catena-Poly[[(5-carb-oxy-2H-1,2,3-triazole-4-carboxyl-ato-κN,O)sodium]-di-µ-aqua-κO:O].

In the title coordination polymer, [Na(C(4)H(2)N(3)O(4))(H(2)O)(2)](n), the Na(I) atom is six-coordinated by one O atom and one N atom from a 2H-1,2,3-triazole-4-carb-oxy-5-carboxyl-ate ligand and four O atoms from four water mol-ecules, forming a distorted octa-hedal geometry. The Na(I) atoms are bridged by water mol-ecules into a chain structure along [100]. Inter-molecular N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds connect the chains. An intra-molecular O-H⋯O hydrogen bond between the carboxyl-ate groups is observed.

[Effect of activated sludge properties on short-term membrane fouling in submerged membrane bioreactor based on statistical analysis].

The influence of activated sludge properties on membrane fouling was investigated using statistical method. The results show that extracelluler polymeric substances (EPS), soluble microbial products (SMP), suspended solids in the supernatant (SSs), dynamic viscosity (micro), relative hydrophobicity (RH) and Zeta potential all have a significant influence on membrane permeability during microfiltration of activated sludge wastewater. The pearson's correlation coefficient (r(p)) for linear correlations between membrane fouling resistance and these sludge properties are 0.898, 0.712, 0.810, 0.691, 0.837, -0.881, respectively. The statistical results also show that SMP, micro, SSs, Zeta potential, and RH are mostly determined by EPS, indicating that EPS is the main and essential factor affecting membrane fouling in activated sludge properties. The pearson's correlation coefficient (r(p)) for linear correlations between total EPS and other sludge properties are 0.682, 0.633, 0.783, -0.953, 0.877, respectively. EPS should be controlled in the operation of membrane bioreactor to achieve a suitable permeation.

Optimizing the atmospheric sampling sites using fuzzy mathematic methods.

A new approach applying fuzzy mathematic theorems, including the Primary Matrix Element Theorem and the Fisher Classification Method, was established to solve the optimization problem of atmospheric environmental sampling sites. According to its basis, an application in the optimization of sampling sites in the atmospheric environmental monitoring was discussed. The method was proven to be suitable and effective. The results were admitted and applied by the Environmental Protection Bureau (EPB) of many cities of China. A set of computer software of this approach was also completely compiled and used.