Reduce Groundwater Pollution Research Articles

Hydrogeological assessment and contaminant transport modelling of Enyimba landfill site in Aba, Nigeria

ABSTRACT Commercial and industrial growth in cities generates hazardous waste, often disposed of in open dump sites, contaminating groundwater. Understanding pollutant movement and numerical models are crucial for effective water resource management. This study assessed hydrogeological dynamics and pollutant transfer in the Enyimba landfill site, Nigeria, using field surveys and contaminant modelling to understand groundwater quality and arsenic contamination spread. The research technique included field and laboratory experiments, as well as water sampling during both dry and wet seasons, to evaluate groundwater quality. The geochemical examination of groundwater samples revealed the amounts of several metals using atomic absorption spectrophotometry. The study used contaminant transport modelling with Visual MODFLOW Flex 6.1 and MT3DMS software to simulate groundwater flow and solute transport within the aquifer layers. Predictive simulations over a 20-year timeframe demonstrated the progressive spread of arsenic pollution from the landfill, resulting in an ellipsoid-shaped plume stretching from its source. Arsenic levels have gradually increased, posing a serious threat to groundwater quality and human health. The research highlights the need for remedial measures to reduce groundwater pollution, including waste recovery and recycling facilities and geo-membrane use. It emphasizes proactive actions to protect groundwater supplies and promote environmental sustainability in the Enyimba landfill site.

Improving prediction accuracy of CSM-CERES-Wheat model for water and nitrogen response using a modified Penman-Monteith equation in a semi-arid region

Context or problemThe implementation of crop models for water and nitrogen management are important in preserving water resources and reducing groundwater pollution. The Decision Support System for Agrotechnology Transfer (DSSAT) is a collection of field-scale process-based crop models that simulate crop growth and yield in response to water and nitrogen management as well as many other factors. Objective or research questionThe objective of this study was to improve the simulation of irrigation and nitrogen fertilizer effects on growth and yield of winter wheat using locally modified Penman-Monteith (PM) equation. Specifically, we focused on improving the estimation of ETo using a locally modified Penman-Monteith (PM) equation in the CSM-CERES-Wheat model. MethodsField measured data from a two-year experiment (2009–2010 and 2010–2011) in a semi-arid region were used to calibrate and evaluate the CSM-CERES-Wheat model in a region with strong advective condition. In this experiment, the irrigation treatments were 1.2, 1.0, 0.8, 0.5 times by full irrigation requirements and rain-fed, and nitrogen treatments were 0, 46, 92, and 136 kg N ha−1. ResultsUsing the CSM-CERES-Wheat model with the unmodified PM equation resulted in some growth variables such as: aboveground dry matter, grain yield, and grain nitrogen uptake with high normalized root mean square error (NRMSE) of 0.51, 0.35, and 0.32, respectively. However, using the modified PM equation for ETo module under semi-arid condition improved the soil water content estimation and the model outputs, such as the above ground dry matter, grain yield and grain nitrogen uptake with NRMSE of 0.2, 0.15 and 0.16, respectively, that are accurate. This modification provided more accurate estimations, particularly in our experimental site in semi-aid region with strong advective conditions. ConclusionsThe findings of this study indicated that the locally modified PM equation in the CSM-CERES-Wheat model enhanced the accuracy of estimating irrigation and nitrogen fertilizer on the growth and yield of winter wheat. By improving the estimation of ETo value, the model's performance in simulating crop responses to water and nitrogen management was significantly enhanced. Implications or significanceThe utilization of the accurately estimated ETo value of the modified PM equation has significant importance in the practical application of the CSM-CERES-Wheat model. Furthermore, this modification greatly enhances the accuracy of model outputs, particularly at our experimental site located in a semi-arid region with robust advective conditions.

Development of Software for 3D Well Visualization Modeling Using Acoustic, Gamma, Neutron and Density Logging for Fossil Energy Sources Sustainable Production

Achieving the UN Sustainable Development Goals is impossible without sustainable oil and gas production, both in terms of ensuring equal access to cheap energy and preserving the environment, as well as caring for non-renewable fossil energy sources. This actualizes the need for the digital 3D modeling of wells, which allows one to assess their current condition and predict their future condition as well as determine the feasibility of investing in their reconstruction and the expansion of the well network. This is possible due to the fact that the visualization of a well, reflecting its physical and technical parameters, gives engineers, designers and ecologists the opportunity to recognize the defects of the well (cracks, cavities, behind casing and interlayer leaks, etc.) and predict their appearance and proliferation on which the service life, hydrocarbon flow rate, pollution, operating and capital costs directly depend. The software required for this must be versatile enough to cover different types of logging and fit different operating systems. The goal of the study is to develop a software for creating visual 3D models of wells based on acoustic and various types of radioactive logging data, capable of integrating drilling rig parameters and geophysical survey data with modern 3D modeling and programming methods. The developed software meets the requirements of various operating systems and the specifics of different types of logging, which is designed to help in increasing the productivity of oil and gas wells, save energy consumption and reduce groundwater pollution from chemicals used in hydrocarbon production. This is achievable by ensuring trouble-free execution and the operation of well systems, minimizing the risks of collapses and the destruction of well walls through accurate monitoring and forecasting their dynamic condition in real time using 3D models, which is not available for static 2D models.

Impact of different land use types on groundwater quality in Ibadan, Nigeria

Studies of comparative analysis of groundwater quality under different land use types are scarce, and such studies remain critical in achieving sustainable water resource management. This study used suitable multi-statistical techniques alongside the Water Quality Index (WQI) to assess and compare the effects of residential, industrial, and agricultural land use types on groundwater quality in a region of Ibadan, Nigeria, primarily underlain by banded gneisses. The study also established the appropriateness of the water samples for human consumption. Thirty water samples, consisting of 10 samples each from three different land use types, were randomly collected and subjected to established methods of analysis for nine physicochemical parameters. The results from the Kruskal-Wallis test and Dunn's test showed that average concentration levels of pH, total hardness, calcium, magnesium, chloride, bicarbonate, nitrate, and sulfate in the tested water samples were significantly different (p-value ≤ 0.05) among the three land use types investigated. The results also suggested that where poor environmental conditions are common, residential land use type could pose a greater risk to groundwater quality than either agricultural land use or industrial land use. At least, a three-factor model was suggested and explained 63.4 %, 70.2 %, and 91.6 % of the total groundwater quality variation under the residential, agricultural, and industrial land uses respectively using Kaiser's varimax rotation method. In addition, the WQI results showed that 100 % of the water samples from industrial and agricultural land uses were appropriate for drinking but only 20 % of the water samples from residential land use were. The findings indicated that differing land use types affect groundwater quality in different ways. It was thus recommended that an improved sanitation system should be provided by the authorities to help reduce groundwater pollution in the residential area. This can help toward achieving water security mentioned in the African Union's Agenda 2063.

Effect of Soil Amendments on Leaching of Thiamethoxam in Alluvial and Calcareous Soil

In this study, peat, compost and charcoal were added to reduce groundwater pollution with thiamethoxam by soil columns. Iodide has been used as a water tracer at a rate of 10 mL (0.1 M) for each soil column and that leached fast in all soil columns. The breakthrough curve of thiamethoxam was appeared from leachates of calcareous soil column and alluvial soil column with iodide. Accordingly it is considered thiamethoxam is highly mobile compound in tested soils. The addition of soil amendments reduced downward movement and significantly increased cumulative percentage of thiamethoxam from soil columns. After application; 85.21, 93.23, 98.12 and 97.84 % of applied thiamethoxam were recovered in leachates of alluvial soil, 5% peat-soil, 5% compost-soil and 5% charcoal-soil. While; 91.50, 99.30, 94.09 and 86.89 % from calcareous soil, 5% peat-soil, 5% compost-soil and 5% charcoal-soil columns. This is first study to assess, leaching of thiamethoxam and effect of soil amendments on leaching by soil columns. This information can be used to understand how alterations in agricultural practices and potential effects to groundwater.

The importance of biomass in sustainable agricultural soil management

The importance of biomass in sustainable agricultural soil management

A Study on Improvement of Wastewater Disposal System in Jaffna Municipal Council Area, Jaffna Sri Lanka

Jaffna Municipal Council is the heart of Jaffna district with a land area of around 20.20 km2 and 27,820 families are living at present. JMC is maintaining the groundwater recharging ponds, wastewater disposal systems and drainages. At present storm water drainage is using as wastewater drainage and using as a wastewater collecting tank. Therefore, wastewater treatment is needed to provide a quality and affordable environment. A detailed literature review was carried out to understand the reasons for this problem and how to overcome them. A survey with a questionnaire and wastewater testing analysis was carried out. According to the analysis majority of the people are using open dug well, therefore, groundwater should be protected and 55.83% of the lands are 10-20 perches and some main parameters were above the standard level. Based on the findings of the feasibility study centralized conventional wastewater treatment plant with tertiary or advanced treatment is very much feasible. The common conventional process with advanced treatment was used and the treatment plant was designed to 17900 m3 /day to accommodate 109,535 people. The total cost of the project is 473 million. With the propose system waste water quality will be well below the required standard levels. A wastewater treatment plant is most important for JMC to reduce environmental pollution and reduce groundwater pollution and maintain the groundwater table.

"RECONSTRUCTION OF THE ASH AND SLAG REMOVAL SYSTEM IN CHP-2 OF JSC «ARSELORMITTAL TEMIRTAU»"

"This article discusses the modernization of the ash and slag removal system at CHPP-2 of JSC «ArcelorMittal Temirtau», the transition from the wet method of cleaning ash and slag to a more technologically advanced dry one. The long-term use of the hydraulic ash and slag removal system (GZSHU) has led to the accumulation of a huge amount of ash, which is subsequently not used. A comprehensive replacement of wet cleaning equipment for dry cleaning is considered. The wet method offers quenching with water (in this case, up to 1 % of the thermal efficiency of the TP-81 boiler unit is lost), followed by the use of drag pumps and the removal of ash and slag through the hydraulic ash removal channels to the ash dump. In the future, this ash cannot be used. During dry ash and slag removal, extinguishing with water is not used, but a pneumatic system for removing combustion products is used. Ash from gas cleaning plants through a system of pneumatic chamber pumps and intermediate hoppers is fed through ash pipelines to a silo warehouse. The use of this technology allows minimizing the harmful impact on the environment by reducing groundwater pollution with pulp, reducing the area of ​​​​ash dumps, reducing water consumption by the station, using ordinary types of steel in pipeline systems, and reducing the cost of equipment maintenance. Keywords: boiler, slag, ash and slag removal, dust preparation, hydraulic ash removal, fuel, coal, ash."

Assessment of Groundwater Quality Status in Medawachchiya DS Division in Anuradhapura District, Sri Lanka

Medawachchiya DS division in Anuradhapura district is a major agricultural area. Majority of people depend on groundwater for their domestic consumption and agricultural activities. Farmers apply excess amount of chemical fertilizers and pesticides in crop production and a number of CKDu patients are identified in this division. Hence, analysis of groundwater quality in this region is vital to ensure its suitability for various purposes. The present study aimed to assess the groundwater quality in Medawachchiya DS division. Groundwater samples at 25 locations were collected and analysed for major physio-chemical parameters. Water Quality Index (WQI) was estimated to assess the suitability of groundwater for drinking purpose. Results releveled that the quality of groundwater varies spatially in the study area. Groundwater near industrial and dumping sites was acidic. The Color and Turbidity of groundwater exceeded the permissible limit at Kadawathrambewa and Medawachchiya West. Groundwater at more than 50% of the sampling locations was very hard The TDS and Alkalinity levels exceeded the maximum permissible limit at 52% of the sampling locations. Fluoride content was above the acceptable limit at 20% of the sampling locations. The elevated level of Nitrate and Phosphate were observed in the farming areas. However, the Chloride level was within the acceptable limit. According to the estimated WQI, the quality of groundwater was excellent at 44% of the sampling locations. However, groundwater quality at Abayapura, Helabagaswewa, Walpola, and Wiralmurippuwa was very poor and the groundwater at Mahakubukgollewa was unsuitable for drinking purpose. Promoting the usage of organic manure in agriculture, monitoring the industrial wastewater discharge, and converting the open dumpsite to sanitary landfill would be viable options to reduce groundwater pollution in these areas.

A Review of Synthetic and Earth's Resource-Based Slow-Release Fertilizers and Their Potential Role in Reducing Groundwater Pollution

Groundwater is an essential water source for humans. Unfortunately, some groundwater resources have been contaminated by wastes from various sectors. Fertilizer also contributes to groundwater contamination. The nutrients from fertilizer that are not absorbed by the plant move towards groundwater reservoirs and contaminate the groundwater. Slow-release fertilizer is a solution to reduce groundwater pollution while maintaining fertilizer’s function as the sources of nutrients for plants. This paper discusses and reviews the relevant literatures related to groundwater, fertilizer, slow-release fertilizer, and earth’s based slow-release fertilizer. The release rate of nutrient elements from different types of fertilizer is also presented. The synthetic base slow-release fertilizers and earth’s resource-based slow-release fertilizers can hold nutrients longer than conventional chemical fertilizers when exposed to water. Two particular minerals that can be used as raw materials in slow-release fertilizer synthesis are analyzed using XRD. They are from hydrothermal silica and obsidian. The XRD analysis of hydrothermal silica and obsidian shows the presence of amorphous silica and other minerals. Silica in compacted slow-release fertilizer can control the release rate of nutrient elements from fertilizer.

Ultrafiltration concentrated biogas slurry can reduce the organic pollution of groundwater in fertigation

Biogas slurry has the problems of having a low concentration, having a large production volume, and containing many small-molecule organic pollutants. During the fertigation process of biogas slurry, many small-molecule organic pollutants may pose potential pollution risks to groundwater. In this study, the ultrafiltration membrane technology was used to separate small-molecule organics in the biogas slurry to prepare ultrafiltration concentrated biogas slurry (UCBS). To research the impact of UCBS and raw biogas slurry (RBS) on the small-molecule organic pollution of groundwater, a laboratory soil column simulation leaching device was used to conduct leaching experiments with 4 types of UCBS and RBS in acric ferralsols and hydragric anthrosols for two quarters (8 fertilization periods). The results of the study show that both UCBS and RBS caused nitrate pollution to groundwater. UCBS has a lower risk of organic pollution to groundwater than RBS. Irrigating UCBS in hydragric anthrosols has a higher risk of organic pollution of groundwater than that in acric ferralsols. Analysis of the molecular weight distribution of dissolved organic matter (DOM) in the leaching solution showed that the organic pollutants were mainly small molecules <10 kDa. According to 3D excitation-emission matrix (3D-EEM) analysis, the main organic pollutants in the leaching solution were fulvic acid, microbial protein metabolites and humic acid organic compounds. The research results show that the pretreatment of biogas slurry by ultrafiltration can reduce the risk of small-molecule organic pollution of groundwater in land application, which can provide a new scientific basis to standardize biogas slurry land application technical guidelines and reduce groundwater pollution.

SALEACH: A new web-based soil salinity leaching model for improved irrigation management

Leaching is essential in irrigated croplands where natural precipitation is insufficient to control salinity buildup. Several useful models exist for salinity management; however, leaching requirement (LR) calculations are based on steady-state approaches that only consider salinity tolerance of crops and irrigation water salinity to estimate the LR. In this study, a web-based soil salinity leaching management model (SALEACH) was developed as an online tool to assist growers for better and easier management of soil salinity to sustain agricultural production in irrigated croplands. SALEACH employs the traditional steady-state approach to estimate LRs but improves outputs by not only considering irrigation water salinity (ECiw) and salinity tolerance of specific crops (ECt), but also root water uptake patterns to account for irrigation system differences, and soil types for differences in hydraulic characteristics, as well as water stress and rainfall input. The SALEACH model can calculate the required irrigation water depth by using the estimated LR or any user-specified leaching fraction (LF) values; it can predict the drainage water salinity and soil salinity in the rootzone based on the applied leaching; and it can estimate relative crop yield for a given LF. SALEACH-estimated LRs were assessed in different soil types and irrigation systems by comparing them with LRs, soil water and drainage water salinity values obtained from an existing steady-state model (WATSUIT) and a transient-state model (HYDRUS-1D). Statistical analyses showed that SALEACH-estimated LRs, soil salinity, and drainage water salinity were all in the acceptable ranges of the corresponding values derived from other models. Thus, we conclude SALEACH is reliable and can be employed by practitioners to produce satisfactory estimations of LRs and soil salinity by considering the soil, crop, water quality, and irrigation system. Adoption of the model can improve water use efficiency and reduce groundwater pollution.

Effects of Sheep Manure Combined with Chemical Fertilizers on Maize Yield and Quality and Spatial and Temporal Distribution of Soil Inorganic Nitrogen

In order to explore the influences of sheep manure mixed with chemical fertilizers upon the yield and quality of maize and the spatial and temporal distribution of soil inorganic nitrogen under the wheat‐maize rotation system, achieve increased yield and efficiency with rational fertilization of maize in this area, and at the same time provide a reasonable scientific basis for green production, an experiment was performed at Wanbei Comprehensive Experimental Station of Anhui Agricultural University in 2020 accordingly. The soil for the experiment is sand ginger black soil, and the subject is Zhengdan 958. The experiment adopts a randomized block design with 6 treatments: no fertilizer (T1), single application of the chemical fertilizer (T2), 15% sheep manure mixed with the chemical fertilizer (T3), 30% sheep manure combined with the chemical fertilizer (T4), 45% sheep manure added with the chemical fertilizer (T5), and only sheep manure (T6). The amount of nitrogen, phosphorus, and potassium applied in each treatment remains the same. The result of the experiment shows that T1 treatment has the lowest yield, followed by T6 treatment. The yield of sheep manure combined with the chemical fertilizer is much higher than that of pure sheep manure and no fertilizer. Among them, the yield of T3 is the highest and T4 is the lowest. There is no obvious variation between the combined treatments. Compared with single usage of the chemical fertilizer, the fat content of maize kernels treated with T3 and T4 is 8.9% and 5.6% higher than that of T2 treatment. The protein content of maize kernels treated with T3, T4, and T5 is 2.3%, 2.5%, and 2% higher than that of T2. It shows that the mixture of sheep manure and chemical fertilizer can improve the quality of maize kernels in some degree. The partial productivity of the nitrogen fertilizer in T3 and T5 treatments is 3.7% and 0.8% higher than that of T2 treatment, and the agronomic utilization rate of the nitrogen fertilizer is 10.9% and 1.6% higher than that of T2 treatment. T6 is much lower than that of T2 treatment. It certifies that the combined application of chemical fertilizers with sheep manure can increase the partial productivity and the agronomic utilization rate of the nitrogen fertilizer and increase crop yields and farmers’ income. The nitrate nitrogen of 40–60 cm soil layer is increased by 30.4%, 60–80 cm soil layer is increased by 56.5%, and 80–100 cm soil layer is increased by 11.6%. It shows that the mixed usage of organic and inorganic fertilizers can prevent nitrate nitrogen from moving to deep soil and reduce groundwater pollution.

Removal of nitrate using modified pumice as adsorbent for reducing groundwater pollution

Nitrate adsorption onto the physically and chemically modified pumice was investigated as an effort for reducing groundwater pollution. The treatments were heating at temperatures of 300°C, 450°C, and 600°C for physical and soaking in acid solutions (HCl, H2SO4, and HNO3) for chemical treatments. The adsorption was performed in a batch system at room temperature (25±1°C) with the optimum condition (pH 4; 0.3 g/L of adsorbent dose; &lt;63 µm of adsorbent diameters and 30 minutes of contact time). The results indicated that the physically and chemically modified pumice resulted in increasing removal efficiency and nitrate uptake compared to the natural pumice. The highest removal efficiency and nitrate uptake were achieved from 300°C of heating temperatures (62.04% and 155.09 mg/g) and H2SO4 for the acid solution (83.30% and 208.25 mg/g), while by using the natural pumice only reached 57.02 % and 142.55 mg/g. The SEM images of the modified pumice confirmed the change in the surface morphology of pumice including the pore structure and surface area which can be proper sites for adsorption of pollutants. This study demonstrated that physical and chemical modification could be the potential treatment to increase the removal efficiency and nitrate uptake of the natural pumice, thus can solve the problem of groundwater pollution.

Land-use change caused by anthropogenic activities increase fluoride and arsenic pollution in groundwater and human health risk

Groundwater pollution is becoming a more serious issue because of various anthropogenic activities. A large proportion of the population living in the urbanized and industrialized world is exposed daily to hazardous materials. However, despite the knowledge that protecting groundwater is necessary, little is known about the role of land-use change for human health risks. In this study, we analyzed the temporal and spatial variation of groundwater fluoride (F) and arsenic (As) during 2010–2018 in Shanxi Province of Northern China. Distribution areas of high F and As increased from 2010 to 2018 and spread over time. We assessed human health risk by calculating carcinogenic risk and non-carcinogenic risk. The results showed that F exposure, frequency of high concentration, and risk from 2016 to 2018 were higher than that in 2010–2015, and similar results were obtained for As exposure. Further, land-use change caused by anthropogenic activities increased F and As pollution in groundwater and placed humans at a higher health risk. Our study sheds light on anthropogenic activities that could increase human health risks caused by groundwater F and As via changing land-use. The study provides supports and suggestions for policy-makers to reduce groundwater pollution and prevent adverse health risks to residents.

Securing the critical role of groundwater for the resilient water-supply of urban Africa

Abstract The provision of secure water-supplies for the rapidly expanding cities of sub-Saharan Africa experiencing climate-change stress will be one of the great infrastructure and environmental challenges of the next 20–50 years. Most African cities are blessed with usable groundwater, and some with the presence of major aquifers, but urban water utilities will need to take a more proactive approach to groundwater resource management and quality protection if the opportunity of a secure water supply is to be sustainably secured. Among the key policy issues that need more attention are rationalising utility groundwater use, prioritising installation of mains sewerage to reduce groundwater pollution risk, promoting enhanced groundwater recharge to improve resource sustainability, using groundwater in ‘decentralised closed-loop water-service systems’ to meet the demands of new outer urban districts, and implementing a consistent policy response to the ‘boom’ in private self-supply from waterwells. The consequences of non-action in terms of much increased exposure to water-supply crises, potentially hazardous water-supply pollution incidents, and irrational public and private investment in water-supply access are highlighted.

Are Arid Regions Always that Appropriate for Waste Disposal? Examples of Complexity from Yucca Mountain, Nevada

The study of the hydrology of arid regions greatly expanded at the end of the 20th century as humans sought to reduce groundwater pollution from landfills, waste dumps and other forms of land disposal. Historically viewed as wastelands where little or no water percolated to the underlying water table, the discovery of large-scale contamination beneath arid disposal sites such as the Hanford nuclear complex in eastern Washington jumpstarted an industry in studying the hydrology of arid vadose zones and their transport behavior. These studies showed that, in spite of hyper aridity in many areas, precipitation often did infiltrate to deep water. The efforts at Yucca Mountain, Nevada to design a high-level nuclear repository stand out as one of the largest of such studies, and one that fundamentally changed our understanding of not only water flow in fractured rocks, but also of the range of our uncertainty of hydrologic processes in arid regions. In this review and commentary, we present some of the initial concepts of flow at Yucca Mountain, and the evolution in research to quantify the concepts. In light of continued stockpiling of high-level waste, and the renewed interest in opening Yucca Mountain for high-level waste, we then focus on the significant surprises and unanswered questions that remained after the end of the characterization and licensing period; questions that continue to demonstrate the challenges of a geologic repository and our uncertainty about critical processes for long-term, safe storage or disposal of some of our most toxic waste products.

Biochar application and no-tillage practices to minimize the residues of herbicides in the seeding hole

BackgroundNo-tillage is considered as a promising alternative for conventional farming by saving energy input and time, reducing groundwater pollution, and counteracting soil erosion and losses of soil-organic matter. Therefore, this study was carried out in north-eastern Sylhet of Bangladesh during the period of 2015–2016 to evaluate the multiple techniques of implementation in order to find a practically appropriate way to apply biochar.ResultsIn this study, successfully applied of biochar and glyphosate in holes with seeds and consisted of one control (pure soil), glyphosate control, biochar control, and four glyphosate treatments with 1, 2.5, 5, and 10% biochar addition. The Gly + ch1% and Gly + ch2.5% treatments demonstrated a better emergence rate than all treatments, and at the end of the emergence, they reached more than 95%. There was no important distinction found among all the treatments in the event of shooting fresh and dry biomass. Biochar amendment treatments did not show any influence on shoot fresh biomass compared to glyphosate control and biochar 5% treatment, respectively. Gly + ch2.5% treatment showed slightly better performance than all the other treatments. The similar performance was shown in case of shoot dry weight. In case of root fresh weight, there was only a significant different observed between Gly + ch1% and Gly + ch10%. However, Gly + ch1% treatment revealed slightly higher root fresh weight compared to all the other treatments. Considering the results of the germination percentage and root morphology, it could be suggested that lower rate of biochar application showed better performance on root length and development.ConclusionsIt could be concluded that glyphosate application has mitigation effect to absorb herbicidal residues. For successful introduction of biochar application in agriculture, field acts as a huge amount of carbon sink and has also a positive effect to mitigate climate change.

Impact of neem coated urea on rice yield and nutrient use efficiency (NUE)

Neem coated urea not only increase crop yield but also lower input cost to the farmer. Cost of neem coated urea is only 3-4% higher than ordinary urea. Urea constitutes about 82% of the fertilizer nitrogen (N) used in India. Neem coated urea has been observed to improve nitrogen use efficiency and subsequently crop yield, especially in rice and wheat. Nitrification inhibitors when applied along with urea reduce losses of applied N thereby resulting in an improved yield of crops. In rice and wheat more than 50% of the urea consumed in India is applied, the mean increase in grain yield by replacing urea with NCU or NOCU is 5 to 6%. More than 75 studies have been conducted to compare the performance of urea coated with neem cake (NCU) or neem oil (NOCU) in increasing the yield of rice, wheat, and several other crops via uncoated urea. In 2015, the Government of India directed that all fertilizer urea manufactured in the country or imported will have to be coated with neem oil at the rate of 0.5 kg per tonne. This decision was motivated not only by the better performance of NOCU via uncoated urea but also by an expectation that it will lead to reduced consumption of urea. Increasing nitrogen efficiency means-reducing the nitrogen losses through leaching, immobilization and reducing groundwater pollution by nitrates as well as ammonia gas pollution in the air. It also reduces import of costly fertilizers as well as reduces ground, water, and soil pollution.

Assessment of well water pollution by sewage contaminants: A case study of Akure South, Ondo State, Nigeria

This study investigated the extent of well water contamination in dry and rainy seasons through infiltration of coliform bacteria from sewage pits in their proximity in Akure. Total and Faecal coliform counts of twenty household wells were investigated between the months of March and July with respect to proximity of wells to sewage pits, orientation of wells to sewage pits, and other well characteristics. All wells studied were assessed to be vulnerable to contamination with observable differences in characteristics, physicochemical parameters, total coliform counts and faecal coliform counts. Asides pH which was higher in the dry season, all other parameters had lower values in the dry season. At an average distance of 17.6 m from the sewage pits, all well water sampled had greater coliform counts than the WHO recommended level for drinking water (&lt; 1 cfu/mL). Correlations between coliform counts of water samples and the distances of the wells to sewage pits was positive and not significant for both total and faecal coliform in dry season, while it was negative and significant for both total and faecal coliform in the rainy season. Topography, and distance between wells and sewage pits were prominent factors responsible for well water contamination. Amounts of coliforms found in wells were significantly affected by seasonal variation. It is thus suggested that wells be sited up-gradient and at safer distances away from sanitary systems in the ultimate bid to reduce groundwater pollution and the occurrence of water borne diseases.