This paper reviews the ecological environment protection measures of Chinese rural hydropower development schemes. China’s rapid economic growth is making great energy demands and developing rural hydropower currently provides 30.4 GW annually. There is a conflict of interest between hydropower development and ecological and environmental protection. Potential problems include changes in hydrological condition, eutrophication, downstream nutrient reduction, sediment deposition, aquatic ecosystem alteration, and ecological water demand variation. Since most of the rural hydropower resources are located in ecologically fragile regions, it is significantly more important that ecological environment protection is being considered. As exploitation of rural hydropower has developed in China, ecological environment protection schemes had to adapt to changing boundary conditions. Due to improvements in environmental protection management, various environmental impact assessment methods have been applied including fuzzy analysis hierarchy process, ecological scheduling, pressure-state-response, and ecological environment evaluation index. The latter index can both qualitatively and quantitatively analyze ecological environment impacts and has become the most frequently used tool in the evaluation of rural hydropower exploitation. To rebalance the interests regarding energy generation and environmental protection, countermeasures originating from different aspects such as engineering design optimization, management improvement, and ecological restoration were recommended to promote ecological environment protection. The review concludes that by taking ecological environment protection into consideration in the whole rural hydropower plan, adopting ecological scheduling to guarantee river ecological water demand and implementing ecological restoration in watershed management are the most effective approaches in furthering sustainable development of rural hydropower.

Slaughterhouse waste water (SHW) is discarded as unused disposals into the environment every day. The objective of the present study is to explore the possibility on the utilization of SHW for the preparation of culture media to produce mosquitocidal bacterium (Bacillus thuringiensis subsp. israelensis). This would help to overcome the problem of dumping SHW in to environment. A judicial combination of SHW with a mineral salt (MnCl2) was made to produce an enhanced level of bacterial production when compared with other culture media including conventional medium (Luria Bertani, LB). A complete degradation of SHW by the bacteria was observed. The biomass yield, bacterial growth, toxin production, and larvicidal activity against mosquito vectors were satisfactory. Cell mass yield of 4.55 gm l−1 (dry wt) and larvicidal activity of 0.006 mg ml−1 and 0.026 mg ml−1 at LC50 and LC90 levels were observed, respectively, against the filarial vector of Culex quinquefasciatus with bacteria grown in SHW + MnCl2. The B. thuringiensis subsp. israelensis also controlled the larvae in the field significantly for three weeks (>90% mortality) and the effect was comparable with LB. Cost-analysis for production of B. thuringiensis subsp. israelensis showed that it is more economical. Thus, this study suggested the dual benefit of efficient production of mosquitocidal toxin and management of slaughterhouse wastewater.

Clogging is the main operational problem associated with horizontal subsurface flow constructed wetlands (HSSF CWs). The measurement of saturated hydraulic conductivity has proven to be a suitable technique to assess clogging within HSSF CWs. The vertical and horizontal distribution of hydraulic conductivity was assessed in two full-scale HSSF CWs by using two different in situ permeameter methods (falling head (FH) and constant head (CH) methods). Horizontal hydraulic conductivity profiles showed that both methods are correlated by a power function (FH = CH0.7821, r 2 = 0.76) within the recorded range of hydraulic conductivities (0–70 m/day). However, the FH method provided lower values of hydraulic conductivity than the CH method (one to three times lower). Despite discrepancies between the magnitudes of reported readings, the relative distribution of clogging obtained via both methods was similar. Therefore, both methods are useful when exploring the general distribution of clogging and, specially, the assessment of clogged areas originated from preferential flow paths within full-scale HSSF CWs. Discrepancy between methods (either in magnitude and pattern) aroused from the vertical hydraulic conductivity profiles under highly clogged conditions. It is believed this can be attributed to procedural differences between the methods, such as the method of permeameter insertion (twisting versus hammering). Results from both methods suggest that clogging develops along the shortest distance between water input and output. Results also evidence that the design and maintenance of inlet distributors and outlet collectors appear to have a great influence on the pattern of clogging, and hence the asset lifetime of HSSF CWs.

The modification effects of hematite with aluminum hydroxide were investigated on the removal of fluoride ions from water using batch experiments. The effects of pH, contact time, fluoride concentration, and the dose of sorbent on the sorption of fluoride ions by a modified hematite were studied. Characterization of hematite before and after the modification with aluminum hydroxide was studied by X-ray diffraction, scanning electron microscope, and Brunauer–Emmett–Teller. Equilibrium was reached in 48 h of contact time and the maximum sorption of fluoride was found in the pHeq range between 2.34 and 6.26. The Elovich model described the kinetic sorption processes and the Langmuir–Freundlich model, the sorption isotherm process. These results indicated that the sorption mechanism was chemisorption on a heterogeneous material.

This study investigated the encapsulation and photocatalysis of chlorophenol compounds in water using porphyrin-(polystyrene-b-2-dimethylaminoethyl acrylate) star polymer. The chloride ions generated during photocatalytic process were identified and quantified. 2,4,6-Trichlorophenol, pentachlorophenol, and 2,4-dichlorophenol were satisfactorily decomposed in the photoreactor using porphyrin-(polystyrene-b-2-dimethylaminoethyl acrylate) star polymer, with removal efficiencies of 2,454, 498, and 760 mg/g of porphyrin-(polystyrene-b-2-dimethylaminoethyl acrylate) star polymer. The half-life times reached around 30 min, with the exception of that for 2,4-dichlorophenol. The star polymer-impregnated porphyrin is a promising photocatalyst for the removal of chlorophenols.

Tests were conducted to study the influence of non-ionic surfactants Triton X-100 and Tween 80 on the removal of mixed contaminants from a sandy soil using phytoremediation. Cd(II) and Pb(II) were used to form the inorganic contaminant, while used engine oil was selected to form the organic contaminant. The Indian mustard (Brassica juncea) plant was the plant chosen for phytoremediation of the sandy soil that contained the mixed contaminant. Thirty days after the plants were grown in the greenhouse, surfactants were applied to test pots in which the soil had been spiked with 50 mg kg−1 of CdCl2, 500 mg kg−1 of PbCl2 and 500 mg kg−1 of used engine oil. Two control tests were conducted in this study. Planted and unplanted control tests were conducted using soil without surfactants. Following these tests, the tests were completed using the plants and surfactants at different concentrations. Test results showed that Triton X-100 and Tween 80 at concentrations higher than their critical micellar concentration enhanced Cd(II) and Pb(II) accumulation in the plant roots. Further, test data showed that translocation of contaminants to plant shoots occurred for Cd(II) but not for Pb(II). At the same concentrations, Tween 80 was more effective than Triton X-100 in facilitating rhizodegradation of used engine oil. This study demonstrates that simultaneous phytoremediation of Pb(II), Cd(II) and oil can be enhanced by using non-ionic surfactant Tween 80. Leaching test results indicated that the enhanced phytoremediation could remove the mixed contaminants safely from the point of view of limiting groundwater contamination.

Using an automated gas chromatography system coupled with an online sampling/thermal desorption module, benzene, toluene, and their alkylated derivatives were measured in Las Vegas, Nevada from 3 July to 28 August 2008. The levels of hydrocarbons were comparable to those typically found in urban environments. Statistically significant (at 95 % level) higher concentrations were measured on mid-week days as compared with those measured during weekends. This was correlated to a local traffic pattern rather than traffic on highways. The concentrations of aromatic hydrocarbons also increased during periods when transport of smoke from wildfires in central and north California was identified by remote sensing but these levels were comparable to other days with volatile organic compounds concentrations. The high toluene/benzene ratios and the estimated photochemical age of air masses implied the contribution of other local sources. Fuel evaporation accounted for the vast majority of toluene enhanced concentrations in early July (as compared with those measured in June) for sites within the urban grid, but very little for sites located outside the urban area.

OBJECTIVE: This work aims to investigate the correlation between the photocatalytic activity determined by methylene blue bleaching (DIN 52980), stearic acid degradation, and degradation of acetone in gas phase. METHOD: The photocatalytic TiO2 coatings included in this investigation ranged from thin commercially available coatings (ActivTM and BioCleanTM) and ready to use suspensions (Nano-X PK1245) to lab-produced PVD and sol–gel coatings. XRD analysis of the photocatalytic coatings showed that all the coatings consisted of nanocrystalline anatase, although the thickness and porosity varied considerably. RESULTS: The study showed that the reproducibility of the activity measurements was good. However, more importantly, the investigation showed that there is a good correlation between the activities determined by the different methods even though the characteristics of the photocatalytic coatings and the organic probe molecules varied considerably. CONCLUSION: The overall findings of this work suggest that there is a good correlation between the investigated methods. These results are promising for the future work concerning standardization of methods for determination of the activity of photocatalytic films.

PURPOSE: The objectives of this research are to identify the functional groups and determine corresponding pK a values of the acidic sites on dried brown algae Cystoseira barbata using FTIR and potentiometric titrations, and to investigate the biosorption ability of biomass towards divalent nickel, cadmium, and lead ions. Adsorption was studied as a function of solution pH and contact time, and experimental data were evaluated by the Langmuir isotherm model. METHODS: CaCl2 pretreatment was applied to the sorbent for enhancing the metal uptake capacity. The effect of solution pH on biosorption equilibrium was investigated in the pH range of 1.5–5.0. Individual as well as competitive adsorption capacity of the sorbent were studied for metal cations and mixtures. RESULTS: The retention of the tested metal ions was mostly influenced from pH in the range of 1.5–2.5, then stayed almost constant up to 5.0, while Ni(II) uptake showed the highest variation with pH. Potentiometric titrations were performed to find the number of strong and weak acidic groups and their acidity constants. The density of strong and weak acidic functional groups in the biomass were found to be 0.9 and 2.26 mmol/g, respectively. The FTIR spectra of the sorbent samples indicated various functionalities on the biomass surface including carboxyl, hydroxyl, and amino and sulphonate groups which are responsible for the binding of metal ions. CONCLUSIONS: The capacity of the biomass for single metal ions (around 1 mmol/g) was increased to 1.3 mmol/g in competitive adsorption, Pb(II) showing the highest Langmuir intensity constant. Considering its extremely high abundance and low cost, C. barbata may be potentially important in metal ion removal from contaminated water and industrial effluents.

Concentrations of selected organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) are reported in air and surface soil in an extensive spatial survey across Azerbaijan, a country bordering the Caspian Sea with a history of OCP production and extensive use. Polyurethane foam disc passive air samplers (PAS) were deployed during October–November 2008 with soil samples collected in July 2009. Levels of Σ7PCB in ambient air were generally low (mean of 0.046 ng m−3, n = 13) and comparable to concentrations reported in countries within Eastern Europe and similar to or lower than concentrations reported in urban air in the UK and other western countries. Surprisingly, PCB concentrations in rural/background soil fell below the method detection limits at most sites, although concentrations were 0.209 and 0.071 ng Σ7PCB g−1 dry weight (dw) for two urban sites, again comparable to PCB levels measured at background sites in Europe. Levels of α-HCH, β-HCH, γ-HCH and p,p′-DDT/E were elevated in ambient air across Azerbaijan in comparison to PAS-derived concentrations reported elsewhere, with concentrations of α-HCH in air ranging from 0.085 to 2.699 ng m−3 and p,p′-DDE, 0.037–2.290 ng m−3. High concentrations of OCPs occurred at several of the urban sites and at sites in proximity to old pesticide storage facilities with concentrations in soil >0.1 μg g−1 dw for p,p′-DDE and p,p′-DDT at several sites. The ratio of p,p′-DDT/p,p′-DDE was close to unity in the soil at these sites, but elsewhere, the ratio was <1, indicating a weathered DDT pattern, which was also reflected in the air at all sites. A fugacity approach revealed the strong likelihood of net soil-to-air transfer at the majority of sites for all OCPs. The calculated annual fluxes or loading to the atmosphere from a rural/agricultural area (representing land as vineyards and cotton cultivation) were estimated to be on the order of ≈10–100 kg year−1 for the HCH isomers (including the β -isomer) and p,p′-DDE. The high levels of OCPs in soils, particularly in the vicinity of obsolete-pesticide storage facilities and at select urban sites are of concern and warrant regular monitoring activities and the development of containment or mitigation strategies.