Wastewater Discharge In China Research Articles

Incentive mechanism for allocating wastewater discharge responsibility based on cooperative game theory

Clarifying responsibility for wastewater discharges and enhancing reasonable allocation of wastewater emission permits are critical for controlling wastewater discharge in the context global sustainable development plans. The traditional wastewater allocation approach has several drawbacks, such as sub-regional "free-riding," imbalanced regional development and demand, and unfair allocation mechanism. This study developed a model based on cooperative game theory to allocate responsibility for wastewater discharge in China's Tuojiang River Basin. In this model, the level of impact of a watershed sub-region on the water environment is determined, according to which the wastewater discharge responsibility is assigned. The stronger the impact of upstream sub-regions on downstream wastewater discharge, the greater the responsibility for wastewater discharge. Furthermore, by implementing the wastewater cooperation model, sub-regions can monitor and incentivize each other, through which wastewater discharges can be reduced by 16.38%, compared to the baseline mechanism and overall discharges can be reduced by 5007.99 tons. This study provides recommendations for appropriate management authorities to improve the allocation of wastewater discharge responsibility at the watershed scale.

Decomposing the effect of technology on wastewater and related pollutants discharges in China

Technology assumes a pivotal role in both water conservation and pollution reduction. This study deconstructs technology into three categories: source water-saving technology (SST), process control technology (PCT), and end-of-pipe removal technology (ERT). Employing the extended IPAT and decomposition approach, it assesses the diverse impacts of these technologies on wastewater discharge in China. The findings reveal a notable decrease in industrial water consumption and wastewater discharge, yet a significant increase in the domestic sector. This increase is largely attributed to socio-economic factors. Nevertheless, the effects of SST, PCT, and ERT on wastewater discharge vary across sectors, pollutants, and regions. SST and ERT play a crucial role in diminishing industrial wastewater discharge, whereas PCT leads to an increase in approximately half of the regions. Moreover, SST and PCT tend to escalate domestic wastewater discharge in most regions, while ERT exerts a mitigating influence across the majority of regions.

The impact of metal waste imports on industrial wastewater discharge in China

Once the world’s largest waste importer, China alleviated the shortage of raw materials in its related industries; however, such activity incited more prominent ecological and environmental problems. Based on several major sample databases from 2003 to 2006—including the China Industry Business Performance Data, Customs Trade Database, and scrap metal commodity data from Harmonized System code catalogues—this paper establishes a city-level panel data model and a mediation effect model to examine the impact of scrap metal imports on industrial wastewater discharge in China as well as the mechanism of this impact. Furthermore, this paper analyses the impact of scrap metal imports on Chinese enterprises’ pollution fees from the perspective of enterprises to ensure the robustness of results based on the China Industry Business Performance Data in 2004. Results show that scrap metal imports significantly increase industrial wastewater discharge in China and exacerbate environmental pollution. Specifically, results indicate that if scrap metal imports increase by 1%, wastewater discharge will significantly increase by approximately 0.015–0.198 percentage points. In terms of the impact mechanisms, by driving the development of metal smelting, scrap metal imports have increased both the metal smelting rate in total industrial output and cities’ reliance on metal smelting, which has significantly increased industrial wastewater discharge in China. Finally, the robustness test demonstrates that increasing metal waste imports will significantly increase the discharge of pollutants by Chinese industrial enterprises, thereby increasing their pollution fees. Specifically, the results of the Ordinary Least Square and IV 2SLS model indicate that if scrap metal imports increase by 1%, industrial enterprises’ pollution fees will significantly increase by 1.081–11.3 million yuan. On the premise of protecting the environment, the Chinese government can import recyclable scrap metal commodities such as high-grade waste copper and aluminium that can meet the product quality standards for enterprises. Additionally, the Chinese government should raise the standards of the metal smelting and recycling industries, reduce the discharge of industrial waste water, and strive to improve the ecological environment.

Changes in water use and wastewater generation influenced by the COVID-19 pandemic: A case study of China

This paper examines and projects the water use and wastewater generation during and after the SARS-CoV-2 (COVID-19) in China, and discussed the water use/wastewater generation pattern changes among different sectors. Existing studies on the impact of pandemic spread-prevention measures on water consumption and wastewater treatment during the pandemic are reviewed. The water use and wastewater discharge in China through the COVID-19 period are then projected and analyzed using Multivariate Linear Regression. The projection is carried out for years 2019–2023 and covers an (estimated) full process of pre-pandemic, pandemic outbreak, and recovery phase and provides essential information for determining the complete phase impact of the COVID-19. Two scenarios, i.e. the recovery scenario and the business as usual scenario, are set to investigate the water use and wastewater generation characteristics after the pandemic. The results imply that in both scenarios, the water use in China shows a V-shaped trend from 2019 to 2023 and reached a low point in 2020 of 5,813✕108 m3. The wastewater discharge shows an increasing trend throughout the COVID period in both scenarios. The results are also compared with the water consumption and wastewater generation during the SARS-CoV-1 period. The implication for policymakers is the possible increase of water use and wastewater discharge in the post COVID period and the necessity to ensure the water supply and control of water pollution and wastewater discharge.

Decoupling of wastewater eco-environmental damage and China's economic development

Wastewater pollution has been considered as a prominent bottleneck restricting global sustainable development. China is one of the largest discharges and eco-environmental damages of wastewater in the world. Through analyzing wastewater discharge data using emergy method in China from 2011 to 2017, the wastewater eco-environmental damage of 31 provinces is calculated with GDP and area to reveal the fundamental origins of inflection point of wastewater discharge in China. Studies results show that, (i) Chinese “12th Five-Year Plan” (2011–2015) is a watershed in wastewater discharge, and the eco-environment damages caused by China's wastewater accounted for more than 1/4 of GDP; (ii) China has the great potential to reduce eco-environment damages of 1.73 trillion $/year; (iii) In 2016 and 2017, wastewater eco-environmental damage has decreased by about 50% compared with that in 2015, and the effect of government policies was remarkable. We conclude that decoupling of China's economic development form eco-environmental damages of wastewater is began to appear, the strict formulation and implementation of China's environmental policies and the green upgrading of industrial structure are main driving forces, and it is little correlation with economic slowdown. This study offers the detailed list of China wastewater pollution and reveals the relationship between wastewater eco-environmental damages and economic development, and shows the experience and achievements of the Chinese government in the treatment of wastewater pollution, which provides a useful reference for the treatment of wastewater pollution in the world.

Evaluating spatial characteristics and influential factors of industrial wastewater discharge in China: A spatial econometric approach

Although China’s total industrial wastewater discharge (IWD) has shown a downward trend in recent years, it is still at a relatively high level. Based on the panel data gathered from 30 Chinese provinces from 2000 to 2017, this study attempts to investigate the spatial characteristics and influential factors which could potentially pose primary contribution to the IWD. Specifically, the spatial autocorrelation test is used to depict the spatial characteristics of IWD. All statistical test results seem to support that using the spatial Durbin model (SDM) with spatial and time period fixed effects could be properly utilized in assessing over the factors of being considered of affecting the IWD. Those assumed factors involve with economic development, population growth, industrial structure, intensity of environmental governance and the level of technological innovation. The results show that the provincial industrial wastewater effluents exhibit a significant spatial autocorrelation as well as agglomeration characteristics. The relationship between IWD and GDP shows up an inverted U-shape, suggesting a typical dynamic of the Environmental Kuznets Curve (EKC). Perhaps, due to a lagging effect, the government’s investments in IWD governance at the current stage is somehow positively correlated with the volume of IWD while technological innovation and industrial structure are negatively correlated with IWD, and yet it appears no connection between population growth and IWD. Furthermore, the estimated direct and indirect effects indicate that economic development, technological innovation, and environmental governance intensity all impose negative spatial spillover effects on IWD. However, it seems to present a significant positive spatial spillover effect being exerted by the industrial structure. Accordingly, we put forward the general measures and specific measures to address China’s IWD problems.

Prediction of Major Pollutants Discharge from Wastewater in 31 Cities of China

A large amount of wastewater discharge has seriously damaged China's water environment, so it is very significant to accurately predict the future trend of wastewater discharge and pollutants discharge in wastewater. In this paper, the grey prediction model with fractional order accumulation is adopted to predict the discharge of wastewater, chemical oxygen demand and ammonia nitrogen from wastewater in 31 cities of China from 2020 to 2030. The predictive results indicate that the discharge of industrial wastewater, chemical oxygen demand and ammonia nitrogen will decrease in more than 50% of the cities. However, domestic sewage discharge in more than 50% of the cities will show an upward trend. According to the predictive results, reasonable suggestions can be put forward for the effective control of wastewater discharge in China.

Decomposition and attribution analysis for assessing the progress in decoupling industrial development from wastewater discharge in China

China’s strategy of greening industrial development aims to decouple industrial growth from industrial wastewater discharges (IWDs). This study combines decoupling analysis, decomposition analysis, and attribution analysis to support this goal. First, the decoupling analysis is employed to explore the degree of decoupling between industrial growth and IWDs in China, as well as across 30 provinces, from 2000 to 2015. Next, a decomposition analysis focusing on the change in industrial wastewater discharge intensity (IWDI) is performed to reveal the factors influencing decoupling trends. Then, attribution analysis is used to attribute contributions of these factors to different regions. Our decoupling results indicate an increasing decoupling trend between industrial output and IWDs in China in the past 15 years. Meanwhile, there is a convergence in decoupling degrees among provinces. Decomposition results reveal that water intensity plays a dominant role in promoting decoupling, while the wastewater discharge coefficient negatively impacted decoupling before 2005 but contributed to decoupling later on. Regional attribution results indicate provinces in South China have exerted more efforts in both water saving and wastewater treatment during the study period. Water scarce provinces in North China performed better in terms of water saving, while more developed and water-rich provinces in South China performed better in wastewater treatment. This paper suggests targeted policy methods at province level.

Forecasting China's wastewater discharge using dynamic factors and mixed-frequency data

Forecasting wastewater discharge is the basis for wastewater treatment and policy formulation. This paper proposes a novel mixed-data sampling regression model, i.e., combination-MIDAS model to forecast quarterly wastewater emissions in China based on dynamic factors at different frequencies. The results show that a significant auto-correlation for wastewater emissions exists and that water consumption per ten thousand gross domestic product is the best predictor of wastewater emissions. The forecast performances of the combination-MIDAS models are robust and better than those of the benchmark models. Therefore, the combination-MIDAS models can better capture the characteristics of wastewater emissions, suggesting that the proposed method is a good method to deal with model misspecification and uncertainty for the control and management of wastewater discharge in China.

Double decoupling effectiveness of water consumption and wastewater discharge in China's textile industry based on water footprint theory.

As a traditional pillar industry in China, the textile industry has been intensifying the pressure of the water resource load and its reduction of water environment emissions over the years. Decoupling water resource consumption and wastewater discharge require decoupling from economic growth to realise the sustainable development of the textile industry. On the basis of water footprint and decoupling theories, this paper analysed the water consumption decoupling, wastewater discharge decoupling, as well as the double decoupling of water consumption and wastewater discharge of China’s textile industry and its three sub-industries (Manufacture of Textile, Manufacture of Textile Wearing and Apparel, Manufacture of Chemistry) from 2001 to 2015. In those years, the sum of the decoupling index in the double-decoupling years is 249, lower than that in high-decoupling years of water consumption (250) and wastewater discharge (325). Compared with the decoupling of water consumption and of wastewater discharge, the double decoupling is lower, which proves that the conditions for realizing double decoupling are stricter. The double decoupling analysis of water consumption and wastewater discharge, namely, the overall consideration of water resource consumption and water environment pollution, could be used to more effectively promote the realisation of water decoupling in the textile industry.

Water consumption and wastewater discharge in China’s steel industry

ABSTRACTChina’s steel industry is one of the major water consuming and wastewater discharge-producing industries. Based on a water flow model, this study provides reasonable and clear definitions of water usage indexes for steel production. Using a survey of key producers, the status and problems of water consumption and wastewater discharge in Chinese steel industry are analyzed. The developments of water conservation and emission reduction are divided into three different stages, and present a slide decreasing curve. At the process level, coking is the heaviest pollution unit, while ironmaking and steelmaking are key parts of water consumption. Although the water resource efficiency has been significantly improved, the water usage level of key producers in China has exceeded the average world steel level; however, it is still lower than other advanced countries. Therefore, some measures and recommendations need to be implemented for Chinese steel industry to save water and reduce emissions.

Spatial Characteristics and Driving Factors of Provincial Wastewater Discharge in China

Based on the increasing pressure on the water environment, this study aims to clarify the overall status of wastewater discharge in China, including the spatio-temporal distribution characteristics of wastewater discharge and its driving factors, so as to provide reference for developing “emission reduction” strategies in China and discuss regional sustainable development and resources environment policies. We utilized the Exploratory Spatial Data Analysis (ESDA) method to analyze the characteristics of the spatio-temporal distribution of the total wastewater discharge among 31 provinces in China from 2002 to 2013. Then, we discussed about the driving factors, affected the wastewater discharge through the Logarithmic Mean Divisia Index (LMDI) method and classified those driving factors. Results indicate that: (1) the total wastewater discharge steadily increased, based on the social economic development, with an average growth rate of 5.3% per year; the domestic wastewater discharge is the main source of total wastewater discharge, and the amount of domestic wastewater discharge is larger than the industrial wastewater discharge. There are many spatial differences of wastewater discharge among provinces via the ESDA method. For example, provinces with high wastewater discharge are mainly the developed coastal provinces such as Jiangsu Province and Guangdong Province. Provinces and their surrounding areas with low wastewater discharge are mainly the undeveloped ones in Northwest China; (2) The dominant factors affecting wastewater discharge are the economy and technological advance; The secondary one is the efficiency of resource utilization, which brings about the unstable effect; population plays a less important role in wastewater discharge. The dominant driving factors affecting wastewater discharge among 31 provinces are divided into three types, including two-factor dominant type, three-factor leading type and four-factor antagonistic type. In addition, the proposals aimed at reducing the wastewater discharge are provided on the basis of these three types.

An Analysis of Economic Growth and Industrial Wastewater Pollution Relations in China

This paper investigates the relationship between income growth and the trend in industrial wastewater discharge in China during the period 1981-2007. For the data encompassing all the provinces over the entire period considered, both an inverted U-shaped EKC and an N-shaped EKC are statistically significant. An analysis dividing provinces into rich and poor groups reveals that the EKC relations are mainly governed by the rich province group. The EKC relations for the poor province group are either not found or are statistically weak. A further analysis based on dividing the data into before and after the year 2000 is in favour of the quadratic EKC model. The results of this study show that the relationships between a given pollutant and income are temporal and spatial specific depending on the driving forces behind. This implies that results derived from one study for certain regions/countries and for a specific time period may not be generalized for other regions/countries and extrapolated to other periods.

Toxicity evaluation of wastewater collected at different treatment stages from a pharmaceutical industrial park wastewater treatment plant

The toxicity of water-receiving bodies, the effluent and other treatment stages in wastewater treatment plants has recently been of interest to the public due to the lack of a regulated toxicity-based index for wastewater discharge in China. This study aimed to evaluate the conventional pollution parameters and toxicities of wastewaters collected at different treatment stages from a pharmaceutical industrial park wastewater treatment plant through dehydrogenase activity (DHA) and bioluminescent bacteria (Vibrio qinghaiensis) tests. The results of an analysis of conventional parameters indicated that the total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), ammonia nitrogen (NH3N), and total phosphorus (TP) were largely removed after various treatments. However, the TN, NH3N and COD still exceeded the regulated standards. The tested pharmaceutical park effluents were mainly polluted with organic pollutants and nitrogenous. The toxicity test results indicated that the toxicities could be markedly reduced after treatment, with the toxicities of two out of the six effluent samples at different treatment stages being greater than the influent toxicity. Spearman’s rank correlation coefficients indicated a significantly positive correlation between the toxicity values obtained using the DHA and Vibrio qinghaiensis tests. Compared with the DHA measurement, the Vibrio qinghaiensis test was faster and more sensitive. Meanwhile, the toxicity indicators were significantly and positively correlated with the TSS, TN, TP and COD concentrations. These results may aid the understanding of the toxicity of pharmaceutical industrial park wastewaters and toxicity removal using the treatment techniques that are currently utilized in China.

Reduction in toxicity of wastewater from three wastewater treatment plants to alga (Scenedesmus obliquus) in northeast China

The toxicity of municipal wastewater to the receiving water bodies is still unknown, due to the lack of regulated toxicity based index for wastewater discharge in China. Our study aims at gaining insight into the acute toxic effects of local municipal wastewater on alga, Scenedesmus obliquus. Four endpoints, i.e. cell density, chlorophyll-A concentration, superoxide dismutase (SOD) activity and cell membrane integrity, of alga were analyzed to characterize the acute toxicity effects of wastewater from municipal wastewater treatment plants (WWTPs) with different treatment techniques: sequencing batch reactor (SBR), Linpor and conventional activated sludge. Influent and effluent from each treatment stage in these three WWTPs were sampled and evaluated for their acute toxicity. Our results showed that all three techniques can completely affect the algal chlorophyll-A synthesis stimulation effects of influent; the algal cell growth stimulation effect was only completely removed by the secondary treatment process in conventional activated sludge technique; toxic effects on cell membrane integrity of two influents from WWTPs with SBR and conventional activated sludge techniques were completely removed; the acute toxicity on SOD activity was partially reduced in SBR and conventional activated sludge techniques while not significantly reduced by Linpor system. As to the disinfection unit, NaClO disinfection enhanced wastewater toxicity dramatically while UV radiation had no remarkable influence on wastewater toxicity. Our results illustrated that SOD activity and chlorophyll-A synthesis were relatively sensitive to municipal wastewater toxicity. Our results would aid to understand the acute toxicity of municipal wastewater, as well as the toxicity removal by currently utilized treatment techniques in China.

Sensitivity of Chinese industrial wastewater discharge reduction to direct input coefficients in an input-output context

Industrial wastewater discharge in China is increasing with the countrys economic development and it is worthy of concern. The discharge is primarily relevant to the direct discharge coefficient of each sector of the economy, its direct input coefficient and the final demand in input-output models. In this study, we calculated the sensitivity of the reduction in the Chinese industrial wastewater discharge using the direct input coefficients based on the theory of error-transmission in an input-output framework. Using input-output models, we calculated the direct and total industrial wastewater discharge coefficients. Analysis of 2007 input-output data of 30 sectors of the Chinese economy and of 30 provincial regions of China indicates that by lowering their direct input coefficients, the manufactur- ers of textiles, paper and paper products, chemical products, smelting and metal pressing, telecommunication equipment, computers and other electronic equipment will significantly reduce their amounts of industrial wastewater discharge. By lowering intra-provincial di- rect input coefficients to industrial sectors themselves of Jiangsu, Shandong and Zhejiang, there will be a significant reduction in indus- trial wastewater discharge for the country as a whole. Investment in production technology and improvement in organizational effi- ciency in these sectors and in these provinces can help lessen the direct input coefficients, thereby effectively achieving a reduction in industrial wastewater discharge in China via industrial restructuring.

Situation analysis of China's wastewater discharge

Great progress has been made in reducing China’s water pollution after decades of efforts. From the perspective of wastewater discharge, the situation of wastewater discharge since 1985 is analysed in this study, with importance attached to industrial wastewater, including wastewater from township enterprises, and to municipal domestic wastewater. In general, the total wastewater discharge in China is still growing year by year, resulting mainly from the increasing municipal domestic wastewater discharge. Industrial wastewater discharge has been under effective control, with the discharge rate that meets standards being higher than 90%. Take township enterprises as an example, their wastewater discharge and chemical oxygen demand (COD) discharge, which for a time accounted for 21% of the total industrial wastewater discharge and 44.3% of the total industrial COD discharge, respectively, have decreased greatly, after taking a series of measures such as shutting down, stopping run, combination and transferr...

Extraction separation of Cu(II) and Co(II) from sulfuric solutions by hollow fiber renewal liquid membrane

Extraction separation of Cu(II) and Co(II) from sulfuric wastewater is studied with hollow fiber renewal liquid membrane (HFRLM) technique. The organic solution of LIX 984N in kerosene is used as the liquid membrane phase to selectively separate and concentrate Cu(II) from aqueous solution; and the extractant of CYANEX 272 is used as carrier to remove and concentrate Co(II) from aqueous solution. In the selective separation process, LIX 984N has good selectivity on Cu(II); the interactions among metal ions can be negligible; the pH in the feed aqueous solution has significant influence, while the influence of hydrogen ion concentration in the stripping phase is slight. The removal efficiency of Cu(II) increases with the increasing flow rate on lumen side, while decreases with the increasing flow rate on shell side. The results of lab-scale cascade experiments show that the HFRLM technique is a promising treatment method for simulated sulfuric wastewater containing copper and cobalt with separation factor higher than 100. The Cu(II) and Co(II) concentrations in the raffinate are lower than 0.50 mg L −1 and 1.0 mg L −1, respectively, which are both below the standard of wastewater discharge in China. Based on the surface renewal theory, resistance-in-series model and mass balance law, a corresponding mass transfer mathematical model is developed; and the calculated results are in good agreement with experimental data.

Long-term efficiency and stability of wetlands for treating wastewater of a lead/zinc mine and the concurrent ecosystem development

A constructed wetland system in Guangdong Province, South of China has been used for treating Pb/Zn mine discharge since 1985. The performance in the purification of the mine discharge and the concurrent ecosystem development within the system during the period of 1985–2000 has been studied. The untreated wastewater contained rather high concentrations of cadmium (Cd) (0.05 mg L −1), lead (Pb) (11.5 mg L −1), and zinc (Zn) (14.5 mg L −1), which greatly exceed the upper limits for industrial wastewater discharge in China. The constructed wetland system effectively removed Cd by 94.00%, Pb by 99.04%, Zn by 97.30%, and total suspended solids (TSS) by 98.95% from the mine discharge over a long period (over 16 years) leading to significant improvement in water quality; it was also found that there were no significantly annual or monthly variations in pH values, As, Cd, Hg, Pb, and Zn concentrations in water collected from the outlet of the wetland. Moreover, diversity and abundance of living organisms, including protozoan, higher plants, terrestrial animals, and birds, increased gradually. The 16-year monitoring results showed a reciprocal relationship, at a certain extent, between restoration of the wetland ecosystem, in other words, the maturity of the wetland, and the long-term efficiency and stability on purifying heavy metal-contaminated wastewater.