Effect of Saline Water on Soil Acidity, Alkalinity and Nutrients Leaching in Sandy Loamy Soil in Rwamagana Bella Flower Farm, Rwanda

The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific considerations and limitations. One way to decrease undesirable effects of sodic waters on the physical and chemical properties of soils is to apply organic and chemical amendments within the soil. This study aimed to assess the effectiveness of saline water on soil acidity, alkalinity and nutrients leaching in sandy loamy soil at Bella flower farm, in Rwamagana District, Rwanda. The water used was from the Muhazi Lake which is classified as Class I (Saline water quality). Column leaching experiments using treated soils were then conducted under saturated conditions. The soil under experimental was first analyzed for its textural classification, soil properties and is classified as sandy loamy soil. The t-test was taken at 1%, 5% and 10% levels of statistical significance compared to control soil. The results indicated that the application of saline water to soils caused an increase in some soil nutrients like increase of Phosphorus (P), Potassium (K+), Magnesium (Mg2+), Sulphur (S), CN ratio and Sodium (Na+) and decreased soil texture, physical and chemical properties and remained soil nutrients. Consequently, the intensive addition of saline water leachates to soil in PVC pipes led to decreased of soil EC through leaching and a raiser Soluble Sodium Percentage (SSP). The rate of saline water application affected the increase accumulation of SAR and Na% in the top soil layers. The study indicated that saline water is an inefficient amendment for sandy soil with saline water irrigation. The study recommends further studies with similar topic with saline water irrigation, as it accentuated the alkalinity levels.

Dynamically-evolved surface heterojunction in iridium nanocrystals boosting acidic oxygen evolution and overall water splitting

Simultaneously realizing improved activity and stability of acidic oxygen evolution reaction(OER) electrocatalysts is highly promising for developing cost-effective sustainable energy in the splitting of water technique.Herein,we report iridium nanocrystals embedded into 3D conductive clothes(Ir-NCT/CC) as a low iridium electrocatalyst realizing ultrahigh acidic OER activity and robust stability.The well-designed Ir-NCT/CC requires a low overpotential of 202 mV to reach the current density of 10 mA cm^(-2)with a high mass activity of 1754 A g^(-1).Importantly,in acidic overall water splitting,Ir-NCT/CC merely delivers a cell voltage of 1.469 V at a typical current density of 10 mA cm^(-2)and also maintains robust durability under continuous operation.We identify that a low working voltage drives the formation of a highly stable amorphous IrOxactive phase over the surface of Ir nanocrystals(surface heterojunction IrOx/Ir-NCT) during operating conditions,which contributes to an effective and durable OER process.

Recent progress of precious-metal-free electrocatalysts for efficient water oxidation in acidic media

The realization of efficient oxygen evolution reaction(OER) is critical to the development of multiple sustainable energy conversion and storage technologies, especially hydrogen production via water electrolysis. To achieve the massive application of hydrogen energy and mass-scale hydrogen production from water splitting drives the pursuit of competent precious-metal-free electrocatalysts in acidic media, where the hydrogen evolution reaction(HER) is more facilitated. However, the development of high-efficient and acid-stable OER electrocatalysts, which are robust to function stably at high oxidation potentials in the acidic electrolyte, remains a great challenge. This article contributes a focused, perceptive review of the up-to-date approaches toward this emerging research field. The OER reaction mechanism and fundamental requirements for oxygen evolution electrocatalysts in acid are introduced. Then the progress and new discoveries of precious-metal-free active materials and design concepts with regard to the improvement of the intrinsic OER activity are discussed. Finally, the existing scientific challenges and the outlooks for future research directions to the fabrication of emerging, earth-abundant OER electrocatalysts in acid are pointed out.

Interfacial engineering of holey platinum nanotubes for formic acid electrooxidation boosted water splitting

Both structure and interface engineering are highly effective strategies for enhancing the catalytic activity and selectivity of precious metal nanostructures.In this work,we develop a facile pyrolysis strategy to synthesize the high-quality holey platinum nanotubes(Pt-H-NTs)using nanorods-like Pt^(Ⅱ)-phenanthroline(PT)coordination compound as self-template and self-reduction precursor.Then,an up-bottom strategy is used to further synthesize polyallylamine(PA)modified Pt-H-NTs(Pt-HNTs@PA).PA modification sharply promotes the catalytic activity of Pt-H-NTs for the formic acid electrooxidation reaction(FAEOR)by the direct reaction pathway.Meanwhile,PA modification also elevates the catalytic activity of Pt-H-NTs for the hydrogen evolution reaction(HER)by the proton enrichment at electrolyte/electrode interface.Benefiting from the high catalytic activity of Pt-H-NTs@PA for both FAEOR and HER,a two-electrode FAEOR boosted water electrolysis system is fabricated by using Pt-H-NTs@PA as bifunctio nal electrocatalysts.Such FAEOR boosted water electrolysis system only requires the operational voltage of 0.47 V to achieve the high-purity hydrogen production,showing an energy-saving hydrogen production strategy compared to traditional water electrolysis system.

Effects of Drinking Slightly Acidic Electrolytic Water on Growth Performance and Behavior of Broilers

[Objective]The paper was to study the effects of drinking slightly acidic electrolytic water on growth performance and behavior of Rose 308 broilers,and to provide reference for the application of slightly acidic electrolytic water in broiler breeding.[Method]A total of 300 healthy 10-day-old Rose 308 broilers with similar body weight were randomly divided into five groups,three replicates each group,20 broilers each replicate.The broilers in control group were supplied with normal drinking water,and the broilers in experimental groups consumed slightly acidic electrolytic water with 0.3,0.5,0.7,1.0 mg/L residual chlorine,respectively.The test lasted 21 d.[Result]At 10-30 days of age,the water consumption of broilers in 0.7 and 1.0 mg/L electrolytic water groups were increased by 9.27%and 7.67%respectively compared with the control group(M<0.05).The average daily feed intake(ADFI)of broilers in 0.7 and 1.0 mg/L electrolytic water groups were increased compared with the control group(Q0.05).The average daily gain(ADG)of broilers in 0.7 mg/L electrolytic water group was 11.99%lower than that in control group(M<0.05).The feed gain ratio(F/G)of broilers in 0.5 mg/L electrolytic water group was 12.29%lower than that in control group(M<0.05),and the mortality was the lowest in 0.5 mg/L electrolytic water group.The standing,feeding and drinking frequency of broilers in experimental groups were higher than that in control group,and the flapping behavior of broilers in 0.5 mg/L electrolytic water group was the lowest.[Conclusion]Drinking slightly acidic electrolytic water has positive effect on the growth and behavior of broilers.

Sulfide precipitation flotation for treatment of acidic mine waste water

Sulfide precipitation flotation of copper iron bearing acidic waste water from a large copper mine and the stimulated waste water were studied. The pH of the waste water was 2.2, with 130 mg/L Cu 2+ and 500 mg/L Fe 3+ (Fe 2+ ). Results show that, when Na 2S was added as precipitating agent, sodium butylxanthate as collector and at pH 2.0, the removal of copper could be as high as 99.7% and the residual copper decreased to 0.2 mg/L, however, almost no iron was removed. When the floated solution was neutralized to pH=8.0, more than 98% iron was precipitated and the residual iron was less than 10 mg/L. In experiment on actual mine effluents, after the use of precipitate flotation technology to recover copper and pH neutralization to precipitate iron, the treated waste water does meet the emission standards for sewage and valuable floating copper graded 37.12%. The chemical calculation and mechanism of solution were also presented.

Esterification by the Plasma Acidic Water:Novel Application of Plasma Acid

This work explores the possibility of plasma acid as acid catalyst in organic reactions. Plasma acidic water was prepared by dielectric barrier discharge and used to catalyze esterification of n-heptanioc acid with ethanol. It is found that the plasma acidic water has a stable and better performance than sulfuric acid, meaning that it is an excellent acid catalyst. The plasma acidic water would be a promising alternative for classic mineral acid as a more environment friendly acid.

Electrokinetic-mechanism of water and furfural oxidation on pulsed laser-interlaced Cu_(2)O and CoO on nickel foam

The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and Cu_(2)O/Ni O/NF electrodes via in situ pulsed laser irradiation in liquids(PLIL)for the bifunctional electrocatalysis of oxygen evolution reaction(OER)and furfural oxidation reaction(FOR),respectively.Simultaneous oxidation of NF surface to NiO and deposition of CoO and/or Cu_(2)O on NF during PLIL offer distinct advantages for enhancing both the OER and FOR.CoO/NiO/NF electrocatalyst provides a consistently low overpotential of~359 m V(OER)at 10 m A/cm^(2),achieving the maximum FA yield(~16.37 m M)with 61.5%selectivity,79.5%carbon balance,and a remarkable Faradaic efficiency of~90.1%during 2 h of FOR at 1.43 V(vs.reversible hydrogen electrode).Mechanistic pathway via in situ electrochemical-Raman spectroscopy on CoO/NiO/NF reveals the involvement of phase transition intermediates(NiOOH and CoOOH)as surface-active centers during electrochemical oxidation.The carbonyl carbon in FF is attacked by hydroxyl groups to form unstable hydrates that subsequently undergo further oxidation to yield FA products.This method holds promise for large-scale applications,enabling simultaneous production of renewable building materials and fuel.

Effects of fulvic acid and humic acid on aluminum speciation in drinking water

This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species investigated in the experiments included inorganic mononuclear, organic mononuclear, mononuclear, polymer, soluble, and suspended forms. It was found that the effects of fulvic acid and humic acid on aluminum speciation depended mainly on their molecular weight. Fulvic acid with molecular weight less than 5000 Dalton had little influence on aluminum speciation; while fulvic acid with molecular weight larger than 5000 Dalton and humic acid would increase the concentration of soluble aluminum significantly even at concentration below 0.5 mg/L （calculated as TOC）. Aluminum species, in the present of fulvic acid with molecular weight larger than 5000 Dalton and humic acid, were more stable than that in the present of fluvic acid with molecular mass less than 5000 Dalton, and varied little with reaction time. Within pH range 6.5-7.5, soluble aluminum increased notably in water with organic matter. As the concentration of residual chlorine increased, the effects of fulvic acid and humic acid became weak. The reactions between humic acid, fulvic acid with large molecular weight, and aluminum were considered to be a multi-dentate coordination process. With the consideration of aluminum bioavailability, reducing the concentration of fulvic acid and humic acid and keeping the pH value among 6.5-7.5 were recommended during drinking water treatment.

Preparation and Catalytic Application of Novel Water Tolerant Solid Acid Catalysts of Zirconium Sulfate/HZSM-5

Esterification of acrylic acid（AA） to produce AA esters has widespread application in the chemical industry. A series of water tolerant solid acid catalysts was prepared, and characterized by XRD, nitrogen adsorption, TGA-DTA, XPS, and ammonia adsorption FTIR. The effects of Si/Al ratio, zirconium sulfate（ZS） loading on HZSM-5 and calcination temperature on the esterification were investigated. When 20% （mass fraction） ZS is loaded on HZSM-5, the conversion of AA reaches 100%. XRD analysis indicates that ZS is highly dispersed on HZSM-5 because no crystalline structure assigned to ZS is found. Catalytic activity and hydrophobicity of ZS supported on HZSM-5 are higher compared with those of parent ZS or HZSM-5. Results show that this kind of novel catalysts is an efficient water tolerant solid acid catalyst for esterification reactions.

Occurrence of Haloacetic Acids in Drinking Water in Certain Cities of China

Objective Since haloacetic acids (HAAs), which are nonvolatile and of high carcinogenic risk, are common species of chlorinated disinfection by-products(DBPs) in drinking water, and little has been known in China, it is necessary to make a survey about the kinds and levels of HAAs in drinking water of the nation. Method HAAs were analyzed using gas chromatography with electron capture detector(GC/ECD) and relatively complex pretreatment process of sample was applied. Five main cities in different areas of China were chosen in the survey. Results Studies showed that the main species of HAAs in drinking water in China were DCAA and TCAA, ranging from 0.4 礸/L to 12.85 礸/L and from 0.56 礸/L to 10.98 礸/L, respectively. MBAA and DBAA were also detected in one city, ranging from 2.20 礸/L to 4.95 礸/L and 1.10 礸/L to 2.81 礸/L, respectively. Therefore, the contents of HAAs varied, usually no more than 25 礸/L. Based on the acquired data to date, it is known that the concentrations of HAAs in drinking water in China were surely under the limits of Sanitary Standard for Drinking Water Quality (China, 2001). Conclusion A wider survey of HAAs in drinking water should be conducted throughout the nation to get adequate data and information, the ultimate aim of which is to control HAAs pollution and keep the balance between microbiological safety insurance and chemical risk control, minimize the formation of DBPs and ensure the safety of water supply at the same time.

Preparation and photocatalytic properties of ilmenite NiTiO_3 powders for degradation of humic acid in water

The powders of ilmenite structure NiTiO3 were prepared by a modified Pechini process using tetrabutyl titanate and nickel acetate as raw materials, and using citric acid and ethanol as a chelating agent and a solvent respectively. The powder samples were characterized by thermogravimetric and differential thermal analysis （TG-DTA） and X-ray diffraction （XRD）. The photocatalytic activity of NiTiO3 under the irradiation of ultraviolet rays （UV） light was evaluated by degrading hurnic acid （HA） in water as a probe reaction. The possible photodegra- dation mechanism was studied by the examination of active species .OH, .O2, and holes （h＋） through adding scavengers. The TG-DTA and XRD results indicated that the good crystal structure of ilmenite phase NiTiO3 could be obtained when the Ni-Ti citrate complex was cal- cined at 600℃. The photocatalytic activity experiments indicated that NiTiO3 had favourable photocatalytic activity under the irradiation of UV light, and the photocatalytic degradation rate of HA reached 95.3% after a 2.5 h reaction with the photocatalyst calcined at 600℃ and a photocatalyst dosage of 0.4 g/L. The possible photocatalytic mechanism was deduced that holes （h＋） and .OH radicals are the major reactive active species in the photocatalytic reaction, and dissolved oxygen plays a weak role in the degradation of HA.

Evaluation of trans-ferulic acid degradation by dielectric barrier discharge plasma combined with ozone in wastewater with different water quality conditions

In this study, dielectric barrier discharge plasma and ozone(O_3) were combined to synergistically degrade trans-ferulic acid(FA), and the effect of water quality on FA degradation was studied. The results showed that 96.9% of FA was degraded after 40 min treatment by the plasma/O_3 process. FA degradation efficiency increased with the p H values. The presence of suspended solid and humic acid inhibited FA degradation. FA degradation efficiency increased as the water temperature increased to 30 °C. However, the further increase in water temperature was adverse for FA degradation. Effects of common inorganic ions on FA degradation were also investigated. The addition of Cl^- inhibited the FA degradation, whileCO_3^(2-) had both negative and positive influences on FA degradation.NO_3^- andSO_4^(2-) did not have significant effect on FA degradation. Fe^(3+)and Cu^(2+)benefited FA degradation through the Fenton-like and catalytic ozonation reactions.

Effect of Humic Acid, Mycorrhiza Inoculation, and Biochar on Yield and Water Use Efficiency of Flax under Newly Reclaimed Sandy Soil

In order to examine the application of different soil and foliar organic fertilizers as well as biofertilizing flax under sandy soil conditions, two field experiments were carried out at the Research and Production Station of the National Research Centre (NRC), Al Nubaria district, El-Behaira Governorate, Egypt during 2012/2013 and 2013/2014 winter seasons. The trials aimed to study the effect of humic acid (HA) as low cost natural fertilizer, inoculation with mycorrhiza, and biocharcoal on on yield, quality and water use efficiency of flax variety (Amon) under newly reclaimed sandy soil. The treatments consisted of HA (25 kg/feddan), inoculation with mycorrhiza (1 kg/ feddan), and biochar (4 tons/feddan) and all the combinations among the treatments. Results showed that the treatment combination of (humic acid + mycorrhiza + biochar) was significantly superior compared to all the other treatments in number of capsules/plant, biological yield/plant (g), seed yield/plant (g), seed yield (kg/feddan), straw yield (tons/feddan), oil percent (%), and oil yield (kg/feddan). However, it gave the highest fruiting zone length (cm) but not significantly different from (mycorrhiza + biochar) and (humic acid + biochar), also it gave the highest seed index (g) but not significantly different from humic acid and (humic acid + mycorrhiza). The treatment combination of (humic acid + biochar) gave the highest plant height (cm), technical stem length (cm), and number of branches/plant.

Influence of Water Stress on the Citric Acid Metabolism Related Gene Expression in the Ponkan Fruits

To explore the influence of water stress on fruit quality and gene expression related to citrate metabolism of ponkan. The test were conducted from May 15 to December 24 in 2013 using six-year-old ponkan (C. blanco cv. Ponkan) trees with 40% soil water conditions by taken regular watering as control. The content of acids in fruit were determined by HPLC, and relative expression of related genes of citric acid metabolic were determined by relative fluorescence quantitative PCR. The results showed that the content of citric acid, malic acid, quinic acid and total organic acids per gram sarcocarp were extremely increased by 285.2%, 320%, 480% and 299.1%, and the content of per-fruit organic acid were 77.39%, 89.64%, 117.24% and 75.9% respectively compared to those control in the fruit mature stage. Relative expression of CitCS1, CitCS2 were higher than control, and relative expression of CitAco1, CitAco2, CitAco3 had a certain increase in the late fruit development, were lower in mature stage. Three relative expression of CitIDH gene were higher than control in mature stage. Low CitGAD4 relative expression and undetectable in mature stage, the relative expression of CitGAD5 gene had a role in promoting under water stress. Furthermore, the relative expression of CitCS1, CitCS2, CitACO1, CitACO3, CitIDH1, CitIDH2, CitIDH3, CitGAD4 and CitGAD5 were influenced by water stress through the correlation analysis. Water stress caused the accumulation of citric acid, declined fruit quality, leaded to change of the genetic rela- tive expression about citric acid synthesis and degradation. The down-regulation of CitACO1, CitGAD4 and up-regulation of CitCS1, CitCS2 might be one of the reasons that promoted to the accumulation of citric acid.

Behaviour of Haloacetic Acids in Drinking Water Distribution Systems

To guarantee the safety of drinking water quality after chlorination,the formation,distribution and factors influencing the concentrations of haloacetic acids(HAAs)in a water distribution system(WDS) were investigated both on a full-scale WDS(FWDS) and pilot-scale WDS(PWDS) within a city in northern China.The results of both investigations showed that trichloroacetic acid(TCAA) and dichloroacetic acid(DCAA) were the dominating types of HAAs.In the FWDS,variations in the HAA content showed negative correlations with total residual chlorine,pH and non-purgeable organic carbon(NPOC)and positive correlations with temperature and UV_(254).In the PWDS,the concentration of HAAs after rechlorination followed the rule of 'first rise and then fall';therefore,locating an appropriate rechlorination point and lowering the single chlorine dosage could be used as effective measures to control the HAA content in WDSs.

Electrokinetic chemical characteristics of humic and dannic acids effecting on the natural water and its coagulation

Taking streaming current(SC)as the electrokinetic parameter,this paper demon- strated the electrokinetic chemical characteristics of humic and dannic acids(HA and DA)in sus- pensions including turbid water,coagulated water and HA or DA contained water.Accordingly, the studies were carried out for determining the relationship between streaming current and zeta po- tential ζ(expressed by eleetrophoretie mobility EM)in above water conditions.In addition,the mechanisms of HA effecting on streaming current within or after coagulant addition and the elec- trokinetic detection principles for HA or DA were also investigated on experiments and theoretical analysis.The results indicated that the change of SC like ζ presented meaningful information con- cerning the degree for destabilization of a particulate suspension,and HA or DA in water could re- markably decrease the effect of inorganic coagulant upon streaming current,which is in accordance with their influence on coagulation.

Long-term changes of water acidity in an intact forested watershed in south China

Acid rain is a global environmental issue and causes serious adverse impacts on natural ecosystems and human health.The acid rain and its subsequent impacts have been extensively studied in temperate regions and in big cities globally,but the monitoring of acid rain in non-urban areas in subtropical region is still limited.Here,we analyze 18 years of water acidity observations from a non-urban site in western Pearl River Delta region,south China.From 2000 to 2018,annual mean precipitation pH values in the study site showed a marked increase(P<0.0001)from 4.96 in 2000 to 6.88 in 2018.This 18-year dataset of precipitation acidity shows a clear recovery from acid deposition over the annual period,dry seasons and wet seasons.Within a year,precipitation pH was relatively lower in dry seasons(5.46±0.95)than in wet seasons(5.80±0.89)during the whole study period,and the seasonal pattern of precipitation pH was amplified during drier years as a strong dilution effect was detected between precipitation amount and its acidity.The pH of surface runoff water(4.74±0.70)was significantly lower than that of precipitation as a result of the regulating effects of the highly acidified soil and the rich humus on the forest floor.The groundwater pH(6.32±0.63)was significantly higher than the precipitation pH especially during dry seasons.The results of the present study indicated that the groundwater has a strong acid buffer and neutralizing effects and thus plays an important role in supplies of clean water.