A comprehensive assessment of superabsorbent resin produced using modified quinoa husk and coal fly ash - Preparation, characterization and application.

About 200 million tons of coal fly ash (CFA) is not effectively used in China every year. To enhance the utilization of biomass waste quinoa husk (QH) and solid waste CFA and reduce the preparation cost of superabsorbent resin (SAR), a low-cost, biodegradable modified quinoa husk-g-poly (acrylic acid)/coal fly ash superabsorbent resin (MQH-g-PAA/CFA SAR) was synthesized using modified quinoa husk (MQH), acrylic acid and CFA and used to improve the drought resistance and fertilizer conservation ability of soil. The surface morphology and performance of SAR were characterized by Fourier transform infrared (FTIR) spectrometry, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA), which provided evidence for improving the properties of SAR by grafting MQH and adding CFA.

Biochar/nano-zerovalent zinc-based materials for arsenic removal from contaminated water.

In this study, we explored the potential of a newly prepared nano-zero valent zinc (nZVZn), biochar (BC)/nZVZn and BC/hydroxyapatite-alginate (BC/HA-alginate) composites for the removal of inorganic As species from water. Relatively, higher percentage removal of As(III) and As(V) was obtained by nZVZn at pH 3.4 (96% and 94%, respectively) compared to BC/nZVZn (90% and 88%) and BC/HA-alginate (88% and 80%) at pH 7.

Electrified nanohybrid filter for enhanced phosphorus removal from water.

Phosphorus (P) has been identified as a major cause of eutrophication. One feasible way to deal with P-containing wastewater is to employ advanced adsorbents with high P affinity. Towards this end, the loading of these sorbents onto a conductive scaffold would facilitate the introduction of an electric field into the reaction system thereby permitting a continuous-flow operation and improved P sorption kinetics.

The key factors and removal mechanisms of sulfadimethoxazole and oxytetracycline by coagulation.

The effects of coagulant dosage, alkalinity, turbidity, ionic strength, and dissolved organic matter (DOM) on the removal of sulfadimethoxazole (SMZ) and oxytetracycline (OTC) by coagulation were studied and the reaction mechanisms of the coagulation process were revealed in this research. From our results, alkalinity, turbidity, ionic strength, and DOM had different effects on the removal of antibiotics. The SMZ and OTC removals were improved with increase in poly-aluminum chloride (PACl) dosage, whereas the turbidity had less influence on the removal of SMZ and OTC because the adsorption of SMZ and OTC to kaolin was low, confirmed by a control when no PACl added.

Evaluation of the treatability of various odor compounds by powdered activated carbon.

This study focused on evaluating the use of powdered activated carbon (PAC) adsorption for the treatability of various odor compounds with different structures. The adsorption performance of 14 odor compounds under various PAC dosages were fitted with two isotherm models (the Langmuir and Freundlich models) to evaluate the adsorption ability. The results indicated that the adsorption capacities estimated from isotherm model predictions were not suitable for the evaluation of treatability of the odor compound due to the neglection of odor threshold.

Removal of active dyes by ultrafiltration membrane pre-deposited with a PSFM coagulant: Performance and mechanism.

A new, environmental friendly, polysilicate ferric manganese (PSFM) coagulant, composed of Fe, Mn and Si, was designed and developed. As part of the process, the PSFM flocs were then deposited onto an ultrafiltration (UF) membrane to increase the removal of active dyes and its antifouling properties in the presence of the active dye was tested. Influencing factors, such as dosage of coagulant and solution pH, were systematically investigated and included as the process optimization.

[Optimization of Dyeing Wastewater Treatment with New Eco-friendly Polysilicate Ferromanganese].

To improve the efficiency of the removal of dye wastewater, a new type of coagulant "polysilicate ferromanganese (PSFM)" has been synthesized using sodium silicate, ferrous sulfate, and potassium permanganate. Three dyes (direct red, disperse blue, and active yellow) were used for the coagulation tests. The effects of the alkalinity and turbidity on the performance of PSFM were studied.

[Adsorption of Tetracycline on Simulated Suspended Particles in Water].

The mechanism of adsorption of a typical antibiotic (tetracycline, TC) on particles in the aquatic environment and the parameters affecting adsorption were investigated. Experiments were conducted to elucidate the effects of pH and various cation species with different concentrations. The results show that the adsorption of TC on particles is rapid during the first four hours in the mixing stage.

Influences of dissolved organic matters on tetracyclines transport in the process of struvite recovery from swine wastewater.

Due to the extensive existence of tetracyclines (TCs), struvite (MgNHPO·6HO) recovery from swine wastewater will pose TCs-pharmacological threats to the agricultural planting and environment. This study investigated the influences of dissolved organic matters (DOM), as an important medium in the wastewater, on TCs transport during struvite recovery from swine wastewater. Compared to TCs concentrations of 1.

Spatial and seasonal changes of arsenic species in Lake Taihu in relation to eutrophication.

Spatial and seasonal variations of arsenic species in Lake Taihu (including Zhushan Bay, Meiliang Bay, Gonghu Bay, and Southern Taihu) were investigated. Relatively high levels of total arsenic (TAs) and arsenate (As(V)) were observed in hyper-eutrophic regions during summer and autumn, which is attributed to exogenous contamination and seasonal endogenous release from sediments. The distributions of TAs and As(V) were significantly affected by total phosphorus, iron, manganese, and dissolved organic carbon.

[Health risk assessment of heavy metals in typical township water sources in DongjianG River basin].

In order to clarify the distribution characteristics and risk levels of heavy metals in typical drinking water sources of towns in Dongjiang River Basin, several regular water quality indexes as well as concentrations of Fe, Cu, Mn, Zn, As, Cr, Hg, Pb and Cd were analyzed in the 45 random water samples of 9 towns in the study area. The risk assessment was conducted according to different drinking water types using the environmental health risk assessment model recommended by U. S.

Multistep, microvolume resin fractionation combined with 3D fluorescence spectroscopy for improved DOM characterization and water quality monitoring.

Conventionally, resin fractionation (RF) method has been widely used to characterize dissolved organic matter (DOM) found in different source waters based on general and broad DOM fractions grouping. In this study, a new refined method using multistep, microvolume resin fractionation combined with excitation emission matrix fluorescence spectroscopy (MSM-RF-EEMS) was developed for further isolation and characterization of subfractions within the primary DOM fractions separated from using the conventional RF method. Subsequently, its feasibility in indicating the occurrence of urban pollution in source waters was also assessed.

Application of a new combined fractionation technique (CFT) to detect fluorophores in size-fractionated hydrophobic acid of DOM as indicators of urban pollution.

For pollution monitoring, we developed a new combined fractionation technique (CFT) to characterize dissolved organic matter (DOM) in natural water by combining resin adsorption (RA) and ultrafiltration (UF) with 3D-fluorescence measurement. We tested the new technique on 4 polluted and 4 unpolluted samples. The 3D-fluorescence characteristics of size sub-components in the hydrophobic acid (HPOA) fraction could distinguish unpolluted from polluted DOM.

Characterization of dissolved organic matter from Australian and Chinese source waters by combined fractionation techniques.

The character of dissolved organic matter (DOM) in source waters from two countries (Australia and China) was investigated using an extended fractionation technique by combining resin adsorption, ultrafiltration and high performance size exclusion chromatography. There are distinctive chemical characteristics associated with DOM origins. Australian sourced DOM had higher hydrophobic acid (HoA) content and exhibited a more pronounced humic character, indicating a higher influence from allochthonous organics (decayed plant bodies from vegetated catchments).

Effects of engineered nano-titanium dioxide on pore surface properties and phosphorus adsorption of sediment: its environmental implications.

Understanding the environmental safety and human health implications of engineered nanoparticles (ENPs) is of worldwide importance. As an important ENPs, engineered nano-TiO(2) (Enano-TiO(2)) may have been substantially deposited in aquatic sediments because of its widely uses. Sediment pore surface properties would be thus significantly influenced due to the large surface area of Enano-TiO(2).

Distributions of typical contaminant species in urban short-term storm runoff and their fates during rain events: a case of Xiamen City.

The pollutants in urban storm runoff, which lead to an non-point source contamination of water environment around cities, are of great concerns. The distributions of typical contaminants and the variations of their species in short term storm runoff from different land surfaces in Xiamen City were investigated. The concentrations of various contaminants, including organic matter, nutrients (i.

Competitive effect of Cu(II) and Zn(II) on the biosorption of lead(II) by Myriophyllum spicatum.

Batch experiments were conducted to assess the effects of Cu(II) and Zn(II) on the biosorption of Pb(II) ions by fresh tissues of Myriophyllum spicatum. The biosorption of Pb(II) was examined for single, binary and ternary solutions at different initial concentrations and different pH values. The experimental results showed that the biosorption capacity increased with increasing pH from 2.

Degradation characteristics of humic acid over iron oxides/Fe 0 core-shell nanoparticles with UVA/H2O2.

Iron oxides coated on Fe(0) core-shell nanospheres (nIOCI) were synthesized through the reduction of ferrous sulfate aqueous solution by sodium borohydride at ambient atmosphere. The catalyst was highly effective for the degradation of humic acid (HA) in the presence of H(2)O(2) and UVA at neutral pH. Under deoxygenated conditions in the dark, the generation of hydroxyl radicals in aqueous nIOCI dispersion verified its galvanic cell-like performance, which enhanced the interfacial electron transfer and led to its higher reactivity.

Transformations of particles, metal elements and natural organic matter in different water treatment processes.

Characterizing natural organic matter (NOM), particles and elements in different water treatment processes can give a useful information to optimize water treatment operations. In this article, transformations of particles, metal elements and NOM in a pilot-scale water treatment plant were investigated by laser light granularity system, particle counter, glass-fiber membrane filtration, inductively coupled plasma-optical emission spectroscopy, ultra filtration and resin absorbents fractionation. The results showed that particles, NOM and trihalomethane formation precursors were removed synergistically by sequential treatment of different processes.

Size and resin fractionations of dissolved organic matter and trihalomethane precursors from four typical source waters in China.

Dissolved organic matter (DOM) and its potential to form disinfection by-products (DBPs) during drinking water treatment raise challenges to water quality control. Understanding both chemical and physical characteristics of DOM in source waters is key to better water treatment. In this study, the DOM from four typical source waters in China was fractionated by XAD resin adsorption (RA) and ultrafiltration (UF) techniques.

Seasonal variations of chemical and physical characteristics of dissolved organic matter and trihalomethane precursors in a reservoir: a case study.

Dissolved organic matter (DOM) and its potential to form disinfection by-products (DBPs) during water treatment are of great public health concern. Understanding the seasonal changes in DOM composition and their reactivity in DBP formation could lead to a better treatment of drinking water and a more consistent water quality. DOM from the East-Lake, a reservoir in the south-China, was fractionated and characterized by XAD resin adsorption (RA) and ultrafiltration (UF) techniques during different seasons within a year.