Quantification of Industrial Wastewater Discharge From the Major Cities in Sichuan Province (China) from 2003 to 2018

Wastewater discharge is produced as a side effect of socio-economic activities and exerts severe pressure on the environment, its characteristics depend on the rate of urbanization and industrialization. We used spatial autocorrelation, environmental Kuznets curve (EKC), and logarithmic mean Divisia index (LMDI) model to study the spatial characteristics and driving factors of industrial wastewater discharge in Sichuan province (2003–2018). We showed that the amount of industrial wastewater discharge in Sichuan province for the period was reduced from 116580 to 42064.96 million tons as observed from the Moran index ranging from -0.31 to 0.30. We identified five types of the EKC (monotonically decreasing, N, inverted N, U, and inverted U shape) in 18 major cities of Sichuan province. The technical effect (from -0.28 to -16.37) can reduce the discharge of industrial wastewater, while structure effect (0.05–3.83), economy effect (0.19–7.79) and population effect (from -0.08 to 0.46) can promote the industrial wastewater discharge. Our findings suggest that industrial wastewater discharge was reduced and showed a scattered distribution characteristic in Sichuan Province from 2003 to 2018. It is necessary to strengthen technical management measures to reduce industrial wastewater discharge in Sichuan province.

Ecological State of Lake Gusinoe—A Cooling Pond of the Gusinoozersk GRES

The study of the transformation of substances in the basin of the Selenga River—the main tributary of Lake Baikal—under anthropogenic pressure and in the context of global climate change, is especially important for the lake, a globally important source of drinking water. The ecosystem of Lake Gusinoe is one of the key objects in the Selenga River basin that is exposed to significant anthropogenic pressure. This study presents the results of an analysis of water level changes and physicochemical parameters of the water mass of Lake Gusinoe; literature data from 1951 to 2017 and own data from 2017 to 2021. The water level in the lake had depended on natural factors before the Gusinoozersk GRES was launched; however, since the plant has begun using the lake as a cooling pond, its level has actually been regulated by the economic entity. Over the years, there has been a significant increase in mineralization, sulfate, sodium, fluoride and organic matter fractions resistant to oxidation. Seasonal increases in iron and manganese concentrations in water were detected. Increased concentrations of nutrients and organic matter fractions resistant to oxidation were registered at the wastewater discharge sites. Heavy metals in the bottom sediments of Lake Gusinoe accumulate mainly in the silt of the deep zone of the lake. Plants growing in the zones of influence of the Gusinoozersk GRES and Gusinoozersk wastewater discharge accumulate the largest amount of metals.

Organic Removal Treatment Using Microbubble Generator (MBG) in Eutrophic Disorder Condition

The Techno Park basin, built as an extension of a small tributary of the Code River primarily acts as a retention basin for runoff during the rainy season. It improves the quality of water that has been degraded by domestic wastewater discharge from the surrounding community. Therefore, this study aims to assess the extent to which water quality of the basin can be improved with aeration technology. The aeration technology is a Microbubble Generator (MBG) built using a 100 Watts submersible pump with three horizontal nozzles at a depth of 40 cm from the water surface. Furthermore, the profiles of dissolved oxygen (DO) concentration were measured at the basin’s inlet and outlet, as well as the depths of 1 m below surface water and the bottom of the basin. Diurnal DO was measured to investigate the causes of supersaturation. The aeration performance was also determined from the COD parameters at the inlet and outlet. Discharge measurements were then conducted on the tributary/drainage channel to the inlet basin. The result showed that the DO supersaturation concentration has been attributed to the contribution of photosynthesis from phytoplankton such as algae. Furthermore, no change in DO concentration was observed in a range of 1 m depth from the surface of the water to the bottom (0.3 - 0.14 mg-DO/l). In this eutrophic state, DO increased exponentially during the daytime hours and then decreased during the night. The daily measurement showed an increase in the average DO of 2.31 mg/l (standard deviation of 1.56 mg/l), with average CODinlet fluctuations of 18.79 mg/l (standard deviation of 13.56 mg/l) and average CODoutlet of 14.38 mg/l (standard deviation 2.94 mg/l). Due to additional DO concentration coming from eutrophication during daylight, it was not possible to make a precise assessment of the effectiveness of the MBG aerator.

New Insight Into The Spatial Autoregressive Model of Industrial Wastewater Discharge In The Yellow River Basin

This article has carried out a statistical analysis of the industrial wastewater discharge (IWD) and gross regional product (GRP) of 79 cities in the Yellow River Basin from 2003 to 2019. By calculating the Moran index of IWD and GRP, the study has found that a certain spatial autoregressive in space. There is an environmental Kuznets curve (EKC) between the environmental pollution and economic development of cities in the Yellow River Basin, and a spatial autoregressive is modelled by a set of random effects that are assigned a conditional autoregressive prior distribution. In the Bayesian environment, Markov chain Monte Carlo (MCMC) is used for inferencing, and the spatial weight matrix is ​​selected to be U-shaped matrix, and the error of the model is minimized. The parameter posterior distribution results of the model showed that the GRP did not show a significant decline. The modified EKC showed that the discharge of industrial wastewater in the entire Yellow River Basin will be reduced. Generally, cities with high pollutant emissions should learn from other cities to reduce emissions, and cities with low GRP need to increase local economic development.

Environmental and Epidemiological Aspects of V. cholerae O1 Contamination of Water Bodies in the Republic of Kalmykia

Background: Within the framework of cholera surveillance in the Russian Federation, annual isolation of nontoxigenic V. cholerae O1 strains from water bodies is registered in the Republic of Kalmykia. This fact is the rationale for the present study and analysis of data on contamination of water bodies with V. cholerae O1 with account for some environmental and quality indicators of water bodies used for recreational purposes. Objective: To study contamination of water bodies with V. cholerae O1 as a component of cholera control surveillance in the Republic of Kalmykia. Materials and methods: We used notifications issued by Offices of the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor) in the constituent entities of the Russian Federation, passports for V. cholerae O1 strains, and information from “Cholera vibrios. Russia” database for 1991–2019. Results: In the 1970s, 1980s and 1990s, several outbreaks, sporadic and single imported cases of cholera were registered in the republic. The total of 446 strains of V. cholerae O1 El Tor were isolated during the analyzed period. The PCR analysis identified them as V. cholerae O1 ctxA–tcpA– and V. cholerae O1 ctxA– tcpA+. We observed an increasing trend in the number of isolated strains with the approximation coefficient of 0.374 against its general decrease in the country in 1991–2019. Strains were isolated annually, mainly from the Elista River, Zayachy Pond and other water bodies with poor microbiological and chemical water quality parameters. V. cholerae O1 ctxA– tcpA+ were isolated mainly at the wastewater discharge sites, which indicated their imported origin, along with V. cholerae O1 ctxA– tcpA– with InDel and PCR genotypes not previously found in this region. We consider the contamination of water bodies with V. cholerae O1 ctxA– tcpA– and V. cholerae O1 ctxA– tcpA+ as prerequisites for possible deterioration of the local epidemiological situation due to cholera importation from endemic areas. Conclusion: When analyzing the pollution of water bodies in the Republic of Kalmykia with V. cholerae O1, we established a long-term annual isolation of cholera vibrios from some water bodies in the city of Elista, including Elistinka river, Zayachy and Kolonsky ponds, notorious for poor microbiological and chemical water quality indicators. The contamination was mainly attributed to domestic wastewater discharge and poorly treated effluents of sewage treatment plants into the Elistinka river within the city boundaries, as well as watercourses from hollows. This proves the imported origin of the bacterium confirmed by isolation of V. cholerae O1 ctxA– tcpA– with InDel- and PCR-genotypes not previously found in this region.

Influence of digital economy on industrial wastewater discharge: evidence from 281 Chinese prefecture-level cities

The development of digital economy affects environmental pollution emission and green sustainable development. However, the relationship between digital economy and industrial wastewater discharge has rarely been examined. This study establishes the urban digital economy evaluation index system, measures the digital economy indexes of 281 prefecture-level cities in China from 2011 to 2016, and examines the impact effect of digital economy development on industrial wastewater discharge using the system generalized method of moment method and the intermediary effects model. The empirical results indicate that the digital economy reduces the industrial wastewater discharge. As evidence shows, the digital economy significantly promotes the upgrading of industrial structure, which is an important factor affecting the industrial wastewater discharge. Additionally, the inhibiting effect of digital economy on industrial wastewater discharge is more significant in big cities. This study provides a scientific base and guidance for reducing environmental pollution emissions and promoting the development of digital economy.

Formulation of Plant Nutrient with Synbiotic Enhancement

Oleochemical wastewater discharge from the industry into water sources is one of the main causes of water pollution. A proper treatment is required before the effluent is discharged to the environment. Since the oleochemical wastewater contains nutrients and probiotics that are good for plants, it could be used as a nutrient provider for the plants instead. Therefore, the formulation of synbiotic plant nutrients from this effluent is an effective way of using the oleochemical effluent. This study aimed to formulate the plant nutrients by using industrial wastewater, which contains the synbiotic enhancement and validating the significance of the formulated plant nutrients into three types of plants; Abelmoschus esculentus (Okra), Solanum Melongena (Brinjal), and Capsicum annuum (Chilli peppers). Synbiotic is a combination of both prebiotics and probiotics that benefit the host by stimulating the growth of a limited number of health-promoting bacteria. To formulate the plant nutrient, the wastewater was filtered using a cotton cloth before the pre-biotics solution was added. Sample A (filtered wastewater was mixed with Sample B (prebiotics solution) by different percentages, namely F1 (100%:0%), F2 (75%:25%), F3 (50%:50%), F3 (25%:75%), 0%:100% (Sample A to Sample B respectively) and lastly, 50%:50% (Sample C (unfiltered wastewater) to Sample B respectively). The height of the plant and the number of leaves are measured weekly for four months. From the data, it can be seen that F3 gave significant results for the okra plant, in which it gains the highest height of plant compared to the other two plants. On the other hand, F6 give the best results for both the brinjal and the chilli plant where their leaves grow the highest from the second until the fourth month of plant growth. Hence, this research gives an added value to the wastewater, whereas the wastewater is used as the synbiotic plant nutrient enhancer and work best for the plants.

Quantification of Industrial Wastewater Discharge From The Major Cities in Sichuan Province (China) From 2003 To 2018

Wastewater discharge is produced as a side effect of socio-economic activities and exerts severe pressure on the environment, its characteristics depend on the rate of urbanization and industrialization. We used spatial autocorrelation, environmental Kuznets curve (EKC), and logarithmic mean Divisia index (LMDI) model to study the spatial characteristics and driving factors of industrial wastewater discharge in Sichuan province (2003–2018). We showed that the amount of industrial wastewater discharge in Sichuan province for the period was reduced from 116580 to 42064.96 million tons as observed from the Moran index ranging from -0.31 to 0.30. We identified five types of the EKC (monotonically decreasing, N, inverted N, U, and inverted U shape) in 18 major cities of Sichuan province. The technical effect (from -0.28 to -16.37) can reduce the discharge of industrial wastewater, while structure effect (0.05–3.83), economy effect (0.19–7.79) and population effect (from -0.08 to 0.46) can promote the industrial wastewater discharge. Our findings suggest that industrial wastewater discharge was reduced and showed a scattered distribution characteristic in Sichuan Province from 2003 to 2018. It is necessary to strengthen technical management measures to reduce industrial wastewater discharge in Sichuan province.