Competitive adsorption of Alizarin Red S and Bromocresol Green from aqueous solutions using brookite TiO2 nanoparticles: experimental and molecular dynamics simulation.

In this work, the effective adsorption and the subsequent photodegradation activity, of TiO2 brookite nanoparticles, for the removal of anionic dyes, namely, Alizarin Red S (ARS) and Bromocresol Green (BCG) were studied. Batch adsorption experiments were conducted to investigate the effect of both dyes' concentration, contact time, and temperature. Photodegradation experiments for the adsorbed dyes were achieved using ultraviolet light illumination (6 W, λ = 365 nm). The single adsorption isotherms were fitted to the Sips model. The binary adsorption isotherms were fitted using the Extended-Sips model. The results of adsorption isotherms showed that the estimated maximum adsorption uptakes in the binary system were around 140 mg g-1 and 45.5 mg g-1 for ARS and BCG, respectively. In terms of adsorption kinetics, the uptake toward ARS was faster than BCG molecules in which the equilibrium was obtained in 7 min for ARS, while it took 180 min for BCG. Moreover, the thermodynamics results showed that the adsorption process was spontaneous for both anionic dyes. All these macroscopic competitive adsorption results indicate high selectivity toward ARS molecules in the presence of BCG molecules. Additionally, the TiO2 nanoparticles were successfully regenerated using UV irradiation. Moreover, molecular dynamics computational modeling was performed to understand the molecules' optimum coordination, TiO2 geometry, adsorption selectivity, and binary solution adsorption energies. The simulation energies distribution exhibits lower adsorption energies for ARS in the range from - 628 to - 1046 [Formula: see text] for both single and binary systems. In addition to that, the water adsorption energy was found to be between - 42 and - 209 [Formula: see text].

Development of a Conceptual Framework for Occupational Safety and Health in Palestinian Manufacturing Industries.

The annual increase in the number of occupational accidents and diseases in the Palestinian manufacturing industries confirms a serious problem that threatens the Occupational Safety and Health (OSH) in such industries, with negative consequences in the society and economy. As the Palestinian OSH data are insufficient, tightwad, and with discrepancies in published data by different agencies, this study aimed to investigate the OSH status in the Palestinian manufacturing industries and determine the Palestinian OSH trends rates based on international practice in the EU and USA. Also, to shed light on the OSH situation in the manufacturing sector and warrant the inspection and monitoring of industries by the respective officials. The OSH data of 175 industrial establishments and 199 industrial employees was collected by meetings, interviews, and structured questionnaires for the period 2009-2016. The US and EU OSHA (Occupational Safety and Health Administration) formulas were used to calculate the OSH rates. The analysis showed that 32.30% of the industrial employees suffered from occupational injuries. The average injury rate was 7566 per 100,000 workers, indicating a low OSH level in the Palestinian manufacturing industries. The leather industry was found as the most dangerous in terms of OSH, with an average safety performance factor (SPF) of 145.6 off days/accident. Pearson's chi-square test (χ2) revealed a correlation between occupational accidents and injuries and the employees' commitment and lost working days. An OSH framework was developed based on safety and sustainable development pillars to assure effective enforcement of the OSH law and prevent future occupational accidents and diseases.

Sustainable competitive adsorption of methylene blue and acid red 88 from synthetic wastewater using NiO and/or MgO silicate based nanosorbcats: experimental and computational modeling studies.

The competitive adsorption of cationic and anionic model molecules; methylene blue (MB) and acid red 88 (AR88), respectively, in aqueous solutions onto NiO and/or MgO SBNs was studied. Adsorption isotherms, kinetics and pH effect were investigated in batch modes. Computational modeling was conducted on Acclerys Material Studio for MB and AR88 adsorption. pH study showed that the adsorption is strongly pH dependent, increases for MB while decreases for AR88 with increasing the pH from 4 to 11. Isotherm studies revealed that the Sips model was the best fit for both molecules in single cases, and thus the Extended-Sips model for the binary systems. The kinetics for the binary systems were well-described by the external mass transfer model; thus, film diffusion is the most dominant in the adsorption of both organic onto the SBNs. The adsorption uptakes in binary systems exceed 130 mg g-1 for AR88 (167.7 MgO-SBNs, 132.93 NiO-SBNs, and 178.5 mg g-1 NiO-MgO-SBN), while it reached an uptake of 76.2 MgO-SBNs, 81.5 NiO-SBNs, and 94.7 mg g-1 NiO-MgO-SBNs for MB within the time needed to reach equilibrium (10 min). The adsorption of these two molecules in binary systems showed a synergistic effect onto the three types of SBNs, that enhanced the adsorption uptakes. Computational modeling confirmed the synergistic effect, the adsorption energy of binary systems was lower than that in single systems. Regeneration study was conducted over four adsorption cycles to confirm the sustainability of SBNs. They were stable under thermal oxidation at 400 °C, without any impact on the adsorption capacity.

Solid olive waste in environmental cleanup: enhanced nitrite ion removal by ZnCl2-activated carbon.

This communication describes how olive solid wastes can be used to prepare activated carbon (AC), with soundly high surface areas, suitable to remove nitrite ions from water. Solid olive wastes, so called Jeft, separated as unwanted bi-products from olive oil mills, have been converted into charcoal. The charcoal was then physically and/or chemically activated using different compounds namely conc. H3PO4 or ZnCl2. Charcoal carbonization was performed under inert atmosphere to avoid loss of heated carbon by oxidation with air. Surface area measurements and SEM micrographs showed that activation using ZnCl2 yields AC with highest surface area and more porous surfaces. The ZnCl2-activated carbon was then used to remove nitrite ions from water by adsorption. Effects of different parameters on value of surface area and adsorption capacity of the AC were investigated. Commercial AC materials were used as reference for comparison. The AC showed higher adsorption capacity toward nitrite than other reported adsorbents. The results suggest that using 5 g of the ZnCl2-activated carbon per liter of heavily nitrite-contaminated water (50 ppm) may bring the contaminant concentration down to the WHO accepted concentration limits within 60 min. This work highlights the future feasibility of using olive waste as feed stocks to produce useful renewable materials while keeping in mind the wisdom "make wastes work in environmental protection".

Logistical management and private sector involvement in reducing the cost of municipal solid waste collection service in the Tubas area of the West Bank.

This paper addresses the problems of the municipal solid waste (MSW) collection system in the Tubas district of Palestine. More specifically, it addresses the often-voiced concerns pertaining to low efficiency as well as environmental problems. This was carried out through a systematic methodological approach. The paper illustrates how a private company applied a logistical management strategy, by rescheduling the MSW collection system, reallocating street solid waste containers and minimizing vehicle routing. The way in which the MSW collection timetable was rescheduled decreased the operating expenses and thus reduced MSW collection costs. All data needed to reschedule the collection timetable and optimize vehicle routing were based on actual field measurements. The new MSW collection timetable introduced by a private company was monitored for a period of a month. The new system resulted in an improvement in the MSW collection system by reducing the collection cost to a level that is socially acceptable (US dollars 3.75/family/month), as well as economically and environmentally sound.

Solid olive waste in environmental cleanup: oil recovery and carbon production for water purification.

A potentially-economic three-fold strategy, to use solid olive wastes in water purification, is presented. Firstly, oil remaining in solid waste (higher than 5% of waste) was recovered by the Soxhlet extraction technique, which can be useful for the soap industry. Secondly, the remaining solid was processed to yield relatively high-surface area active carbon (AC). Thirdly, the resulting carbon was employed to reversibly adsorb chromate ions from water, aiming to establish a water purification process with reusable AC. The technique used here enabled oil recovery together with the production of a clean solid, suitable for making AC. This process also has the advantage of low production cost.