Irrigation Water Quality Standards Research Articles

Impacts of illegal mining activities on water quality for irrigation and implications for public health: A case study of the Oda River in the Ashanti Region of Ghana

ABSTRACT This study evaluated the biological and physicochemical parameters of the Oda River, including the detection of heavy metals. To achieve this purpose, a quantitative experimental research design was employed. Twenty-four water samples were taken along the Oda River from Obeng ne Obeng, Abuakwaa, and Odaso communities. The samples were analysed in a laboratory, and the results were compared to the irrigation water quality standards from the Food and Agricultural Organization (FAO). The study found that the concentration of turbidity and total suspended solids exceeded the recommended standards of FAO, while the river's pH, electrical conductivity, and total dissolved solids concentrations were within permissible boundaries. Lead, cadmium, mercury, arsenic, and fluoride were present at concentrations lower than the recommended guidelines, whereas copper and cyanide were not discovered. However, iron concentrations exceeded the FAO guidelines. Escherichia coli concentrations in the Obeng ne Obeng were lower than the FAO irrigation standards but were higher in the Abuakwaa and Odaso. The Pearson correlation coefficient highlighted significant correlations between the physicochemical parameters. This paper concludes that unregulated mining activities may endanger vital water resources for irrigation, public health, food safety, ecosystems, and livelihoods.

Groundwater Balance Estimation and Quality For Irrigation In The Food Estate Area, Central Sumba Regency, East Nusa Tenggara, Indonesia

Abstract Food estate in Central Sumba Regency is one of Indonesia’s Nasional Strategic Projects that aim to increase the national food supply. Groundwater has been the main water supply by residents around the food estate area in Central Sumba Regency. Groundwater exploitation in the research area uses dug wells, bore wells, and springs. They mostly use groundwater for domestic use and irrigation purposes. Aquifer depletion and declining groundwater levels can occur as groundwater is exploited too much due to the growing need for groundwater. Hence, determining the groundwater budget is required to ensure the basin’s sustainability. This study aims to determine groundwater quality for irrigation in the food estate and estimate the groundwater budget. Besides, water quality is also an important feature of groundwater, and it expresses how sufficient the water is for various needs, each having its requirements represented as water quality standards. Groundwater samples were taken from various areas in the research area, and groundwater’s physical-chemical properties, such as TDS, EC, temperature, and pH, were measured in the field and compared with Government Regulation no. 22, 2021, and FAO for irrigation water quality standards. The results show that the research area has a low to medium groundwater potential. The result of physical-chemical properties measurement are as follows TDS value is 183 mg/L on average, EC value is 366 μS/cm on average, the temperature value is 25.4°C on average, and pH value is 7.3 on average. It can be concluded that all of the samples met the standards.

Sustaining Irrigation Supplies through Immobilization of Groundwater Arsenic In Situ.

Geogenic arsenic (As) in groundwater is widespread, affecting drinking water and irrigation supplies globally, with food security and safety concerns on the rise. Here, we present push-pull tests that demonstrate field-scale As immobilization through the injection of small amounts of ferrous iron (Fe) and nitrate, two readily available agricultural fertilizers. Such injections into an aquifer with As-rich (200 ± 52 μg/L) reducing groundwater led to the formation of a regenerable As reactive filter in situ, producing 15 m3 of groundwater meeting the irrigation water quality standard of 50 μg/L. Concurrently, sediment magnetic properties were markedly enhanced around the well screen, pointing to neo-formed magnetite-like minerals. A reactive transport modeling approach was used to quantitatively evaluate the experimental observations and assess potential strategies for larger-scale implementation. The modeling results demonstrate that As removal was primarily achieved by adsorption onto neo-formed minerals and that an increased adsorption site density coincides with the finer-grained textures of the target aquifer. Up-scaled model simulations with 80-fold more Fe-nitrate reactants suggest that enough As-safe water can be produced to irrigate 1000 m2 of arid land for one season of water-intense rice cultivation at a low cost without causing undue contamination in surface soils that threatens agricultural sustainability.

Evaluation of treated wastewater quality from Cap-falcon plant for agriculture irrigation

Wastewater reuse is a useful tool for minimizing the amount of wastewater discharged into the environment. However, it is associated with threats to the environment and public health; consequently, effluent quality assessment is essential prior to reuse. The aim of this study is to assess the physicochemical and microbiological quality of treated wastewater from Cap Falcon wastewater treatment plant for reuse in irrigation. The suitability of treated wastewater from Cap Falcon plant for irrigation was assessed based on its composition and Algerian irrigation water quality standards. The average biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) values decrease from 316 mg/L to 21 mg/L with a mean removal efficiency of 93.0% and from 659 to 40 mg/L with removal efficiency of 93.7% respectively. For total suspended solids (TSS), the concentration at the inlet of the treatment plant is very high but reduces greatly after biological treatment with a removal efficiency over 94.5%. The physico-chemical analyses of treated wastewater samples from the storage reservoir indicated that pH varied from 6.81 to 8.20 with an average value of 7.43, which is slightly alkaline in nature. Electrical conductivity is one of the criteria used to evaluate the suitability of water for agricultural use; the average value was found less than 1500 μS/cm, indicating that the treated wastewater is considered as suitable for irrigation use. On the other hand, microbiological analyses indicate that faecal coliforms are high compared with Algerian water quality reuse standards. Furthermore, the overall quality of tertiary treated wastewater was analyzed by calculating the water quality index. The calculated index for the physicochemical and microbiological parameters was 96, which corresponds to a water quality type “very poor” signifying that this effluent can only be used for restricted irrigation practices.

Agroclimate‐centric irrigation water quality guidelines

AbstractThe suitability of a given water source for irrigation warrants the diagnosis of potential salinity, sodicity and toxicity hazards. Region‐specific irrigation water quality standards and guidelines formulated worldwide are too conservative. After a comprehensive assessment of newer insights from re‐analysis of the available data and examination of the associated evidence covering diversified conditions of saline water use, existing guidelines are updated to adjust for site‐specific conditions. The updated versions for rating both saline and alkali waters include the chemical composition of irrigation waters, soil type (texture, clay mineralogy), salt tolerance rating of crops and rainfall for broader adaptability. As modified by soil texture and rainfall, crop salt tolerance is the decisive factor for fixing upper salinity limits in hyper‐arid, arid, semi‐arid and semi‐humid regions. The customized recommendations include conjunctive use, leaching/rainfall management, irrigation methods, ionic ratios, fertilizers and manures. Guidelines for sodic/alkali waters are based on both crop responses and sodicity‐induced water infiltration problems. The amendment requirements stand defined. In view of the increasing water scarcity, the established guidelines are expected to promote saline and alkali water irrigation in arid and semi‐arid regions while safeguarding the environment.

Physicochemical Analysis of Surface Water in Rohri Canal from Sukkur Barrage to Mehrabpur

The purpose of this study was to assess the effect of domestic and industrial waste discharge on the surface water quality of Rohri Canal in the stretch of the canal from Sukkur Barrage to Mehrabpur town. Eight sampling points were selected along the canal focusing on canal locations near major settlements. The parameters studied were temperature, pH, turbidity, hardness, alkalinity, total dissolved solids and suspended solids, chlorides, biochemical oxygen demand (BOD), chemical oxygen demand (COD) and E-coli. The average value of BOD and COD at the sampling stations were recorded as 212 mg/L and 423 mg/L respectively, which exceed the permissible surface water limits for drinking and irrigation purposes. The results indicate significantly higher value of BOD in sampling locations where there are major settlements and there is a continuous inflow of untreated sewage into the canal. The pH values at all the sampling sites were found within the drinking and irrigation water quality standards whereas the TDS values at only sampling stations (3 and 4) exceeded these limits. The turbidity values of the samples ranged from 237 to 821 NTU, exceeding the WHO drinking water quality standards for this parameter. The values of the water quality parameters including hardness (range 146 to 300 mg/L), chlorides (range 36 to 103 mg/L) and alkalinity (range 120 to 230 mg/L) were found well below the limits of WHO drinking water quality standards. The turbidity values of the samples ranged from 237 to 821 NTU and exceeded the WHO drinking water quality standards for this parameter. At all the sampling sites located near major settlements low levels of dissolved oxygen and the presence of E.coli were recorded. The results revealed that the continuous inflowing of untreated or un-treated sewage and industrial effluents into the canal has changed its physicochemical and biological characteristics, which make it unfit for human consumption and can have long-term irrevocable ecological threats if left unmanaged

Use of wind energy for desalination of seawater for irrigation

AbstractIn the context of the scarcity of water resources and the population growth that the world is experiencing, the only resource still available in inexhaustible quantities is seawater. The exploitation of this resource is possible only through the use of desalination techniques. The cost of energy was always the main constraint to water desalination; scientists had to develop new techniques to use renewable energies, in particular wind energy, to satisfy the high energy consumption of desalination plants. Morocco enjoys a privileged geographical location. In fact, Morocco is surrounded by two seas: the Atlantic Ocean and the Mediterranean. In terms of energy, Morocco has a large wind potential, especially in the south. In fact, according to the, Morocco is the fourth renewable energy producer in Africa with a capacity of 3061 MW. Within this framework, an ambitious project is currently being prepared by the Ministry of Agriculture, Maritime Fisheries, Rural Development and Water and Forests of Morocco, the construction of a desalination plant for irrigation and a 40‐MW wind farm in Dakhla, which will serve a new irrigated area in Dakhla of 5000 ha. This desalination station and sea intake will be located 75 km north of Dakhla and will have a capacity of 100,000 m3/d, 30 million cubic meters per year. It will use reverse osmosis technology to produce water that meets international standards for irrigation water quality. This megaproject will have a significant economic impact on the Dakhla‐Oued Eddahab region: first, the production of nearly 500,000 t of agricultural production for an added value of about 50 million USD per year and second, the creation of nearly 10,000 permanent jobs.

Water quality for agricultural irrigation produced by two municipal sewage treatment plants in Santiago Island-Cape Verde: Assessment of chemical parameters and pharmaceutical residues

Abstract Cape Verde, a West Africa Island country, is exposed to climate change effect. An effective way of reducing its poverty and achieving food security is to provide its agricultural sector with water. The purpose of this study is to monitor treated water quality to ensure that any pollutants are below the limits set to ensure the safety and sustainability of reuse because only 10% of its treated wastewater is reused. For the first time on Cape Verde islands, besides chemical quality, the occurrence of 11 pharmaceutical compounds (PhC) in the influent and effluent of two natural wastewater treatment plants (WWTPs) was monitored to assess the effectiveness of the treatment technologies and removal efficiencies of these pollutants. Of the 11 target PhC, nine were detected in influent samples within the ng·L−1 to μg·L−1 range. Lower concentrations were detected in one WWTP vs. the other. Nevertheless, the removal efficiencies for most compounds were similar in both WWTPs: within the ranges of 82–92% for beta-blockers, 48–99% for stimulants and 44–95% for nonsteroidal anti-inflammatories, while carbamazepine (anticonvulsant) concentrations increased in effluents. WWTPs produce water that meets water quality standards for irrigation if a properly designed and managed reusing system is adopted.

Effect of Hydraulic Loading Rate on Treatment Performance of a Pilot Wetland Roof Treating Greywater from a Household

To solve the upcoming environmental problems, sponge city concepts as well as new technologies are being developed these days. One of the future challenges is to reduce drinking water demand by using decentralized water recycling systems. This study aimed to investigate the performance of a specially designed pilot wetland roof (PWR) treating domestic greywater (GW) at ground level under outdoor conditions and to evaluate the effects of different hydraulic loading rates (HLRs) for a period of two years. The results showed highly efficient removal of typical greywater pollutants from the system, e.g., five-day biochemical oxygen demand (BOD5) > 96%, chemical oxygen demand (COD) > 93%, total suspended solids (TSS) >94%, anionic surfactants (AS) > 94%, ammonium-nitrogen (NH4-N) > 84%, total nitrogen (TN) > 71%, total phosphorous (TP) > 87%, and E. coli (1.86 ± 1.54 log-removal). The mean concentrations of the targeted parameters at the outflow were in compliance with the requirements for discharge to the environment and met reclaimed water quality standards for agricultural irrigation, except for E. coli. Statistically significant (p < 0.05) results of pollutant mass removal rate across different HLRs indicated the potential effect of HLR on treatment performance, and HLR in a range of 67–80 L m–2 d–1 contributed to a higher removal efficiency without compromising the limit values. A comparatively low HLR of 45 L m–2 d–1 should be applicable if pathogen removal is the most important requirement. Plant species showed good plant vitality and adapted well to the water storage mat. The higher the mean ambient air temperature, the greater runoff reduction (>50%) was observed due to high evapotranspiration. The results showed the system is a promising green technology for GW recycling and can be scaled up for application to urban buildings.

Determinan Terpilih untuk Kualitas Air Embung pada Lahan Tadah Hujan di Karanganyar, Jawa Tengah

Water conservation is needed to overcome the shortage of irrigation water through harvesting rainwater on rainfed land using small farm reservoir. Intensive agricultural activities cause a reduction in land resources which disrupts hydrological functions (water quantity and quality). This study aims to determine the selected parameters for small farm reservoir water quality and identify water quality based on irrigation water standards according to FAO (1994) and PP No. 82 of 2001. The research was conducted from March to December 2014 in Karanganyar Regency, Central Java Province. This study used a descriptive exploratory survey method with purposive sampling. Water quality data was analyzed using Principal Components Analysis (Multivariate Test) MINITAB 16 to determine the main components as the selected determinants. Furthermore, based on the results of the PCA analysis, 5 variables were obtained whose eigenvalue proportions met the main criteria, including DHL of 0.467; SAR of 0.542; pH of 0.538; Actual Savings Ratio (ASR) of 0.662; and water-air temperature deviation of 0.612. Furthermore, a match is made between the selected determinant measurement data and the water quality standard. The results of matching to the selected determinants for water quality in the reservoir have met the water quality standards for irrigation based on FAO (1994) and Government Regulation no. 82 (2001). The soil characteristics of the catchment area also affect water quality because in rainwater harvesting, surface runoff in the catchment area will flow and be accommodated by the small farm reservoir.
 
 Keywords: water quality, small farm reservoir, PCA, water conservation, rainfall harvesting

Low-cost ceramic filter bioreactor for treatment and reuse of residential septic tank effluent: A decentralized approach for small communities

Membrane biological reactors (MBRs) have recently become widely accepted as an advanced technology for treating domestic wastewater for improved water recovery, reuse, and recycling. The present study investigated the application of a low-cost ceramic filter bioreactor (CFBR) to treat septic tank effluent for smaller communities in Saudi Arabia (KSA). Filter fouling behavior, pollutant removal, and effluent quality were assessed under varying flux (0.2, 0.4, and 0.65 m/d) and aeration on/off cycle (60 min/60 min, 40 min/80 min, 30 min/90 min, 24 h/24 h) conditions. Operating CFBR at a flux value of 0.4 m/d ensured moderate fouling propensity, reasonable flux decline, and a higher volume of treated effluent. In the continuous aeration mode experiments, CFBR demonstrated the removal of various pollutants. Except for NO3N, CFBR effectively reduced all other pollutants of concern (BOD, COD, TSS, NH3N) in the effluent to acceptable levels meeting the water quality standards for unrestricted irrigation set by the KSA. An enhanced NO3N removal at the 24 h/24 h on/off cycle, indicating the effectiveness of cyclic aeration for promoting both nitrification/denitrification in the CFBR, with sufficient removal of other pollutants, is an original finding of the present study. Simple and cost-effective operations, high-quality effluent, and reduced energy consumption with shorter aeration duration promote the sustainability of the CFBR system for wastewater reclamation and reuse in small communities and rural settlements.

Determination of pollution status of Nilüfer river by water and bottom sediment analysis

Abstract This study aims to evaluate the Nilüfer river in terms of water quality standards. Bottom sediment and water samples were taken from six different locations. The analysis of the physicochemical parameters of water compared with FAO for irrigation water quality standards. In addition, the SAR (sodium adsorption ratio), % Na, MAR (magnesium adsorption ratio), RSC (residual sodium carbonate), KR (Kelley's ratio) and % PI (permeability index) parameters were evaluated in water samples. The bottom sediment pollution situation was evaluated in terms of pollution index such as TEC (threshold effect concentration) and PEC (probable effect concentration). According to the results of the study, the irrigation water classes of the samples were determined as C2S1 and C3S1. Especially, sample sites S4, S5 and S6 were not suitable for irrigation in terms of RSC, KR. The bottom sediment exceeded the TEC and PEC limit values in terms of Zn, Cu, Cr and Ni contents. This may cause adverse effects on the majority of sediment-dwelling organisms.The use of alternative water sources should be preferred. The river can be used for irrigation with precaution but extensive treatment is required before use for irrigation purposes to prevent adverse public health effects.

Assessment of Agricultural Irrigation water from Groundwater in Lobalain District, Rote Ndao Regency, East Nusa Tenggara Province, Indonesia

Determination of water availability for irrigation consists of quantity and quality. However, water quality is generally often neglected. This study aims to determine the groundwater quality in order to meet the standard of agricultural irrigation quality standard in the Lobalain District, East Nusa Tenggara Province, Indonesia. The results showed that the groundwater quality with a predominantly pH value did not meet the standard. The none restriction on use class dominated the total dissolved solids (TDS) value. The average electrical conductivity (EC) value is less than 750 μs/cm. The chloride is dominated by less than the tolerance threshold (Cl-<4.0 meq/l), for sulfate (SO4), which is within the threshold (<20 meq/l), and the nitrate (NO3N) dominated as slight to moderate. The boron (B) showed positive results, which in all areas was very satisfactory because it is below the tolerance threshold (B<0.7 mg/l). The sodium percentage (Na%) analysis was dominated by excellent and good class, and the excellent category dominated the sodium adsorption ratio (SAR). Eight locations are highly recommended as agricultural irrigation sources due to their groundwater quality. Only one location is not recommended in Kuli Village because only three parameters (Na%, EC, and Cl-) meet the irrigation water quality standard.

A multi-pronged approach to source attribution and apportionment of heavy metals in urban rivers.

Heavy metal (HM) contamination of water bodies is caused by both first generation (industries) and second generation (distributed sources, domestic sewage, sediments) sources. We applied a multi-pronged approach to quantify the contribution of first and second generation sources to the HM load in a stream located in an industrialised catchment. We found that, despite strict regulation, first generation sources contributed significantly to the HM load (60%-80%), showing the ineffectiveness of current regulation. Domestic sewage contributed significantly to Cu, Ni, and Mn load (15%-20%). The contribution of distributed sources and sediments to HM load is insignificant. In a 24-hour cycle, HM concentrations frequently exceeded FAO's irrigation water quality standards, with the highest concentrations observed at night. Empirically, the study highlights the continued plight of urban streams in rapidly industrialising centers and the failure to regulate first-generation sources. Methodologically, it demonstrates the importance of temporally intensive measurement of contaminant concentration and load. Policy implications include the need for ambient water quality standards, inclusion of HMs in such standards, load-based regulation, and a problem-oriented monitoring and enforcement approach.

Effect of brewery wastewater irrigation on soil characteristics and lettuce (Lactuca sativa) crop in Ethiopia

Due to the shortage of water for irrigation, brewery wastewater is currently used as a source of irrigation for crops in developing countries including Ethiopia. However, there is little information about the influence of brewery wastewater on soil properties, crop nutrients and productivity in Ethiopia. Thus, this study was conducted to investigate the effect of brewery wastewater on soil physical and chemical characteristics, agronomic traits and nutrients composition of lettuce crop. Wastewater and wastewater irrigated soil samples were collected for laboratory analysis. The pot experiment was also conducted in completely randomized design (CRD) with three replications using four treatments where 100%, 75%, 50%, and 25% of the water demand was covered by brewery wastewater (WW), where one additional treatment namely 100% control water(CW) was used. The analysis of physical-chemical contents for brewery wastewater samples indicated that the values for EC, TSS, BOD, COD, HCO3-, K+, SSP and SAR levels were above the permissible limit of the FAO irrigation water quality standard. The mean values of T, pH, TDS, NO3-N, Ca+2, Mg+2, Na+, and Magnesium Hazard (MH) were below the permissible limit of the FAO standard. The pot experiment showed that 100%WW irrigated soils non-significantly (p < 0.05) enhanced the lettuce traits of leaf length, number of leaves, and fresh leaf weight by 12%, 22%, and 24% over 100%CW irrigated soils. In addition, 100%WW irrigation significantly (p < 0.05) enhanced the plant height and nutrient compositions (Ca2+, Mg2+, Na+, K+ Fe, Zn, Mn and TN) of lettuce leaf. The study concludes that the brewery wastewater is saline-sodic and it affects soil characteristics and lettuce crop. Therefore, ameliorative measures such as gypsum seem to be inevitable, and, there should be continuous monitoring and evaluation for the quality status of brewery wastewater before use for irrigation.

Water quality analysis of old and new Phuleli Canal for irrigation purpose in the vicinity of Hyderabad, Pakistan

Abstract Irrigation-water quality plays an important role in agriculture productivity. In this study, water quality of the old and new Phuleli canal located in Hyderabad, Pakistan, was characterized for irrigation purpose. Water samples were collected from four different locations of both the old and new Phuleli canal. Twelve different irrigation-water quality standards were assessed under the study: pH, Electricity Conductivity, Biochemical Oxygen Demand (BOD), Total Dissolved Solids, Chemical Oxygen Demand (COD), Dissolved Oxygen, Calcium, Magnesium, Sodium, Potassium, Sodium adsorption ratio, Fecal Coliforms. The results showed that the Electricity Conductivity ranges from 910–3,090 MS/cm, Potassium 13–112 mg/l, BOD 61–285 mg/l, COD 97–361 mg/l and Fecal Coliforms 400–2,350 MPN/100 ml concentrations in water of both canals were higher than the National Environmental Quality Standards permissible limits. It was found that the water quality parameters were higher than the permissible pollution level of canal water for the use of irrigation in agriculture.

An In-Depth Analysis of Water Quality Using GIS and Heavy Metal Pollution Index near a Gold Mining Area, Qorveh, Iran

Introduction: Inappropriate management of mining activities may bring about water pollution and pose a heavy complication on aquatic ecosystem and humans. The study aimed to evaluate the effect of Qorveh gold mining activities on the quality of nearby groundwater. Materials and Methods: The concentration of seven eco-toxic metals along with some general hydrochemical parameters were investigated for 27 sampling stations in the study area using Atomic Absorption Spectrometry (AAS) and conventional hydrochemical methods. The analysis results were further applied to compute pollution indices, namely heavy metal pollution index (HPI) for irrigation purposes. Results: The main elements were within the World Health Organization (WHO) and Iranian National Water Standards (INWS) for irrigation water quality, except for NH4+ in some sampling points. The concentration of heavy metals followed the order Cu &gt; Zn &gt; Pb &gt; Hg &gt; Cd &gt; As. The contents of Hg, As, Cd, and Cu in most sites were higher than the recommended values. Except for two stations, the value of HPI based on the mean concentration was found to be far beyond the critical pollution index value of 100, suggesting that the area is highly polluted with some heavy metals. Conclusion: Elevated concentration of trace elements found in groundwater of this area represented the release of harmful elements from gold mining activities on surrounding environment.

Quality Assessment of Groundwater of Barind Area, Bangladesh using Integrated Hydrochemical Method

The study was conducted for assessing water quality for drinking and irrigation purposes of groundwater sources. Total 50 water samples were collected from different locations of Nachol and Niamatpurupazilla of Chapainawabgonj and Naogaon district in January 2019 and January 2020. Water quality parameters like pH, electrical conductivity (Ec), iron (Fe), manganese (Mn), calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), sodium (Na), potassium (K), total hardness (TH), alkalinity, sulphate (SO4), nitrate (NO3), nitrite (NO2), ammonia (NH4), phosphate (PO4), chloride (Cl), dissolved oxygen (DO), and total dissolved solids (TDS) were analyzed in the laboratory. All the analyzed parameters were compared with national and international drinking and irrigation water quality standards to understand the overall groundwater quality status of the study area. The study showed that the water samples of almost all the locations were suitable for consumption and irrigation.

Irrigation with Coal Mining Effluents: Sustainability and Water Quality Considerations (São Pedro da Cova, North Portugal)

Two water effluents that drain from the abandoned coal mine of São Pedro da Cova (NW Portugal) were characterized in terms of their physic-chemical properties and suitability for irrigation purposes. Samples were also collected in a local surface stream, upstream and downstream from the mine drainage points, also used for irrigation by local farmers. Water samples were analyzed for major and minor ions and for trace element concentrations. Sampling campaigns started in 2017 and ended in 2019 and there were 46 water quality parameters tested. There were also proposed all-inclusive indices (the Water Quality Index and the Contamination Index, and also the Trace Element Toxicity Index) based on specific groups of 18 and 17 physic-chemical parameters, respectively, to achieve adequate monitoring requirements for mine effluents and surface water from coalfield. From the physical and chemical aspects of mine water it is inferred that the mine is not producing acid mine drainage. The coal mine water is of medium to high salinity, having almost neutral pH and a high thermal stability during the year, which is a distinguishing feature of the effluents. When compared to international irrigation water quality standards, as Food and Agriculture Organization of the United Nations admissible concentrations, the impacted waters are unsuitable for irrigation. The major outliers to the guidelines were iron, manganese, potassium, magnesium and bicarbonates, being also detected carcinogenic polycyclic aromatic hydrocarbons. Cost-effective ways of monitoring water quality parameters are needed to help control and manage the impact of coal mine effluents that should be treated before releasing into a ditch system that could be then used by local farmers to irrigate their crops.

Pollution and Irrigation Applicability of Surface Water from Wet, Normal, and Dry Periods in the Huixian Karst Wetland, China

To reveal the hydrochemical characteristics of karst wetland located in a subtropical area and at lower elevations in China, 27 surface water samples were collected during three periods (wet, normal, and dry) in the Huixian karst wetland to investigate the distributions, pollution, and irrigation application of 12 inorganic ions and 10 heavy metals. Based on their concentrations, the Nemerow index and the four evaluation systems of the sodium adsorption ratio (SAR), sodium concentration (SC), permeability index (PI), and residual sodium carbonate (RSC) were applied to evaluate the pollution characteristics and irrigation application. It was found that the water type in this area was Ca2+-HCO3- and weakly alkaline. Regarding the 12 inorganic ions and 10 heavy metals, NH4+ exceeded the Chinese standards for drinking water with an exceedance rate of 25.93%, and the exceedance rates of Al, Mn, and Hg were 11.11%, 44.44%, and 37.04%, respectively. The spatiotemporal scaling effect on inorganic ions was lower than that of heavy metals, and the distributions of the inorganic ions and heavy metals were in the order of wet period > normal period > dry period. However, the surface water quality in the Huixian karst wetland was generally well-protected based on the pollution assessment. The Nemerow index ranged from 0.75 to 2.69, which recognized the main pollution contributors as NH4+, Mn, Al, and Hg with the contamination grade from slight pollution to moderate pollution, especially in the core area during the wet period. According to the limits of standards for irrigation water quality and environmental quality for surface water, as well as the evaluation results of the SAR, SC, PI, and RSC, the surface water in the Huixian karst wetland was generally suitable for irrigation, and the water quality in the dry period was better than that in the wet and normal periods. The surface water from site PH1 during the normal period with 19.1 μg·L-1 of Hg and site FH8 during the wet period with 13.7 mg·L-1 of NH4+ were not suitable for agricultural irrigation.