Environmental impact assessment of tannin-based coagulants production from chestnut shells.

The increasing demand for freshwater faces challenges and assessing the environmental sustainability of wastewater treatment is crucial. The coagulation-flocculation-sedimentation process is common in water treatment plants, with chemical coagulants playing a pivotal role. However, conventional coagulants like aluminum and iron salts present challenges, prompting a search for environmentally friendly alternatives.

A sustainable solution for aquaculture wastewater treatment: Evaluation of tannin-based and conventional coagulants.

The global population faces increasing challenges in securing fresh water and food production. Aquaculture, a key source for obtaining protein, contributes significantly to environmental pollution, releasing suspended solids, organic matter, nitrogen, and phosphorus into water bodies. Some wastewater treatment methods can be expensive due to high equipment, energy, reagents, and maintenance costs, prompting the search for more sustainable alternatives.

Natural coagulants from chestnut shells: A sustainable approach for textile wastewater treatment.

The textile industry contributes to 2-10% of global greenhouse gas emissions, water extraction, and biodiversity loss, consuming 93 billion cubic meters of water annually with low reuse rates. Coagulation/flocculation is commonly used for industrial wastewater treatment, typically using conventional coagulants. Recently, interest in natural alternatives, particularly tannin-based coagulants, has grown.

Arsenic and antimony desorption in water treatment processes: Scaling up challenges with emerging adsorbents.

The metalloids arsenic (As) and antimony (Sb) belong to the pnictogen group of the periodic table; they share many characteristics, including their toxic and carcinogenic properties; and rank as high-priority pollutants in the United States and the European Union. Adsorption is one of the most effective techniques for removing both elements and desorption, for further reuse, is a part of the process to make adsorption more sustainable and feasible. This review presents the current state of knowledge on arsenic and antimony desorption from exhausted adsorbents previously used in water treatment, that has been reported in the literature.

Efficient removal of arsenic from aqueous solution by continuous adsorption onto iron-coated cork granulates.

The search for low-cost technologies for arsenic removal from water is in high demand due to its human toxicity, even at low concentrations. Adsorption can be a cost-effective water treatment technique if applied with inexpensive materials. Arsenic continuous removal by adsorption onto an alternative modified biosorbent, iron-coated cork granulates (ICG), was investigated in this work.

Tannin-based coagulants: Current development and prospects on synthesis and uses.

Population growth, industrialization, urbanization, and agriculture lead to a decrease in the availability of clean water. Coagulation/flocculation is one of the most common operations in water, urban wastewater, and industrial effluents treatment systems. Usually, this process is achieved using conventional coagulants that have their performance affected by pH, are poorly biodegradable, produce a huge volume of sludge, and are associated with degenerative diseases.

Antimony removal from water by pine bark tannin resin: Batch and fixed-bed adsorption.

Antimony is present in water by natural causes but is also mobilized in the environment by anthropogenic activities, particularly mining. Considering its toxicological behavior, antimony removal from contaminated groundwater and mine effluents is necessary. In this work, Sb(III) and Sb(V) removal from aqueous solution was studied using a resin prepared from pine bark tannins.

Establishing the state-of-the-art on the adsorption of coexisting pnictogens in water: A literature review.

The occurrence of pnictogens, namely phosphorus, arsenic, and antimony, can be observed in soils, sediments and mining areas, and their coexistence requires a multifaceted approach to the design of adsorption systems to maximize their simultaneous removal efficiency. Therefore, this work aims to provide an extensive literature review of P, As, and Sb adsorption in multicomponent systems and the statistical treatment of the quantitative results. Binary As-P systems have been the most studied in the literature.

Multicomponent adsorption of pentavalent As, Sb and P onto iron-coated cork granulates.

The assessment of multicomponent adsorption of pentavalent metalloids is important since they are often found together in groundwaters and mining runoff. For this purpose, adsorption of As(V), Sb(V) and P(V) onto iron-coated cork granulates was studied in binary and ternary systems. Data from equilibrium and kinetic studies revealed that uptake of these contaminants is a multilayer, heterogeneous process well described by Freundlich, extended Freundlich and Elovich models.

Tannin-Adsorbents for Water Decontamination and for the Recovery of Critical Metals: Current State and Future Perspectives.

Biosorption is known as an effective way to clean-up water from organic and inorganic contaminants and has also emerged as a promising technology to recover critical substances. Tannins are renewable materials, coming from multiple vegetable sources. A variety of biosorbents have been developed from tannins, including tannin resins, rigid foams, composites with mesoporous silica, cellulose, collagen, and magnetic adsorbents.

Bioadsorptive removal of Pb(II) from aqueous solution by the biorefinery waste of Fucus spiralis.

In the context of developing the circular economy that enables a more sustainable use of the available resources and minimum waste generation, marine macroalgae have attracted the attention of researchers and industry due to its potential as a renewable resource. The current work aims to contribute to the design of a complete biorefinery processing, using Fucus spiralis seaweed (brown division) as starting material, and to determine the potential of the derived waste as biosorbent of heavy metals in aqueous solution. The macroalgae waste was obtained after the sequential separation of polyphenols, fucoidan and alginate extracts from F.

Arsenate and arsenite adsorption onto iron-coated cork granulates.

There is a growing demand for low-cost, effective adsorbents for arsenic removal from water intended for human consumption in affected rural areas. This work presents a novel adsorbent based on the coating of cork granulates with iron (oxy)hydroxides for the removal of As(III) and As(V) from aqueous matrices. A 2 fractional factorial design was used to determine the optimal conditions for the iron coating procedure.

Arsenic removal from water using iron-coated seaweeds.

Arsenic is a semi-metal element that can enter in water bodies and drinking water supplies from natural deposits and from mining, industrial and agricultural practices. The aim of the present work was to propose an alternative process for removing As from water, based on adsorption on a brown seaweed (Sargassum muticum), after a simple and inexpensive treatment: coating with iron-oxy (hydroxides). Adsorption equilibrium and kinetics were studied and modeled in terms of As oxidation state (III and V), pH and initial adsorbate concentration.

Water quality modelling of Lis River, Portugal.

The aim of the study was to predict the impact of flow conditions, discharges and tributaries on the water quality of Lis River using QUAL2Kw model. Calibration of the model was performed, based on data obtained in field surveys carried out in July 2004 and November 2006. Generally the model fitted quite well the experimental data.

Use of cork powder and granules for the adsorption of pollutants: a review.

Cork powder and granules are the major subproducts of the cork industry, one of the leading economic activities in Portugal and other Mediterranean countries. Many applications have been envisaged for this product, from cork stoppers passing through the incorporation in agglomerates and briquettes to the use as an adsorbent in the treatment of gaseous emissions, waters and wastewaters. This paper aims at reviewing the state of the art on the properties of cork and cork powder and their application in adsorption technologies.

Water quality in Lis river, Portugal.

In the past 30 years, the Lis river basin has been subjected to constant ecological disasters mainly due to piggery untreated wastewater discharges. The aim of this study was to evaluate the effect of existing domestic, agricultural, and industrial activities on the water quality, and to propose a watershed plan to protect and manage surface water resources within the Lis river basin. For this purpose, 16 monitoring stations have been strategically selected along the Lis river stretch and its main tributaries to evaluate the water quality in six different sampling periods (2003–2006).

A review of the use of red mud as adsorbent for the removal of toxic pollutants from water and wastewater.

Red mud (an aluminium industry waste) has received wide attention as an effective adsorbent for water pollution control, showing significant adsorption potential for the removal of various aquatic pollutants. In this review, an extensive list of red-mud-based adsorbents has been compiled and their adsorption capacities (maximum uptake value of the adsorbent for the pollutant or adsorbate being removed) for various aquatic pollutants (metal ions, dyes, phenolic compounds, inorganic anions) are presented. The review provides a summary of recent information obtained using batch studies and deals with the adsorption mechanisms involved.

Coconut-based biosorbents for water treatment--a review of the recent literature.

Biosorption is an emerging technique for water treatment utilizing abundantly available biomaterials (especially agricultural wastes). Among several agricultural wastes studied as biosorbents for water treatment, coconut has been of great importance as various parts of this tree (e.g.

Application of the Nernst-Planck approach to lead ion exchange in Ca-loaded Pelvetia canaliculata.

Ca-loaded Pelvetia canaliculata biomass was used to remove Pb(2+) in aqueous solution from batch and continuous systems. The physicochemical characterization of algae Pelvetia particles by potentiometric titration and FTIR analysis has shown a gel structure with two major binding groups - carboxylic (2.8 mmol g(-1)) and hydroxyl (0.

Copper removal by algal biomass: biosorbents characterization and equilibrium modelling.

The general principles of Cu(II) binding to algal waste from agar extraction, composite material and algae Gelidium, and different modelling approaches, are discussed. FTIR analyses provided a detailed description of the possible binding groups present in the biosorbents, as carboxylic groups (D-glucuronic and pyruvic acids), hydroxyl groups (cellulose, agar and floridean starch) and sulfonate groups (sulphated galactans). Potentiometric acid-base titrations showed a heterogeneous distribution of two major binding groups, carboxyl and hydroxyl, following the quasi-Gaussian affinity constant distribution suggested by Sips, which permitted to estimate the maximum amount of acid functional groups (0.

Continuous biosorption of Pb/Cu and Pb/Cd in fixed-bed column using algae Gelidium and granulated agar extraction algal waste.

Continuous metal ions biosorption from Pb/Cu and Pb/Cd solutions onto seaweed Gelidium sesquipedale and a composite material prepared from an industrial algal waste was performed in a packed bed column. A binary Langmuir equation describes well the equilibrium data and indicates a good adsorption capacity. In the sorption process, Cd and Cu break through the column faster than Pb due to its lower affinity for the biosorbent.

Effect of Cu(II), Cd(II) and Zn(II) on Pb(II) biosorption by algae Gelidium-derived materials.

Biosorption of Pb(II), Cu(II), Cd(II) and Zn(II) from binary metal solutions onto the algae Gelidium sesquipedale, an algal industrial waste and a waste-based composite material was investigated at pH 5.3, in a batch system. Binary Pb(II)/Cu(II), Pb(II)/Cd(II) and Pb(II)/Zn(II) solutions have been tested.

Biosorption of copper by marine algae Gelidium and algal composite material in a packed bed column.

Marine algae Gelidium and algal composite material were investigated for the continuous removal of Cu(II) from aqueous solution in a packed bed column. The biosorption behaviour was studied during one sorption-desorption cycle of Cu(II) in the flow through column fed with 50 and 25 mg l(-1) of Cu(II) in aqueous solution, at pH 5.3, leading to a maximum uptake capacity of approximately 13 and 3 mg g(-1), respectively, for algae Gelidium and composite material.

Chromium and zinc uptake by algae Gelidium and agar extraction algal waste: kinetics and equilibrium.

Biosorption of chromium and zinc ions by an industrial algal waste, from agar extraction industry has been studied in a batch system. This biosorbent was compared with the algae Gelidium itself, which is the raw material for agar extraction, and the industrial waste immobilized with polyacrylonitrile (composite material). Langmuir and Langmuir-Freundlich equilibrium models describe well the equilibrium data.

Copper removal by algae Gelidium, agar extraction algal waste and granulated algal waste: kinetics and equilibrium.

Biosorption of copper ions by an industrial algal waste, from agar extraction industry has been studied in a batch system. This biosorbent was compared with the algae Gelidium itself, which is the raw material for agar extraction, and the industrial waste immobilized with polyacrylonitrile (composite material). The effects of contact time, pH, ionic strength (IS) and temperature on the biosorption process have been studied.