Ambiente e Agua - An Interdisciplinary Journal of Applied Science

Statistical process control in pulsed drip irrigation systems

Thu, 11 Jan 2024 00:00:00 +0000

Pulse drip application is a management option to prevent clogging and improve water-use efficiency. The measurement of distribution uniformity is opportune for pulse irrigation projects to ensure efficiency since the shorter the pulse time, the more negative influence the transition periods have. The objective of the present work was to monitor the quality of a drip irrigation system with different emitter models and different pulse times. The experiment was conducted under laboratory bench conditions, and 25 tests were performed for each pulse application (2, 3, 6 and 12 minutes) and emitter model (non-compensated and auto-compensated). Uniformity was determined using Christiansen's uniformity coefficient (CUC) and distribution uniformity coefficient (DUC) and monitored by Shewhart control charts and exponentially weighted moving average (EWMA). The decrease in pulse time caused a decrease in flow rate and uniformity only in drip irrigation systems with non auto-compensated emitters. However, this decrease is subtle, to the point that uniformity presented an excellent performance for all pulses tested. The use of the Shewhart and EWMA control charts were effective in monitoring the uniformity of the pulsed drip irrigation system. The Shewhart control chart was more robust in identifying isolated non-compensated uniformities, while the EWMA control chart was more sensitive in identifying unstable propensity. In the treatments with the non-compensated emitter, the statistical process control was able to identify that shorter pulse times resulted in greater application instability. As for the auto-compensated emitters, the statistical process control highlighted the concern with application uniformity after maintenance interference.

Keywords: anti-drain emitter, high-frequency irrigation, irrigation interval, statistical quality control.

Bioaugmentation with Advenella kashmirensis for the treatment of a kraft pulp effluent by aerated lagoon

Wed, 10 Jan 2024 00:00:00 +0000

Brazil is considered a world leader in paper production. It is estimated that the sector contributes 46.5% of the national gross domestic product, and its effluents have high concentrations of organic matter and recalcitrant compounds which can cause coloration and ecotoxicity, generating impact if not properly treated. A potential strategy for the treatment of this wastewater is bioaugmentation with native bacteria isolated from the industrial sludge and effluent, which, due to their potential metabolism adapted to adverse environmental conditions, may favor the removal of specific compounds. When associated with immobilization techniques, the inoculum can develop as a biofilm adhered to a support medium, which provides surfaces for adhesion, growth and survival of bacteria. We therefore investigated the treatment of Kraft pulp effluent by bioaugmentation with the autochthonous bacterium Advenella kashmirensis both immobilized in a spongy support medium - Aqua Porous Gel (APG) - and in free-swimming (planktonic) form, denominated Phase I and II, respectively. The investigation was performed in a bench-scale aerated lagoon system with untreated industrial effluent. The effect of the use of bacteria in bioaugmentation was assessed by the removal parameters of Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD₅), Color, Total Phenolic Compounds (TPC) and Lignin Compounds (LC). The results indicate that both Phases I and II were efficient for the treatment of COD, BOD₅ and color parameters. However, the biofilm form provided better stability to the biological system in the treatment of the Kraft pulp effluent.

Keywords: adhered, kraft effluent, SEM, suspended solids.

Antimicrobial resistance profile of Aeromonas spp. isolated from tambaqui fish (Colossoma macropomum)

Wed, 10 Jan 2024 00:00:00 +0000

The current study assesses the resistance profile of Aeromonas spp. individuals isolated from tambaqui fish (Colossoma macropomum) grown in fish farms located in São Luís Metropolitan Region - MA. In total, 114 bacterial strains belonging to species Aeromonas spp. were used in the experiment. Antimicrobial resistance profile was defined based on using the disk diffusion method and 10 antimicrobials. Isolates were classified as susceptible, susceptible upon increased exposure and resistant to the assessed principles; phenotypes showing resistance to multiple tested drugs (MDR) were classified. Bacterial strains presented widespread resistance to penicillin; as well as high oxacillin-, cefepime-, cefadroxil- and azithromycin-resistance rates. Ampicillin associated with sulbactam, neomycin and ofloxacin were the antimicrobials recording the highest sensitivity rate; high frequency of isolates (34.21%) were categorized as MDR phenotypes. Antimicrobial resistance was observed in the herein assessed Aeromonas spp. isolates, despite the lack of antimicrobials registered in Brazil to be used for C. macropomum fish farming purposes.

Keywords: Aeromonadaceae, bacterial resistance, fish farming.

Effect of anthropized water on eukaryotic organisms

Natan Kasper, Suzymeire Baroni, Rodrigo Patera Barcelos — Wed, 17 Jan 2024 00:00:00 +0000

This work explored whether anthropized environments have the potential to promote cellular alterations in eukaryotic organisms. Wild fish that are in constant contact with anthropized water were evaluated using the following variables: presence of nuclear alterations and micronuclei in erythrocytes using the Feulgen method; and tissue analysis of the gills and liver through histological sections using Hematoxylin and Eosin staining. Therefore, 200 individuals were analyzed over 24 months. The results show that these environments are promoters of significant changes in liver and gill tissue and induce nuclear changes in erythrocytes. The analyses were subjected to statistical tests at a significance level of 0.5%.

Keywords: aquatic environments, bioindicator, genotoxicity, histopathology.

Effectiveness and management of terrestrial protected areas: a bibliometric analysis

Javier Orozco Ospino, Gloria Yaneth Florez Yepes — Wed, 17 Jan 2024 00:00:00 +0000

Effectively managed protected areas (PAs) are an efficient strategy to promote sustainable development and human well-being. The objective of this study was to examine aspects related to the evaluation of PA effectiveness and management, for which a bibliometric analysis was performed by taking as a reference the English language publication made globally from 2013 to 2022 in the Scopus database. Three research trends were found. The first is studies on conservation planning, management, and evaluation, with multiple approaches aimed at developing tools to determine PA effectiveness objectively. The second studies the impacts of human activities on PAs and considers human pressure, the impacts of anthropogenic climate change, and the valuation of ecosystem services, among others. The third studies specific indicators to determine the effectiveness of a specific set of PAs or one in particular. Finally, conservation management was identified as a basic topic that has not been sufficiently developed, so the convenience of developing management and evaluation models for PA management should be evaluated in future research.

Keywords: assessment, conservation area, efficacy.

Use of singular spectral analysis to reconstruct average monthly flow time series with complex behavior

Wed, 17 Jan 2024 00:00:00 +0000

Time series analysis is a useful tool for many practical water resource management applications, such as planning and anticipating conflict around water use. These analyses are also necessary for the use, design and operation of hydrotechnical works and for the protection of aquatic ecosystems. Basically, his review focuses on classic models such as Box and Jenkins. However, restrictive assumptions about data and residuals make its use difficult. As an alternative, non-parametric approaches are interesting due to their application versatility. One of the techniques that has been widely used in the analysis of flow time series is Singular Spectral Analysis (SSA). However, its application is concentrated as a pre-processor or in hybrid approaches and, because of this, many studies focus only on the model to be improved, leaving gaps in the process understanding that underlie the SSA. Within this context, and because of this, the objective of this study is to present the SSA technique in detail, through an application to a time series of monthly average flows with complex behavior (Jucu River, located in Southeast Brazil), in order to overcome gaps associated to a rigorous understanding of the procedures that make up the SSA. The Sequential SSA technique was used to decompose signal and noise components. The reconstructed series preserved the dynamics of the observed series, suggesting a strong influence of the signal component (trend and seasonality) on its behavior. It’s expected that the technique can be used with greater fluidity by specialists and contribute to the management of water resources.

Keywords: decomposition, reconstruction, singular spectrum analysis.

Effect of dissolved oxygen concentration on biomass production in wastewater

Wed, 24 Jan 2024 00:00:00 +0000

Biological wastewater treatment is a process that removes pollution caused by carbon, nitrogen and phosphorus. For this purpose, aerobic microorganisms must have an adequate amount of oxygen to avoid slowing down this process. This research therefore evaluated the influence of dissolved oxygen concentration and time on the rate of microbial growth in wastewater samples. To do so, a mixed culture of aerobic microorganisms was used with an equivalent concentration of SSV=150 mg/L, dissolved oxygen levels of 2, 3, 4 ppm, observation time of 5 days and concentration of pollutants equal to 800 ppm. It was determined that the growth of microorganisms responded to the cell synthesis phase, and it increased from 150 mg/L of SSV to 386.9, 412.07 and 423.7 mg/L, depending on the level of dissolved oxygen (2, 3 and 4 ppm). On the other hand, as the treatment time elapsed, the rate of microbial growth decreased, despite the fact that the significance of the effect of dissolved oxygen concentration was negligible. Finally, time and the interaction of both variables were relevant.

Keywords: batch reactor, bioremediation, microbial growth, oxygenation, wastewater.

Development and validation of a method to determine pesticides in river water using QuEChERS combined with UHPLC-MS/MS

Wed, 24 Jan 2024 00:00:00 +0000

The continuous increase in the use and release of pesticides is worrisome because water contamination can affect health and the environment. This study optimized and validated a multi-residue method in water. The method was developed using the QuEChERS method (Quick, Easy, Cheap, Effective, Rugged, and Safe) followed by ultrahigh- performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The validation was performed on the matrix (river water) regarding accuracy, precision, linearity, limits of detection (LODs) and limits of quantification (LOQs). LODs were below 3.03 µg L^-1and LOQs were from 6.25 to 9.18 µg L^-1. The accuracy (recoveries in the range of 80-117%) and for Inter-day precision, the coefficients of variation ranged from 0.35 to 15.71%, and for Intra-day precision were in the range of 0.48 to 7.02%.

Keywords: multi-residue analysis, pesticide, QuEChERS, water.

Effects of different agricultural systems on organic matter and aggregation of a medium-textured soil in subtropical region

Tue, 05 Mar 2024 00:00:00 +0000

This work evaluates the impact of different agricultural systems on the humic fractions of organic matter (SOM) and soil aggregation in a medium-textured soil in a subtropical region of Brazil. Three managed areas and a reference area were evaluated: permanent pasture (PP), no-till (NT), no-till+Brachiaria (NT+B) and native forest (NF). Deformed soil samples were collected in the layers 0-0.05; 0.05-0.10; 0.10-0.20 and 0.20-0.40 m, and unformed soil samples in the layers 0-0.05 and 0.05-0.10 m. After collection, total organic carbon (TOC) analysis, chemical fractioning of SOM and aggregate stability analysis were performed. The PP area presented the highest TOC and C-FA contents in the first three layers evaluated. In the 0.10-0.20 m layer, the C-HUM contents in the NT+B area were 1.9 times higher than in the NT area, and in 0.20-0.40 m they were 6.6 times higher. The PP area obtained the best structural indicators, especially higher WMD, GMD and % of macroaggregates. The two areas using direct seeding presented a percentage of macroaggregates higher than 37.28% in the superficial layer. The PP management provided increases in TOC levels and, consequently, humic substances, besides the formation of more stable aggregates. The NT+B system showed promise in increasing TOC and humic substances, especially at depth, even with a short implementation period. The increase in TOC and humic substances provided by the grasses contributes to the formation of more stable aggregates and, consequently, to the improvement of the quality of medium-textured agricultural soils.

Keywords: aggregate stability, carbon fractions, climate change, humic substances.

Defining management zones for a papaya culture considering soil chemical attributes by fuzzy c-means

Tue, 05 Mar 2024 01:47:17 +0000

In precision agriculture, one of the major problems is the need for a dense sampling grid. A solution to this problem has been the generation of management zones and the correlation between them. This work aims at defining management zones for a papaya culture using the fuzzy C-means grouping method, based on the following soil attributes: phosphorus, calcium, magnesium and potassium; and base saturation. The work was conducted in an approximately 1.2 ha area planted with a commercial culture of Carica papaya L. cultivated in typical Argisol found on the coastal terraces, in the municipality of São Mateus, ES, Brazil. The management zones were defined by the proposed method, based on the following analyses: soil chemical parameters P, Ca, Mg, and base saturation (V), analyzed together; soil chemical parameters P, Ca, Mg, and V, analyzed separately; and, the following combinations of soil chemical attributes Ca-Mg, Ca-V, Ca-Mg-V, P-Ca, P-Mg, P-V, P-Ca-Mg, P-Ca-V, Mg-V, and P-Ca-Mg-V. The generated management zones facilitated an understanding of the spatial variability of the attributes in the study area and the observed similarities between management zones generated from different attributes. In addition, the data were influenced especially by the P and V% attributes.

Keywords: Carica papaya L, geostatistics, grouping analysis, precision agriculture.

Decay of pathogens (indicators of Escherichia coli and Salmonella spp.) in soil due to the application of reuse water

Tue, 12 Mar 2024 17:13:41 +0000

Reuse water is defined as the reuse of water from treated effluents, it requires careful monitoring to avoid damage to environmental health. This study evaluates the decay of Escherichia coli and Salmonella spp. bacteria in soil irrigated with reused water for agricultural reuse, without damaging public or environmental health. The decay of Escherichia coli and of Salmonella spp. was verified using the Filter Membrane method SS AGAR culture medium was used. The decay curves over time were made using the Sigmaplot program. Each experimental group had 4 pots (one group irrigated with recycled water and the other with drinking water), two pots containing vegetation cover and two containing only soil. In crops irrigated with reused water, the survival time of Salmonella spp. was double compared to the others, and E. coli survival did not vary between groups. Pots with bare soil irrigated with uncontaminated reused water showed a faster decline in Salmonella spp. For agricultural reuse, irrigation must be done by drip and with the use of personal protective equipment. It is essential to create national legislation to protect public and environmental health.

Keywords: agricultural reuse, decay analysis of microorganisms, public health.

Dalbergia nigra (Vell.) grown using hydrogel planting methods in the establishment of a silvopastoral system in a degraded soil

Tue, 12 Mar 2024 17:15:53 +0000

This work tested the use of a superabsorbent polymer (hydrogel) in a silvopastoral system with Brazilian-rosewood (Dalbergia nigra (Vell.) Allemão ex Benth.) in a degraded pasture area. The experimental site is part of the Bananal do Norte experimental farm, Cachoeiro de Itapemirim, Espírito Santo, Brazil. Over 480 seedlings were planted and submitted to the treatments: Dry hydrogel (DRY); Hydrated hydrogel around the root ball (HAR); Hydrated hydrogel mixed with soil (HMS); and water only (WAT). The design was in randomized blocks, with three repetitions. The tested variables were plant survival, height and root collar diameter until 672 days after planting, soil moisture at 93 days after planting and total biomass and leaf chemical analysis at 184 days after planting. Survival was positively influenced by the application of the hydrogel, but there was little or no effect regarding the application method. The hydrogel and its application techniques did not alter growth in height and root collar diameter. The polymer did not influence the development in biomass and nutritional content of the leaves, but did influence the biomass distribution. The use of the superabsorbent polymer was therefore not effective in accelerating plant growth and anticipating the stages in the implantation of the silvopastoral system.

Keywords: agroforestry, brazilian-rosewood, degraded pasture.

Evaluation of the environmental quality monitoring protocol for Amazonian streams: a systematic review

Tue, 12 Mar 2024 17:17:31 +0000

The Amazon Rainforest is renowned for its extraordinary biodiversity and the ravages of pervasive deforestation. The removal of natural vegetation significantly affects Amazonian streams, leading to alterations in their environmental conditions. In the United States, the Environmental Protection Agency has devised a comprehensive protocol to monitor changes in the environmental quality of streams. Since 2011, the Sustainable Amazon Network has implemented this protocol in Amazonian streams. Our systematic review aimed to address the following questions: i) How widely has the protocol been employed in Amazonian streams?; ii) Is the utilization of this protocol well-distributed across the Amazon Basin?; iii) Which types of land use have been assessed using this protocol?; iv) Which components of the aquatic biota have been studied in conjunction with the protocol?; and, v) Which metrics of the protocol are most crucial for elucidating aquatic biota distribution? We conducted searches using the Web of Science and Google Scholar databases, identifying 34 studies that directly aligned with our objectives. It was observed that the Eastern Amazon had the highest number of streams evaluated. Additionally, aquatic insects emerged as an effective tool when utilized alongside the protocol for evaluating the impacts of changes in land use. Ultimately, the most important metrics for assessing impacts on aquatic biota were shelter availability in the channels, the preservation status of riparian forests, and water quality. We recommend developing a simplified version of this protocol to facilitate its application for research teams with limited personnel and financial resources available for fieldwork.

Keywords: aquatic conservation, biomonitoring, land use change, sampling efficiency, stream ecology.

The use of Moringa Oleifera and Salvia Hispanica as auxiliaries in the solar disinfection water treatment process by Sodis

Tue, 09 Apr 2024 02:07:27 +0000

Solar Water Disinfection, known as SODIS, is a treatment method involving the exposure of water to solar radiation (UVA light and heat) to eliminate pathogenic microorganisms. Organic coagulants extracted from Moringa oleifera (T1) and Salvia hispanica (T2) were used in conjunction with the filtration process as auxiliaries. This process included sand filters with particle sizes ranging from 0.25 mm to 0.850 mm and a non-woven geotextile placed at its base. After undergoing the coagulation/flocculation/sedimentation/filtration process, the samples were exposed to sunlight in a solar concentrator using bottles painted on half of their surface (PR) and unpainted bottles (BR). The analyzed parameters included physicochemical properties such as pH, electrical conductivity, turbidity, and apparent color, as well as microbiological parameters, including E. coli and total coliforms. The results of physicochemical analyses demonstrated the superiority of T1 in terms of turbidity and apparent color. Regarding microbiological analyses, they showed the effective removal of E. coli and total coliforms, with 100% inactivation observed in the samples. It was observed that the applied treatment sequence significantly reduced the microbiological load of the samples; however, it cannot be stated with certainty whether the coagulants exerted any influence on this result.

Keywords: coagulants, coliforms, filtration, microorganisms.

Nitrogen and phosphorus removal from synthetic aquaculture water through electrocoagulation

Tue, 09 Apr 2024 02:09:17 +0000

In this research, we utilized multivariate analysis to evaluate the efficient removal of nitrogen and phosphorus from synthetic aquaculture water using the electrocoagulation process. The elimination of nitrogen and phosphorus is a critical issue in various wastewater treatment plants and aquaculture systems, especially in instances of intensive or super-intensive cultivation. To avert the buildup of pollutants in the water, be it within internal recirculation systems or bodies of water receiving effluents from rearing tanks, it is imperative to employ treatment methodologies designed to effectively eliminate nitrogen and phosphorus nutrients. These nutrients have the potential to induce eutrophication in aquatic ecosystems. However, conventional biological treatment technologies can be ineffective, as they often only remove one pollutant or the other. Furthermore, the individual operations for these systems are complex and require substantial space. Electrocoagulation is a compact and promising technology for treating aquaculture water and effluents for raw nutrient removal. In this context, our findings showcase the simultaneous removal of both nitrogen and phosphorus through the electrocoagulation method. The best treatment was verified for the highest electrical current density (74 A. m^-2), the shortest distance between electrodes (4 cm), and the lowest electrolysis time (50 min). In these conditions, the efficiency removal in ammonia nitrogen and total phosphorus were 30.5% and 100% respectively.

Keywords: electrochemical treatment, eutrophication, water pollution control.

Evaluation of chemical attributes of soils: definition of management zones in silvipastoral system

Tue, 23 Apr 2024 00:38:44 +0000

Soil chemical analysis is a fundamental to achieve optimal cultivation conditions in a productive silvopastoral system, essential for the planning and management of this activity. The objective of this research is to map the spatial distribution of nutrients in the soil in a 5-year-old silvopastoral system composed of brachiaria-brizantha and jacarandá-da-bahia, and to analyze the effect of tree density and canopy on nutrient levels. The study was conducted at the experimental area of the Capixaba Institute for Research, Technical Assistance, and Rural Extension (INCAPER) in the district of Pacotuba, ES. The delimitation of the work area was done using geographic information systems, to create a regular grid of points to enable systematic soil sampling. A total of 75 disturbed soil samples were collected at depths of 0-0.10 m to obtain quantitative soil nutrient data. High-quality images obtained using a remotely piloted aircraft (RPA) allowed for the overlay of soil nutrient data, pasture data, forest inventory data, and sample plot data to assist in comparative analyses. This enabled identification of the areas with lower canopy development, particularly in the northeast portion. By cross-referencing the spatialized soil nutrient data with the data obtained through RPA, it was possible to correlate them with the lower or higher development of the system. The use of RPA, together with a georeferenced database, proved to be an innovative and powerful tool to support decision-making, allowing for the monitoring of system evolution and serving as a basis for evaluating the relationship between chemical elements and tree canopies.

Keywords: geostatistics, precision agriculture, soil nutrients.

Water quality and sustainable solutions for drinking water supply in the Taquari-Antas watershed, RS, Brazil

Tue, 23 Apr 2024 01:41:34 +0000

Access to safe drinking water is a fundamental human right and a critical component of sustainable development. This study is conducted in the context of the Taquari-Antas Hydrographic Basin, Rio Grande do Sul, Brazil, and assesses the quality of drinking water in 101 rural properties, focusing on identifying problems of potability, especially regarding excessive fluoride concentration, which is a known problem for the water in this region. The study involves the collection of water samples from rural properties, a survey to understand water use and quality perception by users, and water quality analysis using established analytical methodologies. Results show that 58.4% of the investigated rural properties have potability issues, with excessive fluoride being the most prevalent concern, affecting 39.6% of properties. High fluoride levels have significant health implications, including dental and skeletal fluorosis, with global relevance. To address this issue, activated bone charcoal filtration systems were installed in ten properties, effectively reducing fluoride concentrations to within acceptable limits for human consumption. These defluoridation systems are characterized as sustainable, cost-effective, and scalable, offering a practical solution for regions facing similar challenges.

Keywords: groundwater, rural properties, water stewardship.