogenic processes (rock weathering and ion exchange) are the only mechanisms controlling groundwater chemistry in deep aquifers. Besides geogenic processes, evaporation and anthropogenic activities also affect the chemistry of shallow groundwater. Quality assessment reveals that both shallow and deep groundwater are generally suitable for drinking and irrigation purposes. The quality of deep groundwater is more excellent for drinking than shallow groundwater. However, long-term use of deep groundwater for irrigation exhibits higher potential risks to deteriorate soil property due to the relative higher permeability indexes (PI). Therefore, it is recommended that deep groundwater is preferentially used for drinking and domestic purpose, and shallow groundwater for agricultural irrigation.

Aeration and Water Hyacinths in Waste Stabilization Ponds

1987 ◽  
Vol 19 (12) ◽  
pp. 265-271
Author(s):  
P. R. Thomas ◽  
H. O. Phelps
Keyword(s):  
Biochemical Oxygen Demand ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
Substantial Improvement ◽  
Additional Treatment ◽  
Coliform Bacteria ◽  
Effluent Quality ◽  
Stabilization Ponds ◽  
Water Hyacinths

The investigation was based on two facultative stabilization ponds initially designed to operate in parallel, and now receive wastewater in excess of their capacities from a fast expanding housing estate in the Caribbean Island of Trinidad. Because of the deterioration of the effluent quality relative to acceptable standards, an attempt was made to upgrade the ponds using water hyacinths at the early stages. However, from the results, it was clear that the introduction of water hyacinths in the test pond did not lead to any substantial improvement in the effluent because of the high loading on the pond. Therefore the ponds were modified to operate in series with surface aerators installed in the first pond. Initially, the effluent quality was monitored in terms of total suspended solids, volatile suspended solids, biochemical oxygen demand, faecal coliform bacteria, pH and dissolved oxygen with aeration in the first pond and no aquatic plants in the second pond. Although there was a significant improvement in the effluent quality, the values remained above the standards. As a result, water hyacinths were introduced in the second pond and the effluent quality monitored together with aeration in the first pond. The effluent quality improved with total suspended solids and biochemical oxygen demand values both as low as 10 mg/l in certain months, but additional treatment was needed to reduce faecal conforms.

scholarly journals Innovative Hydrogeophysical Approaches as Aids to Assess Hungarian Groundwater Bodies

2021 ◽  
Vol 11 (5) ◽  
pp. 2099
Author(s):  
Péter Szűcs ◽  
Norbert P. Szabó ◽  
Mohammad Zubair ◽  
Sándor Szalai
Keyword(s):  
Geophysical Methods ◽  
Shallow Groundwater ◽  
Clay Content ◽  
Management Plan ◽  
Statistical Interpretation ◽  
Multivariate Statistical ◽  
Joint Application ◽  
Shallow Groundwater Table ◽  
Horizontal Variations ◽  
Resistivity Log

The Hungarian water management plan has lately identified 185 groundwater bodies based on the concepts given by the European Water Framework Directive. Achieving and maintaining the good quantitative and chemical status of these groundwater bodies is of primary importance. It is demonstrated how innovative hydrogeophysical methods can be applied successfully to assess the Hungarian or other international groundwater bodies. By applying geoelectric methods, horizontal layering or large uniform rock units can be well characterized by Wenner–Schlumberger array, also enabling accurate depth determination of the shallow groundwater table. Horizontal variations in the rock type or its state can be well described by dipole–dipole array or, even better, by the newly developed quasi-null arrays. Their joint application may be very straightforward to investigate different aquifer types by giving high-resolution resistivity images as input for hydrogeological modeling. In the identification of porous formations, multivariate statistical interpretation of wireline logs using cluster analysis allows reliable lithological separation of potential aquifers. Their clay content is estimated by robust factor analysis, while their hydraulic properties are directly derived from the resistivity log. For a more effective interpretation, a combination of surface and borehole geophysical methods can be recommended for meeting challenges in hydrogeology and groundwater management.

scholarly journals Classification of groundwater suitability for irrigation purposes using a comprehensive approach based on the AHP and GIS techniques in North Kurdufan Province, Sudan

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Elsiddig Eldaw ◽  
Tao Huang ◽  
Adam Khalifa Mohamed ◽  
Yahaya Mahama
Keyword(s):  
Water Quality ◽  
Spatial Distribution ◽  
Groundwater Quality ◽  
Irrigation Water ◽  
Research Effort ◽  
Sodium Absorption ◽  
Irrigation Water Quality ◽  
Middle Income ◽  
Sodium Absorption Ratio ◽  
Deep Aquifers

AbstractDeterioration of groundwater quality due to drastic human interventions is rising at an alarming rate particularly in lower- and middle-income countries. Yet, limited research effort has been devoted to monitoring and ascertaining groundwater quality. The present study develops a comprehensive irrigation water quality index (IWQI) for rating water quality of shallow and deep aquifers in North Kurdufan province, Sudan. The new approach is developed to overcome the deficiencies of the existing irrigation indices and coming up with a unified decision for classifying water quality for irrigation purposes. Because of these indices like permeability index (PI), sodium absorption ratio (SAR), etc., depending on specific elements, entirely subjective, as well as the great variations in their results, particularly when classifying water quality. Thus, IWQI is created based on eight indices that are generally used to evaluate irrigation water quality, plus three physicochemical parameters have been proven an impact on water quality. The analytic hierarchy process (AHP) is applied to minimize the subjectivity at assign parameter weights under multiple criteria decision analysis tools (MCDA). The spatial distribution of IWQI agrees with the spatial distribution of the most parameters. The results of our approach reveal that the majority of samples are suitable for irrigation uses for both aquifers except few wells in the confined aquifer. Also, noted that there are very variations in the irrigation indices results for classifying water quality. The comparison result showed that the new index robust, fair calculations and has best classifying of water quality.

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