Removal of divalent nickel from aqueous solutions using Carissa carandas and Syzygium aromaticum: isothermal studies and kinetic modelling

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Adsorptive behavior, isothermal studies and kinetic modeling involved in removal of divalent lead from aqueous solutions, using Carissa carandas and Syzygium aromaticum

This study is focused on the biosorption of lead(II) ion onto surface of Carissa carandas and Syzygium aromaticum biomass from aqueous solution. The operating parameters, pH of solution, biomass dosage, contact time, initial metal ion concentration, and temperature considerably affect the biosorption efficiency of Pb(II). Biosorbent C. carandas leaf powder showed higher sorption efficiency than that of biosorbent S. aromaticum powder under identical experimental conditions. It was observed that the lead(II) removal percentage was found highest of 95.11% for C. carandas and 91.04% for S. aromaticum at contact period of 180 min. Also, it was observed that the regression coefficient (R2 = 0.99) for the pseudo-second-order kinetic model is higher in comparison with the pseudo-first-order kinetic model and the calculated value of qe for the pseudo-second-order kinetic model is very close to the experimental value, which indicates that it fits well with the equilibrium data for Pb(II) sorption from aqueous solutions on biosorbents. Also, the adsorption of Pb(II) onto C. carandas was best described by the Freundlich isotherm model

Characteristics and adsorption capacities of low-cost sorbents for wastewater treatment: A review

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In situ microcosm remediation of polyaromatic hydrocarbons: influence and effectiveness of Nano-Zero Valent Iron and activated carbon

: Nano-zero-valent iron (nZVI) and activated carbon (AC) addition are ongoing techniques for the remediation of hydrophobic organic compound-contaminated sediment and water, but with still unexplored eco(toxico)logical implications, especially when applied in situ. In this study, we investigated AC and nZVI as remediation methods for marine contaminated sediment and water, including chemical and toxicity (Artemia franciscana survival and genotoxicity) surveys. The removal efficiency of AC and nZVI (about 99%) was similar in both sediment and seawater, while the survival of nauplii and adults was mainly impacted by nZVI than AC. At the molecular level, the nZVI-addition induced down-regulation in the expression of two stress and one developmental genes, whereas AC was able to up-regulated only one gene involved in stress response. Results suggested that the use of AC is safer than nZVI that requires further investigation and potential optimization to reduce secondary undesired effects

Water Collection and Distribution Systems in the Palermo Plain During the Middle Ages

It has been said that Palermo is short of available water. However, nothing could be more wrong. Well-documented Arab sources and narrative chronicles reported an abundance of groundwater resources in Palermo Plain since the Middle Ages. The scarcity of sources and surface water in the Palermo Plain, compared to the groundwater abundance, led the inhabitants to use groundwater both for irrigation and domestic usage through a complex and sustainable hydraulic system. Vertical and horizontal (qanāts) wells, conveyed water towards gardens and public fountains making the Arabic Bal’harm (Palermo) a flourishing town. When visitors walk through the streets of Palermo’s historical center, among Arab ruins and Baroque architecture, they hardly imagine that there is a wide and varied cultural heritage of underground cavities hidden in the basements where water flows in intricate networks fed from a numerous springs. Only in recent years was a part of this system brought to light. Moreover, the city still has a wide and fascinating water distribution system consisting of irrigation basin (gebbie), ingenious hydraulic machines named senie, and distribution chessboard of irrigation (saje) and drinking water (catusi) canals. The medieval water collection and distribution systems and their various components in the Palermo Plain are reviewed together with the influence of the Arab water management on environment

Multi-endpoint effects of derelict tubular mussel plastic nets on Tigriopus fulvus

Microplastic debris from direct and indirect human activities is considered a major threat to the marine biodiversity mainly due to its abundance, durability, persistence, and ability to accumulate contaminants from the environment. Derelict tubular plastic nets of various colours (blue (BN), yellow (YN), green (GN), pink (PN), and white (WN) net), used to distinguish mussel farming owners, were collected by scuba-dive from the Mar Piccolo of Taranto (Ionian Sea). All nets were made of polypropylene. Investigations looked for potential acute (mortality) and sub-chronic (mortality, larval development and moult release number, and adult percentage after 5–9 days) effects on Tigriopus fulvus nauplii considering both whole plastics (microplastic (MP), 50 mg/L) and leachates (12.5–100%). Acute test determined a median lethal concentration (LC50) only for BN for both MPs (107 mg/L) and leachates (50.1%). The prolonged exposure (5 days) to microplastics did not affect the T. fulvus survival. After 9 days, YN and BN decreased of approximately 100% larval development

Individual and combined effects of amoxicillin and carbamazepine to the marine copepod Tigriopus fulvus

: Pharmaceuticals can be considered a global threat to aquatic ecosystems due to their pseudo-persistence and their potential toxicity towards non-target species. Amoxicillin (AMX) and carbamazepine (CBZ) and their mixture (1:1) were investigated on the marine copepod Tigriopus fulvus (Fischer, 1860) considering both acute and chronic endpoints. While acute and chronic exposure did not directly affect survival, reproductive endpoints were affected like the mean egg hatching time that was significantly longer than the negative control for treatments with AMX (0.789 ± 0.079 μg/L), CBZ (8.88 ± 0.89 μg/L), and AMX and CMZ as a mixture (1.03 ± 0.10 μg/L and 0.941 ± 0.094 μg/L), in that order

In situ remediation of contaminated marinesediment: an overview

Sediment tends to accumulate inorganic and persistent hydrophobic organic contaminants representing one of the main sinks and sources of pollution. Generally, contaminated sediment poses medium- and long-term risks to humans and ecosystem health; dredging activities or natural resuspension phenomena (i.e., strongly adverse weather conditions) can remobilize pollution releasing it into the water column. Thus, ex situ traditional remediation activities (i.e., dredging) can be hazardous compared to in situ techniques that try to keep to a minimum sediment mobilization, unless dredging is compulsory to reach a desired bathymetric level. We reviewed in situ physico-chemical (i.e., active mixing and thin capping, solidification/stabilization, chemical oxidation, dechlorination, electrokinetic separation, and sediment flushing) and bio-assisted treatments, including hybrid solutions (i.e., nanocomposite reactive capping, bioreactive capping, microbial electrochemical technologies). We found that significant gaps still remain into the knowledge about the application of in situ contaminated sediment remediation techniques from the technical and the practical viewpoint. Only activated carbon-based technologies are well developed and currently applied with several available case studies. The environmental implication of in situ remediation technologies was only shortly investigated on a long-term basis after its application, so it is not clear how they can really perform

A review of plant-based coagulants for turbidity and cyanobacteria blooms removal

In recent years, the proliferation of Harmful Cyanobacterial Blooms (CyanoHABs) has increased with water eutrophication and climate change, impairing human health and the environment in relation to water supply. In drinking water treatment plants (DWTPs), the bio-coagulation based on natural coagulants has been studied as an eco-friendly alternative technology to conventional coagulants for both turbidity and CyanoHABs removal. Plant-based coagulants have demonstrated their coagulation efficiency in turbidity removal, as reported in several papers but its ability in cyanobacterial removal is still limited. This paper mainly reviewed the application of plant-based coagulants in DWTPs, with focus on turbidity removal, including cyanobacterial cells. The future potential uses of these green coagulants to reduce noxious effects of cyanobacterial proliferation are presented. Green coagulants advantages and limitations in DWTPs are reviewed and discussed summarizing more than 10 years of knowledge

Polymer functionalized nanocomposites for metals removal from water and wastewater: An overview

Pollution by metal and metalloid ions is one of the most widespread environmental concerns. They are non-biodegradable, and, generally, present high water solubility facilitating their environmental mobilisation interacting with abiotic and biotic components such as adsorption onto natural colloids or even accumulation by living organisms, thus, threatening human health and ecosystems. Therefore, there is a high demand for effective removal treatments of heavy metals, making the application of adsorption materials such as polymer-functionalized nanocomposites (PFNCs), increasingly attractive. PFNCs retain the inherent remarkable surface properties of nanoparticles, while the polymeric support materials provide high stability and processability. These nanoparticle-matrix materials are of great interest for metals and metalloids removal thanks to the functional groups of the polymeric matrixes that provide specific bindings to target pollutants. This review discusses PFNCs synthesis, characterization and performance in adsorption processes as well as the potential environmental risks and perspectives. (C) 2016 Elsevier Ltd. All rights reserved