Distribution of Pb, Zn and Cd in stream and alluvial sediments in the area with past Zn smelting operations

The sources of Zn, Pb and Cd in alluvial and stream sediments have been studied in the area of historical Zn smelting tradition. 30 samples of stream sediments and samples from 4 alluvial sediment profiles were collected. Fractions 0.125–0.063 and < 0.063 mm were analysed by the means of ICP-MS prior 4-acid digestion. The highest levels of Zn, Cd and Pb were detected in the alluvial sediments in the closest vicinity to the abandoned slag and ore roasting residue waste dumps, reaching 96 and 4520 mg/kg, 522 and 26,800 mg/kg and 3.7 and 31 mg/kg for Pb, Zn and Cd in stream and alluvial sediments, respectively. The Voglajna River then transports contamination particles into the Savinja River, which afterwards flows into the Sava River. Consequently, the anomaly can even be detected in the Sava River, more than 30 km downstream. Higher levels of Pb, Zn and Cd have been found in fraction < 0.063 mm compared to 0.125–0.063 mm fraction. Impacts of historically contaminated soil erosion and in particular the wash-out of Zn-smelting waste from the improperly managed waste dump were recognised as the dominant sources of Zn, Cd and Pb in the stream and alluvial sediments.

Sorption studies of Cd and Cu on Brazilian alluvial soils

The Local Production Arrangement, located in the Pernambuco’s Agreste state, has been significantly developing the region's economy. Despite its importance, industrial activity has caused relevant environmental concerns regarding the disposal of textile effluents, especially from industrial laundries. This waste is made up of many chemicals, and among them are various types of heavy metals. The evaluation of the sorption behavior of contaminant transport mechanisms such as heavy metals is essential to assess the risk of contamination of alluvial aquifers. This study evaluated the sorption of heavy metals (Cu and Cd) in an alluvial sediment deposit in the Capibaribe River. Kinetics and isotherm experiments allowed the analyses of Cu and Cd sorption. Kinetics sorption showed an equilibrium tendency after 16 h for Cu and 18 h for Cd and was better described by a pseudo-second order model. The isotherm data were adjusted to the Linear, Freundlich and Langmuir models. Both linear and Freundlich models satisfactorily described sorption isotherms for the two pollutants. The metals in the study represent a risk of contamination of the groundwater of alluvial aquifers, mainly due to physicochemical attributes of the soil, such as high sand content (85%), low MO (2.1 g kg-1) and alkaline pH (8.2). The environmental conditions decrease absorption and facilitate metal mobility, greatly increasing the environmental risks inherent in pollutant leaching. Cu showed a higher affinity with the soil studied in all assays performed compared with the results of the tests for Cd.

The effect of biochar amendment on chlorinated phenols retention in alluvial sediments during river bank filtration

&lt;p&gt;Amendment of alluvial sediments with carbon rich materials such as biochars can be an effective method for controlling the penetration of hazardous substances from river water into drinking water sources during river bank filtration (RBF). In this work, the transport of chlorinated phenols (CPs) during simulated RBF through Danube alluvial sediment with and without biochar amendment was studied. In order to assess the effect of the biochar amendment on CPs retention in the alluvial sediment, column experiments were carried out, with the addition of biocide to exclude the influence of biodegradation. Four CPs that differ in polarity were used as sorbates: 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP). For the column packing, Danube alluvial sediment was used, characterized as a mesoporous sandy material with low organic carbon content (1.57 %) and small specific surface area (1.65 m&lt;sup&gt;2&lt;/sup&gt;/g). In contrast, the material used as the amendment in the column experiment is a biochar with high organic carbon content (89.8 %) and large specific surface area (341 m&lt;sup&gt;2&lt;/sup&gt;/g). The breakthrough curves obtained for the alluvial sediment column without biochar amendment showed poor retention of all investigated CPs. Retardation factors (&lt;em&gt;R&lt;/em&gt;&lt;sub&gt;d&lt;/sub&gt;) for 4-CP, 2,4-DCP and 2,4,6-TCP were 1.65, 1.98 and 1.48, respectively, whereas for PCP, &lt;em&gt;R&lt;/em&gt;&lt;sub&gt;d&lt;/sub&gt; was somewhat higher (4.28) most likely due to the fact that it&amp;#8217;s nonpolar nature greatly affects its distribution between the solid and aqueous phase. The addition of biochar into the alluvial sediment at a 0.5 % mass ratio significantly increased the retardation of all investigated CPs. The obtained &lt;em&gt;R&lt;/em&gt;&lt;sub&gt;d&lt;/sub&gt; values for 4-CP, 2,4-DCP, 2,4,6-TCP and PCP were 102, 83, 78 and 92, respectively. The general increase in retardation of all investigated CPs can be explained by the increase of organic carbon content in the alluvial sediment by the addition of biochar, which is known to be the main fraction for organic components sorption in sediments and soils. In addition, the enhanced affinity of the alluvial sediment to retain the more polar CPs after biochar amendment indicates that sorption is carried out not only through nonpolar interactions, but also by electrostatic interactions between the CPs and functional groups on the surface of the biochar. The results show that biochar amendment of alluvial sediments could have a great potential for organic contaminants retention in the RBF zone, thus decreasing the risk of groundwater and drinking water sources contamination.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgement: &lt;/strong&gt;The authors acknowledge financial support of the Ministry of Education, Science and Technological Development of the Republic of Serbia (Grant No. &amp;#8234;451-03-68/&amp;#8234;2020-14/ 200125). The authors want to express their gratitude to Basna d.o.o. &amp;#268;a&amp;#269;ak for providing the biochar.&lt;/p&gt;

Irrigation sedimentation tanks in the bed of the pumping station inlet channels

The article analyzes the dynamics of channel processes in the irrigation pumping station inlet channels. The field studies of hydraulic and alluvial sediment regimes in the supply channels of pumping stations are analyzed and summarized. The studies of supply channel water flow under conditions of extremely high turbidity of the flow and variability of the morphometric characteristics of the channel are presented. The conditions under which the Saint-Venant equations satisfactorily describe the channel flows in the bed of the supply channels are given. Saint-Venant's twodimensional equations were numerically implemented using an explicit finite-difference scheme. In addition, the results of calculations of the flow field in the supply channels are presented. According to the results of numerical studies, the width of the sedimentation tank was taken to be equal to the design width of the channel, and the speed of water flow in it was 0.25 m/s. The length of the sedimentation tank, ensuring the retention of sediments of the finest fraction (0.05 mm in diameter), was 1042 m. The siltation time of the sedimentation tank can be reduced by 15…20% and amount to about 15 months, considering the unevenness of the velocity distribution diagram in the horizontal plane and the trapezoidal crosssection of the clarifier. Nevertheless, the arrangement of two parallel chambers of the sedimentation tanks makes it possible to be stable for a sufficiently long time.

Identifikasi Keberadaan Intrusi Air Laut pada Kawasan Pemukiman di Sekitar Pesisir Pantai Daerah Desa Sukajaya Lempasing Kecamatan Teluk Pandan

Sukajaya Lempasing is one of the villages located in Teluk Pandan District, Pesawaran Regency, Lampung Province. Sukajaya Lempasing Village was chosen as a place for research because of its position on the east coast which is directly adjacent to Lampung Bay, of which its groundwater is suspected to be contaminated by seawater, causing the water to be brackish. Field observation, data collection, as well as lithology and air control are needed to see the geological and hydrogeological conditions of this area. Based on the physical and chemical parameters, the well of Hamlet 7 has groundwater and there is no indication of sea water intrusion because the area is very close to hills which may become a catchment area so that groundwater flows out to sea with high pressure. Based on the salinity, TDS, and conductivity values ​​obtained, the well that experienced seawater intrusion was the AJR3 well because it is located closest to the coastline and is supported by an alluvial sediment aquifer that has moderate to high aquifer productivity. The quality of water based on physical parameter data from wells in Hamlet 1, Hamlet 7 and sample AJR4 Hamlet 3 is classified as clean and suitable for daily use. The lithology in the form of alluvial deposits allows seawater intrusion, especially in areas close to the shoreline such as the AJR3 well.

The human impact on North American erosion, sediment transfer, and storage in a geologic context

Humans are primary agents of geomorphic change, and rates of anthropogenic landscape change likely far exceed the pace of change expected from natural geologic processes. Nevertheless, our understanding of the impact of humans on the natural landscape is limited by difficulties in accurately comparing past and present rates of change across wide spatial and temporal scales. Here, we present a compilation of >4000 rates of alluvial sediment accumulation that provide an indirect record of North American erosion, mass transfer and sediment storage from the late Pleistocene to the present day. Continent-wide rates of alluvium accumulation were broadly stable for ~40,000 years, but increased 10-fold during the rapid expansion of agriculture and river system modification associated with European colonization. Interpreted in terms of mass transfer, humans have moved as much sediment in North America in the past century as natural processes can transfer in 700–3000 years.

Discontinuities in sediment connectivity controlled by human-environment interaction along the sediment cascade of a mesoscale catchment in Central Germany

&lt;p&gt;In many Central European river catchments changes in long-term sediment dynamics are caused by external driving forces (e.g. human impact, climate change). In addition, the sensitivity of fluvial systems to environmental change is controlled by the catchment&amp;#8217;s geomorphic connectivity of individual sediment sinks. In this study, we reconstruct the temporal evolution of different types of sediment reservoirs along the sediment cascade in a mesoscale upland catchment to assess its sensitivity to external changes. The chronological evolution of hillslope and floodplain sediments is based on 79 OSL and 83 C&lt;sup&gt;14&lt;/sup&gt; ages. Our results show that deposition of hillslope sediments coincides with the first evidence for human-induced soil erosion triggered by the earliest European farmers, but were decoupled from the river network for more than two millennia when the aggradation of overbank fines started and steadily increased. Therefore, the connectivity between the colluvial and alluvial sediment sinks of the catchment is mainly controlled by the landscape geometry and frequency and magnitude of erosion, transport and deposition processes.&lt;/p&gt;