Activated carbon has been recognized as one of the oldest and widely used adsorbent for the water and wastewater treatment for removing organic and inorganic pollutants. The application of activated carbon in adsorption process is mainly depends on the surface chemistry and pore structure of porous carbons. The method of activation and the nature of precursor used greatly influences surface functional groups and pore structure of the activated carbon. Therefore, the main focus of researchers is to develop or modifies the activation/treatment techniques in an optimal manner using appropriate precursors for specific pollutants. In recent years, emphasis is given to prepare the surface modified carbons using different procedures to enhance the potential of activated carbon for specific contaminants. Various methods such as, acid treatment, base treatment, impregnation treatment, ozone treatment, surfactant treatment, plasma treatment and microwave treatment have been studied to develop surface modified activated carbons. In this paper, these modification methods have been reviewed and the potential of surface modified activated carbons towards water treatment has been discussed. This review article is aimed at providing precise information on efforts made by various researchers in the field of surface modification of activated carbon for water pollution control. (C) 2012 Elsevier B.V. All rights reserved.

The global olive oil production for 2010 is estimated to be 2,881,500 metric tons. The European Union countries produce 78.5 % of the total olive oil, which stands for an average production of 2,136,000 tons. The worldwide consumption of olive oil increased of 78 % between 1990 and 2010. The increase in olive oil production implies a proportional increase in olive mill wastes. As a consequence of such increasing trend, olive mills are facing severe environmental problems due to lack of feasible and/or cost-effective solutions to olive-mill waste management. Therefore, immediate attention is required to find a proper way of management to deal with olive mill waste materials in order to minimize environmental pollution and associated health risks. One of the interesting uses of solid wastes generated from olive mills is to convert them as inexpensive adsorbents for water pollution control. In this review paper, an extensive list of adsorbents (prepared by utilizing different types of olive mill solid waste materials) from vast literature has been compiled, and their adsorption capacities for various aquatic pollutants removal are presented. Different physicochemical methods that have been used to convert olive mill solid wastes into efficient adsorbents have also been discussed. Characterization of olive-based adsorbents and adsorption mechanisms of various aquatic pollutants on these developed olive-based adsorbents have also been discussed in detail. Conclusions have been drawn from the literature reviewed, and suggestions for future research are proposed.

Vitellogenin protein (Vtg) in Oreochromis niloticus plasma has been indirectly quantified through protein-bound phosphate groups also known as alkali-labile phosphates (ALP) using a recently modified method. Such method as described in the literature was originally applied to Crucian carp and resulted in lower detection limits (3.2 mu g PO(4)(3-)per mL). In this study, O. niloticus males were exposed to intermittent doses of oestrogens for 15 days using different concentrations (converted to loads) of 17 alpha-ethinyloestradiol (EE2) (two different aquarium volumes), oestrone (E1) and 17 beta-oestradiol (E2) individually and in combination (1:1:1). The induction of physiologic and genotoxic effects in erythrocytes was investigated. For the tested oestrogen (EE2), load proved to be more relevant than concentration in determining the oestrogenicity. O. niloticus males proved to have lower ALP baseline (4.11 mu g PO43-/mL plasma, IQ(25)=3.38; IQ(75)=5.18) than other fish species, including Crucian carp, which makes it suitable for oestrogenicity detection in water. Exposure to E2, EE2 separately and in combination (1:1:1) all induced significant increases in the ALP levels at loads >= 0.72 mu g/fish. This load was three times lower than the E1 load required to increase ALP (>= 2.2 mu g/fish). All oestrogens with loads >= 0.072 mu g/fish caused significant increase in micronucleus frequency (>= 2 parts per thousand) compared with the control (0.1 +/- 0.4 parts per thousand). The study highlighted the importance of taking into account not only concentration and dose regime but also the mass load and therefore, the volume used in the experimental units, which is rarely addressed in ecotoxicity assays. Considering the good sensitivity of O. niloticus exposed to relatively low concentrations of oestrogens, the combination of the ALP method with auxiliary biomarkers (particularly micronucleus) can be used as a protocol for oestrogenicity and genotoxicity detection in different contaminated waters as part of water environmental monitoring programmes.

There is a worldwide demand for decentralized wastewater treatment options. An on-site engineered ecosystem (EE) treatment plant was designed with a multistage approach for small wastewater generators in tropical areas. The array of treatment units included a septic tank, a submersed aerated filter, and a secondary decanter followed by three vegetated tanks containing aquatic macrophytes intercalated with one tank of algae. During 11 months of operation with a flow rate of 52 L h(-1), the system removed on average 93.2% and 92.9% of the chemical oxygen demand (COD) and volatile suspended solids (VSS) reaching final concentrations of 36.3 +/- 12.7 and 13.7 +/- 4.2 mg L-1, respectively. Regarding ammonia-N (NH4-N) and total phosphorus (TP), the system removed on average 69.8% and 54.5% with final concentrations of 18.8 +/- 9.3 and 14.0 +/- 2.5 mg L-1, respectively. The tanks with algae and macrophytes together contributed to the overall nutrient removal with 33.6% for NH4-N and 26.4% for TP. The final concentrations for all parameters except TP met the discharge threshold limits established by Brazilian and EU legislation. The EE was considered appropriate for the purpose for which it was created.

This paper investigates the effect of estrone (E1), 17 beta-estradiol (E2) and 17 alpha-ethinylestradiol (EE2) individually and mixed at equal proportions (1:1:1) on Desmodesmus subspicatus and Pseudokirchneriella subcapitata in single and combined cultures (S+) at different exposure times basedon algal growth (in vivo chlorophyll fluorescence and cell counting) and coenobium formation. EE2 and E2 were more toxic to individual and combined (S+) cultures than was E1. The frequency of coenobium formation by D. subspicatus increased significantly for all estrogens and all concentrations. After 96 h, D. subspicatus prevailed in S+. The results of the exposure to E+ suggested a less-than-additive effecton D. subspicatus and S+ and additive effect on P. subcapitata. Toxic effects occurred for both species exposed to E+ with individual estrogen concentrations below the NOEC of each species. Assays must include changes in response due to the exposure of more than one species to more than one estrogen.

ABSTRACT: Owing that Oreochromis niloticus is resistant to different aquatic environments,four contaminated sites were selected: decentralized engineered ecosystem(DEE) and conventional wastewater treatment plants(WWTP); urban lagoon; and gasoline-contaminated marshland. Endocrine disruption was assessed by alkali-labile phosphate(ALP) quantification,genotoxicity by micronuclei frequency,and morphological changes by hepatosomatic and gonadosomatic indexes. The ALP baseline of non-exposed O. niloticus males was low,compared with other fish species in the literature. Endocrine disruption was observed in fish exposed to raw wastewater of WWTP and DEE,discharge point of channeled river in the urban lagoon,and water from gasoline-contaminated marshland. After treatment in the DEE,the endocrine disruption effect was removed. The micronuclei frequency corroborated with the ALP results in most cases and proved to be a useful tool to assess genotoxicity in fish. The exposure time of 15 days was not enough to provoke morphological effects in most samples. However,in all gasoline-contaminated samples,the fishes showed an increase in the hepatosomatic index followed by a decrease in the gonadosomatic index. The tested biomarkers showed feasibility,sensibility,reproducibility,and were complementary in the assessment of chronic ecotoxicity; therefore,we recommend them to compose a suitable protocol for aquatic monitoring programs.

Ozone and ozone-based advanced oxidation processes were applied for the treatment of a recalcitrant wastewater generated by wood-based industries that contains different inorganic and organic constituents and high chemical oxygen demand (COD) varying between 3,400 and 4,000 mg/L. The investigation used a tubular ozone reactor combined with an UV reactor designed for different hydraulic retention times. The dependent variables addressed to evaluate the treatment efficiency were the reduction of COD and total organic carbon (TOC) and the biodegradability of the treated effluent based on respirometric studies using activated sludge from a wastewater treatment. The results showed that even though ozonation alone at acid pH promoted COD and TOC reductions of 65 and 31 % respectively, a decrease in the biodegradability was observed. The most effective treatment (COD and TOC reductions of 93 and 43 %, respectively) was obtained when applying ozone combined with UV light at basic pH. The ozone-UV combination was capable of increasing the amount of readily available COD by 75 % with an additional reduction of TOC by 60 %. In conclusion, ozonation at low pH effectively reduces the COD content in wastewater generated by the wood-based industry; however, in order to combine advanced oxidation with biological process, ozone combined with UV is recommended.

There is a need for the development of on-site wastewater treatment technologies suitable for "dry-process industries," such as the wood-floor sector. Due to the nature of their activities, these industries generate lower volumes of highly polluted wastewaters after cleaning activities. Advanced oxidation processes such as Fenton and photo-Fenton, are potentially feasible options for treatment of these wastewaters. One of the disadvantages of the Fenton process is the formation of large amounts of ferrous iron sludge, a constraint that might be overcome with the use of nanoscale zero-valent iron (nZVI) powder. Wastewater from a wood-floor industry with initial COD of 4956 mg/L and TOC of 2730 mg/L was treated with dark-Fenton (nZVI/H2O2) and photo-Fenton (nZVI/H2O2/UV) applying a 2-level full-factorial experimental design. The highest removal of COD and TOC (80% and 60%, resp.) was achieved using photo-Fenton. The supply of the reactants in more than one dose during the reaction time had significant and positive effects on the treatment efficiency. According to the results, Fenton and mostly photo-Fenton are promising treatment options for these highly recalcitrant wastewaters. Future investigations should focus on optimizing treatment processes and assessing toxic effects that residual pollutants and the nZVI might have. The feasibility of combining advanced oxidation processes with biological treatment is also recommended.

There is a need for development of on-site wastewater treatment technologies suitable to "dry-process'' industries, such as the wooden floor sector. Due to the nature of their activities, these industries generate low volumes of highly polluted and recalcitrant wastewaters due to washing and cleaning surfaces and machinery. Advanced oxidation processes such as Fenton and photo-Fenton are potentially feasible options for the treatment of wastewaters with not easily biodegradable pollutants. The wastewater from a wooden floor industry with initial COD value of 4956 mg/L and TOC value of 2730 mg/L was treated with Fenton (Fe/H2O2) and photo-Fenton (Fe/H2O2/UV) applying a 2-level full-factorial experimental design. The highest removals of COD and TOC (79% and 62% respectively) were achieved when photo-Fenton was applied. In conclusion, Fenton and photo-Fenton are promising treatment options for these highly recalcitrant wastewaters, photo-Fenton being a more promising option according to the results.

The objective of this investigation was to study the use of a coupled treatment (electrocoagulation(EC) and sorption/filtration treatment) with different sequencing to reduce the organic pollutantsmeasured as chemical oxygen demand (COD) of five highly polluted wastewater streamsgenerated after washing surfaces and machinery in the wooden floor industry and to evaluate,how different sequencing of these treatment units affects the overall system efficiency. On thebasis of preliminary studies, an EC reactor (1.0 L) was constructed with monopolar electrodes inparallel connection in an array of four Al electrodes with surface area of 93.2 cm2and an appliedcurrent density of 161 A m–2. This reactor was coupled to a sorption/filtration unit with coalactivated carbon. The EC reactor was tested in two different sequences (before and after the sorption/filtration unit). The overall COD reduction varied from 2% ± 0.5% to 77% ± 2.9%, dependingon the sequence and the treated wastewater stream. The best result from efficiency andoperational viewpoints was obtained with the EC reactor placed after the sorption/filtrationcolumn. The increase in efficiency is likely to be due to the removal by sorption in the activatedcarbon of compounds that interfere with EC. Additionally, as desired, the use of EC before thesorption unit extended the activated carbon lifetime.