Comprehensive Pollution Index Research Articles

Pollution in river tributaries restricts the water quality of ecological water replenishment in the Baiyangdian watershed, China.

Natural rivers often have complex water network structures, and the continuous water inflow from tributaries may have crucial impacts on the water quality of ecological water replenishment in the mainstream. This study selected two main inflow rivers of the largest lake in Hebei Province (Baiyangdian), the Fu River and Baigou River, to explore the influence of tributaries on the quality changes of ecological replenishment water in the mainstreams. In December 2020 and 2021, water samples were collected along the two river routes, and eutrophic parameters and heavy metals were determined. The results showed that the tributaries of the Fu River were all severely polluted. With the inflows of the tributaries, the comprehensive pollution index of eutrophication greatly increased along the replenished water route of the Fu River, and the replenished water in the lower reaches of the Fu River mainstream was mostly considered moderate to heavy pollution. Whereas, because the Baigou River's tributaries were only moderately polluted, the water quality in the Baigou River's replenished water was mostly better than moderate pollution. Due to the slight pollution of heavy metals in the tributaries, the replenished water in both the Fu and Baigou Rivers did not show any impact from heavy metal pollution. Correlation and principal component analysis indicated that the main sources of serious eutrophic pollution in the tributaries of the Fu and Baigou Rivers were related to domestic sewage, industrial wastewater, plant decay, and sediment release. This non-point source pollution then caused the decline in the quality of the replenished water in the mainstreams. This study exposed a long-standing but neglected problem in ecological water replenishment and provided a scientific foundation for conducting better water management to improve the inland water environment.

Ecological risk assessment and early warning of heavy metal cumulation in the soils near the Luanchuan molybdenum polymetallic mine concentration area, Henan Province, central China

The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining. The environmental impact of long-term mining activities cannot be ignored. It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution. Taking the Taowanbeigou River Basin in the mine concentration area as the research object, the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method, potential ecological risk assessment method and geoaccumulation index method. On this basis, the cumulative exceeding years of specific heavy metals were predicted by using the early warning model. The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate, and the single element Cd is the main ecological risk factor, with a contribution rate of 53.6%. The overall cumulative degrees of Cu and Pb in the soil are “none-moderate”, Zn and Cd are moderate, Mo has reached an extremely strong cumulative level, Hg, As and Cr risks are not obvious, and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg. According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard, the locations over standard rates of Cu, Zn and Cd will exceed 78% in 90 years, and the over standard rate of Pb will reach approximately 57% in 200 years. The cumulative exceeding standard periods of As, Cr and Hg are generally long, which basically indicates that these elements do not pose a significant potential threat to the ecological environment. Mining activities will accelerate the accumulation of heavy metals in soil. With the continuous development of mining activities, the potential pollution risk of heavy metals in the soil of mining areas will also increase.©2023 China Geology Editorial Office.

Modeling Analysis of Heavy Metal Evaluation in Complex Geological Soil Based on Nemerow Index Method

To accurately understand soil environmental quality and improve the problem of the traditional method, which is that it has a single evaluation factor and cannot reflect the overall condition of the soil, a complex geological soil heavy metal evaluation modeling method based on the Nemerow index method is proposed. Index evaluation methods, ArcGIS technology, and a human health risk assessment were carried out to obtain the spatial distribution of heavy metals in the soil and the current status of pollution accumulation. The comprehensive pollution index (CPI) method, geo-accumulation index (GAI) method, and potential ecological hazard (PEH) index were adopted to analyze the pollution degree of soil heavy metals. On this basis, the Nemerow index method was used to establish a complex geological soil heavy metal evaluation model, and the standard Nemerow index was calculated to complete the evaluation of heavy metal pollution in complex geological soils. The research results showed that this method could make the evaluation factors obtain reasonable scores and obtain more reasonable soil evaluation results.

Spatial Distribution Characteristics and Potential Risk Assessment of Heavy Metals in Sludge of Shanghai Sewage Treatment Plant: A Case Study

Sewage treatment is an important indicator of the urban environment and an important method of sustainable development. In this paper, the spatial distribution characteristics of 8 heavy metals in sewage sludge from 44 sewage treatment plants in Shanghai were analyzed. The pollution degree and potential ecological risk of heavy metals in sludge were evaluated by the Nemerow comprehensive pollution index and Hakanson potential ecological risk index. First, the single factor pollution index of heavy metals was ranked. The Nemerow comprehensive pollution index showed that five sewage treatment plants in Nanxiang, Dongqu, Liantang, Songjiang west, and Xinhe were heavily polluted. Second, the single factor potential ecological risk index of each heavy metal was analyzed. Finally, it is concluded that in the monitoring and control of sewage treatment, Shanghai should pay attention to the sewage treatment plants with high potential ecological risks and gain an excellent performance in the reduction in the emissions of pollution sources, so as to improve environmental quality and reduce the potential ecological risks. This paper provides the basis for studying the characteristics of heavy metal pollution of sewage sludge.

Determination of tungsten’s toxicity coefficient for potential ecological risk assessment

The potential ecological risk index (RI), proposed by the Swedish geochemist Hakanson, has been widely used for quantitatively evaluating the pollution degree caused by various pollutants. As an emerging contaminant, tungsten (W) poses ecological risks to the environment, and the quantitative assessment of the risk is of extraordinary significance. However, the lack of a determined W toxicity coefficient has limited the use of the RI in evaluating the W pollution degree. In this study, the toxicity coefficient of W (= 2.00) was calculated based on Hakanson’s theory, then verified via a case study conducted by 23 sediment samples in Taojiang River near a W mining area in southern Jiangxi. The risk factor (E w ) and geoaccumulation index (I geo ) of W, and RI and Nemerow comprehensive pollution index (NCPI) of eight heavy metals at each sampling site were calculated and compared, respectively. The results showed consistent correlations and trends of pollution levels for the investigated sites, which means the rationality of assigning a toxicity coefficient of 2.00 for W. These results can contribute to the use of the RI method for the scientific evaluation of W pollution levels.

Assessment of water quality for suitability and human health risk: a study of the Owan River, Edo State, Nigeria

Suitability assessment of water bodies for human consumption and its implication on human health is critical to water resources utilisation and sustainable development. This study investigated the water quality of the Owan River and the potential health risk to users. Examined physico-chemical parameters were within the Nigerian National Environmental Standards and Regulation Enforcement Agency permissible limits, except for the lead concentration. Water quality index values (Water Quality Index: 84.50–316.20) indicated that surface water from the sampling locations were of poor quality and unsuitable for drinking (Water Quality Index: > 50). The comprehensive pollution index values (Comprehensive Pollution Index: 0.31–0.57) indicate the water is sub–clean to slightly polluted. Evaluated non–carcinogenic risk to human health showed that children in the receptor population were predisposed to risk from heavy metals through oral ingestion (Oral Hazard Index: > 1), while the water was safe for dermal contact (Dermal Hazard Index: < 1) for adults and children. Integrated carcinogenic risk values classified the surface water as Grade IV (Medium risk), with cadmium having the highest carcinogenic risk. Cadmium accounted for approximately 94% of the total carcinogenic risk and hence a concern for public health. Natural runoff and anthropogenic activities were identified as sources of pollutants within the watershed. The study has provided data for water resource quality monitoring and public health management.

Ecological risk under the dual threat of heavy metals and antibiotic resistant Escherichia coli in swine-farming wastewater in Shandong Province, China

Mineral elements and antibiotic-resistant bacterial pollutants in livestock and poultry farms’ wastewater are often sources of ecological and public health problems. To understand the heavy-metal pollution status and the characteristics of drug-resistant Escherichia coli (E. coli) in swine-farm wastewater in Shandong Province and to provide guidance for the rational use of mineral-element additives, common antibiotics, and quaternary ammonium compound disinfectants on swine farms, 10 mineral elements were measured and E. coli isolated from wastewater and its resistance to 29 commonly used antibiotics and resistance genes was determined. Finally, phylogenetic and multi-locus sequence typing (MLST) analyses was performed on E. coli. The results showed serious pollution from iron and zinc, with a comprehensive pollution index of 708.94 and 3.13, respectively. It is worth noting that average iron levels in 75% (12/16) of the districts exceed allowable limits. Multidrug-resistant E. coli were found in every city of the province. The E. coli isolated from swine-farm wastewater were mainly resistant to tetracyclines (95.3%), chloramphenicol (77.8%), and sulfonamides (62.2%), while antibiotic resistance genes for quinolones, tetracyclines, sulfonamides, aminoglycosides, and β-lactams were all more than 60%. The clonal complex 10 (CC10) was prevalent, and ST10 and ST48 were dominant in E. coli isolates. Multidrug-resistant E. coli were widely distributed, with mainly A genotypes. However, the mechanism of the effect of iron on antibiotic resistance needs more study in this area. Thus, further strengthening the prevention and control of iron and zinc pollution and standardizing the use of antibiotics and mineral element additives in the swine industry are necessary.

Assessing the potential of a surface water body for multiple uses. Case study: the Anambra River Basin, south-eastern Nigeria

Anthropogenic activities causing deterioration in water quality and a decrease in meeting the ecosystem service potentials of surface water are considered one of the major basic environmental challenges. Water samples were collected from three sampling stations (Ogurugu, Otuocha, and Otu- Nsugbe) in the Anambra River Basin and analyzed following standard protocols and procedures for nine months. The cosystem services potentials of the Anambra River Basin were evaluated using physico-chemical parameters and some indices: Comprehensive pollution index (CPI), nutrient pollution index (NPI), salinity potential, and soluble sodium percentage (SSP). All the water quality parameters were within the standard level for drinking water, aquaculture practice, recreation (swimming/bathing) and agricultural purposes, with the exception of pH and phosphate, whereas dissolved oxygen met aquaculture criteria only in station II. Comprehensive pollution index (0.150 – 0.449), nutrient pollution index (0.07 – 0.46), and soluble sodium percentage (6.0% -26.92%) were within the category of non-polluted or excellent to sub-clean. Potential salinity (39.39 - 97.19) was high, indicating water from the Anambra River Basin contained crystallized solutes. Conclusion: the Anambra River Basin is not at risk of eutrophication but may not support irrigation program due to the high potential salinity. However, the river needs to be monitored, and anthropogenic activities need to be regulated.

Assessment of heavy metal content in groundwaters of Ikpe Community, Akwa Ibom State, Niger Delta, Nigeria

Accumulation of heavy metals in groundwater system could portend adverse health consequences to users. Heavy metal content of five randomly selected hand dug wells in Ikpe community, Akwa Ibom State, Nigeria was assessed between April and November 2022. The water was evaluated using standard methods and water quality indices to determine its suitability for human consumption. Eight heavy metals were evaluated using Heavy metal Pollution Index (HPI) and Comprehensive Pollution Index (CPI). The results were compared with the National drinking water standard. Results showed that chromium ranged from 0.001 to 0.20 mg/L, cadmium (0.001 - 0.008 mg/L), nickel (0.01- 0.08 mg/L), manganese (0.001- 0.6 mg/L), zinc (0.36 -1.90 mg/L), iron (0.1 - 0.8 mg/L), lead (0.001 - 0.02 mg/L) and arsenic (0.00 - 0.004 mg/L). HPI and CPI ranged between 44.62-126.30 and 0.18-1.33, respectively. Concentrations of these heavy metals exceeded acceptable limits, except lead and arsenic. The concentration of the metals from wells 2, 4 and 5 were generally higher and/or had values that exceeded acceptable limits. This could be attributed with geogenic and anthropogenic influences as well as the general conditions of the wells and their environment. The water quality indices (HPI and CPI) showed varying levels of heavy metal pollution in line with the heavy metal concentrations. Consequently, it can be concluded that water from wells 2, 4 and 5 is not suitable for human consumption, and it can be used for other purposes.

工矿区不同类型生物结皮对大气降尘重金属的富集规律及其影响因子

PDF HTML阅读 XML下载 导出引用 引用提醒 工矿区不同类型生物结皮对大气降尘重金属的富集规律及其影响因子 DOI: 10.5846/stxb202203220700 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 宁夏自然科学基金项目(2021AAC03007); 国家自然科学基金项目(41961001, 31760144) Enrichment law of atmospheric dustfall heavy metal pollution by different types of biocrusts in mining areas and its influencing factors Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:大气降尘是矿区土壤重金属的主要来源,而生物结皮对大气降尘重金属有显著的富集作用。为探究不同类型生物结皮对大气降尘重金属的富集规律及其影响因子,选取宁东典型火电厂周边生物结皮广布区作为试验样地,3类生物结皮作为研究对象,并以临近裸土作为对照,对比分析了生物结皮富集大气降尘过程中土壤理化性质、酶活性及重金属含量的变化,采用相关分析、冗余分析和方差分解方法探讨了不同类型生物结皮的结皮层(A层)和层下土壤(B层)重金属含量与其土壤物理、化学性质及酶活性之间的关系。结果表明:燃煤烟尘是矿区大气降尘重金属污染的主要来源,涉及重金属元素包括Cd、Cr、Hg、Pb、Zn、As。生物结皮对源自大气降尘的重金属元素均具有显著的富集作用,且在不同演替阶段生物结皮间的富集规律完全一致:藓结皮>混生结皮>藻结皮;重金属综合污染指数评价结果显示:生物结皮对重金属具有表层富集效应,表现为A层污染程度高于B层。不同类型生物结皮A、B层综合污染指数存在显著差异,排序为:藓结皮>混生结皮>藻结皮;和对照相比,三类生物结皮均能通过富集大气降尘增加其A、B层养分和细颗粒物含量并改善土壤质地。方差分解结果表明,土壤化学性质是影响重金属含量解释度最高的单类环境变量,而相关性和冗余分析结果表明:有机质含量、电导率、酶活性、容重等是影响不同类型生物结皮A、B层土壤重金属含量的主要环境因子。 Abstract:Atmospheric dust fall is the main source of soil heavy metals in mining area. Biocrusts have a significant enrichment effect on heavy metal. In order to explore enrichment laws of how biocrust at different succession stages capture and concentrate heavy metals from atmospheric dust fall and its influencing factors, biocrusts wide-spread area around typically thermal power station in Ningdong Energy Industrial Base were taken as experimental site, three types of biocrusts were selected as study objects, and bare soils nearby were set as control. Based on the comparison analysis of changes of soil physicochemical properties, enzyme activities and heavy metal contents during the process of the enrichment of atmospheric dust fall by biocrusts, the relationship between heavy metal contents and soil physicochemical properties, enzyme activities of biocrustal layer (A horizon) and subsoil (B horizon) were analyzed by using the methods of correlation analysis, redundancy analysis and variance partitioning analysis. The results indicated that, flue gas was the main source of atmospheric dust fall heavy metal pollution, the involved heavy metal elements including Cd, Cr, Hg, Pb, Zn, As. Biocrusts had significant enrichment effect on heavy metal elements derived from atmospheric dust fall, and demonstrated a totally consistent law among biocrusts of different types as followed Moss crust >Mixed crust >Algal crust. The comprehensive pollution index indicated that biocrusts had a certain surface enrichment effect on heavy metals, which demonstrated as A horizon had a higher pollution level than that of B horizon. Compared with control, the three types of biocrusts all could enrich atmospheric dust fall and increase the nutrient, fine particles and improve its soil textures of A and B horizons. Variation partitioning results indicated that soil chemical properties were the single environmental variables of the highest degree of explanation influencing the heavy metals content. Redundancy and correlation analysis showed that soil organic matter, electrical conductivity, enzymatic activity, bulk density were the main environmental factors that influenced the heavy metals content in A, B horizons of different biocrusts. 参考文献 相似文献 引证文献

Distribution and health risk evaluation of heavy metal lead in the main production area of rice in Heilongjiang Province

In order to explore the distribution and transfer of lead elements in soil and rice in the five regions of Chahayang, Wuchang, Fangzheng, Xiangshui and Jiansanjiang in Heilongjiang Province, and analyze the impact of rice intake on human health, the samples were tested by ICP-MS. Modeling the lead-element transfer in the soil-rice system, using the Nemero comprehensive pollution index method and the health risk assessment model to evaluate the lead pollution status of rice in the study area and its health risks to adults and children. The results showed that the average content of lead in rice in the study area was Chahayang 0.02 mg/kg, Wuchang 0.03 mg/kg, Fangzheng 0.017 mg/kg, Xiangshui 0.023 mg/kg and Jiansanjiang. 0.024 mg/kg did not exceed the lead content limit specified by China's National Food Hygiene Standard (0.2 mg/kg); Based on the prediction model of heavy metal lead content, pH value, and organic matter in the soil, the transfer of lead elements in the soil-rice system of Chahayang, Fangzheng, Xiangshui, and Jiansanjiang rice fields can be significantly described, with R2 values ranging from 0.224 to 0.419; Both the pollution index and the comprehensive pollution index in the study area were less than 1, which belong to the non-pollution category. The health risk index of heavy metal lead for adults and children in all five regions is lower than the maximum acceptable risk level recommended by USEPA, and there is no risk of causing cancer.

Specificality, Quality Variation, Assessment and Treatment of Estuarine Water in the Pearl River Delta, South China

The Pearl River Delta (PRD) is a major economic and manufacturing area in South China. Using the comprehensive and authoritative monitoring data, this study conducted a systematic review of the regularity of marine disasters (e.g., storm surges, saltwater intrusions, and red tides), water quality variations, water quality risk assessments and wastewater treatment in seven sections of the Pearl River Estuary (PRE). The total water resources in the PRD have been a decreasing in recent years. Seasonal marine disasters occur frequently, causing loss of life and economic damage. A monitoring and early-warning system was constructed to provide a scientific basis for dealing marine disasters response. Based on the water quality monitoring data from the seven main PRE sections from 2015 to 2020, chemical properties, heavy metal concentrations and comprehensive pollution indices were selected as indicators. The water quality of the seven PRE sections, flowing westward into the South China Sea improved over time. According to a water quality risk assessment, Yamen the estuary nearest the sea is at the highest risk. The PRD had a wastewater treatment rate of 97.37%, which was equal to the average of Guangdong Province. These findings can be used to predict future trends in estuarine water, quality and inform future studies of water quality variations in the PRD.

The spatiotemporal variations characteristic and pollution evaluation of water quality in Qujiang River, China

In order to study the spatiotemporal variations characteristic of water quality and potential pollution sources of Qujiang River, the water quality data of twelve water quality parameters at three monitoring sections (Tuanbaoling, Baita, and Sailong) from 2015 to 2019 were analyzed by using comprehensive pollution index (CPI) and multivariate statistical techniques (MST). The water quality parameters of Qujiang River basically meet the class 3 value of environmental quality standards for surface water (GB3838-2002, China). CPI varies from 0.62 to 1.06 and the water quality is characterized by slight pollution at the three monitoring sections. Cluster analysis (CA) results show that the months can be divided into three groups on the basis of similarities of the water quality characteristics: Group 1 (dry season), which includes January-April and November–December; Group 2 (flood season), that is, July; Group 3 (flat season), which consists of May–June and August–October. Principal component analysis (PCA) results identify four principal components (PCs) for the dry season and flood season, and five PCs for the flat season, thus explaining 58.23%, 82.94%, and 73.23% of the total variance, respectively. The results of the independent sample t-test show significant differences among the pH, Permanganate index (CODMn), Ammonia nitrogen (NH3–N), Total nitrogen (TN), Fecal coliform (F.coli), and (Flow) Q in the three monitoring sections. Moreover, the pollution is more serious in Baita than Tuanbaoling and Sailong Section and the main problem in the Qujiang River is the high water organic and nitrogen nutrient pollutant content. Hence, monitoring and protection need to be strengthened in the Baita section of Qujiang River.

Water quality of Bomadi Creek in the Niger Delta of Nigeria: assessment of some physicochemical properties, metal concentrations, and water quality index

In this study, some physicochemical properties, concentrations of metals (Pb, Cd, Cu, Zn, Fe, and Mn), and the overall water quality from Bomadi Creek in the Niger Delta of Nigeria were assessed over two seasons. Water samples were collected from designated areas along the course of the river and were prepared for analysis by standard procedures. The ranges of the mean values for some water quality indicators were found to be as follows: pH: 7.40–8.17, turbidity (NTU): 20.5–42.3, total dissolved solids (mg L−1): 27.5–44.7, total suspended solids (mg L−1): 34.1–61.7, dissolved oxygen (mg L−1): 3.07–6.53, biochemical oxygen demand (mg L−1): 0.13–2.77, total hardness (mg L−1): 28.3–60.0, and nitrate (mg L−1): 0.37–0.92. Only the turbidity values exceeded the permissible limit of 5 NTU. The concentration ranges (mg L−1) for the six metal ions determined were: Pb: 0.01–0.02, Cd: 0.01–0.03, Zn: 0.1–0.3, Cu: 0.03–0.07, Fe: 0.6–0.9, and Mn: 0.01–0.05. There were no significant variations in many of the locations between the wet and dry seasons. The comprehensive pollution index values indicated severe pollution of the Creek, with Cd, Fe, and turbidity, identified as the major contributors to the deteriorated water quality. The sources of high loads of Cd, Fe, and turbidity in this river system include discharges from oil production activities, speed boats, illegal bunkering, and domestic waste dumps. Principal component and cluster analysis were used to establish relationships between the various parameters and sites. The risk assessment indicated adverse non-carcinogenic and carcinogenic risks arising from human consumption of the water. The risk is higher for children than adults. Therefore, the Bomadi water is considered unsuitable for drinking and other domestic purposes, and remediation is required.

Contamination, sources and health risks of potentially toxic elements in the coastal multimedia environment of South China

Coastal ecosystems are vulnerable to the accumulation of potentially toxic elements (PTEs), which pose a threat to marine ecosystems and human health. In this study, the concentrations of eight PTEs in a typical area of South China were analysed, and their distributions, seasonal variations, pollution degrees, potential health risks and sources in seawater, sediment and organisms were evaluated. The comprehensive pollution index (CPI), pollution load index (PLI), potential ecological risk index (PERI) and target hazard quotient (THQ) were applied to assess seawater, sediment and organism quality, respectively. The annual mean concentrations of Zn, Hg, Cr and As in the bottom seawater were higher than those in the surface water while those of Pb, Mn and Cu were higher in the surface seawater. The mean content of Hg was higher than the corresponding background value of that in China Shelf Sea sediment. Marine organisms have a high enrichment capacity for Cu, Zn, Cr, Hg, As and Mn in seawater. Based on CPI, the seawater was generally not polluted by PTEs. The PLI and PERI results demonstrated that Hg was the main contamination element in surface sediment. The total target hazard quotient (TTHQ) analysis illustrated that long-term consumption of some fish by children poses a noncarcinogenic health risk, while that risk to adults is negligible. Natural sources, agricultural activity sources, coal burning and industrial emission sources were the main sources of the PTEs in surface sediments according to positive matrix factorization (PMF) model.

Ecological and Health Risk Assessment of Heavy Metals in Farmland in the South of Zhangbei County, Hebei Province, China

The distribution of heavy metals in the agricultural areas from a cattle-producing area near the Zhangbei Dam grassland, Hebei province, China, was investigated for providing the basis for the control of pollution in a rural farmland. Fifty-three surface soil samples including 28 soils of potato and 25 soils of oats were collected and analyzed for the distribution of Cd, Cu, Pb, Zn, Cr, As, Hg, and Ni. Furthermore, the ecological risk of soils contaminated with heavy metals was evaluated by employing the single factor index, the Nemerow comprehensive pollution index and geo-accumulation index, and potential ecological hazard index. The results showed that the contents of the eight heavy metals in soil planted with potato were below the risk screening values. The single factor index in soils planted with hulless oats showed that the concentrations of Cd, Hg, and Ni surpassed the Chinese screening limits by 8%, 4%, and 8%, respectively. According to the geo-accumulation index, 4% of samples reached the level of medium ecological risk for Cd. According to the results of ecological risk assessment, the studied soils generally showed a mild pollution degree. According to the health risks assessment results, the carcinogenic risks should be considered non-negligible. Arsenic is the dominant carcinogenic pollutant for human beings in the county. The main sources of pollution are mining and application of fertilizers.

Effect of Industrial Effluent on Irrigation Water Quality of Choba River in the Niger Delta Region of Nigeria

Poor irrigation water quality due to oil spillage on surface water can result in food insecurity, health and economic challenges. This paper investigated the effect of total petroleum hydrocarbon (TPHC) and lead (Pb) on irrigation water quality in the oil spill prone area of the Niger Delta region of Nigeria. Water samples were taken from five different sections labelled A, B, C, D, and E along the Choba River, in Rivers State, Nigeria. Sections B, C, D and E were direct industrial effluent discharge points while section A was without direct industrial effluent discharge. Standard methods were employed in the water sampling and analysis. Suitability of Choba river water for irrigation was assessed by comprehensive pollution index (CPI) that incorporated salinity, sodicity, and permeability hazard potentials as well as the specific toxicity hazard potentials of TPHC and Pb. Results showed that all primary water parameters except pH were within the Food and Agriculture Organization (FAO) guidelines. The pH was low, ranging between 4.48 and 5.6. TPHC values for four out of the five samples were greater than the 10mg/l guideline as recommended by the Directorate of Petroleum Resources for surface water. TPHC for the four samples ranged between 14.52 and 174.32mg/l. The parameters with the most impact on CPI include EC, PI and TPHC with TPHC having the most impact. Water samples from sections A, B and E with CPI values 0.14, 0.37, and 0.8 respectively were classified in the clean, sub clean and slightly polluted categories respectively, while water samples from sections C and D with CPI values greater than 1 range from moderately to heavily polluted and not suitable for agricultural irrigation. Only water sample A was found suitable for irrigation.

Assessing the Water Quality of Akwa Ibom State North-West District, Nigeria, using Water Quality Indices and Palmer Pollution Index

Abstract Freshwater bodies of Akwa Ibom State North-West District, Nigeria, were studied between May and December 2021 at seven sampling stations based on human activities. The indices used were water quality index (WQI) for drinking water purpose, comprehensive pollution index (CPI) for aquatic life sustainability, and Palmer pollution index (PPI) for organic pollution. Thirteen physicochemical parameters were scrutinized using standard methods and compared with the World Health Organization (WHO) standards. All the physicochemical parameters evaluated were within the acceptable limits, except pH, biochemical oxygen demand (BOD), dissolved oxygen (DO), and nitrate in some stations. The phytoplankton identified comprised13 genera of pollution indicators out of 41 genera of the total population, among which Bacillariophyceae accounted for 46.55%. The WQI values ranged between 38.86 and 54.63 based on weighted arithmetic method. The CPI values ranged from 0.35 to 0.46, while the PPI score ranged between 1 and 23. The values of WQI and CPI obtained in stations I, III, and IV revealed poor water quality which was unfit for human consumption and sustenance of aquatic life. The obtained value for PPI revealed that stations I, III, IV, VI, and VII were organically polluted. The occurrence of pollution indicator genera in these stations further proved that the water bodies were moderately polluted owing to anthropogenic perturbation. The activities of humans within the watershed should be of concern to the relevant authorities; regulation of these activities should be enforced to minimize the situation of water deterioration and for regaining the natural water quality to support aquatic life and health and make it fit for domestic usage.

Spatial analysis and risk assessment of heavy metal pollution in rice in Fujian Province, China

To comprehensively understand the spatial characteristics and pollution hazards of heavy metals in rice in Fujian Province, the contents of Cd, Hg, As, Pb, Cr, Ni, Cu, and Zn in 260 rice samples were measured based on the field investigation. Their spatial distribution patterns and clustering characteristics were explored by geostatistical methods, and their pollution-health risks were revealed by the pollution index method and exposure evaluation model. The results showed that the average contents of eight heavy metals in rice were below the food safety limits, but the excess rates of As, Cu, and Cd samples reached 33.08%, 22.69%, and 18.85%, respectively. In terms of spatial characteristics, the contents of Cd, Hg, and Ni were higher in the southeastern and northwestern regions, while the contents of As, Cu, and Cr were higher in the southwestern parts of Fujian Province. The hotspots of the corresponding heavy metals were also concentrated in the above-mentioned areas, showing an obvious spatial clustering effect. The pollution risk assessment showed that the single factor pollution index of heavy metals in rice decreased in the order of As (0.536) &amp;gt; Hg (0.505) &amp;gt; Cu (0.421) &amp;gt; Cd (0.378) &amp;gt; Cr (0.318) &amp;gt; Zn (0.304) &amp;gt; Pb (0.286) &amp;gt; Ni (0.116), and the Nemerow comprehensive pollution index was 0.623, which was generally at a safe level with low pollution risk. Furthermore, the non-carcinogenic risk index of heavy metals for adults and children were 3.558 and 6.014, and the carcinogenic risk index were 0.0050 and 0.0084, respectively, with extremely serious health hazards. In contrast, the health damage of heavy metals was higher in children than that in adults, with As and Cd in rice as the pivotal elements. Therefore, attention should be paid to the future monitoring and agricultural management of heavy metal pollution in rice in the region.

Risk Assessment of Heavy Metal Pollution in Farmland Soils at the Northern Foot of the Qinling Mountains, China.

To provide scientific basis for the prevention and control of heavy metal pollution, a field investigation, sample collection and analysis of the heavy metal content in farmland soils at the northern foot of the Qinling Mountains were conducted. Based on the comparative analysis of the single pollution index method, the Nemerow comprehensive pollution index method, the geological accumulation index method, the potential ecological hazard index method, and the geological accumulation index method were used to comprehensively analyze and evaluate the risk of soil heavy metal pollution. The results showed that the heavy metal pollution of farmland soil at the northern foot of the Qinling Mountains was severe, among which Hg and Cr pollution was relatively obvious. Taking the soil screening values of agricultural land as the standard, the quantity of element Hg in agricultural soils at the northern foot of the Qinling Mountains was higher than the relevant screening value. In the two sample sites investigated, the intensity of the heavy metal accumulation index in Baoqizhai Village was Hg > Cr > Cu > As > Pb, and in Dayangyu Village it was Cr > Cu > As > Pb. Among them, in Baoqizhai Village it shows the heavy pollution caused by Hg (Igeo= 3.42) and the light pollution caused by Cr (Igeo < 1) in the two areas. Hg is mostly affected by mining activities and its atmospheric subsidence. At the same time, Cr is mainly derived from the weathering of rock parent material and is also affected by anthropogenic factors to a certain extent. The accumulation of heavy metals in the farmland soil around the northern foot of the Qinling Mountains was relatively high, posing a threat to the surrounding soil environment. Therefore, it is urgent to control farmland soil environmental pollution.