Analysis of environmental sustainability of e-waste in developing countries - a case study from Pakistan.

The electronic waste generation rate is increasing drastically at a rate of 3 to 5% per year in developing countries. The aim of this study is to analyze the environmental sustainability and economic benefits of such e-waste management in the developing economies like Pakistan. The life cycle assessment (LCA) method has been employed for streamlined impact analysis of the end-of-life processing of e-waste focusing mainly on laptop computers and liquid crystal display (LCD) desktop computers in Pakistan. The method of cumulative exergy extraction from the natural environment (CEENE) has also been deployed for the relative assessment of resources' consumption of e-waste recycling versus landfilling scenario. The determined impact scores are 1.79E + 03 kg CO2 eq., 7.19E-07 kg CFC-11 eq., 1.02E + 03 kg 1,4-DCB, 7.13E + 01 kg 1,4-DCB, and 3.41E-03 kg Cu eq. in climate change potential, stratospheric ozone depletion, ecotoxicity potential, human noncarcinogenic potential, and mineral resource depletion impact categories, respectively. The results of CEENE analysis reveal that approximately 80% of the impact on natural resources is reduced by the efficient recycling of e-waste. The comparative assessment of respective scores for current and target material weight recovery (MWR) indicators represented that by increasing the MWR indicator by 33.8% for laptop computers and by 27.2% for LCD computers, the country will achieve an annual economic benefit of US $191.56 million. This is greatly significant for a transitional shift towards e-waste revalorization while realizing the objectives of sustainable resource consumption. Innovative improvement measures ensuring economically feasible, energy-efficient, and environment friendly waste collection, treatment, and recycling practices present an invaluable opportunity for developing countries.

Geochemical fractionation and spectroscopic fingerprinting for evaluation of the environmental transformation of potentially toxic metal(oid)s in surface-subsurface soils.

The contamination of soil by toxic metal(oid)s has emerged as a major concern worldwide, particularly in developing countries. A metals behavior in the soil environment is influenced by organic matter, mineral phases, and oxidation states in which a particular metal exists. However, the spectroscopic evidence of metal(oid)s interactions in soil with organic matter and mineral phases can induce an extensive understanding. The surface and sub-surface soils (0-50 cm) from four sites of upper Indus basin, Pakistan, were collected and analyzed by using FTIR (Fourier-transform infrared spectroscopy), XRD (X-ray diffraction) and XPS (X-ray photoelectron spectroscopy) in addition to ICP-MS (inductively coupled plasma mass spectrometry) and geochemical fractionation. Geochemical fractionation of metal(oid)s indicated that As, Cu, Ni, Pb, and Zn were mostly found in the potentially bioavailable fractions. However, an increase in the residual fraction was observed from top to bottom. The absorption bands of FTIR spectra were divided into three spectral regions 700-400, 1700-800, and 3700-2800 cm-1. The soil was found rich in organic matter and capable of retaining metals as abundant peaks were observed in the mid-infrared region. The mineralogical analysis of soil samples testified silicon oxides and zeolite as major mineral phases. The XPS spectra showed broad peaks of As(III), As2O3, As4S4, PbO2, and PbCo3. The study concludes that the source identification of metal(oid)s in the upper Indus is crucial to find out the particular source of contamination in the soil.

Field testing phytoremediation of organic and inorganic pollutants of sewage drain by bacteria assisted water hyacinth.

The study was carried out to identify the potential of phytoremediation within a flowing drain through Eichhornia crassipes in combination with two bacillus species to treat the inorganic and polycyclic aromatic hydrocarbons (PAHs) from industrial effluent at Kala Shah Kaku (KSK), Lahore, Pakistan. Results showed that the highest metals removal efficiency was found in Cr, Pb, Ni, and Cu as 72.4, 83.3, 82.35, and 63.63%, respectively. However, biochemical oxygen demand (BOD) and chemical oxygen demand (COD) removal efficiencies were also considerably higher (66.66 and 66.67%). The BOD, COD, sulfates, phosphate, and total dissolved solids (TDS) showed a higher reduction rate as 1442.7, 1967.3, 1148.2, 7225.4, and 911.5 g m-2 d-1, respectively. Chlorophyll a + b and carotenoid contents were decreased from 7.92 to 5.78 mg kg-1, 3.03 to 3.01 mg kg-1, respectively and total nitrogen was increased from 22 to 27 mg kg-1 in E. crassipes. Bio-concentration factor was higher for all metals and the maximum was found in Cr (<1). The reduction efficiency of Æ©PAHs was found up to 60% with different rings structure. The use of Bacillus safensis strain showed the higher percentage reduction for BOD, nitrates, sulfates, and phosphates. The Study provide practical reference for bacterial assisted phytoremediation of urban drain.

Critical risk analysis of metals toxicity in wastewater irrigated soil and crops: a study of a semi-arid developing region.

Toxic elemental exposure through consumption of contaminated crops is becoming a serious concern for human health. Present study is based on the environment and health risk assessment of wastewater irrigated soil and crops in a semi-arid region Faisalabad, Pakistan. The concentrations of potentially toxic elements (Cu, Cr, Mn, Fe, Pb, Zn, Ni) were analysed by atomic absorption spectrometer in five different crops (Corn, rice, wheat, sugarcane and millet), while, their topsoil's and multi targeted risks analysis were assessed. Results showed, the mean values of Pb and Zn were higher in crop than Food and Agriculture Organization guidelines for food additives and contaminants. A strong positive correlation was found among wastewater and crop's toxic metals (r2 values in Cu, Zn, Pb, Ni and Cr were 0.913, 0.804, 0.752, 0.694, 0.587 respectively). Whereas, a strong correlation was also found among soil and wastewater lead (r2 = 0.639). The calculations of Nemerow Integrated Pollution Index (NIPI) showed the soil samples maximum pollution limit (NIPI > 3) and Potential Ecological Risk Index (PERI) was found to be higher than maximum limit (PERI > 600) for all samples. While, for non-carcinogenic risk, Hazard Index (HI) values in adult were near threshold (HI > 1) for all crop samples. In children, the HI values for Corn, Rice and Wheat were above threshold limit and for Sugarcane and Millet, these were near to threshold. Cancer risk values for Cr found higher than safe limit (1 × 10-6) in adult and children for crop samples. Crop irrigation by wastewater irrigation is a prominent alternative option for water scarce countries, however prior testing and treatment of such wastewater streams must be employed to minimize the adverse impacts on human health and environment.

Sustainability and CDM potential analysis of a novel vs conventional bioenergy projects in South Asia by multi-criteria decision-making method.

In this study, the multi-attribute utility theory model, one of the most widely utilized multi-criteria decision-making methods, is employed to analyze the relative sustainability and cleaner development mechanism (CDM) potential of a novel bioenergy project in Pakistan and four registered CDM bioenergy installations in China, India, Sri Lanka, and Thailand. Four major sustainability evaluation criteria selected for the study are technology, economy, environment, and social aspects, whereas "simple multi-attribute rating technique" (SMART) and "additive synthesis method" were utilized for the calculation of weighting factors. The most significant indicator was emission reduction, and least significant indicator was job creation with 24% and 15% respective weightages, in the sustainability scoring. Moreover, for three considered evaluation scenarios, (I) base case, (II) per kilowatt, and (III) per kilowatt hour, the bioenergy project in Pakistan has the highest comparative sustainability values of 0.735, 0.592, and 0.492 respectively. This analysis will provide an insight assistance to developing countries for establishing sustainable energy installations under CDM.

Investigating the drinking and surface water quality and associated health risks in a semi-arid multi-industrial metropolis (Faisalabad), Pakistan.

Urban areas under the influence of multi-industrial activities with arid and semi-arid environments witness the significant increase in environmental pollution especially in the water sector. The present study evaluated the water quality and associated health risk assessment through heavy metal pollution. Drinking (n = 48) and surface (n = 37) water samples were collected from semi-arid multi-industrial metropolis, Faisalabad, Pakistan. Physio-chemical and biological parameters and different metals (Al, As, Ba, Cd, Cr, Cu, Fe, Pb, Ni and Zn) were investigated using standard procedures and multivariate water quality assessments. Many physio-chemical and biological parameters and metals especially arsenic were exceeding the permissible limit of Punjab environmental quality standards and the World Health Organization. The results from water quality index showed that < 56% samples have poor, < 8% have very poor and < 6% have unsuitable water quality for drinking purposes. Water quality for the Gugera Branch Canal was found suitable with medium sodium (alkalinity) and salinity hazards, while it was found poor with magnesium absorption ratio. Hazard quotient (HQ) values for arsenic were found at the threshold level (HQ > 1) and carcinogenicity was found in case of arsenic and chromium (1 × 10-4) in adults and children. Semi-arid weather combined with different anthropogenic activities and unusual water features provoked metal contamination. Results of the present study can deliver basic information for effective management of water in the most populous and industrial areas.

Monitoring and spatiotemporal variations of pyrethroid insecticides in surface water, sediment, and fish of the river Chenab Pakistan.

There is a serious concern regarding freshwater resources of Pakistan which have been mismanaged and now are depleting extensively due to other reasons like intensive application of agricultural pesticides and insecticides. The present study was conducted to determine the concentrations of cypermethrin, deltamethrin, permethrin, and bifenthrin in the samples of water, sediments, and fish collected from various locations of River Chenab, Pakistan, during summer and winter seasons. These locations include namely Marala, Khanki, Qadirabad, and Trimu Headworks. High-performance liquid chromatography (HPLC) was deployed for analysis and determination of pyrethroid concentrations in these samples. The analytics show the order of pyrethroid concentrations in river as fish> sediment>water. Whereas maximum concentrations of 0.472 µg g-1 found in fish and minimum concentrations were determined in water, i.e., 0.087 µg L-1 at the sampling locations of Trimu and Marala headworks, respectively. Moreover, highest mean concentrations of pyrethroid, i.e., 1.248 µg g-1 in fish were detected in winter season as compared to summers, i.e., 0.087 µg L-1. However, all the values of pyrethroid were found to be lower than the maximum permissible levels specified by EU and WHO-FAO. Whereas the levels of deltamethrin and permethrin in water were found much higher than the specific limits set by EU.

Comparison of Reed and Water Lettuce in Constructed Wetlands for Wastewater Treatment.

In the present study two designs, vertical and horizontal systems, were used and two different plant species, Water Lettuce (Pistia stratiotes) and Reed plant (Phragmites karka), compared for their removal efficiency. The vertical system appeared to be more stable and efficient for almost all the parameters. The vertical system, planted with Water Lettuce, showed percentage removal efficiency for BOD, phosphate and chloride as 82, 95.4, and 51, respectively, whereas turbidity and total suspended solids removal efficiencies were almost the same. However, fecal coliform removal by the Water Lettuce was 98.8% for both designs (vertical and horizontal), showing the ability of the plant to uptake nutrients and release toxins for pathogen disinfection. It appears that the vertical system could be the better option, planted with Water Lettuce, or with both plants in a co-culture environment.

Phytoremediation of organochlorine and pyrethroid pesticides by aquatic macrophytes and algae in freshwater systems.

Extensive use of Pesticides in agriculture and its surface runoff in river water is a major environmental concern. The present study evaluated the phytoremediation potential of Eichornia crassipes, Pistia strateotes and algae (Chaetomorpha sutoria, Sirogonium sticticum and Zygnema sp.) for organochlorine and pyrethroid pesticides. Water and plant samples were extracted by liquid phase and solid phase extraction respectively and analyzed by high-performance liquid chromatography. Eleven treatments (T1-T11) with and without plants were used for phytoremediation of organochlorine and pyrethroid pesticides. During the experiment, P. strateotes, E. crassipes and algae (C. sutoria, S. sticticum and Zygnema sp.) showed the highest removal efficiency with 62 (71% root, 29% shoot), 60 (67% root, 33% shoot), and 58% respectively for organochlorine and 76 (76% root, 24% shoot), 68 (69% root, 31% shoot), and 70% respectively for pyrethroids for the respective aquatic plants. Dissipation rate constant of treatments with plants (T2, T3, T5, T6, T8, and T9) was significantly higher (p < 0.05) as compared to that of treatments without plants (T10 and T11, control) for both organochlorine and pyrethroid. The bioconcentration factor of pyrethroid treatments (T3, T6, and T9) was significantly higher (p < 0.05) as compared to that of organochlorine treatments (T2, T5 and T8). The removal efficiency of E. crassipes, P. strateotes and algae (C. sutoria, S. sticticum and Zygnema sp.) for pyrethroids was significantly higher (p < 0.01) as compared to that of organochlorine.

Assessing spatio-temporal trend of vector breeding and dengue fever incidence in association with meteorological conditions.

Th aim of this study is to investigate spatio-temporal trends of dengue vector breeding and epidemic (disease incidence) influenced by climatic factors. The spatio-temporal (low-, medium-, and high-intensity periods) evaluation of entomological and epidemiological investigations along with climatic factors like rainfall (RF), temperature (Tmax), relative humidity (RH), and larval indexing was conducted to develop correlations in the area of Lahore, Pakistan. The vector abundance and disease transmission trend was geo-tagged for spatial insight. The sufficient rainfall events and optimum temperature and relative humidity supported dengue vector breeding with high larval indices for water-related containers (27-37%). Among temporal analysis, the high-intensity period exponentially projected disease incidence followed by post-rainfall impacts. The high larval incidence that was observed in early high-intensity periods effected the dengue incidence. The disease incidence had a strong association with RF (r = 0.940, α = 0.01). The vector larva occurrence (r = 0.017, α = 0.05) influenced the disease incidence. Similarly, RH (r = 0.674, α = 0.05) and average Tmax (r = 0.307, α = 0.05) also induced impact on the disease incidence. In this study, the vulnerability to dengue fever highly correlates with meteorological factors during high-intensity period. It provides area-specific understanding of vector behavior, key containers, and seasonal patterns of dengue vector breeding and disease transmission which is essential for preparing an effective prevention plan against the vector.