The amounts of nitrogen and sulfur deposited in the region of the Yellow Sea in both dry and wet forms were estimated focusing on the period between 1999 and 2000. Dry deposition fluxes were obtained using concentrations from ground stations on both Korean and Chinese sides and from shipboard and aircraft measurements. Wet deposition fluxes were determined at ground stations on the Korean side. The dry deposition flux over the Yellow Sea was much greater than those for other world oceans. As a whole, the amounts of wet depositions of nitrogen and sulfur were 1.9 and 1.5 times larger than the amounts of respective dry depositions. Substantial influence from China caused by high emissions in East China and westerly wind was possibly suggested. However, the influence from nitrogen emission in Korea was also confirmed.

Agricultural reuse of treated sewage effluent (TSE) is an environmental and economic practice; however, little is known about its effects on the characteristics and microbial function in tropical soils. The effect of surplus irrigation of a pasture with TSE, in a period of 18 months, was investigated, considering the effect of 0% surplus irrigation with TSE as a control. In addition, the experiment consisted of three surplus treatments (25%, 50%, and 100% excess) and a nonirrigated pasture area (SE) to compare the soil microbial community level physiological profiles, using the Biolog method. The TSE application increased the average substrate consumption of the soil microbial community, based on the kinetic parameters of the average well color development curve fitting. There were no significant differences between the levels of surplus irrigation treatments. Surplus TSE pasture irrigation caused minor increases in the physiological status of the soil microbial community but no detectable damage to the pasture or soil.

Analytical procedures for the determination of pharmaceuticals from different therapeutic groups were proposed. These groups included the corticosteroids prednisolone and dexamethasone; the β-blockers sotalol, metoprolol, propranolol, and carvedilol; and the analgesic nonsteroidal anti-inflammatory drugs paracetamol, aspirin, metamizole, and ketoprofen. Reversed-phase ultrahigh performance liquid chromatography with an ultraviolet detector, different columns, different mobile phases, and gradient elution programmes were used to obtain the best separations within the shortest possible time. Solid-phase extraction was examined as a preconcentration step. The Oasis HLB column, with the highest recoveries (over 90% for most of the drugs), was chosen for the analysis of surface waters. Limits of detection ranged from 0.06 to 0.39 μg L⁻¹ for all drugs after optimisation of all analytical steps.

Literature reports on N₂O and NO emissions from organic and mineral agricultural soil amended with N-containing fertilizers have reached contradictory conclusions. To understand the influence of organic manure (OM) and chemical fertilizer application on N₂O and NO emissions, we conducted laboratory incubation experiments on an agricultural sandy loam soil exposed to different long-term fertilization practices. The fertilizer treatments were initiated in 1989 at the Fengqiu State Key Agro-ecological Experimental Station and included a control without fertilizer (CK), OM, mineral NPK fertilizer (NPK), mineral NP fertilizer (NP), and mineral NK fertilizer (NK). The proportion of N emitted as NO and N₂O varied considerably among fertilizer treatments, ranging from 0.83% to 2.50% as NO and from 0.08% to 0.36% as N₂O. Cumulative NO emission was highest in the CK treatment after NH ₄ ⁺ -N was added at a rate of 200 mg N kg⁻¹ soil during the 612-h incubation period, whereas the long-term application of fertilizers significantly reduced NO emission by 54-67%. In contrast, the long-term application of NPK fertilizer and OM significantly enhanced N₂O emission by 95.6% and 253%, respectively, compared to CK conditions. The addition of NP fertilizer (no K) significantly reduced N₂O emission by 25.5%, whereas applications of NK fertilizer (no P) had no effect. The difference among the N-fertilized treatments was due probably to discrepancies in the N₂O production potential of the dominant ammonia-oxidizing bacteria (AOB) species rather than AOB abundance. The ratio of NO/N₂O was approximately 24 in the CK treatment, significantly higher than those in the N-fertilized treatments (3-11), and it decreased with increasing N₂O production potential in N-fertilized treatments. Our data suggests that the shift in the dominant AOB species might produce reciprocal change in cumulative NO and N₂O emissions.

We evaluated the differences in the use of a quartz filter and a polytetrafluoroethylene (PTFE) filter as a first (F0)-stage filter in a four-stage filter-pack method. A four-stage filter-pack method can completely collect sulfur species (SO₂ and SO ₄ ²⁻ ), nitrate species (HNO₃ and NO ₃ ⁻ ), and ammonium species (NH₃ and NH ₄ ⁺ ) with little or no leakage irrespectively of the first-stage filter used. On the other hand, a seasonal variation was observed in the efficiency of collection between the quartz filter and the PTFE filter depending on the material to be collected. There was no seasonal variation in the efficiency of collection in sulfur species; in contrast, a clear seasonal variation was observed for the nitrate and ammonium species. As for NO ₃ ⁻ , the PTFE filter was more vulnerable than the quartz filter at air temperatures below 21°C, while the quartz filter was more vulnerable than the PTFE filter at air temperatures exceeding 21°C. A similar vulnerability for air temperature was observed for NH ₄ ⁺ , although the threshold air temperature was 23°C for NH ₄ ⁺ . Consequently, the evaporation loss of NO ₃ ⁻ would be mainly attributable to the volatilization of NH₄NO₃, although it is also partially due to the volatilization of NH₄Cl.

The objective of this paper is to design a pilot plant electrochemical reactor and to prove the operational concept of the electrochemical production of ferrate in situ and its online application for sewage treatment. To that end, the first part of this paper focuses on the analysis of the main engineering aspects of the reactor and the electrochemical process that affect the ferrate production, using laboratory scale experiments such as the interelectrode gap, the space-time yield, the area/volume (A/V) ratio, the current efficiency, and the energy consumption. The second part focuses on the production of ferrate using a pilot plant scale to prove the operational concept of the electrochemical generation of ferrate in situ and its online application as a step towards its full scale application for water and wastewater treatment.

This paper presents the results of physicochemical treatment on Pb-, Cu-, Sb-, and Zn-contaminated Canadian small arm firing range (SAFR) backstop soils in order to evaluate the potential of such methods for remediation of SAFR backstop soils. Remediation target for the treatment assays was to attain the Québec Department of Environment commercial C criterion or more realistically, to reach the soil burial D criterion. Two treatment lines (TL) were evaluated. TL-1, consisting of jig and Wilfley table (WT) treatments on the 0.5-3 mm and 53-500 μm soil size fractions (SF), respectively, and chemical leaching on the <53 μm SF and TL-2, consisting of jig on the 1-4 mm SF, spiral, and WT treatments on 250 μm-1 mm SF, and Kelsey jig assays on the <250 μm SF. For both TL, the untreated SF (>3 mm for TL-1; >4 mm for TL-2), and the gravimetric separation concentrates could be sent for recycling in smelter facilities. Results showed that the finer SF (<53 μm SF for TL-1; <250 μm SF for TL-2) were very difficult to treat. Even with metal removed mass proportions up to 78% for Pb, concentrations were still very high after chemical leaching; and the Kelsey jig showed deceiving metal removed mass proportions (up to 47% for Pb). In both TL, the jig and the WT showed Pb removed mass proportions up to 98% and treated mass proportions up to 77% in their respective SF. Whole process efficiencies in the cleaned soils showed that TL-1 led to the remediation of up to 65% of the initial total soil, and TL-2, 36%. TL-1 and TL-2 results showed that the WT effectively treated soils of 53 μm-1 mm SF, and the jig, soils of the 1-4 mm SF. Our study shows that gravimetric concentration techniques are very promising for the treatment of SAFR backstop soils, and further research has to be done in order to treat the SF lower than 53 μm.

This study examines the synoptic conditions controlling NOx pollution in the metropolitan area of Tel Aviv, using a semi-objective synoptic classification for the eastern Mediterranean. A day in which NOx concentration exceeded the Israeli standard in ≥1 of the seven monitoring stations was defined an “exceeding day” and in ≥5 as an “extensive exceeding day”. For 1998–2004, 19% and 3% of the days were found exceeding and extensive exceeding days, respectively, over 85% of them in the winter months, November–March. The inter-annual variation in the occurrence of the synoptic types was found to explain 72% of the variations in the number of exceeding days. A significant negative trend in the occurrence of types with high pollution potential explained the decrease of 10% per year in the number of exceeding days during 1998–2004. The Red Sea Trough, though being cyclonic system, contributed 51% of the exceeding days, while highs, though being more frequent, contributed only 35%. The “pollution potential” of a synoptic type was defined as the percentage of exceeding days belonging to this type. The majority of synoptic types with the highest pollution potential were cyclonic, most being the Red Sea Trough with western axis, with 82% potential. Our findings indicate that the identity of the synoptic system as cyclonic or anticyclonic is not the key factor for the pollution potential in the study region, but rather, the ambient atmospheric conditions they induce, i.e., high temperatures, static stability, and weak easterly offshore flow. Local processes are the direct cause of the pollution and that the role of the synoptic conditions is to enable, or even to reinforce, the supportive meso-scale processes. This study is a first step in downscaling synoptic features to local NOx pollution potential, constituting a basis for alarming against pollution events, based on the predicted synoptic conditions.

The primary purpose of water aeration is to increase the oxygen saturation of the water. This can be achieved by using hydraulic structures because of substantial air bubble entrainment at these structures. This paper reviewed the literature on hydraulic structures used in water aeration processes. The hydraulic structures were divided into two groups as the high-head flow systems and the free-surface flow systems. The high-head flow systems were circular and venturi nozzles, pipe with venturi tube, and high-head conduit, and the free-surface flow systems were weir, stepped cascade, and free-surface conduit. Air/water flow ratio and aeration efficiency in circular nozzles with air holes and venturi nozzles were significantly high. Pipes with venturi tubes showed high aeration efficiency although they had low air/water flow ratio. In high-head and free-surface conduits, almost full oxygen transfer, up to the saturation value, occurred. Forty-five degrees triangular sharp-crested weir had significantly better air/water flow ratio and aeration efficiency than other sharp-crested weir shapes. Stepped cascades, in particular nappe flow regime, were very efficient means of aeration.

This study was carried out to test ex situ growth and soil nutrient removal efficiency of 1-year-old potted willow and poplar plants. Plants were grown under two different water regimes: low irrigation—around soil field capacity (W)—and high irrigation—five times higher than field capacity (W 5). Results showed that plant productivity and water use efficiency were greater when trees were grown in the appropriate level of soil water content rather than at excessive moisture levels. Nutrient leaching was also affected by the high irrigation treatment. However, the poplar and willow clones used in this experiment showed different nutrient allocation patterns in the plant–soil–water system. The poplar clone accumulated the highest quantities of N and P in the soil. Willow accumulated N and P mainly in the biomass due to better root development under both treatments. This indicates the better performance of the willow clone in removing N and P from contaminated aquaculture wastewaters during the first growing season.