Soil and water quality is greatly affected by environmental pollution due to the increasing trend of urbanization and industrialization. In many developing countries, including Pakistan, the situation is more alarming as no preventive measures are still taken to tackle the problem. Although in developed countries, many techniques are used to remediate the environment including phytoremediation. It is the most eco-friendly technique in which plants are used to remove pollutants from the environment. Pakistan has also a great diversity of plants which could be used for the remediation of environmental pollutants. To our knowledge, few studies from Pakistan were reported about the use of flora for phytoremediation. According to recent literature, 50 plant species from Pakistan are studied for remediation purposes. In this review, the potential of different plant species for phytoremediation from Pakistan has been discussed along with their comparison to other countries to relate future perspectives.

This study investigated health risks exerted on electronic waste (e-waste) recycling workers exposed to cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), mercury (Hg), and zinc (Zn) in Hong Kong. E-waste recycling workshops were classified into eight working areas: 1 = office, 2 = repair, 3 = dismantling, 4 = storage, 5 = desoldering, 6 = loading, 7 = cable shredding, and 8 = chemical waste. The aforementioned metal concentrations were analyzed in suspended air particulates, surface dust and floor dust collected from the above study areas in five workshops. Elevated Pb levels were measured in dismantling and desoldering areas (582 and 486 μg/100 cm²in surface and 3,610 and 19,172 mg/kg in floor dust, respectively). Blood lead levels of 10 and 39.5 μg/dl were estimated using United States Environmental Protection Agency's Adult Lead Model as a result of exposure to the floor dust from these two areas. Human health risk assessments were conducted to evaluate cancer and noncancer risks resulting from exposure to floor dust through the combined pathways of ingestion, dermal contact, and inhalation. Findings indicated that workers may be exposed to cancer risks above the acceptable range at 147 in a million at the 95th percentile in the dismantling area. Workers should be informed of associated risks to safeguard their health.

Characterization of aged hydrocarbon-contaminated sites is often a challenge due to the heterogeneity of subsurface conditions. Geoelectrical methods can aid in the characterization of such sites due to their non-invasive nature, but need to be supported by geochemical and microbiological data. In this study, a combination of respective methods was used to characterize an aged light non-aqueous phase liquid-contaminated site, which was the scene of a crude oil blow-out in 1994. As a consequence, a significant amount of crude oil was released into the subsurface. Complex resistivity has been acquired, both along single boreholes and in cross-hole configuration, in a two-borehole test site addressed with electrodes, to observe the electrical behaviour at the site over a two-year period (2010–2011). Geoelectrical response has been compared to results of the analysis of hydrocarbon contamination in soil and groundwater samples. Geochemical parameters of groundwater have been observed by collecting samples in a continuous multi-channel tubing (CMT) piezometer system. We have also performed a biological characterization on soil samples by drilling new boreholes close to the monitoring wells. Particular attention has been given to the characterization of the smear zone that is the sub-soil zone affected by the seasonal groundwater fluctuations. In the smear zone, trapped hydrocarbons were present, serving as organic substrate for chemical and biological degradation, as was indicated by an increase of microbial biomass and activity as well as ferrogenic-sulfidogenic conditions in the smear zone. The results show a good agreement between the intense electrical anomaly and the peaks of total organic matter and degradation by-products, particularly enhanced in the smear zone.

The occurrence and behavior of endocrine disrupting chemicals (EDCs) in sewage treatment plants (STPs), especially estrogens and phenols, have been closely concerned in previous studies. However, the systematical researches about progestogens and androgens were scarce in STPs adopting different treatment technologies. This work investigated the occurrence, removal, and fate of one progestogen, three androgens, four estrogens, and six phenols in six STPs around Dianchi Lake in China, where the influents, effluents of primary treatment, secondary treatment, and advanced treatment, as well as excess sludge samples, were analyzed. All of the above EDCs were detected out in influents of the six STPs. Bisphenol A, nonylphenol-mono-ethoxylate, and nonylphenol-diethoxylate were the dominant EDCs detected in those influent samples with the concentrations that varied from 637.6 to 1,684.0 ng/L, 633.8 to 1,540.0 ng/L, and 648.7 to 2,246.0 ng/L, respectively; E1 and dihydrotestosterone were the major steroids with the mean concentration of 126.8 and 277.4 ng/L. For effluents and sludges, phenols showed higher concentration (366.8–1,233.0 ng/L and 1,478.1–6,948.9 ng/g dry weight (dw)) and detection rate (100 %). The total removal rates were more than 80 % for most compounds in wastewater treatment processes, and high removal efficiency (86–100 %) was found for androgens and progestogens compared with estrogens (75–92 %) and phenols (62–85 %). The secondary treatment processes play significant roles on degrading EDCs, whereas the primary sedimentation has little effects. The treatment capacity of anoxic-anaerobic-anoxic membrane bioreactor and anaerobic/anoxic/oxic technologies was superior to the conventional oxidation ditch in the degradation of EDCs. The advanced treatment process, two units of filter (D-type or V-type), and ultraviolet disinfection were adopted and presented effective to remove these compounds. According to fate analysis, it was obvious that biological degradation was the main pathway on the removal of EDCs in STPs compared with adsorption. Risk quotients were calculated to assess ecological risks of those EDCs. Risk quotients of 54 and 61 % were more than 1 in effluents and sludges, respectively, showing potential hazard of effluents and sludges to the environment.

This work evaluates the treatment of wastewater from a personal care products factory by a full-scale side-stream membrane bioreactor (MBR) intermittently fed. The wastewater contained particulate and soluble chemical oxygen demand (COD) which is partially removed by physicochemical pretreatment. Steady removal efficiencies above 98 % were achieved for BOD5, COD and suspended solids. Fats, oils and grease present in the raw wastewater were also successfully removed. The MBR was operated at an average permeate flux of 12 L/m2 · h (LMH) working at a transmembrane pressure of 272 ± 97 mbar. The soluble microbial products concentration remained fairly stable at 175 ± 25 and 85 ± 15 mg/L for proteins and carbohydrates, respectively. This maintained the filtration characteristics of the mixed liquor unaltered over a long-term basis, which was evidenced by a constant permeability of 43 ± 19 LMH/bar. Most of the trace organics detected in the wastewater were completely removed and only some fragrances were detected in the permeate at trace concentrations.

Europium (Eu³⁺)-labeled antibody was used as a fluorescent label to develop a highly sensitive time-resolved fluoroimmunoassay (TRFIA) for determination of clothianidin residues in agricultural samples. Toward this goal, the Eu³⁺-labeled polyclonal antibody and goat anti-rabbit antibody were prepared for developing and evaluating direct competitive TRFIA (dc-TRFIA) and indirect competitive TRFIA (ic-TRFIA). Under optimal conditions, the half-maximal inhibition concentration (IC₅₀) and the limit of detection (LOD, IC₁₀) of clothianidin were 9.20 and 0.0909 μg/L for the dc-TRFIA and 2.07 and 0.0220 μg/L for the ic-TRFIA, respectively. The ic-TRFIA has no obvious cross-reactivity with the analogues of clothianidin except for dinotefuran. The average recoveries of clothianidin from spiked water, soil, cabbage, and rice samples were estimated to range from 74.1 to 115.9 %, with relative standard deviations of 3.3 to 11.7 %. The results of TRFIA for the blind samples were largely consistent with gas chromatography (R² = 0.9902). The optimized ic-TRFIA might become a sensitive and satisfactory analytical method for the quantitative monitoring of clothianidin residues in agricultural samples.

The present paper provides an overview of mercury studies performed in the Mediterranean Sea region in the framework of several research projects funded by the European Commission and on-going national programmes carried out during the last 15 years. These studies investigated the temporal and spatial distribution of mercury species in air, in the water column and sediments, and the transport mechanisms connecting them. It was found that atmospheric concentrations of Hg compounds, particularly oxidised Hg species observed at five coastal sites in the Mediterranean Sea Basin, are significantly higher compared with those recorded at five coastal sites distributed across N Europe, most probably due to natural emissions. Hg levels in water are comparable to other oceans. Anthropogenic and natural point sources show locally limited enrichments, while natural diffusive sources influence Hg speciation over larger areas. Results and statistic comparison of mercury species concentrations within Mediterranean compartments will be presented and discussed.

Industrially contaminated sites with hazardous materials are a priority and urgent problem all over the world. Appropriate risk assessment is required to determine health risks associated with contaminated sites. The present study was conducted to investigate distribution of potentially hazardous, heavy metal (As, Cd, Cr, Cu, Ni, Pb and Zn) concentrations in surface and groundwater samples collected during summer (pre-monsoon) and winter (post-monsoon) seasons from an industrially contaminated site, Hyderabad, India, with potential source of metal contamination because of industrial effluents and usage of pesticides in agriculture. Heavy metal (HM) concentrations were analysed by using inductively coupled plasma-mass spectrometer and were compared with permissible limits set by the World Health Organisation. Data obtained was treated using multivariate statistical approaches like R-mode factor analysis (FA), principal component analysis, cluster analysis, geoaccumulation index, enrichment factor, contamination factor and the degree of contamination. Health risk assessment like chronic daily intake (CDI) and hazard quotient (HQ) were also calculated. Relatively high levels were noted in surface water with average concentrations during summer and winter seasons showing 16.13 and 11.83 for As, 7.91 and 1.64 for Cd, 88.33 and 32.90 for Cr, 58.11 and 28.26 for Cu, 53.62 and 69.96 for Ni, 173.8 and 118.6 for Pb, and 2,943 and 1,889 μg/L for Zn. While in groundwater, the mean metal levels during two seasons were 18.18 and 3.76 for As, 1.67 and 0.40 for Cd, 29.40 and 5.15 for Cr, 17.03 and 4.19 for Cu, 25.4 and 6.09 for Ni, 81.7 and 2.87 for Pb and 953 and 989 μg/L for Zn, respectively. FA identified two factors with cumulative loadings of F1—60.82 % and F2—76.55 % for pre-monsoon surface water and F1—48.75 % and F2—67.55 % for groundwater. Whereas, three factors with cumulative loadings of F1—39.13 %, F2—66.60 % and F3—81.01 % for post-monsoon surface water and F1—50.31 %, F2—66.18 % and F3—81.54 % for groundwater. The health risk assessment like CDI and HQ indices with increased levels of hazardous elements in the surface and groundwater were safe for drinking purposes provided some water treatment methodologies are adopted.

Rare earth element accumulation in the soil and elevated ultraviolet (UV)-B radiation (280–315 nm) are important environmental issues worldwide. To date, there have been no reports concerning the combined effects of lanthanum (La)(III) and elevated UV-B radiation on plant roots in regions where the two issues occur simultaneously. Here, the combined effects of La(III) and elevated UV-B radiation on the growth, biomass, ion absorption, activities, and membrane permeability of roots in soybean (Glycine max L.) seedlings were investigated. A 0.08 mmol L⁻¹La(III) treatment improved the root growth and biomass of soybean seedlings, while ion absorption, activities, and membrane permeability were obviously unchanged; a combined treatment with 0.08 mmol L⁻¹La(III) and elevated UV-B radiation (2.63/6.17 kJ m⁻² day⁻¹) exerted deleterious effects on the investigated indices. The deleterious effects were aggravated in the other combined treatments and were stronger than those of treatments with La(III) or elevated UV-B radiation alone. The combined treatment with 0.24/1.20 mmol L⁻¹La(III) and elevated UV-B radiation exerted synergistically deleterious effects on the growth, biomass, ion absorption, activities, and membrane permeability of roots in soybean seedlings. In addition, the deleterious effects of the combined treatment on the root growth were due to the inhibition of ion absorption induced by the changes in the root activity and membrane permeability.