Chitosan-based beads as sustainable adsorbents for wastewater remediation: a review

Environmental Chemistry Letters - Water contamination is increasing worldwide, yet actual methods of water and wastewater treatment are limited, in particular by actual fossil-fuel derived...     

Assessment of pesticide contamination in Akkar groundwater,northern Lebanon

According to its high production and value, Akkar is considered as the second agricultural region in Lebanon. Groundwater constitutes the principal source of water in Akkar including drinking water of local inhabitants in Akkar. As such, the contamination of groundwater by organic pollutants can impact directly the population health. In this study, we evaluated the contamination status of groundwater in this region. Three classes of pesticides including 19 organochlorine (OC) pesticides, 8 organophosphorus (OP) pesticides, and 6 organonitrogen (ON) pesticides were monitored in 15 groundwater samples collected from different villages on the Akkar plain. Samples were extracted by using solid phase extraction (SPE) and analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The results showed high contamination of Akkar groundwater by OCs with levels that can reach 58.9 μg/L. They were detected in the majority of the sample and represent 95–100% of ∑pesticides. Our results showed the recent use of these molecules with an average level of 0.3 and 0.39 μg/L for ∑HCHs and DDTs, respectively. Their concentrations were higher than those observed in the same region in 2014 and other regions elsewhere. OPs were also detected at high levels and among them, methylparathion was the predominant OP detected (44.6 μg/L). For ONs, lower levels were measured in all samples with a mean value of 5.6 μg/L. As a conclusion of this work, groundwater on the plain of Akkar was remarkably contaminated by the studied pesticides; indefinitely, more efforts should be taken to manage the pesticide use in this region, assess, and reduce their effects on human health. In the future, the application of organic farming can be a great solution to the groundwater contamination problem.     

EFFICIENCY IN THE USE OF WATER FOR IRRIGATION: THE ROLE OF PRICES AND REGULATIONS

Efficiency in the use of water for irrigation is normally defined in a physical sense - engineering and agronomic; and it is often assumed that higher efficiency is desirable. However, in an economic sense, there is an optimum range in the level of physical efficiency. Normally it can be said that as water prices increase, it becomes more rational to increase physical efficiency by selecting and adopting improved methods of controlling, measuring and applying water, and to design systems of pricing and regulations that will promote optimal allocation and efficient use. However, the value of water is often extremely low, in which case there may be little economic incentive to improve physical efficiency unless forced by physical factors that affect production and productivity such as soil characteristics, waterlogging or nutrient leaching.
The combination of regulations and prices that are used to allocate irrigation water reflect the conflicting goals of redistribution of income in favor of agriculture and needs to encourage efficient use of water. Regulations and pricing systems also depend on the value of water, the dependability of supplies, systems of delivery and the extent to which flows can be regulated.
Using examples and case studies, this paper discusses physical and economic efficiencies and their interrelationships. It emphasizes the role of pricing and regulations and provides general guidelines.     

Health care system hazard vulnerability analysis: an assessment of all public hospitals in Abu Dhabi

Hazard vulnerability analysis (HVA) is used to risk‐stratify potential threats, measure the probability of those threats, and guide disaster preparedness. The primary objective of this project was to analyse the level of disaster preparedness in public hospitals in the Emirate of Abu Dhabi, utilising the HVA tool in collaboration with the Disaster Medicine Section at Harvard Medical School. The secondary objective was to review each facility's disaster plan and make recommendations based on the HVA findings. Based on the review, this article makes eight observations, including on the need for more accurate data; better hazard assessment capabilities; enhanced decontamination capacities; and the development of hospital‐specific emergency management programmes, a hospital incident command system, and a centralised, dedicated regional disaster coordination centre. With this project, HVAs were conducted successfully for the first time in health care facilities in Abu Dhabi. This study thus serves as another successful example of multidisciplinary emergency preparedness processes.     

Co-pyrolysis of sewage sludge and biomass for stabilizing heavy metals and reducing biochar toxicity: A review

The huge amounts of sewage sludge produced by municipal wastewater treatment plants induce major environmental and economical issues, calling for advanced disposal methods. Traditional methods for sewage sludge disposal increase greenhouse gas emissions and pollution. Moreover, biochar created from sewage sludge often cannot be used directly in soil applications due to elevated levels of heavy metals and other toxic compounds, which alter soil biota and earthworms. This has limited the application of sewage sludge-derived biochar as a fertilizer. Here, we review biomass and sewage sludge co-pyrolysis with a focus on the stabilization of heavy metals and toxicity reduction of the sludge-derived biochar. We observed that co-pyrolyzing sewage sludge with biomass materials reduced heavy metal concentrations and decreased the environmental risk of sludge-derived biochar by up to 93%. Biochar produced from sewage sludge and biomass co-pyrolysis could enhance the reproduction stimulation of soil biota by 20‒98%. Heavy metals immobilization and transformation are controlled by the co-feed material mixing ratio, pyrolysis temperature, and pyrolysis atmosphere.

     

The clayey quarry sludge from a waste to a valuable raw material for red ceramics

Journal of Material Cycles and Waste Management - This study aims to evaluate the reuse of clayey quarry sludge generated during the washing process of aggregates in crushing plants as a raw...     

Elevated ozone phytotoxicity ameliorations in mung bean {Vigna radiata (L.) Wilczek} by foliar nebulization of silicic acid and ascorbic acid

The present work provides an insight into the development of biochemical adaptations in mung beans against ozone (O₃) toxicity. The study aims to explore the O₃ stress tolerance potential of mung bean genotypes under exogenous application of growth regulators. The seeds of twelve mung bean genotypes were grown in plastic pots under controlled conditions in the glasshouse. Six treatments, control (ambient ozone level 40–45 ppb), ambient O₃ with ascorbic acid, ambient ozone with silicic acid, elevated ozone (120 ppb), elevated O₃ with ascorbic acid (10 mM), and elevated ozone with silicic acid (0.1 mM) were applied. The O₃ fumigation was carried out using an O₃ generator. The results revealed that ascorbic acid and silicic acid application decreased the number of plants with foliar O₃ injury symptoms in different degrees, i.e., zero, first, second, third, and fourth degrees; whereas 0–4 degree symptoms represent, no symptoms, symptoms occupying?<?1/4, 1/4–1/2, 1/2–3/4, and?>?3/4 of the total foliage area, respectively. Application of ascorbic acid and silicic acid also prevented the plants from the negative effects of O₃ in terms of fresh as well as dry matter production, leaf chlorophyll, carotenoids, soluble proteins and ascorbic acid, proline, and malondialdehyde (MDA) contents. Overall, silicic acid application proved more effective in reducing the negative effects of O₃ on mung bean genotypes as compared to that of the ascorbic acid. Three mung bean genotypes (NM 20–21, NM-2006, and NM-2016) were identified to have a better adaptive mechanism for O₃ toxicity tolerance and may be good candidates for future variety development programs.