Probing the potential of polyester for CO2 capture

Global warming, the major environmental issue confronted by humanity today, is caused by rising level of green house gases. Carbon capture and storage technologies offer potential for tapering CO2 emission in the atmosphere. Adsorption is believed to be a promising technology for CO2 capture. For this purpose, a polyester was synthesized by polycondensation of1,3,5-benzenetricarbonyl trichloride and cyanuric acid in pyridine and dichloromethane mixture. The polymer was then characterized using FT-IR, TGA, BET surface area and pore size analysis, FESEM and CO2 adsorption measurements. The CO2 adsorption capacities of the polyester were evaluated at a pressure of 1 bar and two different temperatures（273 and 298 K）.The performance of these materials to adsorb CO2 at atmospheric pressure was measured by optimum CO2 uptake of 0.244 mmol/g at 273 K. The synthesized polyester, therefore, has the potential to be exploited as CO2 adsorbent in pre-combustion capture process.     

Sludge granulation and e ciency of phase separator in UASB reactor treating combined industrial e uent

Sludge granulation and the effect of gas-liquid-solid separator （GLSS） design on the efficiency of upflow anaerobic sludge blanket （UASB） and upflow anaerobic sludge filter （UASF） reactors, operating at HRTs ranging from 3 to 12 h was investigated. VSS/TS ratio gradually increased in both the reactors with increasing sludge age （from 0.5 to more than 0.7 for UASB reactor and 0.012 to 0.043 for UASF reactor）. X-Ray diffraction analysis of the UASF sludge showed the presence of expanding clays revealing its additional absorption capability. Fuoraphyllite and albite precipitation related to excellular polymers of the microbial shell structure, showed the extended growth of microorganisms during sludge granulation. A gradual decrease （82%-69%） in COD removal with decreasing HRT was apparent in UASF reactor. In case of UASB reactor, this decrease was marginal because addition of GLSS device significantly improved （14%-20%） the overall efficiency of the UASB reactor. GLSS enhanced the efficiency of the UASB reactor by increasing the settleability of suspended particles and accelerating the coagulation of colloidal particles due to the velocity gradient.     

Pesticides exposure in Pakistan: a review

This is the first systematic review of studies done since 1960, and to give an integrated picture of pesticides exposure to humans, animals, plants, waters, soils/sediments, atmosphere etc. in Pakistan. Authors have extracted data from different departments, published literature in research journals and National reports. Although the wide-spread usage of pesticides in Pakistan has controlled the pests, but like other countries, it has started causing environmental problems in the area. In some areas of Punjab and Sindh groundwater has been found contaminated and is constantly being under the process of contamination due to pesticide use. There is considerable evidence that farmers have overused and misused pesticides especially in cotton-growing areas. It is evident from the biological monitoring studies that farmers are at higher risk for acute and chronic health effects associated with pesticides due to occupational exposure. Furthermore, the intensive use of pesticides (higher sprays more than the recommended dose) in cotton areas involves a special risk for the field workers, pickers, and of an unacceptable residue concentration in cottonseed oil and cakes. The authors have also discussed the merits and demerits of different studies. The review will set the future course of action of different studies on pesticide exposure in Pakistan. Data limitations are still the major obstacle towards establishing clear environmental trends in Pakistan. The authors suggest that a reliable monitoring, assessment and reporting procedures shall be implemented in accordance with appropriate environmental policies, laws and regulations in order to minimize the pesticides exposure.     

Health risk assessment and oxidative stress in workers exposed to welding fumes

The aim of this study was designed to determine the influence of welding fumes on oxidative stress in humans and the role of metals. A questionnaire was designed to collect information regarding personal characteristics, including age, weight, height, and medical history; life style such as smoking status and exercise habits; and occupational history such as working history, working environment, employment duration, and use of protective equipment. Body mass index (BMI) in kg/m² was then calculated for each participant. Blood samples were also drawn to determine malondialdehyde (MDA) levels and various metals in plasma. Significantly higher plasma MDA (4.08 µg/L) was observed as compared to controls (1.61 µg/L). Blood metal analysis also showed elevated level of metals in welders for cadmium, chromium, lead,and nickel. Data indicated that workers occupationally exposed to welding fumes for prolong periods possessed higher metal levels associated with increased oxidative stress as evidenced by elevated MDA levels.     

Succinate-bonded pullulan: An efficient and reusable super-sorbent for cadmium-uptake from spiked high-hardness groundwater

Chemically modified pullulan was evaluated for its sorption efficiency and selectivity to remove cadmium(Cd) from spiked high-hardness groundwater(GW). Pullulan esterified with succinic anhydride using dimethylaminopyridine showed a fairly high degree of substitution value as confirmed by1 H NMR spectroscopy. Pullulan succinate(Pull-Suc) was converted into the sodium salt(Pull-Suc-Na). The effect of contact time(5–200 min) and p H(2–8) on Cd-uptake by the sorbent(Pull-Suc-Na) was investigated. The sorbent showed more than 90% Cd-removal in first 15 min from distilled water(DW) and GW solution,respectively. Comparison of Pull-Suc-Na with other polysaccharidal sorbents suggested its high efficiency(DW 476.2 mg/g and GW 454.5 mg/g) and selectivity for the removal of Cd by an ion exchange mechanism, which is further supported by the negative Gibbs free energy values calculated from Langmuir isotherms. A Langmuir isotherm kinetic model provided the best fit for the sorption of Cd using Pull-Suc-Na. The sorbent showed a negligible decrease in Cd-uptake over three regeneration cycles. The thermal stability testing of the sorbents indicated that Pull-Suc-Na(sorbent) is more stable than Pull-Suc.     

Self-healing concrete for sustainable buildings. A review

Environmental Chemistry Letters - A total of 12 billion tons of concrete materials are produced annually, about 2 tons per person. More sustainable buildings are thus needed to decrease the carbon...     

Microalgae binary culture for higher biomass production,nutrients recycling,and efficient harvesting: a review

Environmental Chemistry Letters - Microalgae are photosynthetic cell factories of global interest for fuels, food, feed, bioproducts, carbon sequestration, waste mitigation, and environmental...     

Assessment of cobalt in wheat grains as affected by diverse fertilizers: implications for public health

Environmental Science and Pollution Research - Present study was conducted to check the heavy metal content in wheat treated with municipal solid waste, Although municipal solid waste was enriched...     

Anticancer properties of medicinal plants and their bioactive compounds against breast cancer: a review on recent investigations

Environmental Science and Pollution Research - Breast cancer (BC) is one of the most common and recurring diseases and the second leading cause of death in women. Despite prevention, diagnostics,...