Search Results (17)

The rapid expansion of shrimp aquaculture has led to the generation of nutrient-rich effluents, which contribute to environmental degradation if inadequately managed. This study evaluated the potential of Dunaliella salina for the reuse of shrimp aquaculture wastewater (SAW) in biofloc production systems under varying dilution levels (0%, 25%, and 50%) and the simultaneous production of high-value biomass. Growth kinetics were modeled using a four-parameter logistic model, and nutrient removal, biochemical composition, and fatty acid profile were assessed. D. salina exhibited substantial growth in undiluted SAW, achieving over 80% removal of total nitrogen and reducing the organic load, as measured by a chemical oxygen demand reduction of more than 79%. In SAW treatments, the protein content ranged from 24.7% to 26.3%, while the lipid content reached up to 67.1% in a 25% SAW dilution. Chlorophyll a and total carotenoids were measured at 5.3–7 µg/mL and 4.1–5.7 µg/mL, respectively, in SAW treatments. The polyunsaturated fatty acid content in undiluted SAW was 34.5%, with α-linolenic acid (C18:3n3) and linoleic acid (C18:2n6) comprising 12% and 7.5%, respectively. This study demonstrates the ability of D. salina to valorize shrimp aquaculture wastewater in biofloc systems into lipid-rich, bioactive biomass, supporting its use in integrated aquaculture biotechnology systems for sustainable wastewater management and bioproduct generation. Full article

This study investigated the use of ultrafiltration for sustainable protein recovery and the treatment of shrimp washing wastewater (SWW). Three ultrafiltration membranes with molecular weight cut-offs of 5, 10, and 50 kDa were tested using a combined ultrafiltration–diafiltration process (UF-DF). The performance of each membrane was assessed based on protein recovery efficiency, chemical oxygen demand (COD) reduction, turbidity, fouling behavior, and cleaning efficiency. The 5 kDa membrane showed superior performance, achieving over 90% protein and COD rejection and producing the highest protein-enriched retentate. It also exhibited the lowest fouling index and best cleaning recovery, confirming its suitability for protein concentration and wastewater treatment. This research highlights UF-DF as a promising, eco-efficient technology for valorizing seafood processing effluents by recovering high-value proteins and reducing environmental discharge loads. Full article

The aquaculture industry requires green solutions to solve several environmental challenges, including adequate wastewater remediation and natural drug applications to treat bacteria- and virus-related diseases. This study investigated the feasibility of cultivating the dinoflagellate Durusdinium glynnii in aquaculture wastewater from shrimp rearing in a synbiotic system (AWW-SS), with different dilutions of f/2 medium (FM). Interestingly, D. glynnii demonstrated enhanced growth in all AWW–SS treatments compared to the control (FM). The highest growth rates were achieved at AWW-SS:FM dilutions of 75:25 and 50:50. The removal of total nitrogen and total phosphorus reached 50.1 and 71.7%, respectively, of the crude AWW–SS. Biomass extracts of D. glynnii grown with AWW–SS were able to inhibit the growth of the bacteria Vibrio parahaemolyticus (inhibition zone of 10.0 ± 1.7 mm) and V. vulnificus (inhibition zone of 11.7 ± 1.5 mm). The presented results demonstrate that the dinoflagellate D. glynnii is a potential candidate for the development of circularity for sustainable aquaculture production, particularly by producing anti–Vibrio compounds at a near-zero cost. Full article

Ninh Thuan is a coastal province in the central region of Vietnam and is characterized by a climate that is the hottest and driest in the country. Vietnam is also one of the top five countries most vulnerable to the effects of climate change worldwide. The objective of this study was a thorough evaluation of the quality of water supply sources and the impacts of water effluents from shrimp farms in Ninh Thuan province. The comprehensive evaluation was based on an understanding of the water–wastewater cycle employed in coastal shrimp cultivation. We combined qualitative and quantitative analyses in undertaking this study. Secondary data of groundwater and coastal water from the local periodic water quality monitoring program and national technical regulations were collected in the qualitative approach. We also integrated participatory rural appraisal techniques and field observations to understanding shrimp cultivation and the environmental and social impacts of shrimp farm effluents. The quantitative assessment consisted of measuring groundwater and wastewater contamination from shrimp ponds. As a result, four main reasons for water pollution issues were determined including extreme weather events, shrimp cultivation practices, degraded infrastructure, and mismanagement by local governance. Shrimp cultivation practices (feeding, using chemicals) have resulted in elevated levels of suspended solid (TSS, total Coliform), organic and carbon matter (BOD₅, COD), and excessive nutrients (total Nitrogen, NO₂-N, NO₃-N, PO₄-P). According to a local monitoring program, the coastal water and groundwater have experienced nutrient pollution. Groundwater sampling near the shrimp farms identified salinization elevated levels of Coliform from local domestic sewage sources. This study resulted in an integrated approach that evaluated the combined effects of extreme weather events and shrimp farming practices on the quality of coastal water. Also, the finding can be useful in recommending remedial water treatment technologies as a follow-on phase. Full article

In recent years, there has been a challenging interest in developing low-cost biopolymeric materials for wastewater treatment. In the present work, new adsorbents, based on different types of chitosan (commercial, commercial chitin-derived chitosan and chitosan synthesized from shrimp shell waste) and inorganic–organic composites have been evaluated for copper ions removal. The efficacy of the synthesis of chitosan-based composite beads has been determined by studying various characteristics using several techniques, including FTIR spectroscopy, X-ray diffraction, porosimetry (N₂ adsorption), and scanning electron microscopy (SEM). Adsorption kinetics was performed using different adsorption models to determine the adsorption behavior of the materials in the aqueous media. For all composite beads, regardless of the type of chitosan used, good capacity to remove copper ions from simulated waters was observed (up to 17 mg/g), which proves that the new materials hold potential for heavy metal retention. However, the adsorption efficiency was influenced by the type of chitosan used. Thus, for the series where commercial chitosan (CC) was used, the removal efficiency was approximately 29%; for the series with chitosan obtained from commercial chitin (SC), the removal efficiency was approximately 34%; for the series with chitosan enriched with CaCO₃ (SH), the removal efficiency was approximately 52%. Full article

This study explores the potential of modified shrimp-based chitosan (MSC) as an innovative adsorbent for eliminating heavy metals (HMs) from contaminated water sources. The modifications encompassed various chemical treatments, surface functionalization, and structural optimization to enhance the chitosan’s adsorption capabilities. Comprehensive analyses using FT-IR and SEM-EDS were conducted to evaluate the properties of the chitosan. The adsorption capacity of MSC was assessed using ICP-MS before and after the adsorption process. Moreover, the study investigated the efficiency of HM removal by MSC under different conditions, including variations in pH, adsorbent dosage, and contact time. Under neutral pH conditions, the highest adsorption rates of copper, zinc, cadmium, and lead were determined as 99.72%, 84.74%, 91.35%, and 99.92%, respectively, with corresponding adsorption capacities of 20.30 mg/g for copper, 7.50 mg/g for zinc, 15.00 mg/g for cadmium, and 76.34 mg/g for lead. Analysis based on the Langmuir and Freundlich isotherm models revealed highly significant adsorption of HMs, supported by strong correlation coefficients (r² > 0.98) obtained from the data. The pseudo-second-order kinetic model with linear coefficients (r²) greater than 0.97 effectively explained the kinetic studies of metal adsorption employing modified shrimp shells. These coefficients indicate a robust fit of the models to the experimental adsorption data for heavy metals. Further confirmation of the effectiveness of the adsorbent was obtained through FT-IR spectroscopy, which confirmed the presence of specific functional groups on the adsorbent, such as N–H joined with –COO−, H–O, C−O−C, and C–H. Additionally, the SEM-EDS analysis detected the presence of elements on the surface of MSC chitosan. The results emphasize that MSC is a highly effective and cost-efficient adsorbent for eliminating Cu, Zn, Cd, and Pb from wastewater, making it a promising eco-friendly choice. Full article

Background: The objective of this work was to propose the treatment of the wastewater from Laguna da Jansen using adsorptive processes of residues of pineapple crown and shrimp chitosan. Methods: Residual substrates were distributed in 11 Erlenmeyers, and 250 mL of residual pond water were added; the solution was incubated under agitation at the times and amounts established by the Experimental Design (DCCR). After this period, analyses of pH, electrical conductivity, turbidity, nitrate, and nitrite, morphological analyses by SEM, and structural analyses by FTIR and XRD were performed. Results: The FTIR and SEM results showed that the biomass presented active chemical groups and a morphology rich in pores. The experimental design showed that the substrate content was the variable that influenced the lagoon effluent treatments for both tested biomasses; however, when observing the specific values of the response variables, the vegetable adsorbent was more efficient with the conditions of 15g of substrate and 30 days of process. Conclusion: Plant biomass is more efficient in the treatment of effluents rich in organic materials. It can be used in treatment plants as an alternative for the removal of toxic compounds present in wastewater and effluents. Full article

The present work aims to study the influence of ammonium-quaternary monomers and chitosan, obtained from different sources, upon the effect of semi-interpenetrating polymer network (semi-IPN) hydrogels upon the removal of waterborne pathogens and bacteria from wastewater. To this end, the study was focused on using vinyl benzyl trimethylammonium chloride (VBTAC), a water-soluble monomer with known antibacterial properties, and mineral-enriched chitosan extracted from shrimp shells, to prepare the semi-IPNs. By using chitosan, which still contains the native minerals (mainly calcium carbonate), the study intends to justify that the stability and efficiency of the semi-IPN bactericidal devices can be modified and better improved. The new semi-IPNs were characterized for composition, thermal stability and morphology using well-known methods. Swelling degree (SD%) and the bactericidal effect assessed using molecular methods revealed that hydrogels made of chitosan derived from shrimp shell demonstrated the most competitive and promising potential for wastewater (WW) treatment. Full article

The major sources of waste from aquaculture operations emanates from fish or shellfish processing and wastewater generation. A simple technique called coagulation/flocculation utilizes biowaste from aquaculture to produce chitosan coagulant for wastewater treatment. A chemical method was applied in the present study for chitin and chitosan extraction from carapace of Macrobrachium rosenbergii and subsequent application for removal of turbidity and salinity from shrimp aquaculture wastewater. Box-Behnken in RSM was used to determine the optimum operating conditions of chitosan dosage, pH, and settling time, after which quadratic models were developed and validated. Results show that 80 g of raw powder carapace yielded chitin and chitosan of 23.79% and 20.21%, respectively. The low moisture (0.38%) and ash (12.58%) content were an indication of good quality chitosan, while other properties such as water-binding capacity (WBC), fat-binding capacity (FBC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM) confirmed the structure and the α-group, as well as the rough morphology of chitosan. In addition, the high solubility (71.23%) and DDA (85.20%) suggested good coagulant potentials. It was recorded in this study that 87.67% turbidity was successfully removed at 20 mg/L of chitosan dosage and 6.25 pH after 30 min settling time, while 21.43% salinity was removed at 5 mg/L of chitosan dosage, 7.5 pH, and 30 min settling time. Therefore, the process conditions adopted in this study yielded chitosan of good quality, suitable as biopolymer coagulant for aquaculture wastewater treatment. Full article

Waterborne ammonia is becoming one of the most notorious pollutants in aquatic habitats and has been shown to induce a range of ecotoxicological effects on aquatic animals. High ammonia concentrations occur mainly in intensive aquaculture systems, and effective wastewater treatment and agricultural systems are necessary to treat excessive nitrogenous compounds. Ammonia can enter aquatic decapod crustaceans through their gills, thereby reducing the oxygen-carrying capacity of blood cells and damaging the structures of organs such as the gills and hepatopancreas. This ultimately results in oxidative stress, immunotoxicity, and high mortality. Crustaceans have the ability to exert detoxification functions against ammonia stress by regulating the permeation of ammonia and related nitrogenous compounds through membranes. To the best of our knowledge, a comprehensive review of the acute toxicity of ammonia to crustaceans is lacking. The present review focuses on the literature on the problems and mechanisms concerning ammonia-induced acute toxicity and aims to synthesize the knowledge of the relationship between ammonia stress and defense responses in crustaceans (mainly shrimp and crabs). This review also emphasizes the uptake, elimination, and detoxification of ammonia in crustaceans. Full article

Effective integrated methods for oil-water separation and water remediation have signifi-cance in both energy and environment fields. Materials with both superlyophobic and superlyophilic properties toward water and oil have aroused great attention due to their energy-saving and high-efficient advantages in oil-water separation. However, in order to fulfill the superlyophobicity, low surface tension fluorinated components are always being introduced. These constituents are environmentally harmful, which may lead to additional contamination during the separating process. Moreover, the heavy metal ions, which are water-soluble and highly toxic, are always contained in the oil-water mixtures created during industrial production. Therefore, material that is integrated by both capacities of oil-water separation and removal of heavy metal contamination would be of significance in both industrial applications and environmental sustainability. Herein, inspired by the composition and wettability of the shrimp shell, an eco-friendly chitosan-coated (CTS) cotton was developed. The treated cotton exhibits the superhydrophilic/underwater superoleophobic property and is capable of separating both immiscible oil-water mixtures and stabilized oil-in-water emulsions. More significantly, various harmful water-soluble heavy metal ions can also be effectively removed during the separation of emulsions. The developed CTS coated cotton demonstrates an attractive perspective toward oil-water separation and wastewater treatment in various applications. Full article

The scarcity of high-quality water resources may lead to the use of lower quality water for plant production. Quinoa (Chenopodium quinoa) plants have great potential for human nutrition, but poor water quality, such as metal contamination in wastewater, affects the seed quality. This study aims to investigate the effects of shrimp-waste-derived biochar (SWB) on the uptake of toxic metals from wastewater by quinoa plants. Additionally, the study investigates how quinoa plants’ antioxidant defenses respond to wastewater and SWB treatments. Shrimp-waste-derived biochar (SWB) was prepared by pyrolysis at 350 °C for 3 h and added to the soil at the levels of 0, 1, and 2% (based on soil weight), which are namely C, SWB₁, and SWB₂, respectively. SWB was applied to quinoa plants cultivated in pots filled with sandy soil and irrigated with fresh or wastewater for a continuous 90 days. The wastewater was contaminated with manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb). Quinoa seeds that were irrigated with wastewater had Cd and Pb concentrations that were above the allowable levels (for human consumption) in the absence of biochar (C) or addition of SWB₁. Wastewater significantly reduced quinoa growth and photosynthetic pigments, while SWB significantly mitigated the metal toxicity and improved growth. SWB₂ significantly reduced the Pb and Cd concentrations in quinoa leaves by 29 and 30% compared with C. The Cd and Pb concentrations in quinoa seeds were safe for human consumption and below the maximum allowable limits when the soil was amended with SWB₂. SWB improved the synthesis of photosynthetic pigments and increased the activity of antioxidant enzymes such as polyphenol oxidase and ascorbate peroxidase. SWB reduced the toxic metal availability and uptake, mitigated the oxidative stress, and minimized the levels of malondialdehyde and hydrogen peroxide. The SWB addition stimulated quinoa’s antioxidant defense and protected plant cells by eliminating reactive oxygen species. The addition of 2% (w/w) shrimp waste biochar improved the quality of quinoa seeds irrigated with wastewater and decreased their toxic metal content. The obtained results contribute to sustainable development and the exploitation of wastewater to irrigate quinoa plants in arid degraded soil; additionally, it also helps in the recycling of shrimp waste. Full article

Biological settling ponds are a practicable approach for treating super-intensive shrimp aquaculture wastewater for almost all shrimp producers in the Vietnamese Mekong Delta (VMD). The optimization of the hydraulic retention time (HRT) of biological settling ponds plays a crucial role in establishing the stability of outflow wastewater quality and suitability of the settling pond area (SPA). This study aims to suggest appropriate HRT and SPA for super-intensive shrimp wastewater treatment systems based on the National Standard (QCVN 02-19:2014/BNNPTNT) and the best aquaculture practices (BAP) standards and guidelines. We investigated 20 typical super-intensive shrimp farms in the VMD and collected effluent samples from siphoning process, daily water exchange, and outflow of biological effluent-treatment settling ponds. The results showed that the average of each super-intensive shrimp farm produced wastewater at approximately 218 m³ ha⁻¹ day⁻¹. The contaminant loads of TSS, COD, TKN, and TP were commensurate to 177, 113, 9.86, and 4.19 kg ha⁻¹ day⁻¹, respectively. Based on the relationship between outflow COD, TSS concentrations, and HRT of biological-surveyed settling ponds, a 13.4-day HRT and 1934-m² SPA were suggested to optimize the super-intensive shrimp wastewater treatment systems. Our recommendation for further work is to continuously optimize the HRT and SPA rates of functional ponds (anaerobic, facultative, and maturation) to ameliorate the engineering configuration of the recommended biological settling pond. Full article

The study aimed to determine the performance of whiteleg shrimp culture in relation to temporal and spatial aspects and characteristics and water quality status. Measurement and sampling of water were carried out before stocking/initial stocking of culture whiteleg shrimp (rainy season) and end of culture/after harvesting of whiteleg shrimp (dry season) at two locations in the coastal area of Bulukumba Regency, namely Bonto Bahari Subdistrict (BB) and Gantarang Subdistrict (GT), and one location as a control, namely in the coastal area of Ujung Loe Subdistrict. Variables measured and analyzed included temperature, salinity, pH, dissolved oxygen, nitrate, nitrite, ammonia, phosphate, total suspended solids, and total organic matter. Data were analyzed by descriptive statistics, multivariate statistics, and non-parametric statistics. Water quality status was determined using the Storet (Storage and Retrieval) method. The results showed that the culture of whiteleg shrimp was technology intensive with a stocking density of 110–220 ind/m² with productivity between 13.9 and 44.4 tons/ha/cycle. The predicted waste load of N is 28.00 tons/cycle and P reaches 6.61 tons/cycle. Another result was that changes in water quality status during the rainy season were classified as moderately polluted at the BB location and complying with quality standards at the GT location. In the dry season, both locations were categorized as heavily polluted. Variables of water quality that caused the decrease in water quality status in both locations (BB and GT) were observed to increase salinity, nitrate concentration, and ammonia concentration and decreased dissolved oxygen concentration in the dry season. It is recommended to carry out proper feed management, use of probiotics, and increase the capacity and capability of wastewater treatment plants to reduce ammonia and nitrate concentrations in water in coastal areas. It is necessary to determine a more precise time for whiteleg shrimp stocking by reducing the possibility that whiteleg shrimp culture will still occur at the dry season’s peak. Full article

A novel liquid chitosan-based biocoagulant for treating wastewater from a Moroccan fish processing plant was successfully prepared from shrimp shells (Parapenaeus longirostris), the most abundant fish by-products in the country. The shells were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transforms infrared spectroscopy. Using chitosan without adding acetic acid helps to minimize its negative impact on the environment. At the same time, the recovery of marine shellfish represents a promising solution for the management of solid fish waste. In order to test the treatment efficiency of the biocoagulant developed, a qualitative characterization of these effluents was carried out beforehand. The optimization process was conducted in two steps: jar-test experiments and modeling of the experimental results. The first step covered the preliminary assessment to identify the most influential operational parameters (experimental conditions), whereas the second step concerned the study of the effects of three significant operational parameters and their interactions using a Box–Behnken experimental design. The variables involved were the concentration of coagulant (X₁), the initial pH (X₂), and the temperature (X₃) of the wastewater samples, while the responses were the removal rates of turbidity (Y₁) and BOD₅ (Y₂). The regression models and response surface contour plots revealed that chitosan as a liquid biocoagulant was effective in removing turbidity (98%) and BOD₅ (53%) during the treatment. The optimal experimental conditions were found to be an alkaline media (pH = 10.5) and a biocoagulant dose of 5.5 mL in 0.5 L of fish processing wastewater maintained at 20 °C. Full article