Management of recycling in the Gulf Co-operation Council states

Although some of the Gulf Co-operation Council (GCC) member states have placed recycling at the top of their waste management priorities, the low cost of landfill and the availability of land, usually old sand or gravel quarries, make recycling programs infeasible, uneconomical and unachievable. The only comprehensive form of recycling available within the GCC states is recycling of paper and cartons. The majority of the GCC states never set national or regional recycling targets. The cost of recycling in the GCC states region could be moderate to high depending on the collection system selected for the recycling program. Almost all of the cities within the GCC states use mechanised systems for daily collection of municipal solid waste (MSW). Therefore, the same daily collection system used for MSW might well be used for collection of recyclable materials, both on the same day and at the same time, or according to a different timetable. This paper provides strategies for developing an effective recycling marketing program and discusses regional co-ordination options.     

Applicability of risk-based management and the need for risk-based economic decision analysis at hazardous waste contaminated sites

Decision analysis in subsurface contamination management is generally carried out through a traditional engineering economic viewpoint. However, new advances in human health risk assessment, namely, the probabilistic risk assessment, and the growing awareness of the importance of soft data in the decision-making process, require decision analysis methodologies that are capable of accommodating non-technical and politically biased qualitative information. In this work, we discuss the major limitations of the currently practiced decision analysis framework, which evolves around the definition of risk and cost of risk, and its poor ability to communicate risk-related information. A demonstration using a numerical example was conducted to provide insight on these limitations of the current decision analysis framework. The results from this simple ground water contamination and remediation scenario were identical to those obtained from studies carried out on existing Superfund sites, which suggests serious flaws in the current risk management framework. In order to provide a perspective on how these limitations may be avoided in future formulation of the management framework, more matured and well-accepted approaches to decision analysis in dam safety and the utility industry, where public health and public investment are of great concern, are presented and their applicability in subsurface remediation management is discussed. Finally, in light of the success of the application of risk-based decision analysis in dam safety and the utility industry, potential options for decision analysis in subsurface contamination management are discussed.     

Determining short chain fatty acids in sewage sludge hydrolysate：A comparison of three analytical methods and investigation of sample storage effects

In anaerobic digestion, the production of short-chain fatty acids （SCFAs） can be beneficial or harmful to the overall process, depending on the concentration of accumulated acids. Therefore, the accurate determination of the SCFA concentration in both fresh and stored sludge hydrolysates is important. To select a suitable method for monitoring SCFAs during the anaerobic digestion of sewage sludge, the accuracy of three available analytical methods, including 5 pH point acid titration （TITRA5）, gas chromatography （GC）, and spectrophotometry, were compared in the present study. The results revealed that TITRA5 and GC displayed better agreement in the achieved measurements and higher precision and accuracy than the spectrophotometric assay, as supported by the application of different statistical models. TITRA5 excelled in titrating unfiltered hydrolysate while simultaneously measuring the alkalinity, whereas the GC method provided detailed information on the contribution of different fatty acids to the total acidity. In contrast, the spectrophotometric assay suffered from many forms of interference, depending on the sample＇s matrix. SCFA production followed the pattern of enzymatic reactions and fitted the Michaelis-Menten model. In addition to promoting TITRA5 as an accurate and robust analytical tool for routine SCFA analyses, this comparative study also demonstrated the possibility of storing hydrolysate samples at different temperatures and durations without altering the SCFA measurements.     

Effects of different pretreatment methods on anaerobic mixed microflora for hydrogen production and COD reduction from palm oil mill effluent

Effects of different pretreatment methods on sludge inocula were evaluated with respect to hydrogen (H₂) production enhancement using palm oil mill effluent (POME) in a batch system. The experimental results showed that the pretreatment methods (chemical, acid, heat-shock, freezing and thawing, and base) at 35 °C and initial pH 5.5 had a positive influence on H₂ production yield and chemical oxygen demand (COD) removal efficiency during the fermentative H₂ production as compared to the control experiments (without pretreatment). Heat-shock pretreatment method was shown to be a simple and useful method for enhancing both H₂ producing and COD removal processes from POME with highest H₂ yield and COD removal efficiency at 0.41 mmol H₂/g COD and 86%, respectively.     

Hydrochemical characteristics and identification of groundwater pollution sources in tropical savanna

Groundwater pollution of the watershed is mainly influenced by the multifaceted interactions of natural and anthropogenic processes. In this study, classic chemical and multivariate statistical methods were utilized to assess the groundwater quality and ascertain the potential contamination sources affecting the groundwater quality of Galma sub-watershed in a tropical savanna. For this purpose, the data set of 18 groundwater quality variables covering 57 different sampling boreholes (BH) was used. The groundwater samples essentially contained the cations in the following order of dominance: Ca²⁺ ?>?Na⁺ ?>?Mg²⁺ ?>?K⁺. However, the anions had HCO₃^–?>?Cl^–?>?SO₄^–2?>?NO₃^– respectively. The hydrochemical facies classified the groundwater types of the sub-watershed into mixed Ca–Mg–Cl type of water, which means no cations and anions exceeds 50%. The second dominant water type was Ca–Cl. The Mg–HCO₃ water type was found in BH 9, and Na–Cl water type in BH 29 of the studied area. The weathering of the basement rocks was responsible for the concentrations of these ions in the groundwater chemistry of the sub-watershed. Hierarchical cluster analysis (HCA) grouped the groundwater samples (boreholes) into five clusters that are statistically significant regarding the similarities of groundwater quality characteristics. The principal component analysis (PCA) extracted two major principal components explained around 65% of the variance and suggested the natural and anthropogenic processes especially the agricultural pollutants including synthetic fertilizers, and leaching of agricultural waste as the main factors affecting the groundwater quality. The integrated method proved to be efficient and robust for groundwater quality evaluation, as it guaranteed the precise assessment of groundwater chemistry in the sub-watershed of the tropical savanna. The findings of this investigation could be useful to the policy makers for developing effective groundwater management plans for the groundwater resources and protection of the sub-watershed.

     

The efficacy of clay bentonite,date pit,and chitosan nanoparticles in the detoxification of aflatoxin M1 and ochratoxin A from milk

Aflatoxin M₁ (AFM₁) and ochratoxin A (OTA) are highly toxic mycotoxin metabolites that are found as food pollutants, posing health risks to humans and animals. The objective of the current study is to establish a sensitive, reliable method for determining AFM₁ and OTA using high-performance liquid chromatography (HPLC) and attempting to assess the efficacy of bentonite, date pit, and chitosan nanoparticles for AFM₁ and OTA detoxification from contaminated milk. As revealed, AFM₁ was found in 65.7% of analyzed samples ranging from 4.5 to 502 ng/L, while 25.7% of examined samples contained OTA ranging from 1.45 to 301 ng/L. Furthermore, for AFM₁ and OTA. The advanced procedure was thoroughly validated by evaluating linearity (R²?>?0.999), LOD (0.9615 and 0.654 ng/L), and LOQ (2.8846 and 1.963 ng/L), recovery (93–95% and 87–91%), as well as precision (≤?1%RSD). The experimental data revealed a higher removal efficiency of bentonite and date pit than chitosan nanoparticles in the case of AFM₁ (68%, 56%, and 12%) and OTA (64%, 52%, and 10%), respectively with slight change in nutritional milk components like fat, protein, and lactose. Eventually, it is concluded that bentonite and date pit can be considered efficient adsorbing agents to extract AFM₁ and OTA from contaminated milk.

     

Short-term dynamics and long-term relationship between natural gas consumption and economic growth in Nigeria: an ARDL approach with breaks

Environmental Science and Pollution Research - This paper investigates the short-term dynamics as well as the long-term relationship between natural gas consumption and economic growth in Nigeria,...     

A review of Yemen’s current energy situation,challenges, strategies,and prospects for using renewable energy systems

Environmental Science and Pollution Research -     

Topiramate potential neurotoxicity and mitigating role of ginger oil in mice brain

Environmental Science and Pollution Research - Topiramate has multiple pharmacological mechanisms that are efficient in treating epilepsy and migraine. Ginger has been established to have gingerols...