The hydraulic characteristics of constructed wetland are vital to its performance for pollutant removal. Hydraulic characteristics of a pilot scale vertical flow constructed wetland were studied by tracer experiments with the method of moments (MoM) analyzing. From the residence-time distribution (RTD) of tracer during the experiment, the mean detention time, average water velocity and dispersion coefficients were obtained for the constructed wetland. The results showed that the mean residence time was approximately 15% shorter than nominal residence time indicating 85% of total available pore volume was active in pollutant removal processes. The two peaks observed on the RTD curves suggested short-circuiting flows or dead zones exist in the constructed wetland. The relatively large Peclet number of 11.8 suggested that dispersive processes dominated in the tracer movement. Comparison of tracer profiles at different sampling locations indicated that large amount of tracer transported through the upper portion of the constructed wetland.

In December 2011,April 2012 and September 2012, the surface water of the Fenghe River and its tributaries were collected.The temporal variation characteristics of concentration of nitrate nitrogen (NO3-- N), ammonium nitrogen (NH4+- N), and total nitrogen (TN) in the water were studied. Combined with basin characteristics such as land use and precipitation, causes were analyzed. The results showed that NO3-- N content in water gradually increased along the direction of flow spatially, which was closely related to the spatial distribution of land use and pollution sources distribution. In dry period and flood period, the NO3-- N content in water was less than that in usual discharge period. NO3-- N content t in April,2012 reflected the nitrate nitrogen pollution characteristics in storm period. Fenghe River and its tributaries, from source to import into the Weihe River, the concentration of ammonium salt little changed, and at the most sample sites the ammonium salt concentration were not more than 1 mg/L. NO3-- N is drainage nitrogen main stable form in Fenghe River. TN content in Fenghe River system was obviously higher than that of the vclass of the surface water environment quality standard.

A detection method for organophosphorus pesticides using electrochemical sensor based on enzyme inhibition has been developed. Acetylcholine esterase (AChE) was selected to quantify the pesticides concentration in water samples due to its activity was non-competitively inhibited in the presence of pesticides. To detect parathion and dichlorvos, optimized analytical conditions were that the substrate concentration was 3mmol/L, enzyme solution concentration was 18g/L and reaction time was 20min. Under the optimized detection conditons, a detection limit of 1.2ng/mL and 0.004ng/mL for parathion and dichlorvos was obtained, respectively. The approach was rapid, simple, accurate and of high sensitivity when compared with immunoassays or chromatographic methods.

Using DTAF fluorescent staining technique, the number of bacteria and the distributions of ΣPAHs in two different drilling vertical depths of a field contaminated by PAHs are counted and analyzed. The result showed that the distributions of the number of bacteria and the ΣPAHs in the vertical depth have obvious corresponding relations, and the higher the ΣPAHs is, the more the number of bacteria would be.

In this paper, a layered media was used as substrate in a infiltration treatment system for municipal wastewater treatment. The efficiency of this system on nitrogen removal was compared with that by traditional used gravel and the surface characteristics of the layered media were analyzed using SEM. The results show that the layered media used as substrate in infiltration treatment system for wastewater treatment is more efficient on nitrogen removal than gravel. In the system, artificial soil provides storage for contaminants and bio-ceramics support the living organisms. The alternative running of reactor with 12 hours’ feeding followed by 12 hours’ break may supply changing environments between oxidative and anoxic in the system which is important for nitrogen removal.