The effect of sewage effluent on the physico-chemical and biological characteristics of the Sand River, Limpopo, South Africa

Seanego, K.G.; Moyo, N.A.G.

doi:10.1016/j.pce.2013.08.008

Cited by 17 publications

(10 citation statements)

References 11 publications

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“…The Crocodile River receives sewage effluent from upstream catchment land use activities such as the discharge of sewage effluent into tributaries of the Crocodile River, discharge into Crocodile River itself and agricultural runoff [ 47 , 48 ]. The Sand River (S3) receives municipal nutrient discharge from the Polokwane sewage plants and rainwater runoff that would contain fertilizer from agricultural activities in the river sub catchment [ 49 ]. The sample point on the Mogalakwena River (S4) was downstream of the Mokopane, Modimolle and Mookgophong towns’ sewage plants, golf courses, game farming, livestock farming and irrigated farmlands [ 50 ].…”

Section: Discussionmentioning

confidence: 99%

“…All these tributaries have one in common source of pollution upstream, namely, a municipal sewage plant, and are also surrounded by farmland where commercial irrigation farming is practiced, as in the case of the Crocodile, Notwane, Shashe, Mzingwane and Sand rivers. Subsistence agriculture is practiced in the case of the Mawoni and Mzingwane rivers [ 46 , 48 , 49 , 50 , 51 , 52 ]. The Crocodile River also receives inflows from eutrophic Hartbeespoort Dam [ 47 ].…”

Section: Discussionmentioning

confidence: 99%

“…The river flows disturb the sediments, thus bringing into the water column the cyanobacteria cysts or spores [ 58 ]. The source of nutrients in the Limpopo river basin may be attributed directly to sewage discharge of municipal waste water plants such as Glen Valley and Mahalpye on the Botswana side, and on the South Africa side, the western and northern parts of the city of Johannesburg to the town of Musina and indirectly to the agricultural practices of fertilizer application and animal waste [ 46 , 48 , 49 , 50 , 51 , 52 ].…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health

Magonono

Oberholster

Shonhai

et al. 2018

Toxins

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The presence of harmful algal blooms (HABs) and cyanotoxins in drinking water sources poses a great threat to human health. The current study employed molecular techniques to determine the occurrence of non-toxic and toxic cyanobacteria species in the Limpopo River basin based on the phylogenetic analysis of the 16S rRNA gene. Bottom sediment samples were collected from selected rivers: Limpopo, Crocodile, Mokolo, Mogalakwena, Nzhelele, Lephalale, Sand Rivers (South Africa); Notwane (Botswana); and Shashe River and Mzingwane River (Zimbabwe). A physical-chemical analysis of the bottom sediments showed the availability of nutrients, nitrates and phosphates, in excess of 0.5 mg/L, in most of the river sediments, while alkalinity, pH and salinity were in excess of 500 mg/L. The FlowCam showed the dominant cyanobacteria species that were identified from the sediment samples, and these were the Microcystis species, followed by Raphidiopsis raciborskii, Phormidium and Planktothrix species. The latter species were also confirmed by molecular techniques. Nevertheless, two samples showed an amplification of the cylindrospermopsin polyketide synthetase gene (S3 and S9), while the other two samples showed an amplification for the microcystin/nodularin synthetase genes (S8 and S13). Thus, these findings may imply the presence of toxic cyanobacteria species in the studied river sediments. The presence of cyanobacteria may be hazardous to humans because rural communities and farmers abstract water from the Limpopo river catchment for human consumption, livestock and wildlife watering and irrigation.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health

Magonono

Oberholster

Shonhai

et al. 2018

Toxins

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“…The evident features of NO 3 -N and TN were the slight increase from SY05 to SY06 and sharp decrease in SY04. A gradual decrease was also found in the Sand River (Limpopo, South Africa) impacted by sewage effluents, and this may indicate the self-purification capacity of the river [62]. The peak value of TP was found in SY02 (May), which was higher than in reclaimed water.…”

Section: Water Chemical Compositionmentioning

confidence: 92%

Assessment of Water Quality Using Chemometrics and Multivariate Statistics: A Case Study in Chaobai River Replenished by Reclaimed Water, North China

Song

Zhang

et al. 2020

Water

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Dry rivers could be effectively recovered by reclaimed water in North China, while river water quality would be an important issue. Therefore, it is important to understand the spatiotemporal variation and controlling factors of river water. Water samples were collected during March, May, July, September, and November in the year 2010, then 20 parameters were analyzed. The water environment was oxidizing and alkaline, which was beneficial for nitrification. Nitrate was the main nitrogen form. Depleted and enriched isotopes were found in reclaimed water and river water, respectively. Total nitrogen (TN) and total phosphorus (TP) of reclaimed water exceed the threshold of reclaimed water reuse standard and Class V in the surface water quality criteria. Most river water was at the severe eutrophication level. The sodium adsorption ratio indicated a medium harmful level for irrigation purpose. Significant spatial and temporal variation was explored by cluster analysis. Five months and nine stations were both classified into two distinct clusters. It was found that 6 parameters (chloride: Cl−, sulphate: SO42−, potassium: K+, sodium: Na+, magnesium: Mg2+, and total dissolved solids: TDS) had significant upward temporal variation, and 12 parameters (dissolved oxygen: DO, electric conductivity: EC, bicarbonate: HCO3−, K+, Na+, Ca2+, TDS, nitrite-nitrogen: NO2-N, nitrate nitrogen: NO3-N, TN, TP, and chlorophyll a: Chl.a) and 4 parameters (Mg2+, ammonia nitrogen: NH3-N, and the oxygen-18 and hydron-2 stable isotope: δ18O and δ2H) had a significant downward and upward spatial trend, respectively. The Gibbs plot showed that river water chemistry was mainly controlled by a water–rock interaction. The ionic relationship and principal component analysis showed that river water had undergone the dissolution of carbonate, calcite, and silicate minerals, cation exchange, a process of nitrification, photosynthesis of phytoplankton, and stable isotope enrichment. In addition, gypsum and salt rock have a potential dissolution process.

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“…the use of physicochemical parameters only, though still in use, need to be complimented with bioassessment to determine the health of rivers (Schofield and Davies, 1996). Example of studies that applied both physico-chemical parameters and bioassessment in the Southern Africa Development Cooperation (SADC) region include Dawson, (2003);Dlamini et al (2010) and Seanego and Moyo (2013).…”

Section: Introductionmentioning

confidence: 99%

River health assessment using macroinvertebrates and water quality parameters: A case of the Orange River in Namibia

Munyika¹,

Kongo

Kimwaga

2014

Physics and Chemistry of the Earth, Parts A/B/C

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The effect of sewage effluent on the physico-chemical and biological characteristics of the Sand River, Limpopo, South Africa

Cited by 17 publications

References 11 publications

The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health

The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health

Assessment of Water Quality Using Chemometrics and Multivariate Statistics: A Case Study in Chaobai River Replenished by Reclaimed Water, North China

River health assessment using macroinvertebrates and water quality parameters: A case of the Orange River in Namibia

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