Identification of nitrogen-sources in an aquifer beneath a municipal solid waste landfill in the vicinity of multiple pollutant sources.

Nitrogen contamination of groundwater has become a global issue and has aroused considerable concern among authorities. However, it is difficult to trace nitrogen sources in settings where a municipal solid waste (MSW) landfill site co-exists with intensive agriculture and other human activities. Therefore, a field investigation that combined a statistical analysis (factor analysis: FA) and hydrochemical analysis was designed and undertaken to identify nitrogen-pollutant sources in the shallow groundwater beneath an MSW landfill near to an agricultural area and human settlement. The results of the case study showed that nitrate was the specific pollutant produced by agricultural non-point-sources (Pbi = 15.5) and domestic pollution sources (Pbi = 41.0). The total phosphorus (Pbi = 37.2) and organic matter (Pbi = 16.6) were the specific pollutants released by the aquaculture and animal husbandry point-sources, and chloride (Pbi = 75.4) and organic matter (Pbi = 16.1) were the specific pollutants produced by the landfill. In the investigated area, the domestic pollution sources and agricultural non-point-sources were the most likely sources of nitrate contamination in the shallow aquifer. However, the landfill source and the aquaculture and animal husbandry point sources were the most likely sources of ammonium contamination. The combined method used in this study could successfully identify the nitrogen pollution sources in the shallow groundwater beneath an MSW landfill located in the vicinity of multiple pollutant sources. The method could be used to improve the control of nitrogen contamination and the management of groundwater quality.

Factors that influence public awareness of domestic waste characteristics and management in rural areas.

Public awareness of domestic waste characteristics and management (PADWCM) is a prerequisite for a domestic waste management (DWM) plan. In this study, we considered China as a typical example of developing countries to investigate the public perception of environmental pollution (PEP), its PADWCM, and its socioeconomic factors, using questionnaires and statistical methods. The results indicated that the public PEP was mainly due to obvious environmental contamination in local villages, and the PADWCM is still inadequate in rural areas. However, 83.9% of the respondents agreed that DWM is highly necessary. The PADWCM, including the hazard, recyclability, and characteristic pollution caused by domestic waste, was learned mainly from people's direct PEP, experiences, and repurchasing by recyclers. Education period had highly significant positive correlations and regressions with PEP and PADWCM, respectively. Additionally, education directly affected public awareness in different income and age groups. Demonstration projects had a significant positive effect on the awareness of characteristic pollution caused by domestic waste, which was readily perceived. Propaganda had a significant positive influence on the awareness of treatment necessity. Age and gender had no obvious effects on public PEP and PADWCM. Some aspects of PADWCM requiring a deep understanding became stronger as income increased; however, the PADWCM located close to poor people became weaker. Some aspects of PEP could significantly influence the awareness of characteristic pollution caused by domestic waste and awareness of treatment necessity. Therefore, improving environmental education, performing demonstration projects and effective environmental propaganda, increasing people's income, and attracting young people to participate in DWM will be important for enhancing environmental awareness and DWM in rural areas. Integr Environ Assess Manag 2018;14:395-406. © 2018 SETAC.

Influencing factors of domestic waste characteristics in rural areas of developing countries.

Waste management in rural areas has become a major challenge for governments of developing countries. The success of waste management decisions directly lies in the accuracy and reliability of the data on which choices are based; many factors influence these data. Here, we examined the factors influencing domestic waste in rural areas of developing countries (RADIC), using both field surveys and by reviewing previous literature. The social factors included population, education and culture. There was a positive linear relationship between waste generation amount and population size (R2 = 0.9405). Environmental education, training and demonstration projects played a positive role in improving people's awareness of the benefits of recycling and reducing waste. Traditional and national cultures, consumption and living habits contributed to variations in the generation and composition of domestic waste. Generally, practices related to conservation of and reverence for nature and green consumption encourage people to reduce, reuse and recycle waste in their daily life. Economic factors included household income and expenditure, energy and fuel structure, and types of industry that occurred in villages. A Kuznets inverted "U" curve relationship existed between domestic waste generation and people's income in rural areas of China. However, the waste generation rate had a linear relationship with the gross national income per capita in RADIC. The composition, bulk density and calorific value of domestic waste were variously affected by the energy and fuel structure and the types of industry that occurred. The natural factors included geography and climate (including rainfall, humidity, temperature and harvest seasons). The moisture content of waste was directly influenced by rainfall and humidity. Temperature affected waste characteristics by influencing residential heating modes. The waste characteristics were also influenced by the mixing of agricultural and aquacultural waste into domestic waste in the harvesting season. In different geographies, significant differences of domestic waste characteristics were observed as a result of comprehensive effects caused by multiple factors. Other factors included the administrative levels of communities and survey methods. The characteristics of domestic waste in towns or central villages were similar with those in cities, but were different from those in common villages (the smallest type of community). The domestic waste sampled in households indicated a lower rate of generation and lower ash content than when the waste was sampled at transfer stations or dumping sites. Based on the above analysis, the factors influencing domestic waste must be considered in order to optimize the design of waste management strategies in the RADIC. Furthermore, it is valuable and important to obtain more accurate data about waste characteristics.