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The article presents a study that determines the toxicity of the chemical industrial wastewater from Hangu reservoir in Tianjin, China. It notes the identification of various toxicans from the industrial wastewater that came from the aging chemical industrial plant, which was less biodegradable and has complex hazardous substances, affecting the local ecological services in Hangu reservoir and the safety of the nearby residents. It also mentions the two aspects of the treatment in the aging chemical industrial wastewater that aims to ensure the development of the government's Sino-Singapore Tianjin Eco-city collaboration project with Singapore, and the safety of the residents in the area.

The adsorption of chlorimuron-ethyl in two typical northeastern Chinese soils before and after removal of organic matter and removal of organic matter plus iron/aluminum oxides was investigated using batch equilibrium methods, and the effect of pH on the adsorption was also evaluated. The adsorption kinetics were fitted well with the Elovich and pseudo-second-order kinetic models (R² = 0.973-0.985) and the adsorption isotherms conformed to the Linear, Freundlich, and Langmuir models (R² > 0.963). The mineral fraction appeared to dominate adsorption of chlorimuron-ethyl in brown earth (BE; Alfisols), while organic matter was the major component for the adsorption in black soil (BS; Moliisols). The adsorption of chlorimuron-ethyl in the original and treated soils all decreased with increasing pH. Moreover, the effect of pH on the adsorption of chlorimuron-ethyl in soil minerals was stronger than that in organic matter at acidic conditions. [ABSTRACT FROM AUTHOR]

Purpose: Chlorimuron-ethyl is a sulfonylurea herbicide widely used to control many annual broadleaf weeds, and the residue for a long period posed a heavy hazard to rotational crops or vegetables. Knowledge about effect of soil pH and organic matter on desorption processes of chlorimuron-ethyl remains obscure. In this study, desorption behavior of chlorimuron-ethyl as a function of soil pH and organic matter was investigated. Materials and methods: Two typical soils in northeastern China, brown earth (luvisols) and black soil (phaeozem), were used in this study. Soils were treated with peroxide to remove organic matter. Desorption kinetics of chlorimuron-ethyl in the original and HO-treated soils were simulated. The adsorption and desorption experiments were conducted at three different pH values with the original soils using batch equilibration methods. For the soils after having removed organic matter, the lower concentrations of adsorption were not used for desorption study because the concentrations expected were lower than the limit of detection of the method. Results and discussion: The pseudo-second-order equation could well describe the desorption kinetics and the desorption velocity increased significantly from the soils after the removal of organic matter. The desorption data were well fitted with the Freundlich isotherm with high regression coefficients ( R > 0.97). Besides, the apparent hysteresis was observed for the desorption of chlorimuron-ethyl from the two soils, and the desorption from black soil was weaker than that from brown earth due to the higher content of organic matter and clay, and lower proportion of sand. The desorption of chlorimuron-ethyl from both soils became more difficult with an increase in the initial concentrations as a result of the gradient effect of concentrations. The degree of hysteresis increased as soil pH increased due to the strengthened binding energy of adsorption interactions. Conclusions: The desorption of chlorimuron-ethyl from brown earth and black soil was significantly hysteretic, and the degree of hysteresis was greater for black soil than for brown earth. The increase of soil pH would enhance the retention of chlorimuron-ethyl and thus effectively retard chlorimuron-ethyl from entering the aqueous phase. The method of removing organic matter by HO treatment was not fit for researching effect of organic matter on the desorption of chlorimuron-ethyl from original soils. [ABSTRACT FROM AUTHOR]

Purpose: Organic dyes have been turned into an important emerging type of chemical pollutants with the development of rural textiles, synthetic dye, printing, and dyeing industries and the continuous release from washing fabrics and clothes in recent decades. In order to assess ecological risk of reactive X-3B red dye as a typical dye, the adsorptive and desorptive traits of the dye in soils were investigated and the environmental factors influencing those processes were examined and discussed. Materials and methods: Adsorptive and desorptive isotherms and dynamics of reactive X-3B red dye as a typical emerging pollutant were investigated by the standard batch experiments using four typical soils in China including relatively clean brown earth (burozem), drab soil (cinnamon soil), paddy soil (aquorizem), and red soil (krasnozem) and calculated by mathematical models using the Microsoft Excel software. Results and discussion: It was suggested that the adsorptive behavior of reactive X-3B red dye by the four soils can basically be described using the Langmuir equation, and their maximum adsorbing capacity was in the sequence paddy soil > red soil > brown earth > drab soil. The adsorption could be divided into four stages including high-speed adsorption, slowdown adsorption, tardiness adsorption, and zero-approaching adsorption. It was also indicated that the adsorption ability of the dye decreased with the reduction in soil organic matter or air temperature and under neutral, runny, or unwatered conditions. The increase of desorption was observed with the decrease of soil organic matter and the increase of air temperature or soil moisture, while desorption was inhibited by the acidification or basification of soils. The comparative study validated that the basic adsorption–desorption laws of the dye at high concentrations were basically consistent with those at low concentrations. Conclusions: It could be concluded that reactive X-3B red dye has the potential properties of persistent organic pollutants with high ecological risk, and its release from contaminated soils and uptake by crops can be disturbed and changed by human activities. [ABSTRACT FROM AUTHOR]

In order to solve environmental problems resulting from ammonia released into the atmosphere, the emission of ammonia contamination from monosodium glutamate (MSG) production was quantitatively observed, and the relationships with relevant influencing factors (ammonium-N, nitrate/nitrite-N and pH) were statistically analyzed. The results indicated that the release of gaseous ammonia from MSG production including the treatment and discharge of wastewater was highly dependent on the technical processes utilised. The flux of ammonia released from the fermentation workshop was highest, up to 8.98 × 10 mg m min, and the flux from the sugar-refining workshop was lowest, only 85.1 mg m min. The release of gaseous ammonia during the whole MSG production was significantly proportional to the concentration of ammonium-N in the discharged solution, and exponentially proportional to the concentrations of nitrate–nitrogen and nitrite-nitrogen in the discharged solution. Although there was no linear relationship between the flux of ammonia released during the whole MSG production and pH values in the discharged solution, pH was significantly related to the flux of ammonia released during the treatment and discharge of wastewater. [ABSTRACT FROM AUTHOR]

Soil pollution by cadmium has been a long standing ecological problem in Zhangshi Irrigation Area, Shenyang, China, as a result of the 30-year practice of irrigation with wastewater containing high levels of heavy metals. To evaluate the adverse impact of cadmium contamination on soil ecosystems, the responses of soil microbiota to both long-term and short-term cadmium stress were studied by molecular microbial community profiling with denaturating gradient gel electrophoresis (DGGE) analysis. Our results show that soil characteristics and nutrient conditions were likely more important than cadmium toxicity in shaping the soil bacterial community structure in the long term. In comparison, soil microbial genetic diversity was shown to be more closely correlated to cadmium levels under short-term cadmium stress, with the highest microbial genetic diversity occurring at mild cadmium stress conditions, which might be attributed to the enrichment of metal-resistant microbial populations through mechanisms of competitive selection and genetic adaptation. In contrast, severe cadmium stress likely presented a condition that fewer microbial populations could survive, thus leading to reduced microbial genetic diversity. [ABSTRACT FROM AUTHOR]

This article discusses cadmium and lead speciation in the soil of northeast China as affected by the level of metal loading, aging time and the interaction between the two metals. The concentrations of these heavy metals were analyzed using an atomic absorption spectrophotometer. Sequential extraction was developed for fractions defined as SE (water soluble plus exchangeable); WSA (bound to carbonate or weakly specifically adsorbed); OX (bound to Fe or Mn oxides); OM (bound to organic matter) and RES (residual). According to the authors, good linear relationships were obtained between the soluble exchangeable fraction content of metals in soil and the ionic impulsion. Apparently, for longer aging times there is a movement of cadmium and lead to the weakly specifically absorbed and residual fractions.

Presents a study which investigates the sensitivities to marine pollution of marine organisms in the Zhoushan Sea area of China, through systematic collection of affected marine organisms. Marine ecosystem in Zhoushan Sea Waters; Materials and methods; Discussion of results.

From eastern to western areas, per- and polyfluoroalkyl substances (PFASs) were detected at substantial levels in the outdoor dust across mainland China Urban samples generally showed higher levels compared with those of rural samples. Compared with neutral PFASs, ionizable PFASs (C4-Cl2 perfluoroalkyl carboxylic acids and C4/C8 perfluoroalkyl sulfonic acids) were more abundant, with the highest total concentration up to 1.6 x 10² ng/g and perfluorooctanoic acid (PFOA) being a predominant analogue. Fluorotelomer alcohols (FTOHs) and polyfluoroalkyl phosphoric acid diesters (DiPAPs) were both detected in most samples with total concentrations of 0.12-32 and 0.030-20 ng/g, respectively. Perfluorooctane sulfonamidoethanols/sulfonamides (FOSE/As) were detected at low frequencies (<30%). In addition to partitioning to organic moiety, specific adsorption onto mineral particles can be important for PFASs to bind onto outdoor dust, especially for short-chain ionizable PFASs. The eastern plain areas were characterized by a higher contribution of long-chain ionizable PFASs; whereas the western high plateau areas were characterized by the dominating contribution of short-chain analogues. The difference suggests that the long-range atmospheric transport potential of PFASs from source regions to the inland is probably limited by die increase in altitude, and different sources from adjacent regions may influence the western border area of China. [ABSTRACT FROM AUTHOR]

Despite the frequent detection of benzotriazoles (BTRs) and benzothiazoles (BTHs) in groundwater and surface-water environments, knowledge on their occurrence and profile in tap water is still scarce. This study demonstrates widespread occurrence of these compounds in tap water from 51 major cities in China, which have ranges of

The occurrence of antibiotics and antibiotic resistance genes (ARGs) was quantified in water and sediment samples collected from a 72 km stretch of the Haihe River, China. Tetracycline resistance genes (tetW, tetQ, tetQ, tetT, tetM, tetB, and tetS) were not detected by quantitative PCR in many samples. In contrast, sul1 and sul2 (coding for sulfonamide resistance) were present at relatively high concentrations in all (38) samples. The highest ARG concentrations detected were (7.8 ± 1.0) × 109 copies/g for sul1 and (1.7 ± 0.2) × 1011 copies/g for sul2, in sediment samples collected during the summer. The corresponding total bacterial concentration (quantified with a universal 16S-rDNA probe) was (33 ± 0.4) × 1012 cella/g. Sul1 and sul2 concentrations in sediments were 120-2000 times higher than that in water, indicating that sediments are an important ARG reservoir in the Haihe River. Statistical analysis indicated a positive correlation between the relative abundance of these ARCs (i.e., sul1/16S-rDNA and sul2/16S-rDNA) and the total concentration of sulfamethoxazole, sulfadiazine, plus sulfachlororyridazine, suggesting that sulfonamides exerted selective pressure for these ARGs. A class 1 integron was implicated in the propagation of sul1. Overall, the widespread distribution of sulfonamide ARGs underscores the need to better understand and mitigate their propagation in the environment and the associated risks to public health. [ABSTRACT FROM AUTHOR]