Effects of nature organic matters and hydrated metal oxides on the anaerobic degradation of lindane,p,p'-DDT and HCB in sediments

Effects of natural organic matters(NOM) and hydrated metal oxides(HMO) in sediments on the anaerobic degradation of γ 666, p,p' DDT and HCB were investigated by means of removing NOM and HMO in Liaohe River sediments sequentially. The results showed that the anaerobic degradation of γ 666, p,p' DDT and HCB followed pseudo first order kinetics in different sediments. But, the extents and rates of degradation were different, even the other conditions remained the same. Anaerobic degradation rates of γ 666, p,p' DDT and HCB were 0 020 d -1 , 0 009 d -1 and 0 035 month -1 respectively for the sediments without additional carbon resources. However, with addition of carbon resources, the anaerobic degradation rates of γ 666, p, p ' DDT and HCB were 0 071 d -1 , 0 054 d -1 and 0 088 month -1 in the original sediments respectively. After removing NOM, the rates were decreased to 0 047 d -1 , 0 037 d -1 and 0 066 month -1 ; in the sediments removed NOM and HMO, the rates were increased to 0 067 d -1 , 0 059 d -1 and 0 086 month -1 . These results indicated that NOM in the sediments accelerated the anaerobic degradation of γ 666, p,p' DDT and HCB; the HMO inhibited the anaerobic degradation of γ 666, p,p' DDT and HCB.

ATR-FTIR and XPS study on the structure of complexes formed upon the adsorption of simple organic acids on aluminum hydroxide

Information on the binding of organic ligands to metal （hydr）oxide surfaces is useful for understanding the adsorption behaviour of natural organic matter on metal （hydr）oxide. In this study, benzoate and salicylate were employed as the model organic ligands and aluminum hydroxide as the metal hydroxide. The attenuated total reflectance Fourier transform infrared （ATR-FTIR） spectra revealed that the ligands benzoate and salicylate do coordinate directly with the surface of hydrous aluminum hydroxide, thereby forming innersphere surface complexes. It is concluded that when the initial pH is acidic or neutral, monodentate and bridging complexes are to be formed between benzoate and aluminum hydroxide while bridging complexes predominate when the initial pH is alkalic. Monodentate and bridging complexes can be formed at pH 5 while precipitate and bridging complexes are formed at pH 7 when salicylate anions are adsorbed on aluminum hydroxide. The X-ray photoelectron （XP） spectra demonstrated the variation of C 1 s binding energy in the salicyate and phenolic groups before and after adsorption. It implied that the benzoate ligands are adsorbed through the complexation between carboxylate moieties and the aluminum hydroxide surface, while both carboxylate group and phenolic group are involved in the complexation reaction when salicylate is adsorbed onto aluminum hydroxide. The information offered by the XPS confirmed the findings obtained with ATR-FTIR.

Effects of pre-ozonation on organic matter removal by coagulation with IPF-PACl

Ozone plays an important role as a disinfectant and oxidant in potable water treatment practice and is increasingly being used as a pre-oxidant before coagulation. The purpose of this study is to obtain insight into the mechanisms that are operative in pre-ozonized coagulation. Effects ofpre-ozonation on organic matter removal during coagulation with IPF-PAC1 were investigated by using PDA （photometric disperse analysis）, apparent molecular weight distribution and chemical fractionation. The dynamic formation of flocs during coagulation process was detected. Changes of aquatic organic matter （AOM） structure resulted from the influence of pre-ozonation were evaluated. Results show that dosage of O3 and characteristics of AOM are two of the major factors influencing the performance of O3 on coagulation. No significant coagulation-aid effect of O3 was observed for all experiments using either A1C13 or PAC1. On the contrary, with the application of pre-ozonation, the coagulation efficiency of A1C13 was significantly deteriorated, reflected by the retardation of floc formation, and the removal decreases of turbidity, DOC, and UV254. However, if PACl was used instead of AlCl3, the adverse effects of pre-ozonation were mitigated obviously, particularly when the O3 dosage was less than 0.69 （mg O3/mg TOC）. The difference between removals of UV254, and DOC indicated that pre-ozonation greatly changed the molecular structure of AOM, but its capability of mineralization was not remarkable. Only 5% or so DOC was removed by pre-ozonation at 0.6--0.8 mg/L alone. Fractionation results showed that the organic products of pre-ozonation exhibited lower molecular weight and more hydrophilicity, which impaired the removal of DOC in the following coagulation process.

Combination of chlorine and magnetic ion exchange resin for drinking water treatment of algae

The effectiveness of a magnetic ion exchange resin （MIEX） for the treatment of Hongze Lake water in China was evaluated, The kinetics of natural organic matter （NOM） removal at various MIEX doses and contact time, multiple-loading experiments, impacts of MIEX prior to coagulation on coagulant demands and the effectiveness of combination of MIEX, pre-chlorination and coagulation were investigated. Kinetic experimental results show that more than 80% UV254 and 67% dissolved organic carbon （DOC） from raw water can be removed by the use of MIEX alone. 94% sulfate, 69% nitrate and 98% bromide removals are obtained after the first use of MIEX in multiple-loading experiments. It is suggested that MIEX can be loaded up to 1 250 bed volume （BV, volume ratio of tested water to resin） or more without saturation when regarding organics removal as a target. MIEX can remove organics to a greater extend than coagulation and lower the coagulant demand when combining with coagulation. Chlorination experimental results show that MIEX can remove 57% chlorine demand and 77% trihalomethane formation potential （THMFP） for raw water. Pre-chlorination followed by MIEX and coagulation can give additional organic and THMFP removals. The results suggest that MIEX provides a new method to solve thc problem algae reproduction.

Characteristics of the natural organic matter sorption affects of organic contaminants

Several soil samples were used to study how the characteristics of natural organic matter (NOM) affect sorption of organic compounds. These soils contains different amounts and types of NOM. Aromaticity of NOM (percentage of aromatic carbons) was determined from solid state CPMAS 13 C NMR spectra and the soil effective polarity was computed from the equation developed by Xing et al . Naphthalene was used to examine the sorption characteristics of NOM. Both aromaticity and polarity of NOM strongly affected sorption of naphthalene. Old NOM showed higher affinity than that in the surface, young soils. Sorption increased with increasing aromaticity and decreasing polarity. Thus, the sorption coefficients of organic contaminants cannot be accurately predicted without some consideration of NOM characteristics.

FLOCCULATION/COAGULATION OF NATURAL ORGANIC MATTER FOR PRETREATMENT OF WATER ANDWASTE WATER

Characterization of water, waste water and natural organic matter are involved in this paper, and as well as the features of flocculation and coagulation for removing natural organic matter from water and waste water Novel flocculant and coagualant is strongly asked for improving removal efficiency and environment friendly. Enhanced coagulation is introduced to meet the experimental and practical requirement.

Soil Organic Carbon Contents and Stocks in Coastal Salt Marshes with Spartina alterniflora Following an Invasion Chronosequence in the Yellow River Delta,China

Plant invasion alters the fundamental structure and function of native ecosystems by affecting the biogeochemical pools and fluxes of materials and energy. Native(Suaeda salsa) and invasive(Spartina alterniflora) salt marshes were selected to study the effects of Spartina alterniflora invasion on soil organic carbon(SOC) contents and stocks in the Yellow River Delta. Results showed that the SOC contents(g/kg) and stocks(kg/m^2) were significantly increased(P < 0.05) after Spartina alterniflora invasion of seven years, especially for the surface soil layer(0–20 cm). The SOC contents exhibited an even distribution along the soil profiles in native salt marshes, while the SOC contents were gradually decreased with depth after Spartina alterniflora invasion of seven years. The natural ln response ratios(Ln RR) were applied to identify the effects of short-term Spartina alterniflora invasion on the SOC stocks. We also found that Spartina alterniflora invasion might cause soil organic carbon losses in a short-term phase(2–4 years in this study) due to the negative Ln RR values, especially for 20–60 cm depth. And the SOCD in surface layer(0–20 cm) do not increase linearly with the invasive age. Spearman correlation analysis revealed that silt + clay content was exponentially related with SOC in surface layer(Adjusted R^2 = 0.43, P < 0.001), suggesting that soil texture could play a key role in SOC sequestration of coastal salt marshes.

Investigation of organic fouling of microfiltration membrane

Because the natural organic matters (NOMs) and proteins are the principal foulants of microfiltration membranes in drinking water, the primary aim of this paper is to obtain a better understanding of the interactions between those foulants and the microfiltration membrane from a novel view of coagulation. Based on reviewed literature and our own analysis, the authors consider that the behaviors of NOMs in the fouling of microfiltration membrane are like a form of crystal growth, and we recognize that the extent of the membrane hydrophobicity plays an essential role in NOMs fouling. However, proteins’ fouling is more affected by intermolecular interaction. Additionally, the effect of membrane surface chemistry is not as essential as it is in the situation of NOMs.

Characterization of NOM and THM formation potential in eutrophic reservoir water

Resin adsorption technique with XAD-8 and XAD-4 was used to characterize the raw water from Erlong reservoir in Jilin province of China. The NOM chemical composition sequences of four organic fractions in the raw water, from high to low, are fulvic acid （FA） fraction, hydrophilic non-acid （HPINA） fraction, hydrophilic acid （HPIA） fraction, and humic acid （HA） fraction. Experimental results show that FA is the main precursor of THMFP among the four organic fractions. However, HA or hydrophobie acid exhibits the highest chlorination activity in forming THMs. It is also found that the value of FI/DOC or SUVA and the specific THMFP have better positive correlation. It is implied that certain source water has unique nature of NOM and DBPs.

Adsorption Characteristics of the Powdered Activated Carbon on Pesticide in the Water

The adsorption characteristics of the powdered activated carbon on four kinds of pesticides （ dichlorvos, chlorothalonil, lindane and chlorphyrifos） were studied, and the influential factors of adsorption effect were discussed. Results showed that the powdered activated carbon could effectively remove the above four kinds of pesticides. It was rapid adsorption period before 30 min, and removal rate has reached 90%. Adsorption kinetics of the powdered activated carbon on pesticides corresponded with quasi-two-level kinetic equation, and both Freundlich and Langmuir adsorption isotherms could simulate the adsorption process of the activated carbon on pesticide well. Competitive adsorption between small-molecule organics in the water diverting from Yellow River and Desticides on microDore of the activated carbon would occur.

Microbial Changes in the Fluorescence Character of Natural Organic Matter from a Wastewater Source

Natural Organic Matter (NOM) is a mixture of aromatic and aliphatic organic compounds of natural origin in any type of aquatic system. Human activities impact the constituents of NOM, from its production to its fate, particularly in the treatment of domestic waste waters. In this work, the impact of microorganisms isolated from a Waste Water Treatment Plant (WWTP) was investigated to determine the fate of NOM fractions in raw sewage, using fluorescence spectroscopy. Wastewater samples were taken at three different times from a WWTP, and incubated for 4 days under two treatments: 1) “raw sewage”, and 2) “spiked”, i.e., the same raw sewage, spiked with bacteria previously isolated from the WWTP. The incubated waters were analyzed by fluorescence spectroscopy, digitally resolved into NOM components: humic- and fulvic-like, and two types of protein-like, i.e., tryptophan- and tyrosine-like, using a Parallel Factor Analysis routine (PARAFAC). The results demonstrate that the “spiked” samples showed the largest changes with incubation time. The signals of the tryptophan- and tyrosine-like components decreased, suggesting a net microbial digestion of proteinaceous material. In contrast, the fulvic-like signals, and to some extent, the humic-like signals increased, suggesting the production of the associated molecular materials during the incubation period. This study provides direct evidence of human impact on the make-up of NOM: the cultures of microbes found at a WWTP consume the proteinaceous material, whereas humic-like and fulvic-like materials are produced.

Special Issue on "Response of Polar Organisms and Natural Environment to Global Changes"

High altitude and high latitude regions on Earth are experiencing rapid changes in climate, with impacts on polar organisms and the environment. The persistent cold and sometimes inhospitable conditions create unique ecosystems and habitats for polar organisms.

Inviting Contributions to a Special Issue on "Response of Polar Organisms and Natural Environment to Global Changes"

Dear Colleagues, We would like to invite you to submit manuscripts to a special issue of the journal Advances in Polar Science （APS） on ＂Response of Polar Organisms and Natural Environment to Global Changes＂.

Uptake of Multi-Disperse Starch by Anion Exchangers

Demineralisation plants of power stations are not able to remove organics in all cases to a satisfied degree. The present work focuses on natural organic matter （NOM） and its interaction with anion exchanger and adsorber resins to optimize organics uptake. In this study, four different starches （one of them 14C-labelled） with different molecular size distributions were selected as model substances for the biopolymer fraction of NOM. Their uptake by various anion exchangers and adsorbers was measured in column experiments. Results are discussed in terms of size exclusion, anion exchange, adsorption, and hydrophilic/hydrophobic repulsion. In summary, at neutral pH, starch has been removed preferably by size-exclusion followed by adsorption, whereas anion exchange resins show higher uptake capacities than ＂pure＂ adsorber resins caused by stronger attraction between starch and polar functional groups of the anion exchangers. At acidic pH, the uptake of sulphate, as competitive adsorptive, leads to an earlier starch breakthrough at anion exchangers. Therefore, adsorbers are more effective. It was found that the higher the water content of the resins, the more effective the uptake is.

Investigation of the Photosensitized Mechanisms of PCBs in the Presence of Natural Organic Matter

The structures of 26 different congeners of polychlorinated biphenyls（PCBs, including monothrough deca-chlorinated） were optimized using density functional theory（DFT） calculations with the 6-31＋G（d,p） basis set. The activation energies for the dechlorination of these systems were calculated for direct photodegradation and photosensitized degradation reaction pathways in the presence of natural organic matter（NOM）. The dechlorination mechanism of these PCBs and the ring-opening reaction mechanisms（using QST3 method） of the photosensitive degradation products were analyzed. The results showed that（i） the activation energy for the photosensitized degradation of PCBs was much lower than that of direct photodegradation;（ii） the degradation activities（i.e., C–Cl bond cleavage energies） were the same for both degradation pathways and followed the order ortho 〉 meta 〉 para;（iii） the degradation activities of asymmetric PCBs were higher than those of the corresponding symmetrical PCBs for the direct photodegradation and it was completely opposite in the photosensitive degradation;（iv） there was no correlation between the dissociation energy and the number of C–Cl bonds for the direct photodegradation and dechlorination products were all biphenyl;（v） the degradation activity of PCBs decreased as the number of C–Cl bonds increased in the presence of NOM; and（vi） even when the dechlorination reaction was incomplete, it produced chlorophenol. Furthermore, the free radicals of NOM led to the ring-opening reactions of PCBs via an initial addition step. The main site of these ring-opening reactions was the ortho position. Notably, the likelihood of ring-opening reactions occurring involving the degradation products increased as the degradation degree of PCBs increased.

Virus Removal by Iron Coagulation Processes

Waterborne viruses account for 30% to 40% of infectious diarrhea, and some viruses could persevere for some months in nature and move up to 100 m in groundwater. Using filtration setups, coagulation could lessen virus charges as an efficient pre-treatment for reducing viruses. This work discusses the present-day studies on virus mitigation using coagulation in its three versions i.e., chemical coagulation (CC), enhanced coagulation, and electrocoagulation (EC), and debates the new results of virus demobilization. The complexity of viruses as bioparticles and the process of virus demobilization should be adopted, even if the contribution of permeability in virus sorption and aggregation needs to be clarified. The information about virion permeability has been evaluated by interpreting empirical electrophoretic mobility (EM). No practical measures of virion permeability exist, a clear link between permeability and virion composition and morphology has not been advanced, and the direct influence of inner virion structures on surface charge or sorption has yet to be conclusively demonstrated. CC setups utilizing zero-valent or ferrous iron could be killed by iron oxidation, possibly using EC and electrooxidation (EO) methods. The oxidants evolution in the iron oxidation method has depicted promising findings in demobilizing bacteriophage MS2, even if follow-up investigations employing an elution method are needed to secure that bacteriophage elimination is related to demobilization rather than sorption. As a perspective, we could be apt to anticipate virus conduct and determine new bacteriophage surrogates following subtle aspects such as protein structures or genome size and conformation. The present discussion’s advantages would extend far beyond an application in CC—from filtration setups to demobilization by nanoparticles to modeling virus fate and persistence in nature.

Analysis of Haloacetic Acids(HAA5)in Waters of Public Schools and Residencies in Maringa-Brazil

For water to become suitable for human consumption in most water treatment plants this occurs by making use of the chlorination process where the organic matter is destroyed by the action of chlorine. Chlorine is a disinfectant that at low concentrations meets requirements such as not being toxic to humans and inactivating microorganisms. The reaction of chlorine with organic compounds results in chlorination byproducts, many potentially harmful to human health, such as trihalomethanes, haloacetic acids, among others. The present work aimed to collect and analyze samples of treated water from reservoirs from public schools in the city of Maringá, Brazil. Analyses of haloacetic acids (HAA5: monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid and dibromoacetic acid), natural organic compounds and free residual chlorine were performed (the latter analysis, in loco). The water collection points were chosen in order to maximize the concentration of haloacetic acids that characterize network distant points from treatment station and also samples near the water treatment plant. With the results, the formation of haloacetic acids between the entrance water of the school and the water of the reservoir of the collection points were compared, where higher values were obtained in the reservoirs. Furthermore, the haloacetic acid levels of water supplied to the population close to the treatment station and distant points of the treatment station were compared, resulting in larger values at the distant points. The value of 0.170 mg/L in haloacetic acid (the maximum value allowed by the legislation is 0.080 mg/L) was obtained at a point distant in the network from the treatment plant. The Consolidation Ordinance n.5/2017, current legislation for treated water in Brazil, was used in relation to the maximum allowable values for free residual chlorine and haloacetic acids.

Pelletized Poultry Litter as a Nutrient Source for Turfgrass Sports Fields

Natural organic fertilizers are receiving increased attention as a nutrient source for athletic turf fields. However, the performance of these fertilizers as an alternative to inorganic fertilizers is relatively untested. To address this issue, we initiated a study to evaluate turfgrass response to the use of pelletized poultry litter （PPL） as a nutrient source compared to inorganic fertilizer, and to compare core aeration and vibrating aeration. Four treatments were evaluated： synthetic fertilizer with vibrating aeration （VS）, synthetic fertilizer with core aeration （CS）, PPL with vibrating aeration （VP）, and PPL with core aeration （CP）. The PPL was applied at a nitrogen （N） rate equivalent to the synthetic fertilizer （assuming 50% availability of N）. Application of PPL did not produce significant changes in measured soil parameters during the 2.5 year study compared to the synthetic fertilizer. Minimal differences in tissue concentrations of Mn were observed. Remote sensing indicated that the CS treatment, which is the current management practice at the study site, produced the lowest turfgrass quality of all the treatments. Highest turf quality was achieved with the CP and VS treatments. Application of PPL resulted in greater turfgrass quality when compared to the same N rate of synthetic fertilizer, regardless of aeration method.

Removal of dispersant-stabilized carbon nanotubes by regular coagulants

Coagulation followed by sedimentation, as a conventional technique in the water treatment plant, can be the first line of defense against exposures of carbon nanotubes （CNTs） to aquatic organisms and human beings, which has been rarely documented. This study investigated the removal of dispersant-stabilized CNT suspensions by poly aluminum chloride （PAC1） and KAl（SO4）2-12H20 （alum）, with a focus on the effects of dispersant type, coagulant type and dosage. PAC1 performed better than alum in the removal of tannic acid-, humic acid-, and sodium dodecyl benzenesulfonate-stabilized CNTs, but worse for polyethylene glycol octylphenyl ether （TX100）-stabilized CNTs. Neither coagulant could effectively precipitate cetyltrimethyl ammonium bromide-stabilized CNTs. The removal by PACl first increased up to a plateau and then decreased with the continued increase of coagulant dosage. However, the removal rates leveled off but did not decrease after achieving their highest level with the continued addition of alum. The coagulation and flocculation of the CNT suspensions by PACl could be regulated mainly by the mechanism of adsorption charge neutralization, whereas the coagulation by alum mainly involved electrical double-layer compression.

Effect of Abiotic Factors on the Mercury Reduction Process by Humic Acids in Aqueous Systems

As a global pollutant process, the reduction of mercury （Hg） is especially important. One pathway is through an abiotic reduction with humic acids （HAs）, which is controlled by different factors, including initial Hg and HA concentrations, pH, temperature and light. In this study, three humic acids were selected to illustrate the Hg2＋ abiotic reduction mechanisms by HAs, and to identify the key limiting factors for reduction rates and amounts. In addition, the initial status of the HAs as a solid or in an aqueous solution were also compared, to help explain why HAs show different dominant characteristics （e.g. complexation or reduction） in the reaction process with Hg. Results indicated that HAs were able to reduce Hg abiotically. Higher initial Hg, higher HA concentrations and either high （8.1） or low （3.6） solution pH decreased the HA reduction capacity. In addition, Hg~ production rates increased with increasing temperature, and the same trend was observed with light exposure. Humic acids added as an aqueous solution resulted in significantly greater HgO production than addition as a bulk solid. Finally, the Hg reduction rate and capacity varied significantly （P 〈 0.05） with HAs from different sources. These findings helped to explain why HAs showed different dominant characteristics （e.g. complexation or reduction） in the reaction process with of Hg2＋ reduction, which indicated that humic substances in sink or a source for Hg. Hg, and evidentially demonstrated the existence of a possible pathway natural environments, especially in water bodies, could act either as a