In semiarid regions, deficit and unpredictable precipitation results in yield losses. Uniconazole is a plant growth regulator and its application is beneficial in water saving agriculture and improves maize production in semiarid regions. In order to determine the effects of uniconazole application on seed filling and hormonal changes of maize, a field study was conducted in the summer of 2015 and 2016. Seeds were soaked in uniconazole at concentration of 0 (SCK), 25 (S₂₅), 50 (S₅₀), and 75 (S₇₅) mg kg⁻¹, while in the second experiment, uniconazole was applied to the foliage at concentration of 0 (FCK), 25 (F₂₅), 50 (F₅₀), and 75 (F₇₅) mg L⁻¹ at the eight-leaf. Uniconazole application significantly improves the seed filling rates by regulating the endogenous hormones contents. Uniconazole seed soaking treatments improved significantly the seed filling rate of superior, middle, and inferior seeds compared with foliar application treatments. Uniconazole improved significantly the zeatin (Z) + zeatin riboside (ZR) and abscisic acid (ABA) contents while reducing the gibberellic acid (GA) content in the seeds during the process of seed filling. The Z + ZR and ABA contents were significantly positively correlated while the GA content was negatively correlated with maximum seed weight, maximum seed filling rates, and mean seed filling rates. Treatments S₂₅ and F₂₅ significantly improved the above dry matter accumulation plant⁻¹, seed filling rates, ABA, Z + ZR contents, characters of ear, and grain yield while reduced the GA content. It is concluded from our results that the uniconazole application at concentration of 25 mg kg⁻¹ as seed soaking or 25 mg L⁻¹ foliar applied at the eight-leaf stage is beneficial to improve the seed filling rates and grain yield of maize in semiarid regions.

One of the highest self-reported incidence rates of acute gastrointestinal illness (AGI) in the global peer-reviewed literature occurs in Inuit communities in the Canadian Arctic. This high incidence of illness could be due, in part, to the consumption of contaminated water, as many northern communities face challenges related to the quality of municipal drinking water. Furthermore, many Inuit store drinking water in containers in the home, which could increase the risk of contamination between source and point-of-use (i.e., water recontamination during storage). To examine this risk, this research characterized drinking water collection and storage practices, identified potential risk factors for water contamination between source and point-of-use, and examined possible associations between drinking water contamination and self-reported AGI in the Inuit community of Rigolet, Canada. The study included a cross-sectional census survey that captured data on types of drinking water used, household practices related to drinking water (e.g., how it was collected and stored), physical characteristics of water storage containers, and self-reported AGI. Additionally, water samples were collected from all identified drinking water containers in homes and analyzed for presence of Escherichia coli and total coliforms. Despite municipally treated tap water being available in all homes, 77.6% of households had alternative sources of drinking water stored in containers, and of these containers, 25.2% tested positive for total coliforms. The use of transfer devices and water dippers (i.e., smaller bowls or measuring cups) for the collection and retrieval of water from containers were both significantly associated with increased odds of total coliform presence in stored water (ORₜᵣₐₙₛfₑᵣ dₑᵥᵢcₑ = 3.4, 95% CI 1.2–11.7; ORdᵢₚₚₑᵣ = 13.4, 95% CI 3.8–47.1). Twenty-eight-day period prevalence of self-reported AGI during the month before the survey was 17.2% (95% CI 13.0–22.5), which yielded an annual incidence rate of 2.4 cases per person per year (95% CI 1.8–3.1); no water-related risk factors were significantly associated with AGI. Considering the high prevalence of, and risk factors associated with, indicator bacteria in drinking water stored in containers, potential exposure to waterborne pathogens may be minimized through interventions at the household level.

In this study, a sequential Fe⁰/H₂O₂ reaction and biological process was employed as a low-cost depth treatment method to remove recalcitrant compounds from coal-chemical engineering wastewater after regular biological treatment. First of all, a chemical oxygen demand (COD) and color removal efficiency of 66 and 63% was achieved at initial pH of 6.8, 25 mmol L⁻¹ of H₂O₂, and 2 g L⁻¹ of Fe⁰ in the Fe⁰/H₂O₂ reaction. According to the gas chromatography-mass spectrometer (GC-MS) and gas chromatography-flame ionization detector (GC-FID) analysis, the recalcitrant compounds were effectively decomposed into short-chain organic acids such as acetic, propionic, and butyric acids. Although these acids were resistant to the Fe⁰/H₂O₂ reaction, they were effectively eliminated in the sequential air lift reactor (ALR) at a hydraulic retention time (HRT) of 2 h, resulting in a further decrease of COD and color from 120 to 51 mg L⁻¹ and from 70 to 38 times, respectively. A low operational cost of 0.35 $ m⁻³ was achieved because pH adjustment and iron-containing sludge disposal could be avoided since a total COD and color removal efficiency of 85 and 79% could be achieved at an original pH of 6.8 by the above sequential process with a ferric ion concentration below 0.8 mg L⁻¹ after the Fe⁰/H₂O₂ reaction. It indicated that the above sequential process is a promising and cost-effective method for the depth treatment of coal-chemical engineering wastewaters to satisfy discharge requirements.

The variation in vegetation greenness provides good understanding of the sustainable management and monitoring of land surface ecosystems. The present paper discusses the spatial-temporal changes in vegetation and controlling factors in the Yangtze River Basin (YRB) using Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) for the period 2001–2013. Theil-Sen Median trend analysis, Pearson correlation coefficients, and residual analysis have been used, which shows decreasing trend of the annual mean NDVI over the whole YRB. Spatially, the regions with significant decreasing trends were mainly located in parts of central YRB, and pronounced increasing trends were observed in parts of the eastern and western YRB. The mean NDVI during spring and summer seasons increased, while it decreased during autumn and winter seasons. The seasonal mean NDVI shows spatial heterogeneity due to the vegetation types. The correlation analysis shows a positive relation between NDVI and temperature over most of the YRB, whereas NDVI and precipitation show a negative correlation. The residual analysis shows an increase in NDVI in parts of eastern and western YRB and the decrease in NDVI in the small part of Yangtze River Delta (YRD) and the mid-western YRB due to human activities. In general, climate factors were the principal drivers of NDVI variation in YRB in recent years.

Industrial laundries have water as one of their main inputs and they release effluents in large amounts, with a high polluting load, which are usually discarded into the environment, or they are insufficiently treated for release into the neighboring water bodies. The aim of this study was to evaluate the efficiencies of the biological treatments in an industrial textile laundry and their environmental impact on the surface waters of the stream where the dump is usually made, by using cytotoxicity tests on the meristematic root cells of Allium cepa L. The results have shown, for the most part, that the treated effluents over a period of 24 h showed reductions in their mitotic index. The treatments on the raw effluents showed cytotoxic effects when compared to control, with cell division recoveries after 24 h in the waters. Cytotoxic effects were additionally observed in the stream waters, at a point before the dump, indicating that they received a pollutant load, before the effluent disposal site of the evaluated industrial laundry. Notably, the treatments that were being applied by the industrial laundry were effective throughout the processing, reducing the concentrations of the toxic substances. When considering the data presented, it is now understood that there is a constant need for the evaluation of industrial effluents, as well as for the waters of the streams and the rivers that receive these disposals, in order to preserve and maintain the quality of the waters, the organisms, and consequently, the ecosystems.

Electrochemical oxidation was proposed as a promising technology for algal control in drinking water treatment. To be effective, the electrogenerated oxidants should have long half-lives and could continually inhibit the growth of algae. In this study, we used the electrochemical system equipped with a Ti/RuO₂ anode which focus on generating long half-life chlorines and H₂O₂. We explored the impact of electrical field and electrogenerated oxidants on algal inhibition, and we investigated the production of electrogenerated reactive species and their contributions to the inhibition of Microcystis aeruginosa (M. aeruginosa) in simulated surface water with low Cl⁻ concentrations (< 18 mg/L). We developed a kinetic model to simulates the concentrations of chlorines and H₂O₂. The results showed that electrical field and electrogenerated oxidants were both important contributors to algal inhibition during electrochemical oxidation treatment. The Ti/RuO₂ anode mainly generates chlorines and H₂O₂ from Cl⁻ and water. During the electrolysis at current density of 20 mA/cm², when initial Cl⁻ concentrations increased from 0 to 18 mg/L (0–5.07 × 10⁻⁴ mol/L), the chlorines increased from 0 to 3.62 × 10⁻⁶ mol/L, and the H₂O₂ concentration decreased from 3.68 × 10⁻⁶ to 1.15 × 10⁻⁶ mol/L. Our model made decent predictions of other Cl⁻ concentrations by comparing with experiment data which validated the rationality of this modeling approach. The electrogenerated chlorine species were more effective than H₂O₂ at an initial Cl⁻ concentration of 18 mg/L.

Alkalinity generation and toxic trace metal (such as vanadium) leaching from basic oxygen furnace (BOF) steel slag particles must be properly understood and managed by pre-conditioning if beneficial reuse of slag is to be maximised. Water leaching under aerated conditions was investigated using fresh BOF slag at three different particle sizes (0.5–1.0, 2–5 and 10 × 10 × 20 mm blocks) and a 6-month pre-weathered block. There were several distinct leaching stages observed over time associated with different phases controlling the solution chemistry: (1) free-lime (CaO) dissolution (days 0–2); (2) dicalcium silicate (Ca₂SiO₄) dissolution (days 2–14) and (3) Ca–Si–H and CaCO₃ formation and subsequent dissolution (days 14–73). Experiments with the smallest size fraction resulted in the highest Ca, Si and V concentrations, highlighting the role of surface area in controlling initial leaching. After ~2 weeks, the solution Ca/Si ratio (0.7–0.9) evolved to equal those found within a Ca–Si–H phase that replaced dicalcium silicate and free-lime phases in a 30- to 150-μm altered surface region. V release was a two-stage process; initially, V was released by dicalcium silicate dissolution, but V also isomorphically substituted for Si into the neo-formed Ca–Si–H in the alteration zone. Therefore, on longer timescales, the release of V to solution was primarily controlled by considerably slower Ca–Si–H dissolution rates, which decreased the rate of V release by an order of magnitude. Overall, the results indicate that the BOF slag leaching mechanism evolves from a situation initially dominated by rapid hydration and dissolution of primary dicalcium silicate/free-lime phases, to a slow diffusion limited process controlled by the solubility of secondary Ca–Si–H and CaCO₃ phases that replace and cover more reactive primary slag phases at particle surfaces.

A considerable amount of excess sludge, a kind of hazardous waste, is produced from the conventional wastewater treatment systems such as activated sludge process, and efficient sludge reduction processes are needed. A new chemical method for sludge reduction was proposed by using manganese dioxide as oxidant in this study. A favorable condition for sludge reduction is determined as manganese dioxide dosage of 0.165 g g⁻¹ wet sludge, sulfuric acid concentration of 3 mol L⁻¹, and reduction temperature of 90 °C for 90 min, where the sludge reduction efficiency can reach 73.30%. Reaction kinetic study revealed that the sludge reduction rate was controlled by the surface chemical reaction and the reaction followed a shrinking core kinetic model with apparent activation energy of 37.76 kJ mol⁻¹. Furthermore, reaction process analysis indicated that the sludge hydrolysis included two steps, i.e., floc destruction and microbial cell disruption. Considering the high efficiency and short treatment time, manganese dioxide oxidation is suggested to be a feasible method for disintegration of excess activated sludge.

The present study was conducted on soft drink industry with the objective to reduce wastewater pollution through end-of-pipe treatment and controlling energy loss through steam pipeline insulation approach. For this purpose, the main operation and manufacturing steps were examined. Wastewater was analyzed for 10 physicochemical parameters. Among these parameters, total dissolved solids (TDS), total suspended solids (TSS) and chemical oxygen demand (COD) were above their permissible level of Pakistan national environmental quality standards (Pak NEQS). For wastewater treatment, sedimentation, flocculation, coagulation and adsorption were tested. The active study reduces the pollution load up to 48%. After treatment, all the parameters were below the Pak NEQS level. To reduce the energy loss and economic benefits, the steam pipeline system was galvanized using glass wool, sheet and paper. Through galvanizing, 91.4% of energy was recovered and reduced an extra cost of 91.5%. The net saving of energy and cost are 312 GJ and114098 Rs/year, respectively. The study recommends end off pipe treatment and insulation of bare pipeline system for soft drink industries.

This article presents an example of the application of simulation tools to estimate the post-closure evolution of leachate in a non-hazardous waste landfill. The objective of this work is to predict the behavior of leachate after the closure of the landfill for use as basic information with which to design the leachate management strategy in the following years. The MODUELO 4.0 mathematical landfill simulation software package was used for this purpose. The results of the simulation show that the concentrations in the leachate increase during the post-closure period, from values close to 2200 mg/L of COD and 1500 mg/L of NH₄⁺ at the time of landfill closure to 3200 mg/L of COD and 5300 mg/L of NH₄⁺ 20 years later. This increase is mainly due to the reduction in the flows, from 105 to 17 m³/day on average, since the surface lining was installed. Consequently, pollutant fluxes decrease to values below 100 kg/day in both COD and NH₄⁺ 3 months after closure. This evolution indicates that the management of this leachate will be simpler in the future, especially if it is co-treated with urban wastewater, as its contribution decreases. On the other hand, external water connections to the leachate collectors may cause a relevant increase in the volume of the global landfill effluent. Controlling runoff management and underground infiltrations could lead to important savings in leachate treatment during the aftercare phase.