Salt produced from seawater evaporation contains harmful microplastics (MP). For this reason, a technology that can remove MP from seawater using coagulation and filtration techniques is needed. The purpose of this study is to utilize alum as a coagulant and sand as a filtration media to reduce MP pollution in seawater as a source of raw material for salt making. Seawater from Buo Bay, Padang City, Indonesia was taken as raw material for salt production. The MP abundance of salt made from seawater without alum and sand treatment was found to be 400 particles/kg. To reduce the abundance of MP in the salt, we varied the alum concentration (0.1; 0.3; and 0.5 g/L) and sand particle size (≥2, ≥1-<2, and <1 mm). From the results obtained, the optimal condition is an alum concentration of 0.5 g/L and sand particle size is <1 mm. The optimal condition of salt made from seawater in treatment H obtained MP abundance from 400 particles/kg to 30 particles/kg with an MP reduction efficiency of 92.5%. Visual analysis using optical trinocular microscopy found 4 forms of MP, namely: fragments (51.13%), fibers (28.95%), films (15.41%), and pellets (4.05%). Rewith the most dominant MP size found was >100-300 µm. The results of ATR-FTIR analysis identified the types of MP as Polyethylene (14.28%), Polyethylene Terephthalate (42.85%), Polypropylene (14.28%), and Polyamide (28.57%).

Numerous coagulants, including natural and chemical coagulants, have been examined in the context of water purification. The use of natural coagulants constitutes an affordable and eco-friendly method of purifying water. The main aim of the current study was represented by investigated the feasibility of coagulant extracted from Castanea Sativa Tree Leaves using three different salts and distilled water. The active coagulant component was extracted using 0.25, 0.5, and 1 M of NaCl and KCl, 0.025, 0.05, and 0.1 M of NaOH, and distilled water. Powdered Castanea Sativa Tree Leaves was also used as a coagulant. Jar tests were performed using synthetic turbid water, a turbidity level of 35 NTU to investigate the coagulants’ activity. The pH was measured to study the influence of a range of different pHs, coagulant doses and initial turbidity were also investigated to optimize the coagulation process. The highest level of activity was achieved using 0.5 ml/l of coagulant extracted with 0.5 M NaCl at pH level 8. Coagulant extracted using 0.05 M NaOH demonstrated the second highest level of activity. Poor coagulant activity was observed for the powdered Castanea Sativa Tree Leaves and distilled water extract. The protein content of the extracted coagulant was 0.322, 0.283, and 0.274 mg/ml using 0.05 M NaCl, 0.5 M NaOH, and 0.5 M KCl, respectively. The use of this natural coagulant was also found to moderately increase organic matter content in the treated water, which was proportional to protein contents of the extracts. Coagulation results were statistically examined using SigmaPlot 12.5 software.

The salt obtained from salt sources has a low purity level and contains contaminants. The primary contaminants in the brines were eliminated in this investigation by using analytical separation (titration) techniques. Following the purification method, sodium hydroxide (NaOH) was added to magnesium chloride (MgCl2) to make magnesium hydroxide (Mg(OH)2) coagulate in pH control. This was done by PID and Self-Tuning PID (STPID) Control. Using STPID Control, hydrochloric acid (HCl) at a rate of 20% was employed as an effective acid current, MgCl2 as a coagulant, and NaOH at a rate of 10% as a neutralization base throughout the process. The coagulation technique was carried out with pH values of 7, 9, and 11, respectively. The pH of the medium was adjusted using the PID and STPID algorithms, as well as an on-line computer control system. As the system model, ARMAX was employed. As a forcing function, a pseudo-random binary sequence (PRBS) was used to identify the dynamics of the process to be controlled, and the system output was measured. The Bierman algorithm was used to evaluate the model parameters. The STPID controller's tuning parameters were calculated. Following the coagulation method, an analytical titration procedure was used to find out if there are any trace amounts of Mg(OH)2 in the current environment, and a settlement percentage of 90% to 95% was found. To get the best coagulation, a pH value of 11 was chosen as the optimal value based on the performed calculations.

Produced water is a large amount of water wasted throughout the crude oil extraction process, it's a mixture of the well's deposition water and the water of oil wells extraction water. Produced water contains oil, suspended solids and dissolves solid. This study tested produced water collected from Alahdab oilfield/middle oil company for oil content and suspended solid contamination using chemical precipitation and coagulation-flocculation for reinjection and environmental considerations. Coagulation/flocculation is a common method used as primary purification to oily wastewater treatment due to its usability, performance, and low cost. Coagulant experimental was completed by A jar test device, additives of ferric sulfate and aluminium sulfate were in a range about (10 ـ 40) ppm, as well as polyelectrolyte- (polyacrylamide) as an additional flocculent in the range (1.5-3) ppm. The results show that ferric sulfate was more efficient at removing turbidity than aluminium sulfate under the same conditions, with the best removal of turbidity at dose concentration 30 ppm of Ferric sulfate and a flocculent dose concentration of 2.5 ppm of polyacrylamide, also with oil content decreasing from 396.71 ppm to 53.56 ppm.

Plastic pollution has been a growing concern in recent decades due to the proliferation and ease of manufacturing of single use plastic products and inadequate waste and recycling management. Microplastic, and even smaller nanoplastic, particles are persistent pollutants in aquatic and terrestrial systems and are the subject of active and urgent research. This review will explore the current research on how exposure to plastic particles occurs and the risks associated from different exposure routes: ingestion, inhalation, and dermal exposure. The effects of microplastics on the cardiovascular system are of particular importance due to its sensitivity and ability to transport particles to other organ systems. The effects of microplastics and nanoplastics on the heart, platelet aggregation, and thrombus formation will all be explored with focus on how the particle characteristics modulate their effect. Plastic particle interactions are highly dependent on both their size and their surface chemistry and interesting research is being done with the interaction of particle characteristics and effect on thrombosis and the cardiovascular system. There is significant uncertainty surrounding some of the findings in this field as research in this area is still maturing. There are undoubtedly more physiological consequences than we are currently aware of resulting from environmental plastic exposure and more studies need to be conducted to reveal the full extent of pathologies caused by the various routes of microplastic exposure, with particular emphasis on longitudinal exposure effects. Further research will allow us to recognize the full extent of physiological impact and begin developing viable solutions to reduce plastic pollution and potentially design interventions to mitigate in-vivo plastic effects following significant or prolonged exposure.

Microplastic (MP) has been detected ubiquitously in freshwater systems. Until now MP sampling, however, is predominantly based on short-term net or pumping and filtration systems which can only provide snapshots of MP abundance; especially in flowing water bodies. To improve representativeness in the determination of MP occurrences in these aquatic compartments, an integrative approach that covers larger water volumes for a longer period of time is required. In this regard, surface water supplied drinking water treatment plants (DWTPs) represent an opportunity. In DWTPs, suspended solids from thousands of cubic metres of raw water are continuously removed over several hours and enriched in coagulation/flocculation and filtration processes. Our hypothesis was that MP is also removed to a full extent, like suspended solids, and that an integrative approach for identification and quantification in raw water can be derived from the analysis of MP in the treatment sludge. To prove this hypothesis, treatment sludge from a riverside DWTP (Warnow river, North-Eastern Germany) was analysed for MP > 50 μm. A sample purification protocol overcoming potential matrix effects caused by coagulants and flocculants was developed and validated. MP was analysed using micro-Raman spectroscopy. MP occurrence determined for the Warnow river was compared with in situ reference sampling using an established pumping and filtration system at relatively stable flow conditions. As result, the number of MP particles derived from treatment sludge was extrapolated to 196 ± 42 m⁻³ for the Warnow river and is statistically insignificantly different from 233 ± 36 m⁻³ identified by conventional water sampling. In addition, the polymer distribution and particles shape indicated the validity of the integrative concept. Consequently, the determination of MP abundance for freshwater systems based on DWTP treatment sludge represents an adequate method to estimate MP concentrations in flowing waters in an integrative way.

Nanoplastics are inevitably released into aquatic environments due to their extensive use and the continuous fragmentation of plastics. Therefore, it is imperative to understand the aggregation behaviours that determine the transport and fate of nanoplastics in aquatic environments. In this study, the effects of various metal cations, pH, aging and extracellular polymeric substances (EPS) on the aggregation of polystyrene nanoplastics (nano-PS) in aqueous solutions were systematically evaluated based on aggregation kinetics experiments and Derjaguin–Landau–Verwey–Overbeek (DLVO) theoretical calculation. The concentration, valence and hydration ability of metal cations jointly affected the aggregation of nano-PS. The critical coagulation concentration (CCC) of nano-PS was significantly higher than the ionic strengths in aquatic environments, indicating that the aggregation rate of nano-PS is relatively low in aquatic environments. The results of the aggregation kinetics experiments were consistent with DLVO theory, which showed that the energy barrier of nano-PS was dependent on electrostatic repulsion forces and van der Waals forces, and increased with pH. Nano-PS was artificially aged by UV-H₂O₂, which reduced the hydrophobic nature of the particle surfaces, consequently enhancing the stability of the nanoplastics. EPS (excreted from Chlorella pyrenoidosa) decreased the aggregation rates of nano-PS due to steric effects, which was confirmed by the extend DLVO model. Our results highlight the high stability of nano-PS in aquatic environments, which could help facilitate the evaluation of their environmental impact.

Biodigested coffee processing wastewater (CPW) presents a high organic load and does not meet the limits imposed by legislation (namely in Brazil) for discharge into water bodies. Anaerobic digestion generally cannot provide a satisfactory organic matter reduction in CPW as a significant fraction of recalcitrant compounds still persists in the treated effluent. So, this study aims to find alternative ways to remove refractory organic compounds from this wastewater in order to improve the biodegradability and reduce the toxicity, which will allow its recirculation back into the anaerobic digester. Three treatment approaches (Fenton’s oxidation - Approach 1, Coagulation/flocculation (C/F) - Approach 2, and the combination of C/F with Fenton’s process - Approach 3) were selected to be applied to the biodigested CPW in order to achieve that objective.The application of the Fenton process under the optimal operating conditions (initial pH = 5.0; T = 55 °C, [Fe³⁺] = 1.8 g L⁻¹ and [H₂O₂] = 9.0 g L⁻¹) increased the biodegradability (the BOD₅:COD ratio raised from 0.34 ± 0.02 in biodigested CPW to 0.44 ± 0.01 after treatment) and eliminated the toxicity (0.0% of Vibrio fischeri inhibition) along with moderate removals of organic matter (51.3%, 55.7% and 39.7% for total organic carbon – TOC, chemical oxygen demand – COD and biochemical oxygen demand - BOD₅, respectively). The implementation of a coagulation/flocculation process upstream from Fenton’s oxidation, under the best operating conditions (pH 10–11 and [Fe³⁺] = 250 mg L⁻¹), also allowed to slightly increase the biodegradability (from 0.34 to 0.47) and reduce the toxicity, whereas providing a higher removal of organic matter (TOC = 76.2%, COD = 76.5 and BOD₅ = 66.3% for both processes together). Approach 1 and Approach 3 showed to be the best ones, implying similar operating costs (∼74 R$ m⁻³/∼17 € m⁻³) and constitute an attractive option for managing biodigested CPW.

Chemical conditioning is an effective strategy for improved river sediment dewatering affecting both the dewatering efficiency and subsequent resource utilization of the dewatered cake. Two types of conditioning agents, polyaluminium chloride (PAC)/cationic polyacrylamide (PAM) (coagulation precipitation conditioning agent, referred to as P–P conditioning) and ferrous activated sodium persulfate (advanced oxidation conditioning agent, referred to as F–S conditioning) were examined. With increasing leach liquid to solid (L/S) ratio the concentration of Cd for the real time leachates from the dewatered cakes decreased, but the leaching ratio of Cd in both P–P and F–S dewatered cakes increased. With the same L/S, the leaching ratio was reduced for both types of conditioning, as compared to no conditioning, with the leaching ratio being least with F–S conditioning. The leaching ratio of Cd in the dewatered cake with L/S of 100 L kg⁻¹ was reduced from 21.3% of the total Cd present for the un-conditioned sediment to 12.5% upon P–P conditioning and 11.6% upon F–S conditioning. Furthermore, the different conditioning methods affected the Cd speciation in the dewatered cakes reducing the easy-to-leach speciation of exchangeable and carbonate-bound Cd species and increasing the potential-to-leach speciation of iron-manganese oxide and organically bound Cd species and also the difficult-to-leach species. Risk assessment indicates that the risk due to Cd leaching from the dewatered cakes at L/S of 100 L kg⁻¹ was reduced from high risk to medium risk after P–P and F–S conditioning with reduced bioavailability.

Disinfection means the killing of pathogenic organisms (e.g. bacteria and its spores, viruses, protozoa and their cysts, worms, and larvae) present in water to make it potable for other domestic works. The substances used in the disinfection of water are known as disinfectants. At municipal level, chlorine (Cl₂), chloramines (NH₂Cl, NHCl₂), chlorine dioxide (ClO₂), ozone (O₃) and ultraviolet (UV) radiations, are the most commonly used disinfectants. Chlorination, because of its removal efficiency and cost effectiveness, has been widely used as method of disinfection of water. But, disinfection process may add several kinds of disinfection by-products (DBPs) (∼600–700 in numbers) in the treated water such as Trihalomethanes (THM), Haloacetic acids (HAA) etc. which are detrimental to the human beings in terms of cytotoxicity, mutagenicity, teratogenicity and carcinogenicity. In water, THMs and HAAs were observed in the range from 0.138 to 458 μg/L and 0.16–136 μg/L, respectively. Thus, several regulations have been specified by world authorities like WHO, USEPA and Bureau of Indian Standard to protect human health. Some techniques have also been developed to remove the DBPs as well as their precursors from the water. The popular techniques of DBPs removals are adsorption, advance oxidation process, coagulation, membrane based filtration, combined approaches etc. The efficiency of adsorption technique was found up to 90% for DBP removal from the water.